E PLURIBUS UNUM

NATIONAL TRA SPORTATION

B OARD

SAFE T Y

N

National Transportation Safety Board 

Washington, D.C. 20594 

Railroad Accident Brief

Accident No: DCA-04-FR-012 

Railroad: Alton and Southern Railway Company 

Train: Remote Control Train YAS313 

Location: East St. Louis, Illinois 

Accident date: September 21, 2004 

Accident time: 3:15 a.m. central daylight time

1

Type of Accident: Remote control collision in hump classification yard and 

hazardous materials release 

Fatalities/Injuries: None

Property Damage: $607,365 

Synopsis 

On September 21, 2004, about 3:25 a.m., central daylight time, the Alton and Southern 

Railway Company2

 remote control train YAS313 derailed during switching operations at the east 

end of the Gateway Hump Yard in East St. Louis, Illinois. The remote control operator was 

unable to control the speed of the train as it crested the hump.3

 As the train entered track 066, it 

collided at 9.6 mph with a tank car containing vinyl acetate. During the collision and subsequent 

derailment, vinyl acetate began to leak from two tank cars and the cargo from both cars caught

on fire. 

About 140 people from the surrounding neighborhood were evacuated, and work at the 

hump yard was suspended. The evacuation order was lifted about 6:00 a.m. No injuries were

reported. The weather was clear, about 67° Fahrenheit, with light winds from the south-southeast. It

was dark at the time of the accident, but the area was well lit with stadium type lighting. 

 1

 All times in this report are central daylight time. 

2

 The Alton and Southern Railway Company is a wholly owned subsidiary of the Union Pacific Railroad (UP). 

3

 In a hump switching operation, freight cars are switched by pushing the cars up a hill, or hump. As the cars

crest the hump, a remote control operator uncouples them. The uncoupled cars then roll down the other side of the 

hump on a 2.8 percent average grade into predetermined tracks. The hump crest operator designates which car will

go into each track through a series of automatic switches and speed control retarders. A retarder is a track-mounted

device that controls the speed of freight cars as they roll over the device. At this location, the retarders were 

hydraulically operated and controlled either manually or by the hump computer, which assists in the operation of the 

hump. 

 1 NTSB/RAB-05/04 
The Accident 

Train YAS313 consisted of 71 cars and 2 SD-40 locomotives equipped for remote control

locomotive (RCL) use, which were operated by a conductor and a remote control operator. At the

time of the accident, the conductor was on the trailing locomotive, and the remote control operator 

was on the ground operating the RCL. A hump operator gave instructions to the train crew and

controlled the retarders and switches.

The hump operator told the train crew to hump the 71-car train. At one point during the 

hump switching operation, the hump operator instructed the train crew to stop the operation at the 

48th car, and the crew complied. The hump operator then called the signal maintainer and reported

that cars were getting out of the retarders too fast. Some cars had rolled through their assigned

tracks and were blocking the west end of the yard. The signal maintainer used the hump computer to 

reduce the speed of the cars. Then hump switching resumed for three more cars (49th through 51st). 

The first car, CCBX5123, a loaded gondola, stalled in track 066 and blocked the entrance to track 

065. The next two cars, tank cars UTLX 048044 and ACFX 71703, routed to track 065, were

redirected by the computer-aided antiblocking circuitry to track 066. The hump operator instructed

the train crew to stop hump switching again and couple the three cars from track 066 to the train and 

bring them back up to the hump for reclassification. 

The remote control operator walked down the hump to the three cars on track 066 while the

conductor remained seated in the cab of the trailing locomotive. The hump operator had placed the

hump controls into trim mode, in which all retarders are off line, and lined the route manually from 

the hump crest to track 066. The conductor switched the RCL controls on the locomotive from

hump mode to normal mode. 

The remote control operator requested 4 mph via his remote control device and started 

moving the remaining 20 cars of the train (52nd through 71st) over the hump. After the cars had

traveled about 800 feet, the remote control operator noticed that they were moving too fast. He used

the remote control device to request ìcoupling speedî and asked the hump operator to apply the

master retarder manually. The remote control device then indicated an overspeed condition, and it 

automatically made a full service brake application of the locomotiveís independent brakes. The

remote control operator saw the cars continue for about 300 more feet and said he heard the

retarders being applied. 

The 20-car train struck the first of the three stopped cars on track 066. (See figure 1 for a

diagram of the collision and subsequent derailment.) The lead wheels of the first car in the train 

(tank car UTLX 048044) lifted as the car struck the first stopped car (tank car UTLX 200817), 

which contained vinyl acetate. UTLX 200817 was near, but not coupled to, the second stopped 

car (tank car ACFX 71703), which also contained vinyl acetate. When the train struck UTLX

200817, the two vinyl acetate tank cars (UTLX 200817 and ACFX 71703) missed coupling and 

their shelf couplers breached each otherís tanks, and UTLX 200817 rolled onto its side.

Subsequently, the cargo from both carsó26,000 gallons of vinyl acetate eachócaught on fire. In

addition, the lead three cars of the train, all of which were tank cars containing ethylene glycol, 

derailed. These tank cars derailed in line and were not punctured or involved in the fire. 

 2 NTSB/RAB-05/04 
Figure 1. Diagram of collision and subsequent derailment. 

Train Control 

The train crew started work by performing the daily inspection of the two RCLs, and they 

signed the inspection cards with no exceptions taken. Postaccident inspection of the locomotives

and the remote control system did not identify any brake deficiencies or anything remarkable with 

the remote control system. 

The remote control operator stated that he could not control the speed of the train as it

crested the hump even though it appeared that he followed all the operating rules that were in 

place for that operation. According to railroad employees and their union representatives,

hump train crews frequently need to stop hump switching operations to clear cars that are 

blocking assigned tracks or to retrieve misdirected cars. They also agreed that the ease or

difficulty of train control depends on the length and weight of the train on the hump. 

Initial investigation determined that the weight of the 20 cars of train YAS313 

exceeded the braking capability of the RCLís independent brakes on the hump. The Alton and

Southern Railway Company arranged for a simulation4

 of the accident so it could review 

 4

 Alton and Southern Railway Company contracted with Rail Sciences Inc. to model the accident train and 

simulate the events of the accident. The effects of the hump retarders were not reproduced in the simulation. 

 3 NTSB/RAB-05/04 
humping operations. The simulation used a model of a train traveling 4 mph at brake initiation

with two SD40-2 locomotives; 2,427 trailing tons; a length of 1,061 feet; and the braking ability 

of the two locomotives on an average 2.8 percent descending grade. The simulation indicated 

that the train could not be controlled on the 2.8 percent descending grade using the locomotive

brakes alone. When the train was between 600 and 700 feet from the crest of the hump, it 

accelerated even with the independent locomotive brakes applied with 56 pounds per square inch 

of brake cylinder pressure. The simulation further indicated5

 that the braking ability of two

SD40-2 locomotives could stop a train with no more than 900 trailing tons on a 2.8 percent 

descending grade. 

Postaccident Actions 

The Alton and Southern Railway Company has implemented the following changes for 

operating RCLs during hump switching operations at the East St. Louis Gateway Hump Yard: 

• Smaller groups, or blocks, of cars are maneuvered over the hump instead of heavy 

strings of cars. 

• The tonnage operated over the hump is limited to 900 trailing tons. 

• Before moving a block of cars over the hump, the RCL operator and hump operator

are required to have a job briefing and to determine whether the assistance of the 

retarders is needed and, if so, to determine the necessary retarder application: light, 

medium, or heavy. 

• An additional train crew is assigned to move cars that have stopped short of their 

target tracks and switch cars that are not to be humped. 

Probable Cause 

The National Transportation Safety Board determines that the probable cause of the 

September 21, 2004, accident at the Alton and Southern Railway Companyís Gateway Hump 

Yard in East St. Louis, Illinois, was the inability of the remote control operator to control the 

speed of the cars being switched as they crested the hump because the weight of the cars 

exceeded the braking capability of the remote control locomotives. Contributing to the accident

was the failure of the Alton and Southern Railway Company to have weight limits and adequate 

hump operation procedures in place for maneuvering heavy strings of cars over the hump. 

Adopted: June 27, 2005

 5

 The simulation did not capture all the variables that may have been present at the time of the accident, 

including the added braking of the retarders and the 72 pounds per square inch of brake cylinder pressure. 

 4 NTSB/RAB-05/04