National 

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Safety Board

Washington, D.C.

National Transportation

Safety Board

Washington, D.C. 20594

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NTSB

Permit No. G-200

Railroad Accident Report

Collision of Union Pacific Railroad Train 

MHOTU-23 With BNSF Railway Company 

Train MEAP-TUL-126-D With Subsequent 

Derailment and Hazardous Materials Release 

Macdona, Texas 

June 28, 2004

NTSB/RAR-06/03

PB2006-916303 National Transportation Safety Board

Notation 7675D 490 LíEnfant Plaza, S.W.

Adopted July 6, 2006 Washington, D.C. 20594
National Transportation Safety Board. 2006. Collision of Union Pacific Railroad Train MHOTU-23 

With BNSF Railway Company Train MEAP-TUL-126-D With Subsequent Derailment and Hazardous 

Materials Release, Macdona, Texas, June 28, 2004. Railroad Accident Report NTSB/RAR-06/03. 

Washington, DC.

Abstract: About 5:03 a.m., central daylight time, on Monday, June 28, 2004, a westbound Union Pacific 

Railroad (UP) freight train traveling on the same main line track as an eastbound BNSF Railway Company 

(BNSF) freight train struck the midpoint of the 123-car BNSF train as the eastbound train was leaving the 

main line to enter a parallel siding. The accident occurred at the west end of the rail siding at Macdona, 

Texas, on the UP's San Antonio Service Unit. The collision derailed the 4 locomotive units and the first 19 

cars of the UP train as well as 17 cars of the BNSF train. As a result of the derailment and pileup of 

railcars, the 16th car of the UP train, a pressure tank car loaded with liquefied chlorine, was punctured. 

Chlorine escaping from the punctured car immediately vaporized into a cloud of chlorine gas that engulfed 

the accident area to a radius of at least 700 feet before drifting away from the site. Three persons, including 

the conductor of the UP train and two local residents, died as a result of chlorine gas inhalation. The UP 

train engineer, 23 civilians, and 6 emergency responders were treated for respiratory distress or other 

injuries related to the collision and derailment. Damages to rolling stock, track, and signal equipment were 

estimated at $5.7 million, with environmental cleanup costs estimated at $150,000.

The safety issues discussed in this report are train crew fatigue and the vulnerability, under current 

operating practices, of railroad tank cars carrying hazardous materials.

As a result of its investigation, the National Transportation Safety Board makes safety recommendations to 

the Federal Railroad Administration, the Union Pacific Railroad, the Brotherhood of Locomotive 

Engineers and Trainmen, and the United Transportation Union. In addition, the Safety Board reiterates six 

safety recommendations previously issued to the Federal Railroad Administration.

The National Transportation Safety Board is an independent Federal agency dedicated to promoting aviation, railroad, highway, marine, 

pipeline, and hazardous materials safety. Established in 1967, the agency is mandated by Congress through the Independent Safety Board 

Act of 1974 to investigate transportation accidents, determine the probable causes of the accidents, issue safety recommendations, study 

transportation safety issues, and evaluate the safety effectiveness of government agencies involved in transportation. The Safety Board 

makes public its actions and decisions through accident reports, safety studies, special investigation reports, safety recommendations, and 

statistical reviews.

Recent publications are available in their entirety on the Web at <http://www.ntsb.gov>. Other information about available publications also 

may be obtained from the Web site or by contacting:

National Transportation Safety Board

Records Management Division, CIO-40

490 LíEnfant Plaza, S.W.

Washington, D.C. 20594

(800) 877-6799 or (202) 314-6551

Safety Board publications may be purchased, by individual copy or by subscription, from the National Technical Information Service. To 

purchase this publication, order report number PB2006-916303 from:

National Technical Information Service

5285 Port Royal Road

Springfield, Virginia 22161

(800) 553-6847 or (703) 605-6000

The Independent Safety Board Act, as codified at 49 U.S.C. Section 1154(b), precludes the admission into evidence or use of Board reports 

related to an incident or accident in a civil action for damages resulting from a matter mentioned in the report. 
iii Railroad Accident Report

Contents

Acronyms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi

Factual Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Accident Synopsis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Events Preceding the Accident . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

BNSF Train MEAP-TUL-126-D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

UP Train MHOTU-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

The Accident Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

The Accident . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Emergency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Damages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

UP Lead Locomotive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Tank Car Damages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Flatcar Damages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Monetary Damages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Personnel Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

The UP Engineer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

The UP Conductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

The UP Crewís Work Schedule and Activities Before the Accident . . . . . . . . . . . . . . 15

Toxicological Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Meteorological Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

The Railroad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

The Community . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Tank Car Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Hazardous Materials Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Tests and Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Sight-Distance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Tank Car Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Signal Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Track Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Mechanical Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Operating Rules and Crew Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Delayed Release of UP Crews After Maximum Hours of Service . . . . . . . . . . . . . . . . . . . 26

UP Fatigue Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Fatigue Awareness Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Fatigue Training for the UP Crew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

UP Drug and Alcohol Testing Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

FRA Oversight of the UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Postaccident Actions of the UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Postaccident Actions of Emergency Response Agencies . . . . . . . . . . . . . . . . . . . . . . . . 34
Contents iv Railroad Accident Report

Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

The Accident . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Exclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

UP Train Crew Work, Rest, and Fatigue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

UP Engineerís Activities and Rest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

UP Conductorís Activities and Rest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

UP Crew Performance During the Accident Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

The Engineerís Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

The Conductorís Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Emergency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Tank Car Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Previous Safety Board Actions Regarding Tank Cars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Minot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Graniteville . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Work Schedules and Limbo Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Positive Train Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Train Crew Protection From Inhalation Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Probable Cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

New Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Recommendations Reiterated in This Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Recommendations Reclassified in This Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Appendix A: Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
v Railroad Accident Report

Acronyms and Abbreviations

AAR Association of American Railroads

BLET Brotherhood of Locomotive Engineers and Trainmen

BNSF BNSF Railway Company

CFR Code of Federal Regulations

CRZ Cab Red Zone

DOT U.S. Department of Transportation

EOT end-of-train telemetry device

FRA Federal Railroad Administration

IDLH immediately dangerous to life and health

MP milepost

NIST National Institute of Standards and Technology 

PTC positive train control

Southwest Southwest Research Institute

TDD train defect detector

UMLER Universal Machine Language Equipment Register

UP Union Pacific Railroad

UTU United Transportation Union
vi Railroad Accident Report

Executive Summary

About 5:03 a.m., central daylight time, on Monday, June 28, 2004, a westbound 

Union Pacific Railroad (UP) freight train traveling on the same main line track as an 

eastbound BNSF Railway Company (BNSF) freight train struck the midpoint of the 123-car

BNSF train as the eastbound train was leaving the main line to enter a parallel siding. 

The accident occurred at the west end of the rail siding at Macdona, Texas, on the UPís 

San Antonio Service Unit. The collision derailed the 4 locomotive units and the first 19 

cars of the UP train as well as 17 cars of the BNSF train. As a result of the derailment and 

pileup of railcars, the 16th car of the UP train, a pressure tank car loaded with liquefied 

chlorine, was punctured. Chlorine escaping from the punctured car immediately vaporized 

into a cloud of chlorine gas that engulfed the accident area to a radius of at least 700 feet 

before drifting away from the site. Three persons, including the conductor of the UP train 

and two local residents, died as a result of chlorine gas inhalation. The UP train engineer, 

23 civilians, and 6 emergency responders were treated for respiratory distress or other 

injuries related to the collision and derailment. Damages to rolling stock, track, and signal 

equipment were estimated at $5.7 million, with environmental cleanup costs estimated at 

$150,000.

The National Transportation Safety Board determines that the probable cause of 

the June 28, 2004, collision of Union Pacific Railroad train MHOTU-23 with BNSF 

Railway Company train MEAP-TUL-126-D at Macdona, Texas, was Union Pacific 

Railroad train crew fatigue that resulted in the failure of the engineer and conductor to 

appropriately respond to wayside signals governing the movement of their train. 

Contributing to the crewmembersí fatigue was their failure to obtain sufficient restorative 

rest prior to reporting for duty because of their ineffective use of off-duty time and Union 

Pacific Railroad train crew scheduling practices, which inverted the crewmembersí 

work/rest periods. Contributing to the accident was the lack of a positive train control 

system in the accident location. Contributing to the severity of the accident was the 

puncture of a tank car and the subsequent release of poisonous liquefied chlorine gas.

The safety issues identified during the investigation of this accident are as follows:

ï Train crew fatigue and

ï The vulnerability, under current operating practices, of railroad tank cars 

carrying hazardous materials.

As a result of its investigation of this accident, the National Transportation Safety 

Board makes safety recommendations to the Federal Railroad Administration, the Union 

Pacific Railroad, the Brotherhood of Locomotive Engineers and Trainmen, and the United 

Transportation Union. In addition, the Safety Board reiterates six safety recommendations 

previously issued to the Federal Railroad Administration.
1 Railroad Accident Report

Factual Information

Accident Synopsis

About 5:03 a.m., central daylight time,1 on Monday, June 28, 2004, a westbound 

Union Pacific Railroad (UP) freight train traveling on the same main line track as an 

eastbound BNSF Railway Company (BNSF) freight train struck the midpoint of the 123-car

BNSF train as the eastbound train was leaving the main line to enter a parallel siding. The 

accident occurred at the west end of the rail siding at Macdona, Texas, on the UPís 

San Antonio Service Unit. The collision derailed the 4 locomotive units and the first 19 

cars of the UP train as well as 17 cars of the BNSF train. (See figure 1.) As a result of the 

derailment and pileup of railcars, the 16th car of the UP train, a pressure tank car loaded 

with liquefied chlorine, was punctured. Chlorine escaping from the punctured car 

immediately vaporized into a cloud of chlorine gas that engulfed the accident area to a 

radius of at least 700 feet before drifting away from the site. Three persons, including the 

conductor of the UP train and two local residents, died as a result of chlorine gas 

inhalation. The UP train engineer, 23 civilians, and 6 emergency responders were treated 

for respiratory distress or other injuries related to the collision and derailment. Damages to 

rolling stock, track, and signal equipment were estimated at $5.7 million, with 

environmental cleanup costs estimated at $150,000.

Figure 1. Post-derailment pileup.

1 All times are central daylight time unless otherwise noted.
Factual Information 2 Railroad Accident Report

Events Preceding the Accident

BNSF Train MEAP-TUL-126-D

The struck BNSF train, officially designated MEAP-TUL-126-D, originated in 

Eagle Pass, Texas, and was destined for Tulsa, Oklahoma. At the time of the accident, a 

two-person (engineer and conductor) crew was operating the train.

The BNSF crew had gone on duty in San Antonio, Texas, at 8:15 p.m. on June 27, 2004,

the evening before the accident. Their first assignment was to relieve the crew of an empty 

hopper train and bring that train from Hondo, Texas, to San Antonio, a distance of 42 

miles. After arriving with the train in San Antonio, the crew was then transported (by a 

taxi service under contract to the railroad) the 60 miles to Seco, Texas, where they relieved 

the crew of the accident BNSF train with the expectation of bringing the train to San Antonio.

The train consisted of 123 empty cars and no loads. The trainís tonnage was 4,065 tons, 

and its length was 7,080 feet.

According to the engineer, the dispatcher notified the crew while they were en 

route that they would not be continuing to San Antonio. Instead, they would tie down 

(secure their train) in the siding on the south side of and parallel to the main line at 

Macdona. A taxi service vehicle would be waiting at the siding to take the crew to the 

terminal.

UP Train MHOTU-23

The UP accident train, officially designated MHOTU-23, originated in Houston, 

Texas, on June 26, 2004, and was destined for Tucson, Arizona. At San Antonio, 54 cars 

were removed from the inbound train, and 30 cars were added to create the accident 

consist of 74 loads and no empties. The inbound four-locomotive consist remained 

unchanged, and the train was now about 5,464 feet long. Outbound air brake and two-way 

end-of-train (EOT)2 tests were completed at 12:40 a.m.

The two-person (engineer and conductor) outbound crew, which was to take the 

train as far as Del Rio, Texas, reported for duty at 2:45 a.m. on June 28, 2004, at the UPís 

Kirby Yard in San Antonio. As the conductor was picking up the paperwork for the train, 

he met and talked briefly with the manager of yard operations. The manager observed, but 

did not speak with, the engineer. UP rules did not require a face-to-face meeting between 

supervisory personnel and a train crew before a job assignment. After picking up the 

paperwork for their train, the crew were taken by van to the UPís East Yard, where they 

boarded the train. Train MHOTU-23 began the 154-mile trip to Del Rio about 4:03 a.m.

2 The EOT telemetry device transmits pertinent information, including brake pipe pressure at the rear 

of the train, to the lead locomotive. Two-way EOTs can also activate braking from the rear of the train.
Factual Information 3 Railroad Accident Report

The Accident Trip

Movements over main line track on the Del Rio Subdivision (the portion of the 

San Antonio Service Unit where the accident occurred) are governed by wayside signals 

and power-operated switch machines, both of which are controlled through a centralized 

traffic control system operated by a dispatcher at the UP dispatch center in Spring, Texas. 

The wayside signals along the main track are designed to sense the presence of trains 

within a defined ìblockî of track and automatically display the appropriate signals to 

other trains that may be approaching the occupied block. (Signal indications can also be 

controlled by the train dispatcher, as discussed in the ìTests and Researchî section of this 

report.)

For example, under this system, if a train is present anywhere within a particular 

block of track, the wayside signal immediately before the occupied track segment will 

display a red aspect, indicating stop. At the same time, the signal immediately preceding 

the stop signal will display a steady yellow aspect, indicating approach. Similarly, the 

signal immediately preceding the approach signal will display a flashing yellow aspect, 

indicating advance approach. As a train moves along the main line, sequentially 

occupying and vacating track segments, the signals respond accordingly, giving warning 

to any trailing or opposing trains. (See figure 2.) Railroad operating rules dictate the 

actions a train crew must take in response to signal indications encountered en route. On 

the UP, the following rules apply:

Indication Action

Advance approach

(flashing yellow)

Proceed prepared to stop at the second signal. Freight trains 

exceeding 40 mph must immediately reduce to 40 mph.

Approach

(steady yellow)

Proceed prepared to stop before any part of train or engine 

passes the next signal. Freight trains exceeding 30 mph must 

immediately reduce to 30 mph.

Stop

(red) Stop before any part of train or engine passes this signal.

3

About 30 minutes after departing Kirby Yard, the accident UP train stopped near 

milepost (MP) 214 to allow a Laredo-bound UP train to proceed ahead of it and depart 

onto the Laredo Subdivision. After the stop, at recorder time 4:35:20 a.m., the engineer 

moved the throttle from idle to notch 1, then gradually to notch 4.4

3 The speeds specified under these rules are the maximum speeds permissible under any 

circumstances; they are not necessarily appropriate and safe for every location. Depending on the 

topography, track layout, signal location, type of train, and train weight, the maximum safe speeds may be 

significantly below those specified, and train engineers are expected to operate their trains accordingly.

4 The information in this section regarding train operation is based on event-recorder data. The UP 

train engineer said he had no recollection of the accident trip until after the collision. He therefore could not 

assist in reconstructing the accident scenario.
Figure 2. Portion of Union Pacific Railroad main line between San Antonio, Texas, 

and accident site at Macdona. Signals are identified with indications displayed for 

accident Union Pacific Railroad train.

San

Antonio BEXAR

COUNTY

TEXAS

Bexar County San Antonio City Limits

Nelson Rd.

35 1064

410

N

Stop

signal

Approach signal

Old Pearsall Rd.

Houses

Accident

Not to scale

Siding

Medina River

Macdona Advance

approach

signal

Incident

Command Center

Factual Information 4 Railroad Accident Report
Factual Information 5 Railroad Accident Report

The accident train continued westbound, with the throttle handle manipulated 

between idle and notch 4 and the speed fluctuating but remaining under 20 mph. After the 

Laredo train had diverted to the south, about 4:49, the engineer moved the throttle to notch 

5. At 4:52:33, the train proceeded past the clear signal at Withers, traveling 44 mph with 

the throttle in notch 4.

While still in throttle notch 4, the train speed increased to 49 mph,5 after which the 

throttle was gradually decreased until, at 4:54:01, the throttle was in idle. About 11 seconds 

later (4:54:12), the train passed the signal at Alamo Junction, which was displaying a clear

indication. At this time, the train was traveling 46 mph with the throttle remaining in idle. 

During this portion of the trip, the accident train traversed two rail/highway grade crossings 

without its horn being sounded, as required by UP operating rules.

The speed continued decreasing with the throttle in idle. At 4:55:17, with the speed 

indicating 37 mph, the throttle was moved from idle to dynamic braking.6 Less than a 

minute later, with the train speed at 31 mph, the throttle was moved back to idle for 6 

seconds before being increased to notch 1. The train proceeded past the next signal, which 

was displaying advance approach (because the eastbound BNSF train on the same track 

was nearing the west end of the siding at Macdona), at recorder time 4:57:25. The train 

was traveling 22 mph with the throttle in notch 2. The train speed decreased to 21 mph 

until 4:58:13, when the throttle was moved to notch 4. At 4:59:35, the throttle was placed 

in notch 5, and the train speed began to increase.

The Accident

The UP train traveled past the signal at the east end of the Macdona siding, which 

was displaying an approach indication (the BNSF train was about 1 minute away from the 

west end of the siding), at recorder time 5:00:55 a.m. with the speed indicating 46 mph. The 

engineer reduced the throttle to notch 4, and as the BNSF train was entering the west end of 

the siding at 5:01:47, the speed of the UP train had decreased to 44 mph. (The engineer 

later told investigators that, with the fairly short distance between signals and the limited 

sight distance because of the curve, he would normally slow to about 10 mph if this signal 

was displaying approach in order to be able to stop before the next signal if necessary.)

Within the next minute, the horn was activated three times for 2- to 3-second 

intervals.7 Four seconds later (5:02:52), the throttle was moved to notch 3 with the speed 

still indicating 44 mph. This was the last recorded control input before the accident.

5 The maximum authorized speed over this track segment was 50 mph.

6 Dynamic braking is a method of train braking in which the locomotiveís traction motors are converted 

to electric generators driven by kinetic energy from the moving train. The generated electricity flows into a 

resistor grid on the locomotive and is dissipated as heat. This electrical ìloadî on the traction motor/generator 

acts to slow the motor shaft rotation, resulting in a braking action being applied to the train wheels.

7 The engineer stated during the public hearing after this accident that he habitually sounded the train 

horn three times while exiting the curve at the Macdona siding to warn anyone near the track of the presence 

of the train.
Factual Information 6 Railroad Accident Report

After the last sounding of the horn, the head end of the westbound UP train on the 

main line passed the head end of the BNSF train that was eastbound on the adjacent siding 

track. The BNSF crew stated that they dimmed their trainís headlight as the westbound UP 

train approached but that the UP trainís headlight remained on bright.8 The BNSF crew 

stated that they were unable to see anyone in the UP locomotive cab, but they noted that 

the UP train seemed to be going too fast.

Event recorder data showed that between 5:03:17 and 5:03:19, the UP trainís 

emergency braking automatically activated, and the trainís recorded speed dropped from 

44 mph to 0. The investigation later determined that the UP train had passed the stop

signal at the west end of the Macdona siding, struck the 63rd car of the BNSF train, and 

derailed near the west siding switch. (See figure 3.)

Figure 3. Accident site showing point of collision, driveway leading off Nelson Road 

where conductor was found, and houses where residents were trapped by gas cloud.

San Antonio City Limits

Bexar County

N

Stop signal

Houses

Accident

Not to scale

Siding

Nelson Rd.

Medina River

Village of

Macdona

Campground

Gate

Gravel Pits

x Conductor

At 5:04:26, the UP train control system log at the UPís Spring, Texas, dispatch 

center showed a loss of communication with the west siding switch and signal circuits at 

Macdona. After an unsuccessful attempt to reset the control system, the dispatcher 

8 General Code of Operating Rules Rule 5.9.1 requires that a trainís headlight be dimmed ìwhen 

approaching and passing the head end of a train on the adjacent track.î
Factual Information 7 Railroad Accident Report

attempted to radio the crew of the UP train but received no answer. About 5:07 a.m., one 

of the BNSF train crewmembers radioed the UP train dispatcher to report an automatic 

application of his trainís emergency brakes (when the collision separated the train at the 

63rd car). At that time, he said, he checked his distance counter and noted that his train 

was about 3,200 feet into the siding. About 5:08 a.m., one of the BNSF train 

crewmembers radioed the UP train dispatcher that the UP train on the main line track had 

been ìcoming by us hot [fast],î but was now stopped. He told the dispatcher that he would 

walk back along his train, toward the head end of the UP train, to assess the situation. The 

dispatcher, who had been attempting to contact the UP crew by radio, said he would 

dispatch emergency resources to the location.

As a result of the collision, the 4 locomotive units and the first 19 cars of the UP 

train derailed, as did 17 cars of the BNSF train. As the UP cars derailed and piled up to the 

north of the main line track, the 16th car of the train, a pressure tank car loaded with 

liquefied chlorine, was punctured. Chlorine escaping from the punctured car immediately 

vaporized into a cloud of chlorine gas that engulfed the accident area.9

At 5:14 a.m., the BNSF crewmember, in an emergency radio transmission to the 

UP train dispatcher, said he could see smoke coming from the head end of the UP train at 

the west end of the siding. He told the dispatcher he believed that the UP train had ìrun 

throughî the signal and collided with the side of the BNSF train. He reiterated a request 

for assistance at that location. The UP train dispatcher told him that responders had 

already been notified.

The BNSF crewmember returned to his locomotive cab, where the BNSF 

dispatcher had instructed the crew to remain. Shortly thereafter, the BNSF crew were 

contacted by a UP trainmaster and told to leave the locomotive and walk east where he 

would pick them up. Once they were debriefed by the trainmaster, they were taken for 

mandatory postaccident toxicological testing. The BNSF crew had been more than 3,000 

feet east of the collision and derailment and were not affected by the chlorine leak.

The UP engineer said his first recollection regarding the accident was feeling the 

locomotive ìshakingî and realizing that his left foot was pinned under some debris.10 The

engineer recalled that after the collision, the conductor asked what had happened, and he 

told him, ìWe hit another train.î He said an odor became evident and he knew they had to 

leave. He said he remembered freeing his foot and helping the conductor through the front 

window. He said he followed the conductor out the window, after which the two men 

walked together along a road (an unpaved driveway extending from Nelson Road) to the 

west and away from the accident site. He said the conductor was having difficulty 

9 According to the Environmental Protection Agency, the concentration of chlorine gas in the air 

surrounding the accident site may have reached 400,000 parts per million. The National Institute of 

Occupational Safety and Health immediately dangerous to life and health (IDLH) threshold for chlorine is 

10 parts per million.

10 The engineer was interviewed on two separate occasions about the accident and about his actions 

immediately afterward. The accounts provided by the engineer at the two interviews differed slightly in 

chronology and in minor details. The account presented here is a composite of the two interviews, and while 

it addresses the essential activities, the chronology may not be exact.
Factual Information 8 Railroad Accident Report

breathing; and when they came to an area where the gas seemed to be less intense, the 

conductor sat down.

The engineer stated that he continued walking until he found himself in a wooded 

area, after which he returned to the conductor. He said the two began walking in the other 

direction, but they had not gone far when the conductor could not continue. He said he 

attempted to lift and carry the conductor out of the area but was unable to do so. The 

engineer stated that he continued to walk eastward, passing to the north of the accident 

pileup. He said he happened upon an automobile and, believing the air would be ìcleanerî 

inside the car, climbed in and closed the door. He quickly realized that he was still in danger 

because of the gas, so he left the car and continued walking east (along Nelson Road).

Emergency Response

The initial notification to local emergency response authorities came via a 911 call 

placed at 5:06 a.m. from a residence on Nelson Road to the Bexar County 911 Emergency 

Call Center. The caller reported difficulty breathing and the presence of white smoke 

outside the residence. The caller also, in what could be described as a weak voice, referred 

to a train derailment. The 911 operator heard the word ìsmokeî and understood that the 

caller was experiencing breathing difficulty but apparently did not recognize the words 

ìtrain derailment,î and the caller was transferred to a fire department dispatcher. The 

caller again reported ìtrain derailmentî and ìsmoke,î but the fire dispatcher also did not 

recognize that the incident involved a train derailment. The response was thus processed 

as a ìdifficulty breathing and smoke in the residenceî response action.

The principal agency responsible for responding to emergencies, including 

hazardous materials incidents, within the Macdona District of Bexar County, where the 

accident occurred, was the Southwest Volunteer Fire Department. Fire department 

emergency responders were dispatched to the Nelson Road residence at 5:08 a.m., 

followed shortly thereafter by Bexar County Sheriffís Office patrol units that had been 

dispatched for support. None of the responders were yet aware that they were responding 

to a train accident and that their path to the Nelson Road residence was blocked by 

derailed equipment.

When fire department responders approached the accident site in darkness about 

5:15 a.m., they began to have difficulty breathing as they became exposed to the vapor 

cloud of chlorine from the punctured railcar. They immediately withdrew from the scene 

and requested mutual aid from other agencies. Some of the firefighters obtained protective 

clothing and self-contained breathing apparatus, and commencing about 5:40 a.m., then 

reentered the scene to conduct a search for survivors.

The initially requested mutual aid resources began to respond to the scene shortly 

thereafter, which included the Bexar County Office of Emergency Management. About 

6:10 a.m., the Bexar County Office of Emergency Management established the unified 

(incident) command system, activated the Bexar County Emergency Operations Center, 
Factual Information 9 Railroad Accident Report

and initiated the Bexar County emergency management plan. Additional mutual aid 

resources were also being dispatched to the scene, including the San Antonio Fire 

Department.

About 6:15 a.m., Southwest Volunteer Fire Department officers, who were 

advancing west along Nelson Road, came upon an individual who would later be identified 

as the UP train engineer stumbling along the roadway about 240 feet east of the grade 

crossing. He was in respiratory distress and was transported from the scene for medical 

attention. A short time later, responders determined that the derailment wreckage at the 

grade crossing prevented access to residences at the west end of Nelson Road, one of which 

was their dispatch destination. The obstructed grade crossing also prevented the immediate 

rescue of three individuals who were reported to be trapped in their residence by the vapor 

cloud several hundred feet to the south of the emergency dispatch destination.

Responders told investigators that early in the response effort they considered, 

then rejected, a plan to use a helicopter to access Nelson Road south of the grade crossing 

and evacuate the two occupied residences there. They decided that such a plan was ill-advised

until the gas plume had reduced or stabilized because of the vulnerability of the helicopter 

equipment and crew and the possibility that rotor wash could spread the gas. 

Commencing about 6:33 a.m., hazardous materials response contractors retained 

by the UP began to arrive and conduct a technical assessment of the chlorine release. 

Further access to the accident site through the wreckage pileup at the grade crossing area 

was restricted until the assessment could be made and appropriate personal protective 

equipment (principally level-A hazardous materials suits) could be donned by firefighters 

and hazardous materials personnel. Sunrise occurred at 6:37 a.m., and the wind was 

moderate but steady toward the northwest.

An evacuation zone was established around the accident site with a radius of about 

2 miles. Other than assisting with the evacuation of residents within the evacuation zone 

and assisting hazardous materials release mitigation responders with the technical 

assessment of the chlorine gas release, no further direct rescue attempt activity of the 

responding firefighters and mutual aid responders for the three individuals who were 

reported to be trapped in their residence by the vapor cloud was documented for about the 

next 3 hours. During this time, pursuant to 911 call center instructions, the three residents 

were attempting, without success, to flee and find a safe shelter from the chlorine fumes 

that had engulfed their residence. Also during this time, according to postaccident 

interviews, the principals of the primary responding emergency services agencies (the 

San Antonio Fire Department, the Bexar County Office of Emergency Management, and 

the Southwest Volunteer Fire Department) were involved in what was described as a 

certain amount of discordant debate regarding jurisdictional boundaries and incident 

command authority.

About 9:45 a.m., with a preliminary technical assessment of the chlorine gas 

release having been completed, the first of three firefighter ìentry teamsî entered the 

accident area to attempt a rescue of three trapped persons on Nelson Road who were 

unable to escape the chlorine vapor cloud that had enveloped their residence. This first 
Factual Information 10 Railroad Accident Report

entry team, however, became disoriented while attempting to advance through the 

wreckage pileup and inadvertently diverted down the wrong roadway (actually a long 

driveway leading to another residence) and away from their objective. Along that 

roadway, the team encountered the body of a person who was later identified as the UP 

train conductor. Shortly thereafter, one of the entry team firefighters showed signs of 

dehydration, prompting the dispatch of a second entry team to come to the aid of the first.

About 10:12 a.m., a third entry team, consisting of two firefighters and one UP 

employee, was dispatched to carry on with the rescue mission that had been aborted by the 

first entry team. This team successfully advanced through the wreckage pileup and, about 

10:55 a.m., reached the three persons who had been trapped at their residence by the gas 

cloud. All three were found to be in considerable respiratory distress. About 11:46 a.m., 

after the responders had revived and stabilized them, the three individuals were 

transported by helicopter to a local hospital for medical attention.11 About 11:55 a.m., the 

entry team entered another Nelson Road residence and found two persons who had 

sustained fatal injuries.

Injuries

Three persons died from chlorine gas inhalation as a result of the accident. One 

was the UP train conductor; the other two were occupants of a residence about 220 feet 

south of the grade crossing on Nelson Road.

The UP train engineer, though critically injured, survived the collision and the 

exposure to the chlorine vapor. Investigators reviewed medical records to identify 23 

civilians who were treated at local medical facilities for respiratory distress or other 

ailments likely associated with the gas release or its aftermath. Local media reported other 

individuals as receiving medical treatment after the accident, but investigators were 

unable to locate medical records that would confirm the count.12

Investigators identified six emergency responders who were either treated at the 

scene or transported to local medical facilities. Two of these were firefighters who were 

treated at a local hospital for respiratory difficulties and released. Two other firefighters 

were treated on scene for dehydration. One Bexar County Sheriffís Office deputy officer 

was treated for respiratory difficulty at a local hospital and released. The sixth injured 

responder, an ambulance attendant, was treated at a local hospital and released. Two UP 

technical support employees received treatment at local medical facilities for respiratory 

distress most likely associated with exposure to the chlorine gas.

11 The air quality at the helicopter landing zone was determined to be sufficiently clear by that time, 

such that it was not a threat to helicopter operations.

12 As many as 40 people were initially reported to have been transported to medical facilities. This may 

include an unknown number of people who used their own transportation and reported to their personal 

physicians or to other medical facilities for treatment. This number may also include some individuals who 

presented at a medical facility for treatment but were subsequently found not to have ailments associated 

with exposure to the chlorine release.
Factual Information 11 Railroad Accident Report

The concentrated chlorine vapor cloud was later determined to have a defined 

radius (as measured from its origin) of at least 700 feet.13 The vapor cloud drifted with the 

wind from the accident site and traveled in a northwesterly direction toward several 

residential areas within the city of San Antonio. A large commercial entertainment venue 

(Sea World) about 10 miles northwest of Macdona was in the path of the chlorine vapor 

cloud. Several employees of the facility reported becoming slightly ill, and several 

persons were reported to have been transported to a local medical facility as a result of 

exposure to chlorine vapors.

Damages

UP Lead Locomotive

The lead locomotive unit of the UP train came to rest lying on its left side a short 

distance to the northwest of the Nelson Road grade crossing. The unit was longitudinally 

oriented at about a 30° angle relative to the track, with its cab end skewed away from the 

track and its other end resting relatively close to the track. The front of the locomotive unit 

was an estimated 102 feet west of the Nelson Road grade crossing (measured from the 

edge of the pavement) and about 50 feet north of the main line track. The trailing end of 

the unit was an estimated 30 feet west of the grade crossing and about 10 feet north of the 

main line track, a total distance of about 387 feet from the approximate point of collision.

Because of limited access to the site, the locomotive could not be fully examined 

until it was upright in the open field to the south of the tracks adjacent to the Nelson Road 

grade crossing. The cab compartment was relatively intact and did not sustain significant 

loss of survival space. Collision damages revealed that the lead locomotive unit had struck 

the 63rd car of the BNSF train, which was an empty boxcar measuring about 67 feet long 

and 17 feet high.

Tank Car Damages

Among the 123 empty cars on the BNSF train were 14 tank cars containing 

residues of anhydrous ammonia, phosphoric acid, and alcoholic beverages. None of these 

cars derailed or were otherwise involved in the accident.

The UP train consist included 8 tank cars (the first 7 cars behind the locomotives 

and the 16th car), all of which derailed as a result of the collision. Cars one through seven 

each contained 0.05 percent ammonium nitrate solution, which is not a hazardous material 

regulated by the U.S. Department of Transportation (DOT). These cars collectively 

released about 78,200 gallons of ammonium nitrate solution.14

13 This determination was based on the extent of foliage kill in the area.

14 The entire ladings were released from the first and seventh cars, and partial loads were released from 

the second and fifth cars. The third, fourth, and sixth cars retained their ladings.
Factual Information 12 Railroad Accident Report

The punctured 16th car, containing chlorine, came to rest with its manway facing 

south and rotated 20o from the vertical, with its A-end15 facing west and slightly lower 

than the B-end. The B-end coupler remained coupled to the 17th car, a hopper car.

Three days after the accident, Safety Board investigators inspected the punctured 

car. At the time of inspection, the tank had been moved about 20 feet south of its original 

location and had been rotated such that the manway was oriented 90° from the vertical. 

Hazardous materials responders estimated that about 60 percent (about 9,400 gallons) of 

the original load of liquid chlorine had been released.

The right corner of the A-end had sustained two dents. One was a 4-inch-deep dent 

in the lower quadrant of the head (the curved end) of the tank. This dent contained a 2-inch 

by 11-inch puncture, which terminated 1 inch beyond the seam joining the tank head to the 

tank shell. The response team had plugged the puncture with wooden wedges during the 

initial response. The second dent had overall dimensions of 34 inches by 58 inches. This 

dent contained a rectangular impression measuring approximately 2 inches by 58 inches. 

There was no evidence of additional damage to the remainder of the tank head, shell, or 

pressure-retaining components of the car. (See figure 4.)

Flatcar Damages

Four of the derailed cars of the UP train (cars 12 through 15) were flatcars 

transporting steel plates. The trailing ends of three flatcars (the 12th, 13th, and 15th cars) 

came to rest adjacent to the derailed and punctured chlorine tank car. The side frame 

member and deck plate at the left side of the B-end of the 12th car were found to have 

been displaced 53 inches rearward and 36 inches inward. Shards of yellow foam-like 

material were embedded in several areas along the outer edges of the deformed deck plate. 

The leading edge of the deck plate also contained scuff marks in a semicircular pattern. 

The 13th car came to rest at least a car-length away from the derailed chlorine tank car.

Of the four derailed flatcars, only the 15th car, which was just ahead of the 

punctured chlorine tank car in the train consist, retained its load during the accident. The 

car was a bulkhead flatcar loaded with seven steel plates, each measuring 43 feet by 10.5 

feet by 1.75 inches and weighing about 26,000 pounds. Post-derailment inspection 

revealed that all of the steel plates remained secured to the flatcar; however, two of the 

four steel securement bands had broken.

Monetary Damages

Monetary damages from the accident were estimated as $4,911,397 for locomotives; 

$555,342 for railcars; $184,025 for track; and $50,000 for signals. These estimated damages 

totaled about $5,700,764. These estimates do not include the cost of lading carried by the 

cars and environmental cleanup. According to the UP environmental site remediation 

manager, the cost associated with the environmental cleanup was approximately $150,000.

15 The A-end of a railcar is the end opposite the B-end, which is the end with the handbrake. On the 16th 

car, the A-end was the leading end.
Figure 4. Punctured chlorine tank car at accident site (top) and after recovery (bottom).

Factual Information 13 Railroad Accident Report
Factual Information 14 Railroad Accident Report

UP and contractor personnel conducted the environmental remediation, which 

included application of agricultural lime to treat the acidic soils caused by the chlorine 

release and vacuum truck recovery of pooled diesel fuel. Areas affected by the diesel fuel 

were scraped to a 6-inch depth. Seventy truckloads of hydrolyzed chlorine and ammonium 

nitrate contaminated soils were removed from the site for disposal.

Personnel Information

The UP Engineer

The engineer of the UP train, age 37, was hired on March 16, 1998. Within the first 

7 months on the job, he was trained and worked as a brakeman and conductor and then 

entered training to become an engineer. He was first certified as an engineer on 

October 29, 1999, and had been recertified on March 23, 2004. At the time of the accident, 

he was assigned to a regular freight crew pool16 for trains operating between San Antonio 

and Del Rio. UP records for the engineer showed one failure of an efficiency test during 

the year before the accident. The UP engineerís most recent rules examination had been 

on March 15, 2004, and his most recent observed (by a railroad official) operation of a 

locomotive was June 14, 2004. UP records showed no exceptions taken to his operating 

performance since his hire, and he had not been the subject of any disciplinary action.

The engineerís most recent physical examination had been on February 27, 2004. 

He said that he had 20/50 vision in his left eye and that he wore prescription glasses while 

working. He said that he kept himself in physical condition by running, weightlifting, 

occasional biking, and walking when playing golf and that, in the months before the 

accident, he had been preparing for entering triathlon and marathon competitions.

The engineer told investigators that in the month before the accident he had been 

sleeping at the home of another engineer while he looked for an apartment. He said that 

his ìnormalî sleep time was 7 hours but that he did ìOKî on 4 or 5 hours, depending on 

his work the previous day.

The UP Conductor

The conductor of the UP train, age 23, was hired on July 22, 2002, and was 

promoted to conductor on January 10, 2004. He had received and passed a UP medical 

examination on February 14, 2002, and had no disciplinary actions on his record. The son 

of a UP engineer, the conductor planned to become an engineer himself. He anticipated 

starting a training class in July 2004 and, according to a close friend, had received study 

materials for the engineer class the week of the accident.

16 A crew working in pool service catches the next available train on a first-in-first-out basis.
Factual Information 15 Railroad Accident Report

The UP Crewís Work Schedule and Activities Before the Accident

UP Engineer. The UP train engineerís work schedule for the first 3 weeks of June 

2004 is shown in table 1.

Table 1. UP engineerís work history June 1-28, 2004.

Time 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

00:00

01:00

02:00

03:00

04:00

05:00

06:00

07:00

08:00

09:00

10:00

11:00

noon

13:00

14:00

15:00

16:00

17:00

18:00

19:00

20:00

21:00

22:00

23:00

Black bars indicate hours on duty.

As recorded by the UP crew caller system, the engineer, at the end of his work shift 

on Saturday afternoon, June 26, 2004, called the crew management office and asked a 

crew caller about the possibility that he would be called to work locally in San Antonio the 

next day. He told the crew caller that he needed personal time on Sunday afternoon 

because he was going to pick up his daughter at the airport. The crew caller told the 

engineer that he would possibly be called locally to relieve a crew that had reached their 

maximum hours of service outside the terminal limits. The engineer said he would have to 

lay off (formally make himself unavailable for work) if he did not get a local job, and the 

crew caller gave him the option of taking 12 hoursí undisturbed rest instead. The engineer 

declined and said he would call later to see if a local job was available. The engineer also 

asked the crew caller to make a note for other callers that he would be picking up his 

daughter Sunday afternoon.

The engineer was called to report for work at 11:30 p.m. on Saturday evening and 

worked until 11:30 a.m. on Sunday. UP computer records show that when the engineer 

completed work on Sunday, he used the companyís computer system to request 12 hours 

of undisturbed rest. Once the computerized crew management system accepted the 
Factual Information 16 Railroad Accident Report

request, the system would not show the engineer as available to be called for work until 

the expiration of the 12-hour rest period.

At the time of the accident, the engineer was separated from his wife and was 

looking for an apartment. During that time, he was sleeping at the home of another 

engineer but was spending most of his waking hours elsewhere.17 The engineer said that 

after he went off duty on Sunday morning (and requested 12 hoursí rest), he drove from 

Kirby Yard to his wifeís home, about 15 minutes away. He said he went there to visit with 

the coupleís daughter, who was returning home after visiting a college out of town. He 

said that when he arrived, he learned that his daughter would not be arriving until 6:00 p.m.,

so he spent the next 4 to 4 1/2 hours watching television and napping on the couch. After 

picking up his daughter at the airport, he took her back to his wifeís home, where they had 

dinner. He said he left there about 8:30 p.m. and went to the home of a friend to play cards. 

He said he returned to the home of his engineer friend and went to bed between 11:00 and 

11:30 p.m. Sunday evening.

The engineer said he did not believe he would be called to work until later Monday 

morning and was thus expecting to receive several hoursí rest when he went to bed. UP 

records show that the engineer made four calls to the automated voice response system18

on Saturday. He made no calls to the system on Sunday.

At 12:38 a.m. on Monday, June 28, about 1 to 1 1/2 hours after the engineer said he 

went to bed, he was called by the railroad crew caller. An audio recording of the 

conversation confirmed that the crew caller told the engineer that he was being contacted 

according to designated vacancy procedures and asked him if he would accept the 

assignment. The engineer agreed without further comment and was given an on-duty time 

of 2:45 a.m.

At the April 2005 public hearing on this accident, the engineer said:

I donít believe that there is discipline if they call you and youíre not scheduled to 

go to work. The problem is, the board gets rolled so often that you never know if 

itís your turn or not. I could be 15 times out and miss calls because they rolled the 

board and put me first out. So if the phone rings and itís [the railroad call office], 

I'll answer it.

The residence where the engineer was staying was about 20 minutes from Kirby Yard,

and he was observed on the property at about 2:30 a.m. As he walked from the parking area 

to the yard office, he encountered an acquaintance who was also an engineer. According to 

the acquaintance, the two stood outside the yard office and talked from about 2:30 to about 

2:40 a.m. The acquaintance said the engineer told him about having spent some time during 

17 The engineer told investigators he did not want to impose on his friend, so he made it a point to spend 

his waking hours away from his friendís residence.

18 A railroad employee can telephone the automated voice response system (part of the railroadís crew 

management computer system) to receive information about known vacancies, the lineup of scheduled 

trains, and the employeeís standing among crews or individuals available for work. The same information 

can be accessed via the UPís Web site.
Factual Information 17 Railroad Accident Report

the day with his daughter. He said the engineer appeared tired and that he mentioned 

feeling tired.19

When he was later asked about fatigue on the job, the engineer stated that he did 

not recall ever having been too tired to report for work, but he said:

If you were to take a poll, most of the people at work are tired. I mean, you work 

so often, so many different shifts, your body really doesnít recuperate.

The acquaintance said the engineer told him that he had taken the call for the job 

because he expected that more calls would follow and that he would have been unable to 

sleep anyway. At the public hearing, a UP official stated that, based on the engineerís 

standing on the board and the way trains were called, it appeared that the engineer would 

have been called about 6:40 a.m. Monday morning had he not accepted the earlier call. At 

the time the engineer reported for duty on June 28, he had been off duty for 14 hours 15 

minutes.

UP Conductor. The UP train conductorís work schedule for the first 3 weeks of 

June 2004 is shown in table 2.

A friend who lived with the conductor told investigators that he adhered to a 

routine during his off-duty time. She said he would typically shower as soon as he got 

home and then check the UP Web site for the time he would likely be called to work again. 

She said he would then go to bed, expecting to get about 6 hours of uninterrupted sleep 

before his next call to work. She said that when the conductor returned home after work on 

Friday, June 25, about 10:30 p.m., he expected to be called as soon as he was legally 

rested, so he went directly to bed.

The friend recalled that she had rented a movie for them to watch when the 

conductor returned home from work about 10:30 p.m. on Saturday evening. She said the 

conductor checked the Web site about 1:00 a.m. on Sunday morning to see when he might 

be called to work. Afterwards, the two watched television before retiring about 4:00 a.m. 

They got up about 1:00 p.m. on Sunday and went out for dinner. After they returned home, 

the conductor checked the UP Web site again and told his friend that he was ìsecond or 

third out.î She said they watched television and talked for the rest of the afternoon.

19 The engineer told investigators he could not remember anything that occurred from the time he went 

to bed until after the collision. He therefore did not remember the discussion described here.
Factual Information 18 Railroad Accident Report

Table 2. UP conductorís work history June 1-28, 2004.

Time 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

00:00

01:00

02:00

03:00

04:00

05:00

06:00

07:00

08:00

09:00

10:00

11:00

noon

13:00

14:00

15:00

16:00

17:00

18:00

19:00

20:00

21:00

22:00

23:00

Black bars indicate hours on duty.

Some time before 6:00 p.m., an acquaintance called the conductor and invited him 

to see a house the acquaintance had recently purchased. The friend said the conductor left 

about 6:00 p.m. and returned about 9:00 p.m. She said she did not know if the conductor 

consumed any alcohol while he was away, but he may have had ìone beerî at home when 

he returned. The friend recalled that they watched television and talked for the rest of the 

evening. She said that the conductor knew he was ìsecond outî when they went to bed. 

The UP automated voice response system showed that nine calls were made to the system 

using the conductorís identification information between 8:18 p.m. and 11:07 p.m. on 

Sunday, June 26. The friend said they were awakened about 12:40 a.m. Monday when the 

conductor was called to report for the Del Rio train. The friend said the conductor called 

her about 2:30 a.m. on his way to work and again about 3:00 a.m. She said he sounded 

alert during both calls. At the time he reported for the accident train, at 2:45 a.m., the 

conductor had been off duty for 25 hours 50 minutes.

Toxicological Information

Specimens for postaccident alcohol and drug testing of the train crews were 

collected under the supervision of BNSF and UP railroad officials for their respective 

employees. The custody and control form for the BNSF engineer showed that blood was 
Factual Information 19 Railroad Accident Report

drawn at the Lackland Air Force Base hospital emergency treatment facility at 2:42 p.m. 

on June 28, and urine was collected at 3:02 p.m. The BNSF conductorís blood was drawn 

at the same facility at 2:21 p.m. on June 28, and urine was collected at 2:49 p.m. The 

custody and control form for the UP engineer showed that blood was drawn and urine was 

collected at 5:45 p.m. on June 28.20 The Federal Railroad Administration (FRA) test 

results for the BNSF crew and the UP engineer were negative for alcohol and drugs of 

abuse.21

The custody and control form for the UP conductor showed that postmortem 

specimens were obtained at 12:00 p.m. on June 29 (noted with ìvery mildî 

decomposition). FRA test results for the conductor were positive for ethanol as follows: 

blood concentration 0.013 percent, urine concentration 0.051 percent, and vitreous 

humor22 concentration 0.029 percent. Results were negative for drugs of abuse.

Two capsules containing a white powder-like material were found in the 

conductorís personal effects. To facilitate identification of the material, additional testing 

of the conductorís specimens was performed at the Federal Aviation Administration 

Toxicology and Accident Research Laboratory. The results were negative for the tested 

substances.23

The Safety Board obtained the cooperation of the Federal Bureau of Investigation 

in identifying the substance in the capsules. The Federal Bureau of Investigationís 

chemical laboratory reported that the material was consistent with the antibiotic 

ampicillin. The markings on the capsules were tentatively matched with markings on 

500-milligram ampicillin capsules manufactured in Mexico and marketed as Ambiosol.

Meteorological Information

The weather station closest to the accident site was at the San Antonio Stinson 

Municipal Airport, about 12 miles east of the scene. Observations from this station for the 

day of the accident documented that moonset was at 3:00 a.m. and sunrise was at 6:37 a.m.

No rain accumulation was recorded, but localized thunderstorms prompted flash flood 

warnings for Bexar and adjoining counties overnight. At 4:53 a.m., winds were from the 

20 Federal regulations (49 Code of Federal Regulations 219.209(c)) require a written explanation when 

postaccident drug and alcohol tests are delayed by more than 4 hours. The delays in this case were explained 

by delays in transporting the crews to the test facility and the unavailability (because of the number of 

persons being treated for accident-related injuries) of medical staff to make timely collections of specimens.

21 Specimens were tested for cannabinoids, cocaine, opiates, amphetamine, methamphetamine, 

phencyclidine, barbiturates, benzodiazepines, and ethyl alcohol.

22 Vitreous humor is the clear gel-like mass within the eye that fills the space between the lens and the 

retina.

23 The specimens were tested for cannabinoids, cocaine, opiates, amphetamine, methamphetamine, 

phencyclidine, barbiturates, benzodiazepines, antidepressants, antihistamines, meprobamate, methaqualone, 

and nicotine.
Factual Information 20 Railroad Accident Report

southeast at 5 knots. The temperature was 75° F with a dew point of 73° F. Southeast 

winds continued for about 7 hours after the accident.

Site Description

The Railroad

The collision occurred at MP 225.36 on the UPís Del Rio Subdivision. The 

subdivision is 178 miles long and extends from the UPís Kirby Yard in San Antonio to

Del Rio, Texas. The single-track main line on which the accident occurred was 

constructed by the Galveston, Harrisburg and San Antonio Railroad. It was later operated 

by the Southern Pacific Railroad until that railroad merged with the UP in 1996. Also in 

1996, the BNSF railroad acquired trackage rights along this main line from Eagle Pass to 

San Antonio.

The main line track through the area is oriented in an approximate east-west 

direction and is fairly level and straight, except for a slight curve to the south near the 

eastern end of the Macdona siding. The siding itself is 8,459 feet long and runs parallel 

along the south side of the main line. Although the track in the accident area was 

maintained as Class 4 track, which allows for maximum speeds of 60 mph for freight 

trains and 80 mph for passenger trains, UP Timetable No. 2, effective October 29, 2000, 

allowed maximum speeds of 50 mph for freight trains and 55 mph for passenger trains. At 

the time of the accident, a 45-mph slow order was in effect over the west siding switch 

because of surfacing and tamping that had been done in that area on June 25, 2004. The 

siding switches were approved for a maximum diversion speed of 25 mph.

The Community

Macdona is a mixed rural and suburban area of Bexar County, Texas, which is 

within the San Antonio metro area. The estimated metro area population in 2004 was 

1,493,965. The accident occurred in an unincorporated rural area about 1 mile east of the 

village of Macdona and about 17 miles southwest of downtown San Antonio. A number of 

farms (open agricultural fields) and wooded areas are adjacent to the accident site.

A two-lane paved road, Nelson Road, runs along the north side of the main line for 

about 2 miles, paralleling the main line and the siding, before turning due south to cross 

the main line at grade near the west end of the siding (near the collision point). Several 

residential dwellings and small commercial facilities are situated along the road. At the 

point where the paved roadway turns southward to cross the track, a private driveway 

extends from Nelson Road and parallels the north side of the main line track. An unknown 

number of persons were occupying the two residences on this driveway at the time of the 

accident.24

24 The occupants left the area without using Nelson Road.
Factual Information 21 Railroad Accident Report

The Nelson Road crossing is a conventional rail/highway grade crossing. The 

paved portion of the roadway continues from the grade crossing for about 0.2 mile 

southward. It then turns due west and extends several hundred feet until the pavement 

ends at the gated entrance of a commercial recreational property. Along the paved portion 

of the road south of the grade crossing were two residences. The closer residence to the 

accident scene had a driveway entrance about 210 feet south of the grade crossing, which 

was also the initial destination of the emergency responders. Two occupants were in the 

residence at the time of the accident. The second residence, about 700 feet south of the 

grade crossing, had three occupants.

Beyond the gated entrance to the commercial recreational property, Nelson Road is 

unpaved and continues westward, passing through the commercial property and ending at 

the east bank of the Medina River. The Medina River flows generally in a north-to-south 

direction through this area and, at the time of the accident, it was partially flooded and 

averaging 30 to 40 feet wide. The driving distance from the firehouse (on the west side of 

the river) to the accident site (on the east side of the river) is about 6 miles.

Tank Car Information

The punctured tank car (ACFX 86305) had been loaded on June 10, 2004, at Taft, 

Louisiana, with 180,000 pounds (15,656 gals) of 30o F liquefied chlorine at 37 pounds per 

square inch, gauge. The tank car was being shipped to Hasa, Inc., in Eloy, Arizona.

The tank car was constructed in August 1976 by American Car Foundry Industries, 

Inc. The car was built as a standard 17,360-gallon DOT 105A500W specification tank car. 

The shell and head material was TC-128-B steel. The tank shell was 0.775 inch thick, and 

the head sheet was about 0.875 inch thick before forming. The tank was insulated with a 

4-inch layer of urethane foam, which was covered with a 0.125-inch-thick steel jacket. In 

November 1992, this combination of tank thickness, foam insulation, and jacket was 

subjected to qualification testing and shown to meet the DOTís performance requirements 

for head puncture and thermal protection. In March 2002, as part of its 10-year inspection, 

the tank car was requalified as meeting the requirements of DOT specification 105J500W 

tank cars. Specifically, the shell thickness was inspected along with the attachment welds 

and stub sills. The tank was also pressure tested. Since its construction in 1976, the tank 

car has required only routine maintenance.

Hazardous Materials Information

Chlorine of the type released in this accident is shipped as a compressed liquefied 

gas. Chlorine is regulated by the DOT as a Division 2.3 gas that is poisonous by inhalation. 

Chlorine gas is greenish yellow with a pungent suffocating odor; it is about 2 1/2 times as 

heavy as air. If inhaled, chlorine will react with moisture in the respiratory tract and lungs to 

form hydrochloric acid, resulting in inflammation of these tissues. Severe exposure can 
Factual Information 22 Railroad Accident Report

result in pulmonary edema, suffocation, and death. At atmospheric pressure, liquid chlorine 

will boil at about ñ30o F. Chlorine is an extremely acute toxic chemical with a National 

Institute of Occupational Safety and Health immediately dangerous to life and health 

(IDLH) concentration of 10 parts per million. Concentrations below the IDLH level should 

allow a worker to escape an exposure without permanent health effects.

Tests and Research

Sight-Distance Tests

Sight-distance tests were conducted at the site 2 days after the accident. Time and 

weather were comparable to those at the time of the accident. A single locomotive unit of 

the same type as that involved in the accident and headed in the same direction was used 

for the tests. The signal at MP 222 was set to display an advance approach indication, just 

as it was when the UP train approached it on the morning of the accident. The signal 

became visible and recognizable to the test train crew at 6,764 feet.

The next signal, at MP 223.35, which displayed an approach indication as it had 

on the day of the accident, was first visible and recognizable at 3,580 feet. The signal 

before the west end of the Macdona siding, which was displaying a stop indication, was in 

a 2° 15' curve to the south. Because of the curve, this signal was first visible at 506 feet.

Tank Car Examination

After the accident, the car was transported from Macdona to the General Electric 

railcar repair facility, in Texarkana, Arkansas. On July 27, Safety Board investigators 

convened in Texarkana to survey the tank car. The punctured tank car had yellow urethane 

insulation installed between the shell and jacket. Samples of the yellow foam were 

collected for comparison with similar material found on the damaged corner of the flatcar 

that had been the 12th car in the UP train. Fourier transform infrared spectroscopy analysis 

showed that the spectra from the two materials were almost identical.

The portion of the breached tank that contained the puncture and dent was cut from 

the car for examination. When this excised head portion was placed against the deformed 

corner of the flatcar with the foam residue, the fold on the top surface of the flatcar fit 

snugly into the punctured portion of the head. The size of the puncture and inward 

deformation on the head were consistent with the shape and size of the damaged corner of 

the flatcar.

The thicknesses of the head and shell of the tank of the punctured tank car were 

measured at the Safety Boardís Materials Laboratory. The thickness of the tank head in areas 

with no deformation damage measured between 0.813 and 0.830 inch, confirming that the 

thickness of the head was greater than the nominal thickness specified in the certificate of 

construction (0.8125 inch). The thickness of the wall at the fracture in the area that exhibited 

the most severe deformation measured approximately 0.5 inch. The deformation had 
Factual Information 23 Railroad Accident Report

reduced the thickness of the head wall by 38 percent. The thickness of the tank shell 

measured between 0.783 and 0.793 inch, confirming that the thickness of the shell was 

greater than the nominal thickness specified in the certificate of construction (0.7751 inch).

Although the details of the fracture surface of the puncture were obliterated by 

exposure to chlorine and water, many portions of the fracture were on a slant plane, and 

the tank was severely deformed in the vicinity of the puncture. Such features are 

consistent with ductile failure. To gain more information about the fracture toughness and 

resistance to fracture of the tank head and tank shell, the Safety Board arranged to conduct 

Charpy tests on coupons from those areas.25 The results of the Charpy tests indicated that 

the hot-formed tank head had properties similar to normalized steel,26 with a ductile-tobrittle transition temperature of ñ40° F. The tests revealed that the steel in the tank shell 

had a ductile-to-brittle transition temperature greater than 85° F.27 At 32° F (close to the 

loading temperature of the chlorine in the tank car), the energy absorbed by tank shell 

Charpy specimens oriented transversely to the rolling direction of the steel plate (the 

orientation with minimum fracture toughness) averaged 13 foot-pounds.

Signal Inspection

The traffic control system employed on the Del Rio Subdivision maintains a log of 

communication between the UP dispatch center and the wayside field equipment. 

Postaccident data were downloaded from these logs, and a timeline of relevant signal 

events was generated. The information from these logs showed that at the time of the 

accident, the wayside signals were displaying the proper signal sequence for train 

movements in either direction along the main line. The data logs of each of the relevant 

signals approaching the accident site were found to indicate codes that were in accordance 

with the displayed signal aspects. The lamp and the signal mechanism of the signal at the 

west end of the Macdona siding (which indicated stop at the time of the accident) were 

inspected and tested and found to function as designed.

The east and west ends of the Macdona siding were control points where train 

movements were governed by three wayside signals. At each point, a wayside signal 

governed trains approaching the siding switch from either direction along the main line. A 

third signal governed movements of trains coming out of the siding back onto the main line.

25 Charpy impact testing consists of measuring the energy that notched specimens of a material will 

absorb before fracturing. Materials that absorb a greater amount of energy before fracture are considered to 

be more resistant to catastrophic failure. For a detailed description of Charpy impact testing, see appendix E 

to National Transportation Safety Board, Derailment of Canadian Pacific Railway Freight Train 292-16 and 

Subsequent Release of Anhydrous Ammonia Near Minot, North Dakota, January 18, 2002, Railroad 

Accident Report NTSB/RAR-04/01 (Washington, DC: NTSB, 2004).

26 Normalized steel has undergone a heat treatment process that lowers the temperature at which the 

material transitions from ductile to brittle. The process also increases the amount of energy required to cause 

fracture at most temperatures. Since 1989, pressure tank car shells have been required to be fabricated from 

normalized steel.

27 The ductile-to-brittle transition temperature indicated in this report is for transverse Charpy 

specimens.
Factual Information 24 Railroad Accident Report

The Macdona siding switches themselves were controlled remotely by the train 

dispatcher. Before lining one of the switches from the main line onto the siding or 

returning a switch to its ìnormalî (main line) position, all three signals at that control 

point display a stop indication.28 After the switch has been relined and the control system 

has electronically verified that it is properly positioned, the dispatcher can request that the 

stop indications be cleared so that train operations can resume.

The investigation revealed that the day before the accident, June 27, 2004, a remedy 

ticket was entered into UP maintenance records for the control point signals at the east end 

of the Macdona siding. The ticket was for a track occupancy light, meaning that the track 

circuit was indicating occupied with no trains in the area. On three occasions, including 

Sunday, June 27, the train dispatcher could not clear those signals for train movements (that 

is, the signals continued to display stop) after the switch had been remotely lined for a train 

to leave the siding. On those occasions, a train crewmember checked to be sure the switch 

was properly lined and then flagged the train safely across the switch. After the train had 

left the siding, the crewmember manually returned the switch to its normal position and 

then reset it to be operated remotely. At that point, the dispatcher could clear the signals, 

and train operations returned to normal. The UP scheduled a signal maintainer to check the 

switch circuits on Monday, the day of the accident.

After the accident, it was determined that faulty electrical insulation on a switch 

rod was causing a ìshuntî across the rails when the switch was thrown, as if the block of 

track were occupied by a train. The false occupancy indication prevented the dispatcher 

from displaying a permissive signal while the switch was set for the siding. No anomalies 

had been noted with east Macdona signals when the switch was in its normal alignment, as 

it was at the time of the accident.29

The investigation determined that on the day of the accident there were no track 

occupancy indications in either direction that were not associated with train movements. The 

eastbound signal at the west end of the Macdona siding displayed a diverging indication for 

the eastbound BNSF train (which would be diverging from the main line into the siding) for 

approximately 1 hour 7 minutes. The main line switch at the east end of the siding 

remained lined for movements westbound on the main track. The westbound signal before 

the east end of the siding displayed an approach indication (for the UP train) for 

approximately 22 minutes.

Track Inspection

According to the UP, tracks on the Del Rio Subdivision are inspected 7 days a 

week during the summer because of the severe heat and the effects it can have on rail and 

track. The track supervisor for the Del Rio Subdivision stated that he had inspected the 

track between Withers (MP 218.84) and Uvalde Station (MP 301.0), which included the 

28 With these signals indicating stop, the intermediate signals automatically display advance approach

and approach for trains nearing that location.

29 Even though the BNSF train had been diverted into the west end of the siding, it was to remain there 

and was not intended to return to the main line until some time later.
Factual Information 25 Railroad Accident Report

accident area, on June 26, 2004. The assistant track foreman inspected the same segment 

of track the following day, June 27, 2004, which was the day before the accident. No 

abnormalities were found during either of these inspections. Because 20 switch ties of 

various lengths had been inserted into the switch at the west end of the Macdona siding, 

the foreman had placed a slow order in the switch area. The slow-order maximum speed 

had been increased on Saturday, June 26, to 45 mph, and it was to remain at this speed for 

48 hours, at which time the slow order would be lifted, and the track would be returned to 

normal operating speed.

Mechanical Testing

After the accident, the cars that did not derail were moved from the scene for 

inspection. The non-derailed cars were inspected by UP car department personnel and 

FRA and Texas State inspectors. The inspection revealed 10 FRA defects on the lead 

block of cars on the BNSF train and 8 defects on the rear block of cars. The defects 

consisted of piston travel defects on the brake cylinders or non-response to brake 

applications. The non-derailed cars on the UP train had four similar FRA defects. 

The UP trainís lead locomotive alerter30 was a Wabtec Railway Electronics-Pulse 

Electronics, Inc., Train Sentry, Part No. 17239P, manufactured December 31, 2001. At 

locomotive idle and at speeds up to and including 20 mph, the alerter will alarm if 2 

minutes elapse without manipulation by the engineer. At speeds greater than 20 mph, the 

alerter alarm interval is 40 minutes (2,400 seconds) divided by the trainís speed in mph. 

Thus, at 45 mph, the alarm interval is approximately 53 seconds. The alerter from the lead 

locomotive was tested and found to function as designed.

Some UP locomotives are equipped with video recorders that capture the view 

ahead of the train. Some of these devices are also capable of recording audio external to 

the train. The accident UP train lead locomotive unit was not equipped for video or 

external audio recording, and no locomotives are currently equipped with cab voice or 

video recorders.

Operating Rules and Crew Responsibilities

Both the UP and the BNSF subscribe to the General Code of Operating Rules, 

Fourth Edition, effective April 2, 2000. UP timetable System Special Instructions, 

effective April 1, 2004, also governed operations at the time of the accident.

30 Alerters are devices intended to operate as a fatigue countermeasure. The alerter on a UP locomotive 

provides a visual and auditory alarm if the engineer does not make a control input (including sounding the 

horn) or otherwise physically respond to the control console within a set interval of time. This time interval 

decreases as locomotive speed increases, and each engineer action resets the device for the next interval. If 

the engineer does not respond to an alerter alarm, the train brakes will apply automatically.
Factual Information 26 Railroad Accident Report

General Code of Operating Rules Rule 1.47, ìDuties of Trainmen and 

Enginemen,î states:

The conductor and the engineer are responsible for the safety and protection of 

their train and observance of the rules. If any conditions are not covered by the 

rules, they must take every precaution for protection.

According to the general operating rules, the conductor supervises the operation 

and administration of the train. All persons employed on the train must obey the 

conductorís instructions, unless the instructions endanger the trainís safety or violate the 

rules. If any doubts arise concerning the authority for proceeding or safety, the conductor 

must consult with the engineer, who is equally responsible for the safety and proper 

handling of the train.

At the time of the accident, UP train conductors were required to record certain 

information regarding each trip on a Form 20849, Conductorís Report. Instructions to 

conductors provided at the top of UP Form 20849 were as follows:

This report must be completed by the conductor of the road freight trains on each 

trip or tour of duty. Conductors must keep reports in their possession of the last 5 

round trips, which must be presented to managers upon request. Report all signals 

more restrictive than clear (abbreviations may be used). Report all train defect 

detector (TDD) announcements. Report other train delays.

Information required on the form included:

All block signals that are more restrictive than Clear: Enter the block signal 

number (MP or [control point]), and the signal aspectÖ. Note in the comments 

section when the engineer has acknowledged the restrictive signal and after the 

crew members have discussed positive responses that will be taken to comply 

with that signal. A check mark or an ëXí may be used for this purpose.

The UP train conductorís booklet of forms was found in the cab of the UP lead 

locomotive. The booklet contained completed 20849 forms for the conductorís previous 

two trips but none for the accident trip.

General Code of Operating Rules Rule 1.17, addressing hours of service, states: 

ìEmployees are expected to use off-duty time so they are prepared for work.î

Delayed Release of UP Crews After Maximum Hours of Service

Crews reaching their federally mandated 12-hour service limits sometimes have to 

remain aboard their trains for extended periods awaiting transportation to an appropriate 

terminal. Depending on the distance to that terminal, a crew may then have to spend 

considerable time in transit before actually having the opportunity to obtain rest. This time 

spent awaiting transportation or in transit after the expiration of hours of service, referred 

to as ìlimbo time,î is not directly addressed in the hours-of-service regulations. Although 
Factual Information 27 Railroad Accident Report

time spent in limbo is technically classified as neither on-duty nor off-duty time, it is paid 

time for the crew, and any required minimum rest period does not begin until the limbo 

period ends. As part of this accident investigation, the Safety Board examined records of 

the time spent in pay status by UP train crews on the San Antonio Service Unit and 

systemwide during the 6 months preceding the accident. Figure 5 shows the percentage of 

UP crew assignments held beyond 12 hours for the time periods indicated. 

Figure 5. Percent of Union Pacific Railroad train crews working in extended pay status.

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

>12 >13 >14 >15 >16 >17 >18

Total Hours Paid (Duty Plus Limbo Time)

Percent of Train Crews

San Antonio June 2004

San Antonio January-June 2004

Systemwide January-June 2004

The UP also provided the limbo time information for the accident train crew. The 

number of times those crewmembers were held beyond 12 hours and the amount of time 

they were held is shown in tables 3 and 4.

Table 3. 

Month Total hours in pay status

>12 >13 >14 >15 >16 >17 >18 >19

January 9 1 1

February 4

March 5 2 1

April 4 1 1

May 1 4 2

June 4 4 1

Number of times accident engineer held beyond 12 hours, January-June 2004.
Factual Information 28 Railroad Accident Report

Table 4. Number of times accident conductor held beyond 12 hours, January-June 2004.

UP Fatigue Management

Fatigue Awareness Program

On July 2, 1997, near Delia, Kansas, a UP freight train that had been diverted onto

a siding to await the passing of an opposing UP freight train instead continued through the

siding and struck the side of the other train.31 The investigation revealed that the engineer

of the striking train had dimmed the train’s headlight but did not apply the train brakes

even though the other train was sounding its horn repeatedly. The Safety Board

determined that the engineer of the striking train was probably asleep. The engineer was

fatally injured, and his conductor sustained minor injuries.

As a result of its investigation of the Delia, Kansas, accident, the Safety Board

made several fatigue-related safety recommendations to the UP:

R-99-54

Issue to all employees, including management personnel, updated fatigue

awareness material regarding shift work, work-rest schedules, and proper

regimens of health, diet, and rest.

R-99-55

Revise your fatigue awareness program to include a process for

documenting which employees receive the currently available fatigue

awareness material, any new or updated fatigue-related information, or

both, and for determining whether the recipients understand the dangers of

working while fatigued.

Month Total hours in pay status

>12 >13 >14 >15 >16 >17 >18 >19

January 1 3

February 1

March 6 2

April 5 11

May 53 1

June 532

31 National Transportation Safety Board, Collision Between Union Pacific Freight Trains MKSNP-01

and ZSEME-29 Near Delia, Kansas, July 2, 1997. Railroad Accident Report NTSB/RAR-99/04

(Washington, DC: NTSB, 1999).
Factual Information 29 Railroad Accident Report

R-99-56

Establish at a minimum, an annual management oversight review process 

for the fatigue awareness program to ensure its effectiveness and to identify 

ways of improving it.

R-99-57

In conjunction with the operating unions, discuss the circumstances of this 

accident with employees and advise them about the operating danger of 

working while fatigued.

In response to these safety recommendations, the UP identified various printed 

materials and videos that were issued to employees during training or safety meetings, 

distributed in routine employee mailings, or sent to employees upon request. The new 

materials and activities were described as follows:

ï A book, The Sleep Solution, provided to new hires and regular employees

ï Newsletter items prepared for On Alert, a UP newsletter

ï A leaderís manual developed for use during safety meetings

ï Tips to employees made available at UP Online (a UP Internet site)

ï Face-to-face alertness management training conducted during annual 

employee training classes

ï Employee mailings containing information on scheduling, alertness 

management, and gaining family support

ï Surveys mailed to employees to help them identify their health risk factors

ï Alertness management subject matter delivered during UPís information and 

business television broadcasts to employees

ï An 800 number employees can call for alertness management information

ï Distribution centers that disseminate alertness management materials

ï A series of fatigue-related brochures and videocassettes

ï Health and safety fairs held for employees

On the basis of this and other information provided by the UP regarding its fatigue 

program, the Safety Board, on September 6, 2000, classified Safety Recommendations 

R-99-54 through -57 ìClosed⎯Acceptable Action.î

The Safety Board held a public hearing on March 20, 1998, and a followup hearing 

on February 24, 1999, regarding the Delia accident and a series of other UP accidents in 

which crew fatigue appeared to play a role. On April 26 and 27, 2005, during a public 

hearing about the Macdona accident, the UPís director of occupational health psychology 

was asked to update the Board on accomplishments in fatigue countermeasures since the 

earlier proceedings.
Factual Information 30 Railroad Accident Report

The director elaborated on multiple program activities addressing fatigue and 

stated that the UP had retained a series of consultants to advise the company on fatigue 

issues. The director stated that about 80 percent of his time was dedicated to fatigue and 

that he worked closely with other railroads to develop science-based pilot programs to 

reduce fatigue.

In addition to the distribution of fatigue-related written material and videos, the 

director discussed several other UP fatigue-related initiatives underway or planned:

ï An agreement by which employees returning to work after more than 72 hours 

off would be shown available for work at 8:00 on the first day back instead of 

the traditional mark-up time of midnight; the change was made to help the 

employee readjust to shift work after having adapted to a normal work-sleep 

cycle

ï An agreement to provide employees with 10 hoursí uninterrupted rest at both 

home and away terminals

ï Construction of crew away-terminal lodging specifically designed to facilitate 

rest (17 built and 7 planned at the time of the hearing)

ï Information provided to new employees regarding the railroadís napping 

program32

ï Pilot projects to increase the accuracy of train lineup information to improve 

job assignment predictability

ï Adjustment of employee boards (lists of qualified employees) to manage work 

and to balance mileage and work cycles among crews

ï Ongoing study of potential fatigue avoidance and mitigation practices

ï Workforce accretion

In response to a question about the programs that were in effect at the time of the 

2004 accident, a UP official said that, although resources were inadequate to provide 

employees with classroom instruction in fatigue management and mitigation, all 

employees had received written information. Additionally, officials talked to managers 

about ìmanaging fatigue, being alert, and helping the employees do the best they could as 

far as getting their rest.î He also said:

We had a real aggressive hiring plan. We were working on recrew [relieving crews 

after maximum hours of service] reduction. We were vigorously working on the 

limbo timeÖto try to make ourselves more crewsÖ. So we were working on 

three or four fairly significant initiatives as we were dealing with this sudden 

surge in business with varying degrees of success.

32 General Code of Operating Rules Rule 1.11.1 permits freight train crewmembers, under certain 

circumstances, to nap on their train for up to 45 minutes.
Factual Information 31 Railroad Accident Report

Fatigue Training for the UP Crew

According to the UP, the engineer received some version of fatigue management 

training during the new-hire training in 1998. Also, alertness management training was 

provided to him as part of required annual rules training on April 18, 2000. UP officials 

said the conductor received fatigue training on August 14, 2002, as part of his new-hire 

training. The conductorís training was presented in conjunction with a 1-hour 

videocassette, and he was required to complete a written homework assignment.

UP officials stated that written fatigue training materials are sometimes included 

with payroll documents mailed to employeesí homes. Several employees told 

investigators that the information thus received is frequently treated as ìjunk mailî and 

discarded without being read.

The accident engineer said the company occasionally mailed safety-related 

material to employees. Although he did not recall whether he had received any mailings 

addressing fatigue, he said he remembered having seen a pamphlet ìthat [said] you should 

get eight hoursí sleep [and] you should have a regular sleep cycle, which we don't have. 

[Also] it [said that when you sleep, the room] should be dark and quietÖ.î He also said, 

ìThe things that were in the pamphlet arenít things that we can do.î The engineer said he 

had never been exposed to formal training of any kind having to do with alertness or 

fatigue. At the April 2005 public hearing on this accident, the director of occupational 

health said the company did not mandate periodic fatigue training for UP employees.

The UP, at the time of the accident, did not have a formal process by which 

employees could, without the risk of disciplinary action, decline a job assignment because 

of inadequate rest. UP officials said that the option existed for an employee to decline a 

job based on illness but that excess claims of illness, as with any pattern of being 

unavailable for work, could result in sanctions.

Other Information

UP Drug and Alcohol Testing Program

The FRA has established minimum annual testing rates for random drug and 

alcohol tests of railroad employees who perform covered service (that is, service subject to 

the hours-of-service laws). The FRA may increase or decrease those rates based on the 

reported positive rate for the entire industry.33 The current FRA minimum annual testing 

rates are 25 percent for drugs and 10 percent for alcohol.

According to the FRA, the UP has elected to randomly test through-freight train 

crews at the following rates and times: The crews are randomly drug tested at a 50-percent 

rate annually, with the tests generally administered at the end of a run. About 25 percent of 

all crews are also tested for alcohol at the end of a run. The UP tests an additional 10 

percent of the crews for alcohol at the beginning of a run.

33 See 49 Code of Federal Regulations 219.602 and 219.608.
Factual Information 32 Railroad Accident Report

FRA Oversight of the UP

On November 10, 2004, the UP experienced an impact accident in San Antonio, 

Texas, during switching operations at a local industry. This accident followed previous UP 

train collisions in Carrizozo, New Mexico, on February 21, 2004, and in San Antonio, 

Texas, on May 3, 2004. A UP employee had also been killed during remote control 

operations in San Antonio on December 7, 2003. Each of these accidents involved the 

failure to adhere to UP operating rules or FRA regulations, or both.

In the aftermath of the Macdona accident, the FRA began, in July 2004, an 

extensive and comprehensive review of the UPís safety compliance performance in Texas. 

At the end of the review, the FRA found that the ìUP had failed in its implementation and 

management oversight of its Field Testing Exercise Program, which tests train crew 

compliance with railroad operating rules and other Federal Safety Regulations, a result that 

was unsatisfactory.î On November 16, 2004, the FRA used its authority under 49 Code of 

Federal Regulations (CFR) 209.201(b) to enter into a compliance agreement with the UP. 

The FRAís stated purpose for the compliance agreement was ìto address deteriorating 

operating safety evidenced by the number of human factor accidents and incidents 

occurring on the UP in the San Antonio service area.î The FRA stated that the UPís field 

testing exercise program ìwas not effectively providing a realistic evaluation of the level of 

employee compliance with operating and safety rules and Federal regulations.î

The Safety Board examined FRA inspection data for calendar years 2003 and 

2004, including the time period cited by the FRA in its justification of the compliance 

agreement with the UP. The data were examined to determine if the FRA had used 

enforced sanctions on the UP before it entered into the agreement that compelled the 

railroad to improve its field testing program and increase compliance with operating rules. 

Five defects were reported for the UP under 49 CFR Part 217 in 2003, and 20 were 

reported for 2004. No FRA violation reports were submitted during that period for noncompliance with Part 217. 

Postaccident Actions of the UP

In response to the apparent failure of the crew of the accident UP train to comply 

with signal indications on the day of the Macdona accident, the UP formed a crew 

resource task team in San Antonio to address the issue of signal noncompliance. A 

procedure called the ìCab Red Zoneî was developed to bring about improvement in cab 

operating discipline when encountering critical signal indications.

On February 5, 2005, the UP modified General Code of Operating Rules Rule 

1.47, ìDuties of Trainmen and Enginemenî as follows:

To ensure the train is operated safely and rules are observed, all crew members 

must act responsibly to prevent accidents or rule violations. A ëCab Red Zoneí 

(CRZ) exists during critical times when multiple tasks are occurring such as: 

Copying mandatory directives. Approaching temporary restrictions. Approaching 

the end of the trains authority [sic]. Operating at restricted speed except when 

switching. Or operating on signals more restrictive than Advance Approach or 

Diverging Advance Approach except when switching.
Factual Information 33 Railroad Accident Report

1. During ëCRZí, an environment must be created in the control compartment that 

focuses exclusively on controlling the train and complying with the rules. The 

conductor must be in the control compartment unless required by other duties to 

leave (i.e., to operate switches, be at a road crossing, passenger train duties, etc.). 

The following restrictions or conditions must be met:

ï Cab communication is restricted to immediate responsibilities for train 

operation.

ï Use of cell phones is prohibited unless train operations require their use.

ï A crew member other than the employee operating the controls will be 

required to handle radio and/or cell phone communications when another 

crew member is in the control compartmentÖ.

ï If proper action is not being taken, crew members must remind each other of 

the CRZ condition.

2. Crew members in the control compartment must communicate to each other 

any restrictions or other known conditions and required actions that affect the safe 

operation of their train sufficiently in advance of such condition to allow the 

engineer to take proper action.

If proper action is not being taken, crew members must remind the engineer of 

such condition and required action.

Crew members in the control compartment must be alert for signals. Crew 

members must:

ï Communicate clearly to each other the name of signals affecting their train as 

soon as signals become visible or audible.

ï Continue to observe signals and announce any change of aspect until the train 

passes the signal.

ï Communicate clearly to each other the speed of the train as it passes a signal 

with an indication other than Clear.

ï Immediately remind the engineer of the rule requirement if the signal is not 

complied with.

3. Except when switching, when a train passes a block signal with an indication 

more restrictive than Advance Approach or Diverging Advance Approach, a crew 

member must transmit by radio the engine number, direction, location and signal 

nameÖ.

4. If the engineer and/or conductor fail to comply with a signal indication or take 

proper action to comply with a restriction or rule, crew members must 

immediately take action to ensure safety, using the emergency brake valve to stop 

the train, if necessary.
Factual Information 34 Railroad Accident Report

Postaccident Actions of Emergency Response Agencies

Bexar County. Bexar County officials told the Safety Board that the county had 

taken the following steps as a result of the June 28, 2004, collision and derailment:

ï All county sheriffís office fire alarm dispatchers and call takers have 

completed a course in hazardous materials awareness so that they might better 

understand recommended actions from the field such as shelter-in-place and 

evacuation procedures.

ï A full-scale rail tank car exercise was conducted for the area fire departments.

ï Area fire department personnel participated in incident command and unified 

command classes.

ï Emergency notification procedures were revised to provide more efficient 

notification to residents. The procedures were tested during the full-scale rail 

tank car exercise.

ï An initiative was undertaken to identify property locations accessible by a 

single roadway that could be blocked by a stopped train.

Southwest Volunteer Fire Department. The Southwest Volunteer Fire 

Department reported that it implemented a 15-point improvement plan after the accident. 

The improvements included railroad equipment familiarization as well as classroom and 

practical training that addressed responding to hazardous materials releases and working 

within an incident command and emergency operations management structure. The 

agency also rewrote its manual of standard operating procedures and guidelines to include 

detailed procedures for addressing railroad emergencies.

San Antonio Fire Department. Based on the ìlessons learnedî from the response 

to the Macdona accident, the San Antonio Fire Department took the following 

postaccident actions:

ï A contingent of firefighters was provided with incident command system 

training, with chief officers and aides scheduled for enhanced incident system 

training. A multi-jurisdiction functional exercise was conducted in March 2005 

with about 200 participants from different jurisdictions and disciplines. This 

exercise was preceded by a public information course, a tabletop exercise 

simulating a derailment with hazardous materials release, a 2 1/2-day incident 

command training class with tabletop exercise, and a workshop for senior 

officials.

ï A mapping program was installed on the laptop computer in the departmentís 

incident command bus, and a large-format printer was acquired to facilitate the 

printing of maps.

ï A mobile repeater system was acquired to improve radio communications.
Factual Information 35 Railroad Accident Report

ï A regional command vehicle was ordered that would provide both command 

and communications integration to a large area and reduce mutual aid response 

problems.

UP Railroad. After the Macdona accident, the UP upgraded its mapping software 

to allow the overlay of UP track information on a separate layer of the mapping software.

The company updated its telephone notification database and subscribed to quarterly 

updates of the Public Safety Answering Point data for Texas and the other States where the 

UP operates. The company also instituted advanced in-service training and testing 

protocols for all of its telephone operators.
36 Railroad Accident Report

Analysis

General

Under railroad operating rules, the conductor is responsible for supervising train 

operations and administration, whereas the engineer is primarily responsible for actually 

running the train. The crewmembers share responsibility for ensuring that all train 

movements are conducted safely. Both the engineer and conductor must observe signal 

indications, and both are equally responsible for ensuring that the train is operated in 

compliance with those indications. If the conductor observes that the engineer is not 

operating the train in compliance with the rules or is otherwise acting in an unsafe manner, 

he must remind the engineer of the requirements. If the engineer continues to disregard 

safety or rules considerations, the conductor is expected to take the actions necessary to 

remedy the situation, to include stopping the train. In this accident, neither the UP 

engineer nor conductor fulfilled his responsibilities.

The Accident

The accident UP train, for about the first 50 minutes of its trip, operated at speeds 

under 20 mph while it trailed a Laredo-bound UP freight train. After the Laredo train 

turned south, the accident train engineer, as would be expected, increased the throttle until 

the train was traveling at 49 mph, just under the maximum authorized speed over that 

track segment. Over the next few minutes, however, as the train approached the siding at 

Macdona, the engineer (and, by extension, the conductor) began to operate the train in a 

manner that was inconsistent with known operating conditions or UP rules.

For example, as the train approached and passed the clear signals at Withers and 

Alamo Junction, it traversed two grade crossings. The engineer did not sound the horn at 

either crossing, as required by UP operating rules. Then, after passing Alamo Junction at 

an appropriate speed of 46 mph, the engineer unaccountably slowed the train to 37 mph. 

He then used dynamic braking to slow the train even further as it neared the signal at 

MP 222, which was displaying an advance approach indication (because of the BNSF 

train nearing the Macdona siding). The train passed this signal at 22 mph. Had the train 

continued to operate at such a speed, the engineer would have been well positioned to 

comply with the approach signal displayed at the east end of the Macdona siding, which 

required that he proceed prepared to stop before the west end of the siding. (The engineer 

told investigators that he would normally be operating his train at no more than 10 mph if 

he were preparing to stop the train before the signal at the west end of the Macdona 

siding.) Instead, the engineer increased the trainís speed, passing the approach signal at 

the east end of the Macdona siding at 46 mph. At that point, the UP train was only about 

1 1/2 miles from the BNSF train, which was just entering the siding at its west end.
Analysis 37 Railroad Accident Report

As the UP train passed over the east siding switch and began to parallel the siding, 

the train speed reduced slightly, to 44 mph, and the engineer made three short blasts of the 

horn. After sounding the horn, the engineer made one more control movement, reducing 

the throttle setting by one notch, but the trainís speed remained at 44 mph. The engineer 

did not respond appropriately by dimming the headlight while passing the BNSF train on 

the siding, nor did he take any action when the stop signal at the west end of the siding 

came into view. The engineer continued to operate as if under clear signals up until the 

moment of impact with the 63rd car of the BNSF train.

The Safety Board therefore concludes that on the day of the accident, the crew of 

the accident UP train failed to operate their train in accordance with operating rules and in 

compliance with wayside signal indications, to include failing to take any action in 

response to the stop signal at the west end of the Macdona siding. 

The Safety Boardís investigation focused on the factors that might have caused or 

contributed to the UP crewís failure to operate their train as expected. The investigation 

also addressed the emergency response to the accident and the factors that contributed to 

the puncturing of a tank car and the fatal release of chlorine gas.

Exclusions

The accident occurred during darkness in clear weather. Signal visibility testing 

conducted after the accident revealed that the signals that were displaying advance 

approach and approach would have been visible and discernible from the locomotive cab 

of the UP train well in advance of its reaching the signals. The stop signal just before the 

west end of the Macdona siding would have been visible in time for the UP engineer to 

stop his train had he been proceeding in accordance with the approach signal he had 

passed just before reaching the east siding switch. At that point, it is also likely that he 

would have been able to see the cars of the BNSF train as that train was diverting into the 

siding.

Postaccident examination of data from the locomotive event recorders revealed no 

anomalies that would have contributed to noncompliance with operating rules or wayside 

signal indications. On the day before the accident, a problem was noted with the signals at 

the east end of the Macdona siding, but the investigation determined that the reported 

anomaly occurred only when the siding switch was lined for movements out of the siding; 

no signal problems had been noted when the switch was lined for the main line, as it was 

at the time of this accident. Further, the source of this anomaly (faulty insulation on a 

switch rod) had caused the signals to default to their most restrictive, thus safest, state. 

Finally, a review of signal data logs showed that all signal indications at the time of the 

accident were consistent with the sequence of train movements in both directions along 

the main line.

After the accident, the non-derailed cars from both the UP and the BNSF trains 

were inspected, and although some defects were noted, no defect was found that would 
Analysis 38 Railroad Accident Report

have significantly affected the operation of either train on the day of the accident. Track 

inspections in the area of the accident on the day before the accident revealed no 

abnormalities.

The investigation determined that both the UP engineer and conductor were 

adequately trained and qualified for their jobs and were sufficiently familiar with the 

territory over which they were working. Their medical records showed no health 

conditions that would have affected their ability to perform their work.

Postaccident toxicological tests for the UP and BNSF crews were negative for 

drugs. Although tests for alcohol were also negative for the UP engineer and the BNSF 

crew, the timing of the tests rendered the results inconclusive. There was, however, no 

evidence of alcohol use by the UP engineer or the BNSF crew in the hours before the 

accident.

Based on these findings, the Safety Board concludes that the following were 

neither causal nor contributory to the accident: weather conditions, signal operation, 

equipment performance, track condition, drug use, or crew training and qualifications. 

UP Train Crew Work, Rest, and Fatigue

UP Engineerís Activities and Rest

The investigation determined that in June 2004, the UP engineer worked at least 

part of 22 days and that his time on duty ranged from 9 hours to more than 18 hours. 

Eleven of his work days were longer than 14 hours, with 1 day totaling 22 hours (12 hours 

on duty and 10 hours of paid limbo time). The engineerís schedule reflected several 

demanding periods of work, but they were offset by breaks from service. For example, he 

was off duty for 57 consecutive hours during the first week of June, 69 hours the next 

week, and 41 hours the third week.

The periods of on-duty and off-duty time for the engineer during the month of June 

would have put his circadian processes in a state of continuous readjustment. Based on the 

release-from-duty times shown on the engineerís work schedule, he would have had to 

obtain much of his post-work recuperative sleep primarily during the daytime. Research 

has determined that daytime sleep is typically shorter in duration and is degraded in 

quality as compared with nighttime sleep.34 For the remainder of the month of June, the 

engineerís rest would have included nighttime sleep, either when he worked during the 

day, or when he had multiple-day breaks in service. Such frequent changes in work/sleep 

patterns have been shown to disrupt circadian rhythms in a way that can degrade work 

performance.35

34 A. J. Tilly, R. T. Wilkinson, P. S. G. Warren, B. Watson, and M. Drud, ìThe Sleep and Performance of 

Shift Workers,î Human Factors Vol. 24, No. 6 (1982): 629-641.

35 D. Kripke, M. Marler, and E. Calle, ìEpidemiological Health Impact,î in C. Kushida, ed., Sleep 

Deprivation, Clinical Issues, Pharmacology, and Sleep Loss Effects (New York: Marcel Dekker, 2005) 203.
Analysis 39 Railroad Accident Report

A complicating factor in the case of the UP engineer was that he did not have a 

residence of his own. Because he was staying with a fellow engineer but spending all his 

waking hours elsewhere, he did not have the usual relaxation time preparatory to sleeping 

that would have contributed to his obtaining recuperative rest. The combined effects of 

intermittent day and night work and the obstacles the engineer faced in obtaining adequate 

rest because of his living arrangements likely led to his developing a cumulative sleep 

loss, or sleep debt. Sleep debt occurs when an individual does not obtain sufficient 

restorative sleep over time.36 According to one prominent sleep researcher, the tendency of 

an individual to fall asleep increases progressively in direct proportion to the increase in 

the sleep debt.37

In the 3 days immediately before the accident, the UP engineer engaged in an 

intense concentration of work followed by time spent in personal activities on Sunday. 

Work records show that he had only 9 3/4 hours off duty (after his tour) on Friday, June 25,

and 9 1/2 hours off duty on Saturday, June 26. Based on his statements to investigators, he 

obtained only about 1 1/2 hours of bed rest (in addition to napping on a sofa while 

watching television) in a 31-hour period between his being called for work on Saturday 

evening, June 26, and the time of the accident. This lack of recuperative sleep would have 

increased the sleep debt the engineer was already experiencing because of his work 

schedule and living arrangements. Under these circumstances, the engineer would be 

expected to experience notably high sleep pressure with a resulting reduction in his ability 

to resist falling asleep.

The Safety Board therefore concludes that the UP engineerís combination of sleep 

debt, disrupted circadian processes, limited sleep through the weekend, and long duty 

tours in the days before the accident likely caused him to start the accident trip with a 

reduced capacity to resist involuntary sleep. 

This is not to say that, despite his intense work schedule in the days before the 

accident, the engineer did not have ample time to obtain rest. Had he been determined to 

do so, the engineer could have obtained recuperative rest after his tours on Friday and 

Saturday before the accident. And with some effort, he could have obtained even more rest 

on the Sunday before the accident.

The Safety Board notes that when the engineer went off duty on Sunday, he 

requested 12 hoursí uninterrupted rest. But when he left the work site, he did not return to 

his temporary residence to seek rest. Instead, he drove to the home of his estranged wife, 

where he intended to spend time with his daughter. He said that he did nap on the couch 

while watching television before his daughter arrived, but such napping would not be 

expected to fully ameliorate the effects of the engineerís sleep debt. Similarly, when the 

engineer left his wife and daughter at about 8:30 p.m., he could have gone back to where 

he was staying to go to bed. This would have given him several hours of additional sleep 

before his call to work. But instead of going home, he went to visit a friend and played 

cards for several hours.

36 W.C. Dement, The Sleepwatchers, 2nd ed. (Menlo Park, CA: Nychthemeron Press, 1996).

37 Dement, 1996.
Analysis 40 Railroad Accident Report

The engineer said that he had expected to get more sleep because he did not 

believe he would be called to work until later on Monday morning. But the engineer was 

well aware of the unpredictability of work in pool service. As he acknowledged during the 

public hearing on this accident, ìI could be 15 times out and miss calls because they rolled 

the board and put me first out.î He made no calls to the voice response system on Sunday 

to get up-to-date information on his standing or on job vacancies, although he may have 

accessed this information through the UP Web site.

UP Conductorís Activities and Rest

A review of the conductorís schedule in the 10 days before the accident showed 

that he had had 4 days off followed by 6 consecutive work days leading up to the day of 

the accident. His duty times for the 6 work days would have allowed him to continue the 

nighttime sleep pattern that he probably had adhered to during the preceding 4 off days. 

The conductorís call for the accident trip shortly after midnight on June 28 therefore 

inverted the work/sleep cycle he had developed over the previous 10 days. Such a 

disruption would be expected to produce ìsevere effectsî for sleepiness and 

performance.38

On Saturday, June 26, after working until 10:50 p.m., the conductor had 26 hours 

off duty before reporting for the accident trip. His housemate said that the conductor had 

stayed up until about 4:00 a.m. Sunday morning and slept until about 1:00 p.m. Sunday 

afternoon. He was then active until some time after 9:00, when he returned from the home 

of a friend. Based on the statements of his housemate, the conductor apparently did not go 

to bed immediately after returning home. Thus, at the time the conductor was called for 

the accident train early Monday morning, he had had, at most, only a few hours of sleep in 

the previous 11 hours. This limited amount of sleep could have exacerbated the effects of 

the conductorís inverted work/sleep cycle and could have made it more difficult for him to 

remain alert in the hours before the accident.

Postmortem toxicological tests of the conductor were negative for drugs but 

positive for ethanol (alcohol). The alcohol concentrations were 0.013 percent in the blood, 

0.051 percent in the urine, and 0.029 percent in the vitreous humor. Although the small 

concentrations of alcohol in the blood and urine could be explained as natural byproducts 

of decomposition, the finding of 0.029 percent alcohol in the vitreous humor offers 

evidence that the conductor had ingested alcohol before reporting for work.39 This finding 

was consistent with the housemateís statement that the conductor may have consumed 

some quantity of beer after he returned from his friendís home.

38 M. Rosekind, et al., in National Transportation Safety Board consulting report ìAnalysis of Crew 

Fatigue Factors in AIA Guantanamo Bay Aviation Accident,î pp. 3-4, referenced in National Transportation 

Safety Board, Uncontrolled Collision with Terrain, American International Airways Flight 808, Douglas 

DC-8-61 N814CK, U.S. Naval Air Station Guantanamo Bay, Cuba, August 18, 1993, Aviation Accident 

Report NTSB/AAR-94/04 (Washington, DC: NTSB, 1994).

39 D. Canfield, T. Kupiec, and E. Huffine, ìPostmortem Alcohol Production in Fatal Aircraft 

Accidents,î Journal of Forensic Sciences July (1993): 914-917. Also D. and V. DiMaio, Forensic Pathology

(Boca Raton, FL: CRC Press, 1993) 446-450.
Analysis 41 Railroad Accident Report

The Safety Board does not consider the conductorís alcohol use, in and of itself, to 

be causal to this accident. However, alcohol has been shown to have a sedating effect after 

use or after the concentration of alcohol in the body has begun to decrease.40 Thus, the 

Safety Board concludes that the UP conductorís lack of sufficient rest before reporting to 

work, the disruption to his previous work/rest pattern that resulted from his change in 

work schedule, and his alcohol consumption on the evening before the accident likely 

combined to reduce his capacity to remain awake and alert during the accident trip. 

As with the UP accident engineer, the UP conductor could have made more 

effective use of his off time to obtain rest in view of the unpredictability of his work 

schedule. For example, when the conductor returned home, after 12 hours of work, about 

10:30 p.m. on Saturday evening, June 26, he did not go to bed, even though this would 

have been in keeping with the nighttime sleep pattern he had developed over the preceding 

days. Instead, he stayed up watching movies until about 4:00 a.m. At that point, he would 

likely have been awake for 20 hours or more. He then slept, according to his housemate, 

for about 9 hours. While this sleep was certainly beneficial, its timing would make it 

difficult for him to obtain meaningful additional rest if he should be required to report for 

work late Sunday or, as it happened, early Monday.

The conductor was obviously concerned about the possibility that he would be 

called to work late Sunday or early Monday morning, as evidenced by his checking the UP 

Web site and his calls to the automated voice response system. But even though, according 

to his housemate, the conductor knew fairly early in the evening that he was ìsecond or 

third out,î he did not prepare for possible work by going to bed earlier on Sunday evening 

or by foregoing the use of alcohol. It is not known if the last call the conductor made to the 

voice response system alerted him to the possibility that he would be called before 1:00 a.m. 

on Monday morning. But even if he had been called somewhat later Monday morning, he 

would still have had to report to work after having received very little rest in the preceding 

12 hours and while possibly feeling the sedating effects of alcohol.

The Safety Board therefore concludes that neither the engineer nor the conductor 

of the UP train made effective use of the time that was available to them, between the time 

they were released from their previous assignments and the time they were called for the 

accident trip, to obtain rest. 

UP Crew Performance During the Accident Trip

As noted previously, the crew of the accident UP train failed to comply with 

successive wayside signals approaching the siding at Macdona and then did not make any 

attempt to stop their train when the stop signal, and even the BNSF train itself, came into 

view. The Board considered whether these failures could be explained by the fatigue that 

40 T. Roehrs and T. Roth, ìSleep, Sleepiness, and Alcohol Use,î Alcohol Research and Health Vol. 25, 

No. 2 (2001): 101-109.
Analysis 42 Railroad Accident Report

would have been affecting both crewmembers when they reported for work and during the 

first part of their trip.

During the UP trainís brief accident trip, which started at a time when the 

crewmembersí circadian processes would have been declining to their lowest level, the 

operating conditions were not favorable for resisting impairment from fatigue. The trip 

began with following another train, which did not provide significant operating challenges 

because of the slow speed the train was maintaining. According to event recorder data, the 

train traveled below 20 mph for the first portion of the accident trip. The combination of 

monotonous train operation, predawn darkness, and low level of illumination inside the 

cab would be expected to lower the mental arousal of even a well-rested train crew. 

The Engineerís Performance

Given the operating conditions that favored lowered resistance to sleep pressure, 

the most likely explanation for the UP trainís anomalous speed reduction after passing the 

clear signal at Alamo Junction was that the engineer experienced several moments of 

microsleep,41 or perhaps a brief period of mental confusion, as he approached and passed 

the signal (and as he proceeded over grade crossings without sounding the horn). Sensing 

a discontinuity in his cognitive awareness, the engineer may have begun slowing the train 

until he could reorient himself. He might not have remembered passing the clear signal, 

and a lower speed would have made it easier for him to comply if the next signal were 

restrictive.

Once the train passed the advance approach signal at 22 mph, the engineer once 

again began to operate his train inappropriately. Although the engineerís throttle and horn 

manipulations prevented an alerter alarm and show that he was not completely 

incapacitated by sleep, he was clearly not responding in a way that was consistent with his 

operating environment. He passed the signal at the east end of the Macdona siding as if it 

indicated clear. He continued to make minor throttle adjustments and to sound the horn, 

but his failure to dim his headlight when he passed the head end of the BNSF train on the 

adjacent siding track indicates that he probably was not aware of its presence.

Had the engineer been awake and alert when the two trains met, even if he had 

been sleeping earlier, he would have realized that a moving train on the siding meant that 

the track ahead may be fouled. That should have triggered a reduction in throttle and 

application of brakes to slow the train. Based on speed and distance calculations, the head 

ends of the two trains passed about 30 seconds before the collision. After the stop signal at 

the west end of the siding came into view, the engineer still had 7 seconds to place the 

brakes in emergency and at least mitigate the severity of the inevitable collision. Yet, the 

engineer took no action in response to the available stimuli.

That the engineer could have remained sufficiently alert to make train control 

inputs and yet be unable to respond to vitally important signal indications may be 

41 Microsleeps are brief intrusions of sleep lasting for several seconds that are indicative of restricted 

sleep. Research suggests likely impairment to performance both before and after periods of microsleep.
Analysis 43 Railroad Accident Report

explained by the fact that making such inputs and manipulating the alerter are highly 

practiced, nearly reflexive, motor responses that require only lower level cognitive effort. 

During the engineerís transition from wakefulness into the normal perceptual 

disengagement of unintended sleep, his capacity for information processing would have 

been severely compromised. Thus, he could have been able to continue the reflexive 

control activities while being unable to perform the higher level cognitive tasks of 

extrapolating information from the signal indications. 

In summary, the engineer appears to have been progressively impaired by fatigue 

such that within 45 to 50 minutes of starting the accident trip, he was unable to resist the 

pressure to sleep. He likely experienced at least one brief intrusion of sleep while passing 

Alamo Junction, after which he made a precautionary reduction in speed until he could 

orient himself. He temporarily roused himself as he passed the advance approach signal, 

but in the minutes that followed, he likely experienced a deeper descent into sleep, from 

which he would not awaken until the collision and derailment. The Safety Board therefore 

concludes that the engineer of the UP train likely experienced one or more periods of 

microsleep early in the accident trip, and these were probably followed by a deeper 

descent into sleep as the train traveled past the signal at the east end of the Macdona 

siding. 

The Conductorís Performance

The fact that the train was not operated in compliance with signal indications and 

operating rules before reaching the Macdona siding offers evidence that neither 

crewmember was consistently attentive to his work during the accident trip. Even if the 

engineer had been experiencing microsleeps, an alert conductor would have monitored the 

engineerís performance and prompted him as necessary to ensure that the train was 

operated safely. Not only was this not done, but the conductor also did not make the 

required entries on the conductorís report, Form 20849. Before reaching Macdona, the 

train passed several signals more restrictive than clear, each of which should have been 

noted on the form. The conductor should also have indicated on the form that he and the 

engineer had discussed the responses necessary to comply with restrictive signal 

indications. None of this information had been entered on the conductorís report for the 

accident trip. Finally, the engineer stated that after the collision, the conductor asked him 

what had happened. This indicates that the conductor had not been awake and observant 

for some period of time leading up to the collision. The Safety Board therefore concludes 

that the conductor of the UP train was most likely asleep during much of the accident trip. 

The Safety Board further believes that the UP should use the Macdona collision as 

a case study in fatigue awareness training to illustrate the shared responsibilities of the 

carrier to provide an employee the opportunity for adequate sleep and of the employee to 

acquire sleep sufficient to work at a safe level of alertness, and the options available if 

adequate sleep is not obtained. Because the responsibility for avoiding crewmember 

fatigue is shared by the carrier and the crewmember, the Safety Board believes that the 

Brotherhood of Locomotive Engineers and Trainmen (BLET) and the United 

Transportation Union (UTU) should also use this accident as a fatigue case study to 

illustrate the responsibility of the carrier to provide an employee the opportunity for 
Analysis 44 Railroad Accident Report

adequate sleep and the responsibility of the employee to acquire sleep sufficient to work at 

a safe level of alertness, and the options available if adequate sleep is not obtained. The 

BLET and the UTU also should present this case study to their members at meetings, 

through written materials, and other appropriate methods. 

Emergency Response

The initial accident notification to response agencies was via a 911 call that was 

made within about 3 minutes of the accident from a residence several hundred feet from 

the accident site. Within minutes, emergency responders from the Southwest Volunteer 

Fire Department were en route to the scene, responding to what they believed was a 

routine medical emergency involving smoke in a residence. They were not aware of the 

true nature of the incident.

Once aware that the emergency involved a chlorine gas release, fire department 

responders withdrew and requested mutual aid from surrounding jurisdictions. Some of 

the firefighters also donned personal protective gear and began a search of the area. Within 

about the next hour, additional emergency response resources arrived, and incident 

command was being established to coordinate and direct the response.

The proximity to the accident site of the residences near the Nelson Road grade 

crossing placed the occupants of those residences in immediate peril. While the occupants 

of the residences on the north side of the main line track were able to exit the area via 

Nelson Road or through the nearby open fields, those in the two residences south of the 

grade crossing were unable to escape the chlorine gas cloud. Occupants of one residence 

made 911 calls to report the situation at their location and to urgently request help, and 

although on-scene responders were subsequently made aware of these calls, rescue efforts 

on behalf of the endangered residents did not commence for more than 3 hours after the 

collision. 

The rescue effort was seriously impeded by the limited vehicular access to the 

affected residences. The general typography of the area, the muddy conditions of the 

agricultural fields near the houses, the flooded Medina River, and the blocked Nelson Road

grade crossing all prevented rescue vehicles from accessing the residences and aiding the 

victims. Since the accident, the Bexar County Emergency Management Division has 

undertaken a review of property locations where access could be blocked by a stopped 

train so that alternative emergency access routes can be identified in advance of an actual 

emergency.

Based on the postaccident emergency debriefings and interviews with responders, 

no consideration was given to using the open farm fields to the south of the accident site as 

potential helicopter landing areas or drop sites for firefighters. Responders also did not 

consider accessing Nelson Road south of the crossing via the unpaved and muddy 

roadways to the south of the accident site. Accordingly, the investigation determined that, 

although impassible to vehicle traffic, the open farm fields to the south of the accident site 
Analysis 45 Railroad Accident Report

afforded potential helicopter landing sites or firefighter drop-off sites that were 

sufficiently far from the accident site to avoid the chlorine gas hazard. Further, the 

unpaved roadways south of the accident site (which provided access to the open farm 

fields), although too wet for vehicle traffic, could have allowed firefighters traveling on 

foot to reach the two occupied residences. The failure of the emergency response agencies 

to consider these alternative response and rescue tactics suggests that incident command 

for the accident remained too focused on non-critical elements of the event and was not 

examining unconventional response/rescue tactics to gain access to the two threatened 

residences.

The delay in the search and rescue efforts reflects the lack of immediate, 

concentrated, focused efforts to reach those who were in the most danger. Apparently, 

each of the responding agencies followed its own course of action and did not effectively 

function as a part of a mutually supporting, unified entity. The Safety Board therefore 

concludes that, even though the initial dispatch of emergency response resources to the 

accident was timely, the overall execution of the incident command process during the 

response effort was not timely, effective, or appropriate. 

In response to the deficiencies noted in this investigation and during postaccident 

reviews, a series of training initiatives (for example, incident command classes, 

participation in multi-jurisdiction functional exercises, and revisions of emergency 

response protocols) were undertaken by the emergency services agencies of Bexar County 

to help prevent a recurrence of the problems that were experienced in this incident.

Tank Car Performance

A flatcar loaded with steel plates was positioned four cars ahead of the punctured 

chlorine tank car in the accident train. During the derailment, this car came to rest adjacent 

to the derailed and punctured chlorine tank car (the 16th car in the train). When the 

damaged corner of the flatcar was positioned against the punctured car, it was found to 

match the shape of the indentation in the tank car head. Further, the corner of the flatcar 

also contained shards of urethane that matched the insulation from the chlorine tank car. 

The Safety Board therefore concludes that the chlorine tank car that released a portion of 

its load in this accident was punctured during the derailment by impact with the left side 

frame member of the flatcar loaded with steel plates that was four cars ahead of the 

chlorine car in the train. 

The speed of the train at the time of the collision was about 44 mph. Consequently, 

the punctured tank head of the chlorine car was subjected to severe derailment loading 

forces from its impact with the flatcar. Despite the magnitude of these forces, the puncture 

was relatively small and did not result in a catastrophic failure of the tank. Still, an 

estimated 9,400 gallons (60 tons), or two-thirds of the liquefied chlorine in the tank car, 

were released.
Analysis 46 Railroad Accident Report

The DOT hazardous materials regulations, at 49 CFR 179.16, contain performance 

standards for tank head puncture resistance. The performance standards require that a tank 

head puncture-resistance system be adequate to permit the tank head to sustain, without 

any loss of lading, coupler-to-tank-head impacts at relative car speeds of 18 mph. The 

intent of this standard was to reduce or eliminate head punctures to loaded tank cars 

caused by over-speed impacts during coupling operations in railroad yards.42

In 1995, the hazardous materials regulations43 were amended to require tank head 

puncture-resistance systems for the entire tank head on pressure tank cars. The Research 

and Special Programs Administration acknowledged in the 1995 rulemaking that:

Analysis of data on main-line accidents showed that objects, such as broken rails 

and couplers, may penetrate the top half of the tank head, indicating that head 

protection is essential, even though not 100 percent effective, in a train 

derailment.

Although the punctured tank car did not have separate head shields, the protection 

afforded by the steel jacket, insulation, and enhanced tank head thickness met the 

performance standard of 49 CFR 179.16 for a tank head puncture-resistance system.

The Safety Boardís Materials Laboratory determined that the fracture features of 

the puncture surfaces were consistent with a shear failure. The laboratory also found that 

the head material directly adjacent to the puncture was severely deformed consistent with 

a ductile deformation.

Charpy tests on coupons from the punctured tank head and from the tank shell 

indicated that the hot-formed tank head had properties similar to normalized steel, with a 

ductile-to-brittle transition temperature of ñ40o F, which is considerably below the loading 

temperature of 30o F for the chlorine. The steel in the tank head was therefore ductile at 

the time of the derailment, and this ductility was a significant factor in limiting the size of 

the puncture. In contrast, the steel in the tank shell was not subjected to a normalizing heat 

treatment and had a ductile-to-brittle transition temperature greater than 85o F, indicating 

that the tank shell material would have been brittle under most operating conditions. Also, 

at 32° F (close to the loading temperature of the chlorine in the tank car), the energy 

absorbed by tank shell Charpy specimens oriented transversely to the rolling direction of 

the steel plate (the orientation with minimum fracture toughness) averaged 13 footpounds, which is lower than the corresponding Charpy impact energies for some of the 

catastrophically fractured tank car shells in the Minot, North Dakota, accident. The lower 

Charpy impact energy indicates that the fracture toughness of the steel from the shell of 

42 As early as 1978, the Safety Board recommended the installation of head shields on pressure tank 

cars to protect tank heads from punctures occurring in derailments and other accidents. Between 1978 and 

1991, the Board issued several safety recommendations calling for head shield protection on all pressure 

tank cars transporting any regulated liquefied gas and on tank cars transporting other designated hazardous 

materials.

43 ìCrashworthiness Protection Requirements for Tank Cars; Detection and Repair of Cracks, Pits, 

Corrosion, Lining Flaws, Thermal Protection Flaws and Other Defects on Tank Car Tanks,î 49048 Federal 

Register Vol. 60, No. 183 (September 21, 1995).
Analysis 47 Railroad Accident Report

the Macdona tank car was inferior to that of some of the steels from the tank cars ruptured 

in the 2002 derailment in Minot (discussed in more detail below). However, the structural 

differences between the Macdona tank car and the Minot tank cars would determine the 

loading conditions under which any of these tank cars would catastrophically fail. 

Nevertheless, the Safety Board concludes that the shell of the punctured chlorine tank car 

in this accident would have been susceptible to catastrophic fracture if it had experienced 

a large penetration of several feet or more. 

Previous Safety Board Actions Regarding Tank Cars

Because the punctured chlorine tank car was built before 1989, only the tank heads 

were required to be constructed of normalized steel;44 the tank shell was constructed of 

non-normalized steel. The Safety Board previously addressed the problems with the pre-1989

pressure tank cars in its investigation of the January 18, 2002, derailment in Minot, 

North Dakota.45 The Board most recently addressed the transportation of chlorine and 

other poisonous-by-inhalation gases in its investigation of the collision of two freight 

trains in Graniteville, South Carolina, on January 6, 2005.46

Minot

In the Minot accident, five fully loaded DOT class 105 tank cars sustained 

catastrophic shell failures and instantaneously released about 146,700 gallons of 

anhydrous ammonia. Sections of the fractured tanks were propelled as far as 1,200 feet. 

The tank shells of four of the five tank cars were brittle and thereby had reduced fracture 

toughness properties. The steel of the fifth tank car, although ductile, also had very low 

fracture toughness properties. The Safety Board concluded that the low fracture toughness 

of the non-normalized steels used for the tank shells of the five tank cars that 

catastrophically failed contributed to the carsí complete fracture and separation.

As a result of the Minot investigation, the Safety Board, on March 15, 2005, issued 

the following safety recommendations to the FRA:

44 During the hot forming process, the tank heads were subjected to normalizing temperatures used to 

shape the heads.

45 National Transportation Safety Board, Derailment of Canadian Pacific Railway Freight Train 292-16 

and Subsequent Release of Anhydrous Ammonia Near Minot, North Dakota, January 18, 2002. Railroad 

Accident Report NTSB/RAR-04/01 (Washington, DC: NTSB, 2004).

46 National Transportation Safety Board, Collision of Norfolk Southern Freight Train 192 With 

Standing Norfolk Southern Local Train P22 With Subsequent Hazardous Materials Release at Graniteville, 

South Carolina, January 6, 2005. Railroad Accident Report NTSB/RAR-05/04 (Washington, DC: NTSB, 

2005).
Analysis 48 Railroad Accident Report

R-04-4

Conduct a comprehensive analysis to determine the impact resistance of 

the steels in the shells of pressure tank cars constructed before 1989. At a 

minimum, the safety analysis should include the results of dynamic 

fracture toughness tests and/or the results of nondestructive testing 

techniques that provide information on material ductility and fracture 

toughness. The data should come from samples of steel from the tank shells 

from original manufacturing or from a statistically representative sampling 

of the shells of the pre-1989 pressure tank car fleet.

R-04-5

Based on the results of the Federal Railroad Administrationís 

comprehensive analysis to determine the impact resistance of the steels in 

the shells of pressure tank cars constructed before 1989, as addressed in 

Safety Recommendation R-04-4, establish a program to rank those cars 

according to their risk of catastrophic fracture and separation and implement 

measures to eliminate or mitigate this risk. This ranking should take into 

consideration operating temperatures, pressures, and maximum train speeds.

R-04-6

Validate the predictive model the Federal Railroad Administration is 

developing to quantify the maximum dynamic forces acting on railroad 

tank cars under accident conditions.

R-04-7

Develop and implement tank car design-specific fracture toughness 

standards, such as a minimum average Charpy value, for steels and other 

materials of construction for pressure tank cars used for the transportation of 

U.S. Department of Transportation class 2 hazardous materials, including 

those in ìlow-temperatureî service. The performance criteria must apply to 

the material orientation with the minimum impact resistance and take into 

account the entire range of operating temperatures of the tank car.

In its initial response on August 9, 2004, the FRA described the actions being taken 

to address each recommendation. The FRA subsequently provided updated information 

on actions taken to implement these recommendations in correspondence dated 

December 15, 2005, and in meetings and conference calls held in April and May 2006.

Safety Recommendations R-04-4 and -5. In its initial response on August 9, 2004,

the FRA stated that a task force under the Tank Car Committee of the Association of 

American Railroads (AAR) had developed a plan to sample steels from pre-1989 pressure 

cars as part of a risk assessment to evaluate the appropriateness of placing operating 

restrictions on tank cars. The task force proposed that steel sample coupons would be 

gathered only from the pre-1989 pressure tank cars as they were scrapped or retired; 

samples would not be taken from tank cars remaining in service.
Analysis 49 Railroad Accident Report

On June 22, 2005, the Safety Board responded that the FRAís approach to Safety 

Recommendation R-04-4 did not appear to be random and did not include the 

representative sampling of all steel manufacturers and mill sites, tank car manufacturers, 

the range of steel plate thickness, dates of manufacture, product service, etc. The Board 

added that in order for the sampling to be comprehensive, the program should also 

consider the total number of tank cars to be sampled along with which groups of tank 

cars are to be sampled. Because the FRAís proposed actions did not ensure that the 

analysis would be completed in a timely manner or demonstrate the urgency that the 

Board believes is necessary, Safety Recommendation R-04-4 was classified 

ìOpen⎯Unacceptable Response.î

In addressing the FRAís response to Safety Recommendation R-04-5, the Safety 

Board requested a more detailed description of how and when the ranking process would 

be conducted. The Board added that because of the FRAís commitment to ranking the 

pre-1989 fleet and implementing measures to mitigate the risk of the pre-1989 fleet, the 

Board classified Safety Recommendation R-04-5 ìOpen⎯Acceptable Response.î

On December 15, 2005, the FRA again responded to Safety Recommendation 

R-04-4. The FRA stated that it continues to pursue data gathered from steel samples 

collected from scrapped tank cars; however, the FRA did not provide any further details 

on the number of tank cars to be sampled and the methodology for testing and analysis of 

the data. The FRA also added that the Universal Machine Language Equipment Register 

(UMLER) database has provided useful statistical information on the pre-1989 pressure 

tank car fleet in terms of year of manufacture and type of steel. This information will be 

used to compare the actual cars that failed in Minot and with previous work done by the 

industryís Tank Car Safety Test and Research Project about steels used in pre-1989 cars. 

The FRA also stated that it would implement Safety Recommendation R-04-5 when the 

work under Safety Recommendation R-04-4 was complete.

Seeking further clarification, Safety Board staff met with FRA staff on April 4, 2006.

In regard to Safety Recommendation R-04-4, the FRA indicated that the AAR Tank Car 

Committee task force, in conjunction with the FRA, is currently studying the UMLER 

files to accurately determine the statistical distribution of pre-1989 pressure tank cars and 

the means for collecting representative samples. Testing of the samples has commenced to 

determine the mechanical and chemical properties, including dynamic fracture toughness, 

of the steel samples. The FRA reiterated that steel samples would be taken from tank cars 

as they were retired from service. As of February 2006, test samples from more than 24 

tank cars have been collected and tested. The FRA noted that, at present, in order to obtain 

a complete picture, candidate material samples, especially TC-128B from tank cars 

manufactured between 1978 and 1989, are being sought.

Further, the data available through the UMLER files for an individual tank car 

include only the tank car manufacturer, the year of manufacture, and the grade of steel 

used to construct it. According to the FRA, specific information about the steel plate, such 

as the steel manufacturer, identification of the producing mill, rolling processes, and lot 

number of the steel plates, does not exist and is not available. The absence of such 

information makes it impossible to determine if steel from a specific supplier was of lower 
Analysis 50 Railroad Accident Report

fracture toughness than steel from other suppliers. Given that the UMLER data provide 

the specified grade of steel, the tank car manufacturer, and the year of manufacture, any 

representative sampling of steel from the pre-1998 tank cars would be limited to 

consideration of these three parameters. The limitation of parameters should simplify 

and reduce the number of test samples needed to obtain a representative sampling of the 

pre-1989 pressure car fleet. However, the Safety Board remains concerned that a 

representative sampling will not be obtained under the present sampling plan and asks that 

the FRA explain how it will conduct and complete a representative sampling based on 

accepted and proven principles of statistical analysis.

On April 7, 2006, the Safety Board obtained preliminary information on the testing 

program from representatives of Southwest Research Institute (Southwest), the FRA 

contractor performing the fracture toughness and Charpy tests on the samples from the 

pre-1989 tank cars. Southwest representatives indicated that a major emphasis of the 

testing program is on a fracture mechanics-based approach, because this approach 

traditionally can be applied to design parameters in mechanical structures. Also, the 

testing program is being conducted with a predetermined rate of loading. Southwest 

acknowledged that accident conditions, such as the rate and magnitude of loading, were 

not known but that the predetermined conditions in the testing program provided a starting 

point for collecting data on tank car steels. In the preliminary data reviewed by the Board, 

Southwest classified the fracture toughness of most of the steels tested so far (including 

steel from the Minot tank cars) as generally in the ìacceptableî range, despite, as 

demonstrated by the Minot accident, the possibility that tank car shells made from this 

steel can catastrophically fracture in accident conditions. The Board notes that of the 12 

stress intensity factor values generated at 0o

 F by Southwest for non-normalized TC128B 

steel samples taken from the Minot tank cars that catastrophically failed, five had 

toughness values at or above the toughness value reported by the National Institute of 

Standards and Technology (NIST) for normalized TC128B steel.47 In contrast, the Charpy 

impact data in the NIST report is consistent with Safety Board and literature data, which 

indicate that the non-normalized steels generally exhibit much lower Charpy impact 

energies than the normalized steels. Possible contradictory results such as these should be 

clearly explained and justified before they can be accepted, independent of sampling 

issues.

During a visit to Southwest on May 22, 2006, Safety Board staff discussed the 

preliminary test data in more detail with representatives of the FRA, the Volpe National 

Transportation Systems Center, and Southwest engineers. Board staff noted that the 

preliminary fracture toughness data from the Southwest tests show a large variation in 

fracture toughness among the samples of steel plate tested, with no discernible trends 

correlating with the year of tank car construction or tank car manufacturer. Because of 

these variations, the sampling of steel from retired tank cars should be continued to ensure 

that no trends in the data are being missed due to the limited size of the pre-1989 tank car 

fleet available for testing.

47 NIST report NISTIR 4660, Mechanical Properties and Fracture Toughness of AAR TC128 Grade B 

Steel in the Normalized and Normalized and Stress Relieved Conditions, September 1991.
Analysis 51 Railroad Accident Report

Additionally, in one case, a large variation in toughness was measured for samples 

taken from the same plate. While the level of variance in the data may be representative of 

what should be expected fleet wide, the possibility of a large variation within an individual 

tank car has significant implications for the risk assessment called for by Safety 

Recommendation R-04-5. In order to assess whether this degree of variability is common 

within a single steel plate, the FRA is encouraged to complete additional sampling through 

Southwest to generate a representative database of fracture toughness for multiple 

material samples taken from a single tank car at a fixed temperature, preferably 0° F, and a 

fixed loading rate, or statically.

The low fracture toughness of the steel in the tank shell of the chlorine tank car in 

Macdona reinforces the need to complete action on Safety Recommendation R-04-4. 

Although the Safety Board still has questions about the interpretation and meaning of the 

sampled fracture toughness data collected to date, as noted above, the Board believes that 

the FRA is making positive progress on addressing Safety Recommendation R-04-4, 

which is reclassified ìOpenóAcceptable Responseî in this report. Because of the FRAís 

commitment to implementing Safety Recommendation R-04-5 upon completion of work 

under Safety Recommendation R-04-4, Safety Recommendation R-04-5 remains 

classified ìOpenóAcceptable Response.î 

Safety Recommendations R-04-6 and -7. In its initial response to Safety 

Recommendation R-04-6, the FRA stated, on August 9, 2004, that it had identified 

ongoing programs at the Volpe National Transportation Systems Center and the University 

of Illinois at Chicago to evaluate in-train forces associated with train derailments. The 

FRA anticipated that the modeling program would be completed in early 2006. On 

June 22, 2005, the Safety Board acknowledged that programs to analyze in-train forces 

had been identified. The Board also expressed its expectation that validation of the models 

was to be a standard part of any model development. Based on the FRAís response, Safety 

Recommendation R-04-6 was classified ìOpen⎯Acceptable Response.î

The FRA stated in its initial response to Safety Recommendation R-04-7 that 

further research was required, which may necessitate a ì3-year effortî to develop adequate 

tank car design-specific fracture toughness standards. In its June 22, 2005, response, the 

Safety Board stated that tank car design-specific fracture standards, such as Charpy impact 

values, can be achieved for standard manufacturing processes without waiting for the 

results of the modeling effort associated with Safety Recommendation R-04-6. The Board 

added that evaluation and analysis of the dynamics of the Minot accident can provide data 

about the levels of fracture toughness that may be necessary for pressure tank cars and that 

data from subsequent accidents in Macdona, Texas, and Graniteville, South Carolina, will 

provide additional information. Based on the FRAís response, Safety Recommendation 

R-04-7 was classified ìOpen⎯Unacceptable Response.î

On June 24, 2005, the AAR, in collaboration with the FRA, revised its Manual of 

Standards and Recommended PracticesóSpecifications for Tank Cars. Under this revision,

the steel plate used in the construction of pressure tank cars ordered after July 1, 2005, 

must meet Charpy impact testing standards for the orientation transverse to the rolling 

direction of the steel plate, the orientation that has the weakest impact resistance. The 
Analysis 52 Railroad Accident Report

Charpy test coupons must simulate the in-service condition of the material and must meet 

the minimum requirement of a 15 foot-pound average for three specimens, with no single 

value below 10 foot-pounds and no two below 15 foot-pounds at ñ30o F.

The AARís new standards ensure that a minimum level of impact resistance for 

normalized steel can be verified by a standardized testing method. The new standards also 

require that the Charpy tests be performed in the orientation of the sample material with the 

lowest impact property. With the implementation of these new standards, the emphasis is 

placed, properly, on fracture toughness properties rather than solely on normalization of the 

steel plate. The Safety Board considers the implementation of the AAR standards to be a first 

step in a process of developing a fracture toughness standard for steel in pressure tank cars.

The process of developing meaningful fracture toughness standards that will be 

refined and updated as new steels are developed will be linked to the development and 

refinement of predictive models of forces occurring in rail accidents. As noted previously, 

the FRA is sponsoring ongoing programs at the Volpe National Transportation Systems 

Center and the University of Illinois at Chicago to evaluate in-train forces associated with 

train derailments. Missing from these programs is a structural mechanics approach to 

translate car forces to stress and deformation states in tank car structures. It is this level of 

knowledge that enables the driving forces for crack growth and propagation to be defined, 

an essential step if a fracture toughness requirement is to be quantified. In the view of the 

Safety Board, the fracture toughness requirements for tank cars should be reevaluated and 

adjusted as information from research/modeling on impact dynamics and structural 

response becomes available. Such an approach would help lay the foundation for the 

future design of tank cars with greater puncture resistance and penetration resistance.

As demonstrated by the accidents in Graniteville, South Carolina, and in Macdona, 

punctures in chlorine tank cars with the release of the chlorine gas can be catastrophic, 

even if the operating stresses on the tank are too low to cause the catastrophic growth of 

the cracks generated by the penetration process. Consequently, the Safety Board considers 

a ìdesign-specific fracture toughness standardî as specified in Safety Recommendation 

R-04-7 to include, in addition to a consideration of the lethality of the tank car contents, a 

structural level penetration and crack growth assessment. The Board believes that the data 

being developed at Southwest, particularly on the variability of the fracture toughness of 

the test samples, can also be used to advance Safety Recommendations R-04-6 and -7. The 

Board encourages the FRA to address these points in the modeling work underway at the 

Volpe National Transportation Systems Center and the University of Illinois at Chicago. 

Because it appears that the FRA is making progress on the modeling of accident forces 

and the development of fracture toughness standards, Safety Recommendation R-04-6 

remains classified ìOpenóAcceptable Response,î and Safety Recommendation R-04-7 is 

reclassified ìOpenóAcceptable Response.î

Because the Safety Board is convinced that the successful and timely completion 

of all four of the above safety recommendations is of critical importance to improving the 

safety of pressure tank cars and the protection of the public, the Safety Board reiterates 

Safety Recommendations R-04-4 through -7 to the FRA.
Analysis 53 Railroad Accident Report

Graniteville

The Safety Board also investigated the January 6, 2005, collision and derailment 

in Graniteville, South Carolina, that resulted in a puncture in the shell of a chlorine tank 

car. Nine people died due to exposure to the chlorine gas. The Board concluded that 

even the strongest tank cars in service can be punctured in accidents involving trains 

operating at moderate speeds. As a result of the Graniteville investigation, the Board on 

December 12, 2005, issued the following safety recommendation to the FRA:

R-05-16

Require railroads to implement operating measures, such as positioning 

tank cars toward the rear of trains and reducing speeds through populated 

areas, to minimize impact forces from accidents and reduce the 

vulnerability of tank cars transporting chlorine, anhydrous ammonia, and 

other liquefied gases designated as poisonous by inhalation.

On the afternoon of July 3, 2006, the FRA provided the Safety Board with an 

advance copy of its June 30, 2006, letter responding to Safety Recommendation R-05-16. 

The letter notes that the FRA does not believe that placing tank cars filled with poisonous 

by inhalation cargo at the rear of trains would be prudent. Further, the FRAís letter notes 

that despite the fact that catastrophic releases are very rare events and practical 

impediments to speed restrictions are substantial, it will review the potential benefits and 

costs of slowing trains carrying certain toxic commodities. The Board considers the failure 

of the FRA to respond to the December 12, 2005, safety recommendation in a timely 

manner to be unacceptable. Pending further evaluation of the information provided, Safety 

Recommendation R-05-16, previously classified ìOpenóAwait Response,î is reclassified 

ìOpenóResponse Received.î

The accidents in Macdona and Graniteville clearly demonstrate that punctures of 

tank cars transporting chlorine and other poisonous liquefied gases can, within minutes, 

result in the release of fatal quantities of the toxic gases. The Safety Board recognized in 

the Graniteville investigation that certain poisonous liquefied gases that are poisonous by 

inhalation, if released, present such a severe danger to nearby citizens that operational 

measures, in addition to improving the structural integrity of tank cars, are needed to 

minimize the vulnerability of these tank cars in an accident. Accordingly, the Safety Board 

reiterates Safety Recommendation R-05-16 to the FRA.

Work Schedules and Limbo Time

The Safety Board recognizes that work as a train crewmember entails an 

unpredictable job schedule that can make it difficult for employees to effectively balance 

their personal and work lives. During those periods when the demand for crews exceeds 

the supply, the additional pressure on available crewmembers can make achieving such a 

balance particularly difficult. These conditions make it inevitable that even the most 

conscientious railroad employees will occasionally find themselves ìcaught short,î 
Analysis 54 Railroad Accident Report

without having received adequate rest before being called back to work. Although it 

cannot be known exactly what the engineer and conductor of the UP train would have 

done if they had known they would be called for the accident train shortly after midnight, 

it is clear that they were taking the chance that they would not be called to work when they 

were. In this case, the unpredictability of their work schedules led them to make what 

would prove to be imprudent use of their personal time. The Safety Board therefore 

concludes that the unpredictability of their work schedules may have encouraged the UP 

engineer and conductor to delay obtaining rest in the hope that they would not be called to 

work until later on the day of the accident. 

The minimum rest periods prescribed by Federal regulations do not take into 

account either rotating work schedules or the accumulated hours spent working and in 

limbo time, both of which can affect the ability of an employee to obtain full rest and 

recuperation between job assignments. While limbo time is most often associated with a 

crewís travel time to their final release point after the expiration of their 12-hour service 

limit, the time spent awaiting transportation can be significant, as the Safety Board 

documented for the San Antonio Service Unit and the entire UP system during its 

investigation of the Macdona accident. 

During an 8-week period in 1997, the UP had three collisions that resulted in five 

employee fatalities. The FRA responded by initiating a comprehensive systemwide safety 

review of the UPís operations seeking ways to correct systemic safety shortcomings. The 

FRA concluded that there was:

significant evidence of ineffective crew utilization, which leads directly to crew 

fatigue, stress, a lowering of morale, violations of the hours of service act and 

reduced ability to comply with operating rules. The end effect is train accidents 

and employee fatalities. For example: crews being left on trains after the 

expiration of the Hours of Service. Sometimes in excess of two hours is spent 

awaiting arrival of crew vans or relief crews. Crews expire under the Hours of 

Service Act approximately 75 percent of the time. This severely adds to crew 

unavailability and compounds rest and fatigue issues. [Emphasis added.]

The Safety Board acknowledges that the amount of limbo time incurred by crews on 

the UP system or the San Antonio Service Unit is neither causal nor contributory to the 

Macdona accident. Nevertheless, the Board is concerned that, because minimum rest periods 

prescribed under the hours-of-service regulations do not take limbo time into account, such 

time could have cumulative detrimental effects on crewmember fatigue. The Safety Board 

therefore concludes that limbo time, which is limited neither by Federal regulation nor 

railroad operating rules, could be a factor in crewmember fatigue in that required rest periods 

do not take into account the extended hours of wakefulness before the rest period begins. 

The combination of erratic work schedules and excess limbo time would be expected to have 

a detrimental impact on crewmember fatigue. The Safety Board therefore believes that the 

FRA should require railroads to use scientifically based principles when assigning work 

schedules for train crewmembers, which consider factors that impact sleep needs, to reduce 

the effects of fatigue. Further, the Safety Board believes that the FRA should establish 

requirements that limit train crewmember limbo time to address fatigue.
Analysis 55 Railroad Accident Report

Positive Train Control

The Safety Board remains concerned about the safety of railroad operations where 

backup systems are not available to intervene when, as in this accident, a train crew 

operates a train improperly or fails to comply with wayside signals. Board accident 

investigations over the past three decades have shown that the most effective way to 

prevent train-to-train collisions is through the use of a positive train control (PTC) system 

that will automatically assume some control of a train when the train crew does not 

comply with signal indications.

Over the years, the Safety Board has issued a series of relevant recommendations, 

and PTC has remained on the Boardís Most Wanted Transportation Safety Improvements 

list since 1990. The most recent safety recommendation relating to PTC, Safety 

Recommendation R-01-6, was issued to the FRA as a result of the Boardís investigation of 

a fatal train collision in Bryan, Ohio.48

R-01-6

Facilitate actions necessary for development and implementation of 

positive train control systems that include collision avoidance, and require 

implementation of positive train control systems on main line tracks, 

establishing priority requirements for high-risk corridors such as those 

where commuter and intercity passenger railroads operate.

Based on a March 27, 2002, letter in which the FRA outlined steps that it had taken 

toward ìachieving the proper atmosphere in the rail industry to allow for the development 

and implementation of PTC,î the Safety Board classified Safety Recommendation R-01-6 

ìOpenóAcceptable Response.î

In answer to an April 17, 2003, letter from the Safety Board asking for an update 

on actions regarding this safety recommendation, the FRA responded, in a May 5, 2003, 

letter, that it was ìmoving forward across a broad front to create the conditions under 

which PTC systems can be more widely deployed on the national rail system.î In the 

letter, the FRA detailed some of the steps the agency was taking in the following areas:

ï Providing a radio-navigation infrastructure and ensuring adequate spectrum

ï Facilitating positive train control through regulatory change

ï Supporting the demonstration and deployment of candidate technologies

ï Analyzing costs and benefits

The FRA stated that the agency was ìdoing everything within its power to prepare 

the way for PTC and encourage its rapid deployment.î In the wake of additional accidents 

48 National Transportation Safety Board, Collision Involving Three Consolidated Rail Corporation 

Freight Trains Operating in Fog on a Double Main Track Near Bryan, Ohio, January 17, 1999, Railroad 

Accident Report NTSB/RAR-01/01 (Washington, DC: NTSB, 2001).
Analysis 56 Railroad Accident Report

that would have been prevented had PTC systems been installed, the Board reiterated 

Safety Recommendation R-01-6 in 2003 and again in 2005 after its investigations of 

railroad accidents in Placentia, California49 and Chicago, Illinois.50

The Safety Board hosted a seminar on PTC at the NTSB Academy in March 2005, 

and the Board is aware of several initiatives in the railroad industry to test PTC installations. 

On March 7, 2005, the FRA issued a performance standard for processor-based signal and 

train control systems, which became effective on June 6, 2005. In its May 16, 2006, 

response to the Boardís most recent reiteration of Safety Recommendation R-01-6, the 

FRA noted these accomplishments and elaborated on the various pilot tests underway by 

Amtrak and the Class I railroads. While it is encouraging that the FRA has moved forward 

on performance standards and that other PTC pilot projects are underway, the Safety 

Board remains concerned that it has taken so long for the FRA to require, and for the 

railroad industry to develop and implement, such systems.

The Safety Board concludes that the Macdona, Texas, accident is another in a long 

series of railroad accidents that could have been prevented had there been a PTC system in 

place at the accident location. 

Train Crew Protection From Inhalation Hazards

The Safety Board has found that freight train crews may survive collisions and 

derailments only to be injured or killed by hazardous materials released in the accident. In 

this accident, both UP crewmembers escaped serious injury in the collision only to 

become incapacitated or, in the case of the conductor, fatally injured as a result of the 

subsequent release of chlorine gas. If the UP crewmembers had been wearing appropriate, 

fully functioning emergency escape breathing apparatus when they walked away from the 

collision site, they might have been able to escape the chlorine vapors.

The consequences of this accident are similar to those of the previously referenced 

January 6, 2005, collision and derailment in Graniteville, South Carolina. A misaligned 

switch allowed a main line train to enter a siding and strike a standing train. As a result of 

the collision, a tank car on the striking train was punctured and released chlorine gas. The 

crew of the striking train survived the collision and exited the locomotive unassisted but 

could not escape exposure to the chlorine gas. The conductor and engineer were able to 

walk some distance from the collision where they were then transported to hospitals. The 

conductor was treated and released; the engineer died several hours later from inhalation 

of the toxic gas.

49 National Transportation Safety Board, Collision of Burlington Northern Santa Fe Freight Train With 

Metrolink Passenger Train, Placentia, California, April 23, 2002, Railroad Accident Report NTSB/RAR-03/04

(Washington, DC: NTSB, 2003).

50 National Transportation Safety Board, Derailment of Northeast Illinois Regional Commuter Railroad 

Train 519 in Chicago, Illinois, October 12, 2003, Railroad Accident Report NTSB/RAR-05/03 

(Washington, DC: NTSB, 2005).
Analysis 57 Railroad Accident Report

As a result of the Safety Boardís investigation of the Graniteville collision and 

derailment, on December 12, 2005, the Board issued the following safety recommendation 

to the FRA:

R-05-17

Determine the most effective methods of providing emergency escape 

breathing apparatus for all crewmembers on freight trains carrying 

hazardous materials that would pose an inhalation hazard in the event of 

unintentional release, and then require railroads to provide these breathing 

apparatus to their crewmembers along with appropriate training.

In the advance copy of the FRAís June 30, 2006, letter, the FRA notes that in 

response to the recommendation it will begin a research effort this year to ascertain 

whether and in what way the recommendation can be accomplished. The Safety Board 

considers the failure of the FRA to respond to this safety recommendation in a timely 

manner to be unacceptable. However, because the FRA is initiating a research effort in 

response to this recommendation, Safety Recommendation R-05-17, previously classified 

ìOpenóAwait Response,î is reclassified ìOpenóAcceptable Response.î Further, the 

Safety Board reiterates Safety Recommendation R-05-17 to the FRA.
58 Railroad Accident Report

Conclusions

Findings

1. On the day of the accident, the crew of the accident Union Pacific Railroad train 

failed to operate their train in accordance with operating rules and in compliance with 

wayside signal indications, to include failing to take any action in response to the stop

signal at the west end of the Macdona siding.

2. The following were neither causal nor contributory to the accident: weather 

conditions, signal operation, equipment performance, track condition, drug use, or 

crew training and qualifications.

3. The Union Pacific Railroad engineerís combination of sleep debt, disrupted circadian 

processes, limited sleep through the weekend, and long duty tours in the days before 

the accident likely caused him to start the accident trip with a reduced capacity to 

resist involuntary sleep.

4. The Union Pacific Railroad conductorís lack of sufficient rest before reporting to 

work, the disruption to his previous work/rest pattern that resulted from his change in 

work schedule, and his alcohol consumption on the evening before the accident likely 

combined to reduce his capacity to remain awake and alert during the accident trip.

5. Neither the engineer nor the conductor of the Union Pacific Railroad train made 

effective use of the time that was available to them, between the time they were 

released from their previous assignments and the time they were called for the 

accident trip, to obtain rest.

6. The engineer of the Union Pacific Railroad train likely experienced one or more 

periods of microsleep early in the accident trip, and these were probably followed by 

a deeper descent into sleep as the train traveled past the signal at the east end of the 

Macdona siding.

7. The conductor of the Union Pacific Railroad train was most likely asleep during much 

of the accident trip.

8. Even though the initial dispatch of emergency response resources to the accident was 

timely, the overall execution of the incident command process during the response 

effort was not timely, effective, or appropriate.

9. The chlorine tank car that released a portion of its load in this accident was punctured 

during the derailment by impact with the left side frame member of the flatcar loaded 

with steel plates that was four cars ahead of the chlorine car in the train.
Conclusions 59 Railroad Accident Report

10. The shell of the punctured chlorine tank car in this accident would have been 

susceptible to catastrophic fracture if it had experienced a large penetration of several 

feet or more.

11. The unpredictability of their work schedules may have encouraged the Union Pacific 

Railroad engineer and conductor to delay obtaining rest in the hope that they would 

not be called to work until later on the day of the accident.

12. Limbo time, which is limited neither by Federal regulation nor railroad operating 

rules, could be a factor in crewmember fatigue in that required rest periods do not 

take into account the extended hours of wakefulness before the rest period begins.

13. The Macdona, Texas, accident is another in a long series of railroad accidents that 

could have been prevented had there been a positive train control system in place at 

the accident location.

Probable Cause

The National Transportation Safety Board determines that the probable cause of 

the June 28, 2004, collision of Union Pacific Railroad train MHOTU-23 with BNSF 

Railway Company train MEAP-TUL-126-D at Macdona, Texas, was Union Pacific 

Railroad train crew fatigue that resulted in the failure of the engineer and conductor to 

appropriately respond to wayside signals governing the movement of their train. 

Contributing to the crewmembersí fatigue was their failure to obtain sufficient restorative 

rest prior to reporting for duty because of their ineffective use of off-duty time and Union 

Pacific Railroad train crew scheduling practices, which inverted the crewmembersí 

work/rest periods. Contributing to the accident was the lack of a positive train control 

system in the accident location. Contributing to the severity of the accident was the 

puncture of a tank car and the subsequent release of poisonous liquefied chlorine gas.
60 Railroad Accident Report

Recommendations

As a result of its investigation of the June 28, 2004, collision and derailment in 

Macdona, Texas, the National Transportation Safety Board makes the following safety 

recommendations:

New Recommendations

To the Federal Railroad Administration:

1. Require railroads to use scientifically based principles when assigning work 

schedules for train crewmembers, which consider factors that impact sleep 

needs, to reduce the effects of fatigue. (R-06-14)

2. Establish requirements that limit train crewmember limbo time to address 

fatigue. (R-06-15)

To the Union Pacific Railroad:

3. Use the Macdona collision as a case study in fatigue awareness training to 

illustrate the shared responsibilities of the carrier to provide an employee the 

opportunity for adequate sleep and of the employee to acquire sleep sufficient 

to work at a safe level of alertness, and the options available if adequate sleep 

is not obtained. (R-06-16)

To the Brotherhood of Locomotive Engineers and Trainmen and the United 

Transportation Union:

4. Use this accident as a fatigue case study to illustrate the responsibility of the 

carrier to provide an employee the opportunity for adequate sleep and the 

responsibility of the employee to acquire sleep sufficient to work at a safe level 

of alertness, and the options available if adequate sleep is not obtained. Present 

this case study to your members at meetings, through written materials, and 

other appropriate methods. (R-06-17)
Recommendations 61 Railroad Accident Report

Recommendations Reiterated in This Report

To the Federal Railroad Administration:

R-04-4

Conduct a comprehensive analysis to determine the impact resistance of 

the steels in the shells of pressure tank cars constructed before 1989. At a 

minimum, the safety analysis should include the results of dynamic 

fracture toughness tests and/or the results of nondestructive testing 

techniques that provide information on material ductility and fracture 

toughness. The data should come from samples of steel from the tank shells 

from original manufacturing or from a statistically representative sampling 

of the shells of the pre-1989 pressure tank car fleet.

R-04-5

Based on the results of the Federal Railroad Administrationís 

comprehensive analysis to determine the impact resistance of the steels in 

the shells of pressure tank cars constructed before 1989, as addressed in 

Safety Recommendation R-04-4, establish a program to rank those cars 

according to their risk of catastrophic fracture and separation and 

implement measures to eliminate or mitigate this risk. This ranking should 

take into consideration operating temperatures, pressures, and maximum 

train speeds.

R-04-6

Validate the predictive model the Federal Railroad Administration is 

developing to quantify the maximum dynamic forces acting on railroad 

tank cars under accident conditions.

R-04-7

Develop and implement tank car design-specific fracture toughness 

standards, such as a minimum average Charpy value, for steels and other 

materials of construction for pressure tank cars used for the transportation of 

U.S. Department of Transportation class 2 hazardous materials, including 

those in ìlow-temperatureî service. The performance criteria must apply to 

the material orientation with the minimum impact resistance and take into 

account the entire range of operating temperatures of the tank car.

R-05-16

Require railroads to implement operating measures, such as positioning 

tank cars toward the rear of trains and reducing speeds through populated 

areas, to minimize impact forces from accidents and reduce the 

vulnerability of tank cars transporting chlorine, anhydrous ammonia, and 

other liquefied gases designated as poisonous by inhalation.
Recommendations 62 Railroad Accident Report

R-05-17

Determine the most effective methods of providing emergency escape 

breathing apparatus for all crewmembers on freight trains carrying 

hazardous materials that would pose an inhalation hazard in the event of 

unintentional release, and then require railroads to provide these breathing 

apparatus to their crewmembers along with appropriate training.

Recommendations Reclassified in This Report

To the Federal Railroad Administration:

R-04-4

Conduct a comprehensive analysis to determine the impact resistance of 

the steels in the shells of pressure tank cars constructed before 1989. At a 

minimum, the safety analysis should include the results of dynamic 

fracture toughness tests and/or the results of nondestructive testing 

techniques that provide information on material ductility and fracture 

toughness. The data should come from samples of steel from the tank shells 

from original manufacturing or from a statistically representative sampling 

of the shells of the pre-1989 pressure tank car fleet.

Safety Recommendation R-04-4, previously classified ìOpen⎯Unacceptable 

Response,î is reclassified ìOpenóAcceptable Responseî in the ìPrevious Safety Board 

Actions Regarding Tank Carsî section of this report.

To the Federal Railroad Administration:

R-04-7

Develop and implement tank car design-specific fracture toughness 

standards, such as a minimum average Charpy value, for steels and other 

materials of construction for pressure tank cars used for the transportation 

of U.S. Department of Transportation class 2 hazardous materials, 

including those in ìlow-temperatureî service. The performance criteria 

must apply to the material orientation with the minimum impact resistance 

and take into account the entire range of operating temperatures of the tank 

car.

Safety Recommendation R-04-7, previously classified ìOpen⎯Unacceptable 

Response,î is reclassified ìOpen⎯Acceptable Responseî in the ìPrevious Safety Board 

Actions Regarding Tank Carsî section of this report.
Recommendations 63 Railroad Accident Report

To the Federal Railroad Administration:

R-05-16

Require railroads to implement operating measures, such as positioning 

tank cars toward the rear of trains and reducing speeds through populated 

areas, to minimize impact forces from accidents and reduce the 

vulnerability of tank cars transporting chlorine, anhydrous ammonia, and 

other liquefied gases designated as poisonous by inhalation.

Safety Recommendation R-05-16, previously classified ìOpen⎯Await 

Response,î is reclassified ìOpenóResponse Receivedî in the ìPrevious Safety Board 

Actions Regarding Tank Carsî section of this report.

To the Federal Railroad Administration:

R-05-17

Determine the most effective methods of providing emergency escape 

breathing apparatus for all crewmembers on freight trains carrying 

hazardous materials that would pose an inhalation hazard in the event of 

unintentional release, and then require railroads to provide these breathing 

apparatus to their crewmembers along with appropriate training.

Safety Recommendation R-05-17, previously classified ìOpen⎯Await 

Response,î is reclassified ìOpenóAcceptable Responseî in the ìTrain Crew Protection 

From Inhalation Hazardsî section of this report.

BY THE NATIONAL TRANSPORTATION SAFETY BOARD

Mark V. Rosenker 

Acting Chairman

Deborah A. P. Hersman

Member

Kathryn OíLeary Higgins

Member

Adopted: July 6, 2006

65 Railroad Accident Report

Appendix A

Investigation

The National Response Center notified the National Transportation Safety Board 

of the Macdona accident on June 28, 2004, at 7:22 a.m, eastern daylight time. The 

investigator-in-charge and other members of the Safety Board investigative team were 

launched from the Washington, D.C., Headquarters office and from the Los Angeles, 

California, field office. Investigative groups were established to study operations, track, 

signals, mechanical, survival factors, human performance, and hazardous materials issues. 

No Safety Board Member went to the accident site.

The Union Pacific Railroad, the Federal Railroad Administration, the BNSF 

Railway Company, the Texas Railroad Commission, the Brotherhood of Locomotive 

Engineers and Trainmen, the United Transportation Union, the city of San Antonio, Texas, 

and Bexar County, Texas, assisted the Safety Board in its investigation.

As part of its investigation of the Macdona accident, the Safety Board held a public 

hearing at its Headquarters in Washington, D.C., on April 26 and 27, 2005. Parties to the 

hearing included the Federal Railroad Administration, the Union Pacific Railroad, the 

BNSF Railway Company, the Brotherhood of Locomotive Engineers and Trainmen, and 

the United Transportation Union. Observers at the hearing were the city of San Antonio, 

Texas, and Bexar County, Texas.