U.S. Department of 

Transportation 

Federal Railroad 

Administration

Design and Evaluation of Advanced Systems for 

Locomotive Crew Emergency Egress 

Office of Research 

and Development 

Washington, DC 20590 

DOT/FRA/ORD-06/18 Final Report 

October 2006 

This document is available to the 

U.S. public through the National 

Technical Information Service, 

Springfield, VA 22161. 
NOTICE 

This document is disseminated under the sponsorship of the 

Department of Transportation in the interest of information 

exchange. The United States Government assumes no liability for 

its contents or use thereof. 

NOTICE 

The United States Government does not endorse products or 

manufacturers. Trade or manufacturers’ names appear herein 

solely because they are considered essential to the objective of this 

report. 

 
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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE

October 2006 

3. REPORT TYPE AND DATES COVERED

Final Report, Oct. 2002–Mar. 2004 

4. TITLE AND SUBTITLE

Design and Evaluation of Advanced Systems for Locomotive Crew Emergency Egress 

6. AUTHOR(S)

Judith Gertler, James Carter, John Kidd, Basant Parida, and Alex Viale 

5. FUNDING NUMBERS 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

Foster-Miller, Inc. 

350 Second Avenue 

Waltham, MA 02451-1196 

8. PERFORMING ORGANIZATION 

REPORT NUMBER

DFRA.030059 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. Department of Transportation 

Federal Railroad Administration 

Office of Research and Development 

Washington, DC 20590 

10. SPONSORING/MONITORING 

 AGENCY REPORT NUMBER

DOT/FRA/ORD–06/18 

11. SUPPLEMENTARY NOTES 

COTR: Mr. John Punwani 

12a. DISTRIBUTION/AVAILABILITY STATEMENT

This document is available to the public through the National Technical Information Service, 

Springfield, Virginia 22161. 

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words) 

This report presents the results of the second phase of a program to develop innovative concepts for locomotive crew egress 

following a crash that damages the cab. The roof-mounted hatch system was fabricated as a working prototype and installed in a

full-scale mockup of a toppled locomotive. Usability testing with experienced train crewmembers and emergency responders 

demonstrated the system’s usability. Crewmembers exited the cab in under 20 seconds when uninjured. Two secondary egress 

systems were also designed and fabricated. A windshield that can be removed from the cab interior employs double looped 

cutting wires to sever the window gasket, thus allowing the glazing to be pushed out. A proof-of-concept prototype was installed 

and tested in the locomotive mockup. A removable door hinge, the other secondary egress system, employs a lever-actuated 

mechanism that releases the hinge leaf from the door, allowing a jammed door to be removed and allowing the crew to escape the 

cab. Easily removable hinge pins provide a means for emergency response personnel to easily remove the door from the exterior. 

A training video for emergency responders explains the structure and features of a locomotive and suggests techniques for 

removing crewmembers from the cab following a crash.

15. NUMBER OF PAGES

107 

14. SUBJECT TERMS

Egress, locomotive, safety, emergency rescue, hatch 

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NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) 

Prescribed by ANSI Std. 239-18 

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ii

METRIC/ENGLISH CONVERSION FACTORS 

ENGLISH TO METRIC METRIC TO ENGLISH

LENGTH (APPROXIMATE) LENGTH (APPROXIMATE) 

1 inch (in) = 2.5 centimeters (cm) 1 millimeter (mm) = 0.04 inch (in) 

1 foot (ft) = 30 centimeters (cm) 1 centimeter (cm) = 0.4 inch (in) 

1 yard (yd) = 0.9 meter (m) 1 meter (m) = 3.3 feet (ft) 

1 mile (mi) = 1.6 kilometers (km) 1 meter (m) = 1.1 yards (yd) 

 1 kilometer (km) = 0.6 mile (mi)

AREA (APPROXIMATE) AREA (APPROXIMATE) 

1 square inch (sq in, in2) = 6.5 square centimeters (cm2) 1 square centimeter (cm2) = 0.16 square inch (sq in, in2) 

1 square foot (sq ft, ft2) = 0.09 square meter (m2) 1 square meter (m2) = 1.2 square yards (sq yd, yd2) 

1 square yard (sq yd, yd2) = 0.8 square meter (m2) 1 square kilometer (km2) = 0.4 square mile (sq mi, mi2) 

1 square mile (sq mi, mi2) = 2.6 square kilometers (km2) 10,000 square meters (m2) = 1 hectare (ha) = 2.5 acres 

1 acre = 0.4 hectare (he) = 4,000 square meters (m2) 

MASS - WEIGHT (APPROXIMATE) MASS - WEIGHT (APPROXIMATE) 

1 ounce (oz) = 28 grams (gm) 1 gram (gm) = 0.036 ounce (oz) 

1 pound (lb) = 0.45 kilogram (kg) 1 kilogram (kg) = 2.2 pounds (lb) 

1 short ton = 2,000 pounds 

(lb) 

= 0.9 tonne (t) 1 tonne (t) =

=

1,000 kilograms (kg) 

1.1 short tons

VOLUME (APPROXIMATE) VOLUME (APPROXIMATE) 

1 teaspoon (tsp) = 5 milliliters (ml) 1 milliliter (ml) = 0.03 fluid ounce (fl oz) 

1 tablespoon (tbsp) = 15 milliliters (ml) 1 liter (l) = 2.1 pints (pt) 

1 fluid ounce (fl oz) = 30 milliliters (ml) 1 liter (l) = 1.06 quarts (qt) 

1 cup (c) = 0.24 liter (l) 1 liter (l) = 0.26 gallon (gal) 

1 pint (pt) = 0.47 liter (l) 

 1 quart (qt) = 0.96 liter (l) 

1 gallon (gal) = 3.8 liters (l) 

1 cubic foot (cu ft, ft3) = 0.03 cubic meter (m3) 1 cubic meter (m3) = 36 cubic feet (cu ft, ft3) 

1 cubic yard (cu yd, yd3) = 0.76 cubic meter (m3) 1 cubic meter (m3) = 1.3 cubic yards (cu yd, yd3)

TEMPERATURE (EXACT) TEMPERATURE (EXACT) 

[(x-32)(5/9)] °F = y °C [(9/5) y + 32] °C = x °F

QUICK INCH - CENTIMETER LENGTH CONVERSION

0 1 2 34 5

Inches

Centimeters 01 3 2 6 11 4 5 7 13 8 9 10 12

QUICK FAHRENHEIT - CELSIUS TEMPERATURE CONVERSION

 -40° -22° -4° 14° 32° 50° 68° 86° 104° 122° 140° 158° 176° 194° 212°

 

°F

 °C -40° -30° -20° -10° 0° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100°

For more exact and or other conversion factors, see NIST Miscellaneous Publication 286, Units of Weights and 

Measures. Price $2.50 SD Catalog No. C13 10286 Updated 6/17/98
iii

Contents 

Illustrations ..................................................................................................................................... v 

Tables ..................................................................................................................................viii 

Acknowledgements........................................................................................................................ ix 

Executive Summary........................................................................................................................ 1 

1. Introduction ................................................................................................................. 5 

1.1 Background ................................................................................................................. 5 

1.2 Objectives.................................................................................................................... 6 

1.3 Overall Approach ........................................................................................................ 7 

1.4 Scope ........................................................................................................................... 7 

1.5 Organization of the Report .......................................................................................... 8 

2. Prototype Roof Hatch.................................................................................................. 9 

2.1 Roof Design Changes.................................................................................................. 9 

2.2 Estimation of Roof Strength for Hatch Opening......................................................... 9 

2.3 Design of the Prototype Hatch System...................................................................... 11 

2.4 Prototype Construction.............................................................................................. 14 

2.5 Alleviation of Noise due to Roof Hatch.................................................................... 19 

2.6 Emergency Lighting.................................................................................................. 20 

2.7 Prototype Hatch System ............................................................................................ 20 

3. Usability Testing ....................................................................................................... 27 

3.1 Use of Human Research Participants ........................................................................ 27 

3.2 Participant Recruitment............................................................................................. 27 

3.3 Experimental Study ................................................................................................... 28 

3.4 Results ....................................................................................................................... 31 

3.5 Discussion ................................................................................................................. 34 

4. Removable Windshield ............................................................................................. 37 

4.1 Current Windshield Design ....................................................................................... 37 

4.2 Candidate Designs for a Removable Windshield...................................................... 40 

4.3 Design of Double Loop Cutting Wire ....................................................................... 46 

4.4 Usability Assessment ................................................................................................ 51 

4.5 Prototype Evaluation ................................................................................................. 56 

5. Removable Door Hinge............................................................................................. 59 

5.1 Existing Rear Door Hinge Attachment ..................................................................... 59 

5.2 Design Concept ......................................................................................................... 59 

5.3 Design of Rear Door Hinge Release Mechanism...................................................... 61 

5.4 Considerations for the Modification to Locomotive Rear Door ............................... 64 

5.5 Proof of Concept ....................................................................................................... 65 

5.6 Long-Term Functionality and Maintenance Considerations..................................... 70 
iv

6. Key Findings and Recommendations........................................................................ 71 

6.1 Key Findings ............................................................................................................. 71

6.2 Recommendations for Future Research .................................................................... 71 

7. References ................................................................................................................. 75 

Appendix A. Informed Consent................................................................................................... 77 

Appendix B. Post-Scenario Survey.............................................................................................. 81 

Appendix C. Data Sheet............................................................................................................... 91 

Appendix D. Description of Training Video ............................................................................... 93 

Abbreviations/Acronyms .............................................................................................................. 95 
v

Illustrations 

Figure 1. Locomotive cab mockup with proof-of-concept hatch system ...................................... 6 

Figure 2. Roof structure for GE AC4400..................................................................................... 10 

Figure 3. Roof structure for EMD SD70MAC ............................................................................ 10 

Figure 4. Conceptual design of the emergency escape hatch ...................................................... 12 

Figure 5. Hatch and exterior frame.............................................................................................. 12 

Figure 6. Handle assembly........................................................................................................... 13 

Figure 7. Mechanism schematic .................................................................................................. 13 

Figure 8. Lower enclosure frame................................................................................................. 13 

Figure 9. Latch details.................................................................................................................. 13 

Figure 10. Hand/foothold, stowed ............................................................................................... 14 

Figure 11. Hand/foothold, deployed ............................................................................................ 14 

Figure 12. Latching mechanism near the closed position............................................................ 15 

Figure 13. Latching mechanism in the open position.................................................................. 15 

Figure 14. Side latch cams and latching bar ................................................................................ 16 

Figure 15. Latch cam in the latched condition, interior............................................................... 16 

Figure 16. Latch cam in the latched condition, exterior .............................................................. 16 

Figure 17. Latch cam in the open position, interior..................................................................... 17 

Figure 18. Latch cam in the open position, exterior .................................................................... 17 

Figure 19. Hand/foothold in the stowed condition ...................................................................... 17 

Figure 20. Stowed rung detail...................................................................................................... 18 

Figure 21. Hand/foothold in the deployed condition................................................................... 18 

Figure 22. Detail of locking detent pin ........................................................................................ 19 

Figure 23. Detail of detent socket................................................................................................ 19 

Figure 24. Photoluminescent materials on sides of recessed areas.............................................. 23 

Figure 25. Mockup of toppled locomotive cab with egress system............................................. 24 

Figure 26. Interior view of cab mockup with hatch system......................................................... 25 

Figure 27. Hatch is attached to a tether line................................................................................. 30 

Figure 28. Tether line is run through a pulley system ................................................................. 30 

Figure 29. Pulleys remove hatch from egress path...................................................................... 30 

Figure 30. Counter weights allow hatch to settle gently.............................................................. 30 
vi

Figure 31. Interior and exterior views of crewmember egress .................................................... 32 

Figure 32. Views of emergency personnel entrance, victim preparation, and extrication........... 33 

Figure 33. GE windshield frame assembly.................................................................................. 37 

Figure 34. Closeup view of GE windshield assembly ................................................................. 38 

Figure 35. Detail sectional view of framed windshield assembly ............................................... 38 

Figure 36. Sectional view of a gasket currently used in locomotive windshields ....................... 39 

Figure 37. Sectional view of non-framed locomotive windshield assembly............................... 39 

Figure 38. Single loop folding wire, normal position.................................................................. 40 

Figure 39. Single loop folding wire, released position ................................................................ 40 

Figure 40. Schematic retrieval path of a single loop cutting wire ............................................... 41 

Figure 41. Sectional view of the gasket with modified geometry ............................................... 42 

Figure 42. Sectional view of the assembled gasket with single loop cutting wire ...................... 42 

Figure 43. Sectional view depicting cutting action of single loop wire....................................... 43 

Figure 44. Sectional view showing the severed gasket................................................................ 43 

Figure 45. Schematic retrieval path of double loop cutting wire................................................. 43 

Figure 46. Sectional view of gasket before and after cutting by the double loop wire ............... 44 

Figure 47. Sectional view of the assembled gasket with single loop wire .................................. 45 

Figure 48. A view of the severed gasket after cutting at critical section..................................... 45 

Figure 49. Sketch of retrieval path for twin double loop cutting wire method............................ 47 

Figure 50. Sketch of wire retrieval actuator system .................................................................... 49 

Figure 51. Wire sleeve from windshield frame to winch............................................................. 49 

Figure 52. Wire sleeve for cutting wire ....................................................................................... 50 

Figure 53. Termination block and winch..................................................................................... 51 

Figure 54. Winch pulling wires from sleeves through termination block ................................... 51 

Figure 55. Steel mockup windshield frame installed in mockup................................................. 52 

Figure 56. Exterior view of windshield frame mounted in mockup locomotive......................... 52 

Figure 57. Interior view of windshield frame mounted in mockup locomotive .......................... 53 

Figure 58. Fixed wire and running wire within sleeve exiting windshield frame ....................... 54 

Figure 59. Winch located in overhead console of mockup locomotive....................................... 54 

Figure 60. Winch installed overhead, oriented in rollover position ............................................ 55 

Figure 61. Gasket after being severed by wire ............................................................................ 55 

Figure 62. Removal of glazing after cutting the windshield gasket ............................................ 56 

Figure 63. Interior view of the existing locomotive rear door at a test facility ........................... 59 
vii

Figure 64. Conceptual design for locomotive rear door hinge release mechanism..................... 60 

Figure 65. Hinge mounting block ................................................................................................ 61 

Figure 66. Details of the sliding bar used in hinge release mechanism....................................... 62 

Figure 67. Exterior view of a hinge subassembly attached to the release mechanism with one 

sturdy fastener bolt...................................................................................................... 63 

Figure 68. Closeup view of the release handle attachment to the sliding bar.............................. 63 

Figure 69. Hinge pins and the interference fit small pin-inserts with cap ................................... 64 

Figure 70. Exterior view of an assembled rear door on the test rig............................................. 65 

Figure 71. A closeup view of one hinge in assembled condition ................................................ 66 

Figure 72. Interior view of the rear door with hinge release handle in assembled condition...... 66 

Figure 73. Closeup view of an acorn nut assembled on the narrow slot of the key-hole in the 

sliding bar.................................................................................................................... 67 

Figure 74. Interior view of the door showing the actuation of hinge release handle................... 68 

Figure 75. Final position of the hinge release handle after actuation .......................................... 68 

Figure 76. Interior closeup view of the released fastener nut...................................................... 68 

Figure 77. Exterior view of the fastener bolt and hinge leaf released from the hinge support 

block............................................................................................................................ 69 

Figure 78. Closeup exterior view of a hinge support block after detachment of the hinge leaf.. 69 

Figure 79. Removal of the pin-insert from the hinge pin ............................................................ 70 

Figure 80. Removal of the hinge pin before separation of the rear door..................................... 70 
viii

Tables 

Table 1. Estimated buckling area of locomotive roof.................................................................. 11 

Table 2. Emergency lighting standards........................................................................................ 21 

Table 3. Photoluminescent lighting standards ............................................................................. 23 

Table 4. Average time for train crew participants to exit locomotive ......................................... 31 

Table 5. Time for rescue personnel to extricate victim from cab ................................................ 33 

Table 6. Comparison of performance attributes for removable windshield concepts ................. 46 

Table 7. Costs to retrofit a locomotive with removable windshield............................................ 57 
ix

Acknowledgements 

This report presents the results of the second phase of a program to develop innovative designs 

for a locomotive crew egress system. The Federal Railroad Administration (FRA) Office of 

Research and Development funded this work under Contract DTFR53-01-D-00029. Mr. John 

Punwani, the FRA Contracting Officer’s Technical Representative, provided guidance and 

encouragement to the study team. 

The usability tests would not have been possible without the generous cooperation of officers 

from the Brotherhood of Locomotive Engineers and the United Transportation Union, as well as 

the Fitchburg, MA, Fire Department. The authors wish to thank all of the participants in the 

usability tests who provided valuable feedback on the design and operability of the hatch system. 

The next phase of the development of the hatch system will incorporate their feedback and 

suggestions. 

Special thanks are extended to Ms. Sarah Acton and Mr. John Flynn of Foster-Miller. Ms. Acton 

assisted in the recruiting of participants for the usability tests and in conducting the tests. 

Mr. Flynn was responsible for installation of the hatch system in the mockup. He also assisted 

with prototype construction and testing for the removable windshield and the removable hinges. 

Dr. Peter Boyce, a consultant from the Lighting Research Institute at Rensselaer Polytechnic 

Institute, provided guidance on lighting options for the hatch system. Mr. Allen Bieber, an 

engineering consultant, reviewed the hatch and windshield designs and advised Foster-Miller on 

locomotive cab structural design issues. 

1

Executive Summary 

This report presents the results of the second phase of a program to develop innovative concepts 

for a freight locomotive crew egress system. The Phase I program evaluated three concepts that 

would be of particular use following a crash that toppled the locomotive. These concepts were 

(1) hand/footholds to aid climbing inside a toppled locomotive, (2) a roof-mounted escape hatch, 

and (3) an externally removable windshield. Feedback from train crews and emergency response 

personnel determined that the roof-mounted escape hatch with hand/footholds to facilitate its use 

was the preferred approach. Train crews were unanimous in their opinion that the removable 

windshield would have to be usable from the cab interior to be helpful to the crew. 

Construction of a wooden system mockup in a toppled condition facilitated evaluation of the 

hatch system concept. Two test subjects were able to exit via the hatch system in under 

30 seconds (s), thus demonstrating the concept’s feasibility and utility. 

Based on the results of Phase I, the current project had the following goals: 

• Refine the locomotive cab roof escape hatch concept from a laboratory mockup into a 

working prototype device. 

• Develop improvements in the secondary egress routes from the locomotive cab. 

• Develop a training video suitable for rescue personnel describing the basic configuration 

of the locomotive and suitable techniques for effecting rescue of crewmembers following 

an accident. 

Prototype Roof Hatch System 

The roof-mounted hatch system consists of the hatch along with interior hand/footholds to 

facilitate access to the hatch and exterior grab irons to facilitate crew egress, as well as entry by 

emergency responders. The hatch opening is 21.8 inches (in) wide by 29.5-in long. It is defined 

by a steel frame weldment, with integrated points for the latches. Stiffeners around the roof 

opening maintain roof strength. Turning the handle approximately 40° in either direction and 

pushing the hatch panel outward releases the hatch. The hatch assembly encloses the operating 

mechanism. 

A comparison of the roof areas with and without the hatch and their corresponding buckling 

loads indicate that the overall strength of the roof does not appear to be greatly changed by the 

addition of the roof hatch opening. This assures that the presence of the hatch will not 

compromise the roof’s structural integrity. 

The basic hand/foothold design is similar in approach to the hatch. The basic structure is a steel 

outer frame intended for integration into the roof of the locomotive. The hand/foothold hinges 

into the external frame so that it can be held flush to the interior cab roof when not in use. The 

rung itself is a single steel bar, 1 in. in diameter and approximately 11-in long. 

Existing emergency lighting standards applicable to transportation vehicles formed the basis for 

the design of the lighting and marking scheme that would provide adequate illumination in the 

worst-case scenario of a smoke-filled cab following a nighttime crash. The lighting system 

incorporates two different techniques. The first technique created luminance contrasts for the 

details of the hatch and the hand/footholds. The second technique provided emergency lighting 
2

for the escape hatch and the hand/footholds. Photo-luminescent materials create the desired 

lighting scheme. These materials are inexpensive, reliable, easy to install, and virtually 

maintenance free. 

To evaluate the overall utility of the egress concepts developed under this program, Phase I 

included construction of a full-size mockup of a freight locomotive cab. Phase II involved 

installation of the hatch system, including the hand/footholds and emergency lighting system, as 

well as the removable windshield, in this structure. 

Usability Testing 

Usability testing examined the functionality of the hatch system in the mockup facility. Both 

train crew personnel and emergency response personnel participated in the tests. An Institutional 

Review Board reviewed and approved the study design. A total of six train crewmembers, four 

conductors and two engineers, participated in the usability testing. In addition, an emergency 

rescue crew from the Fitchburg, MA, Fire Department provided the emergency responder 

usability assessment. 

Train crew participants evaluated four different scenarios. Participants were able to use both 

arms and legs to access the hand/footholds and grab irons to quickly extricate themselves from 

the cab. In the uninjured/daylight scenario, the average exit time was under 17 s. Darkness 

added only 3 s to the exit time. 

Teams of emergency responders, dressed in full rescue gear with all necessary rescue equipment 

on hand, attempted to remove an injured 230 pound (lb) male from the cab. A minimum of three 

people was required to carry out the rescue. Rescue time ranged from 8.5 to 9 minutes (min). 

Overall, the usability tests showed that design of the hatch system was effective in its purpose. It 

allowed for a safe and efficient escape for train crewmembers and was sufficient in permitting 

rescuers to successfully retrieve an injured victim from inside the cab using a backboard. The 

hatch and hand/footholds were very straightforward and easy to use, while the grab irons 

provided adequate holds to assist with entry and exit. Photoluminescent materials also 

successfully illuminated the escape route during darkened conditions. 

Train crew and rescue personnel made several suggestions for improving this egress system. 

Their suggestions included placing photoluminescent or retroreflective materials around the 

exterior of the hatch, replacing the folding bars on the hand/footholds with fixed bars, and 

placing small horizontal grab irons above-left and above-right, as well as below-left and belowright of the opening. 

Removable Windshield 

Current locomotive windshields have one of two basic designs: frame mounted or non-frame 

mounted. Development and testing of the removable windshield concept used the non-frame 

mounted design because candidate gasket-cutting methods could more easily be evaluated and 

demonstrated without the frame. 

The researchers evaluated four design concepts for cutting the gasket. The double twin loop 

cutting wire proved to be the most effective technique. With this method, each loop must cut 

half of the gasket on the top of the windshield, the top outer corner, and the entire length of the 

small vertical side of the windshield for a total of 48 in. Prototype testing showed that, with that 

amount of the gasket cut, the bottom length of the gasket acts as a hinge, and the glazing is easily 
3

pushed from the windshield. One actuator, a winch, collects both wires, which are inserted 

through black rubber sleeves as they approach the winch. 

A prototype windshield was fabricated and installed in the mockup. Usability testing 

demonstrated that the maximum force required to activate this emergency egress system was 10 

foot-pounds (ft-lb). Once the gasket was cut, the torque required to maintain the cutting process 

was about 4 ft-lb. The time required to cut the gasket, push out the glazing, and exit the cab was 

approximately 50 s. 

Removable Door Hinge 

A locomotive crash may cause the hinged doors of the locomotive to become inoperable. An 

innovative door hinge provides a means for the crew to release the hinges from the cab interior 

and remove the door. The door side of each hinge is held firmly in place inside a machined slot 

of the hinge attachment steel block with a single fastener bolt. A weld holds the machined block 

to the edge of the door panel. Four compression springs in blind holes of the block hold the leaf 

of the hinge in position. When the emergency hinge release handle is actuated, it releases the 

fastener nuts, which in turn release the hinges. For evaluation of this system, a rear door was 

fabricated along with the hinge release mechanisms. A laboratory test of this door in a test rig 

representing a locomotive door frame verified the functionality of the removable hinges. Easily 

removable hinge pins provide a means to facilitate cab access for emergency rescue personnel 

from the exterior. 

Training Video 

This work also included preparation of a training video, “Locomotive Emergency Response 

Operations,” for emergency response personnel. The video provides rescue professionals with 

the specifics of locomotive construction and features. It also describes potential locomotive 

accident scenarios and suggests appropriate methods for responding to such incidents. 

Recommendations for Future Research 

The results of the Phase II work suggest areas for further research relative to improved egress 

systems for locomotive cabs. These include further refinements to the hatch system design, 

usability tests of the hatch system under a partial rollover condition, and validation of the 

functionality of the removable windshield and door hinges under accident conditions. Advanced 

egress systems that incorporate smart technologies, such as those employed in Intelligent 

Transportation Systems, also merit consideration. 

5

1. Introduction 

In 1992 Congress enacted the Rail Safety Enforcement and Review Act. This legislation 

required the Federal Railroad Administration (FRA) to conduct an inquiry into locomotive 

crashworthiness and the safety effects of cab working conditions on productivity. In response to 

this mandate, FRA undertook a comprehensive study of many aspects of locomotive 

crashworthiness (FRA, 1996). While the focus of this study covered many issues, it did suggest 

that the roof of the cab be considered as an emergency egress route. Since publication of this 

report, FRA has undertaken research projects that address many aspects of locomotive 

crashworthiness and its relationship to crew survivability. This report addresses improvements 

in crew egress routes, as well as access for emergency rescuers following a locomotive crash. 

1.1 Background 

In 2000, FRA initiated a preliminary study of existing cab egress issues (Kokkins, 2002). The 

objectives of this study were to survey, identify, and evaluate many aspects of current 

locomotive design and operation that affect crew egress or access by emergency rescue crews 

after a crash. This work included a broad survey of current egress and survivability issues and 

identified many opportunities for improvements. One area that this study identified as requiring 

improvement was equipment related to egress routes for crewmembers following a crash, 

particularly an accident in which the locomotive sustains structural damage and egress routes are 

limited. 

A subsequent egress research program focused on evaluating three innovative egress concepts 

that would be of particular use following a crash that toppled the locomotive (Carter, Gertler, 

Acton, & Kokkins, 2003). These concepts were (1) hand/footholds to aid climbing inside a 

toppled locomotive, (2) a roof-mounted escape hatch, and (3) an externally removable 

windshield. Feedback from train crews and emergency rescue workers on the three concepts 

determined that the roof-mounted escape hatch with hand/footholds to facilitate its use was the 

preferred approach. This user feedback also led to several improvements in the basic concepts. 

The hatch redesign allowed it to fall away from the roof when opened, and the hand/footholds 

became an accessory to the hatch rather than a stand-alone system. To be a viable egress option 

for the crew, the removable windshield would have to be usable from the cab interior. 

Construction of a system mockup facilitated evaluation of the hatch system concept. The 

research team constructed a full-sized locomotive cab, with an integrated hatch and 

hand/foothold system. The mockup is a wood-framed, plywood-sheathed structure representing 

a generic freight locomotive cab using dimensions common to General Electric (GE) and 

General Motors Electromotive Division (EMD) road locomotives currently in service (Figure 1). 

The mockup orientation represented a toppled locomotive for egress evaluation. 

Two test subjects representing a likely range of personnel working as crew in locomotives 

provided a means to evaluate the utility of the egress system. Neither of the subjects was 

familiar with locomotive equipment or operations. Both were able to exit the toppled cab 

utilizing the hatch in 30 s or less. 

An indepth analysis of the likely cost of the hatch system was not possible at this stage of 

development. A preliminary study, however, identified the cost implications of several aspects 
6

of the design. These issues relate to the initial engineering rather than the recurring component 

costs in manufacturing. As such, the overall cost for implementing the hatch in new locomotives 

should be low. After a working prototype is developed, the issue of cost must be re-examined in 

more detail. 

The results of this phase of egress research demonstrated the potential utility of the hatch system. 

This experience also led to the identification of areas for further research related to improved 

egress for locomotive crews. These areas were (1) the refinement of the design of the roof hatch 

system into one that can be manufactured and installed in new locomotives and (2) re-evaluation 

and development of two secondary egress options, the internally removable windshield and the 

removable door hinge. The work described in this report focused on these two areas. 

Figure 1. Locomotive cab mockup with proof-of-concept hatch system 

1.2 Objectives 

The purpose of the research described in this report was to develop and evaluate a prototype roof 

hatch egress system, as well as secondary systems to enhance crew egress in the event of a crash. 

The project had the following goals: 

• Refine the locomotive cab roof escape hatch concept from a laboratory mockup into a 

working prototype device. By fully developing the roof hatch concept, the major design 

challenges can be addressed, clearing the way for integration into future locomotive 

designs. Usability testing by railroad crews is a key element of the design process. 

Feedback from potential users at this point allows for design refinements and 

improvements before full implementation. 

• Develop improvements in the secondary egress routes from the locomotive cab. Phase I 

of this program evaluated removable windshields and door hinges as possible egress 

enhancements. In this phase, these approaches must be re-evaluated and designed for 

incorporation into the egress mockup. The removable windshield concept would provide 
7

a large opening that would be accessible for both railroad crews and rescue personnel for 

nearly any accident scenario. The removable door hinge pins would provide a means of 

freeing a doorway jammed due to deformation of the cab. 

• Develop a training video suitable for rescue personnel describing the locomotive’s basic 

configuration and suitable techniques for effecting rescue of crewmembers following an 

accident. In the Phase I egress program, feedback from rescue professionals indicated a 

need for more knowledge of railroad accidents. Currently, rescue efforts may be slowed 

while personnel develop procedures on-the-fly. Development of a training video 

provides a means of familiarizing rescue professionals with the specifics of railroad 

equipment and potential accident scenarios, thereby enhancing their capabilities for rapid 

emergency response.

1.3 Overall Approach 

The overall approach to the development of all three egress concepts–hatch system, removable 

windshield, removable hinges–has been to develop a proof-of-concept model and then to 

undertake detailed design and fabrication to produce a working prototype. Since the hatch 

system potentially involves structural change to the locomotive cab, the design and fabrication 

process had several steps. 

Design of the hatch system began with a structural analysis of the roof. This was necessary to 

assure that the roof strength would not be compromised by the presence of the hatch. Once the 

roof structural integrity was established, detailed design of the hatch cover, latching mechanism, 

and seal could proceed. Design of the hand/footholds did not have structural implications so this 

design process focused on the mechanical aspects. After design, fabrication, and installation of 

the complete hatch system in the mockup, the research team could develop and implement a 

lighting, signage, and marking scheme. Usability tests, conducted in the mockup with train 

crews and emergency responders, identified areas for design modification. 

At this stage of development, the removable windshield became a working prototype for the 

purpose of illustrating the concept’s feasibility. The project team installed and tested the 

removable windshield for operability in the mockup. The removable door hinges were designed 

and fabricated first as a working stand-alone prototype. It was not possible to install the door 

assembly in the mockup because the wooden mockup, in its present configuration, could not 

support the weight of the steel door and frame. Installation of the hinge system in a test 

structure, however, did allow evaluation of the door for functionality. 

1.4 Scope 

The scope of this research was limited to road freight locomotives. While the egress concepts 

explored in this effort can potentially be incorporated into passenger and switching locomotives, 

the structural design considerations will differ for each type of locomotive. Since crew egress 

from a toppled locomotive is the most challenging situation, the present study focused primarily 

on the hatch system that addresses this scenario. Improvements in secondary egress options, the 

windshield and rear door, will enhance the crew’s survivability whether or not the locomotive 

remains upright after a crash. The hatch system mockup is a working mechanical prototype. 

The removable windshield and removable door hinges, although operable, only illustrate the 

feasibility of the concepts. 
8

1.5 Organization of the Report 

Section 2 describes the design and construction of the prototype hatch system that consists of 

both the hatch and hand/footholds to facilitate access to the hatch. Section 3 describes the 

usability testing of the hatch system. Sections 4 and 5 focus on, respectively, the removable 

windshield and the removable door hinge. Section 6 provides recommendations for future egress 

research. The appendices contain copies of the materials from the usability test process. The 

training video is a separate stand-alone product. Appendix D describes the content of this video. 
9

2. Prototype Roof Hatch 

This section describes the basic design approach for the prototype roof hatch. The objective of 

this design task was to develop a working model of the hatch, demonstrating possible 

construction techniques that could be used in a deployable system. The project team constructed 

the design described below for use in the egress mockup during usability testing. 

2.1 Roof Design Changes 

Installation of the basic roof hatch concept into an existing locomotive design will require some 

structural alterations to the roof. In general, an opening will need to be provided in the roof, 

sufficient to allow the egress of a crewmember. This must be done in a way that does not 

compromise the integrity of the roof structure. The framing of this opening must provide for the 

installation of a hatch panel to seal the cab from the elements. The frame must be rigid enough 

to maintain its shape and not wedge or jam the hatch in the event of a rollover. Identifying the 

means to implement these changes occurred before the detailed design of the hatch. 

2.2 Estimation of Roof Strength for Hatch Opening 

Before beginning detailed design of the hatch mechanism, the researchers performed some 

simple calculations of the roof structure. This was done to insure the integrity of the cab once 

the hatch was installed. As a first-order approximation, a key assumption was that the roof 

would be subjected to a frontal impact, with the line of force acting through the structural 

centroid of the roof panel. Another assumption was that buckling of the roof structure would be 

a worst-case scenario, causing large off-axis deflections and local deformations in the area of the 

hatch. 

The facing area of the roof structure in the new design matches that of the current roof structure. 

This insures that the installation of a hatch does not compromise the overall strength of the cab 

roof. A shift in longitudinal numbers accommodates the required 22-in wide opening. The 

redesigned roof follows the same basic welded construction techniques as current cab designs. 

Designers assumed that all structural members are formed from 0.09 steel stock welded to the 

roof panel. The roof panel itself is assumed to be 0.187-in thick. 

A simplified plate buckling analysis provided a baseline estimation of roof strength. This 

analysis assumed that the roof panel acts as a flat plate with clamped edges and that the principal 

loading is along the width of the roof panel (along the axis of the cab roof). Using these 

parameters, the critical bending stress is given by Young (1989) as: 

( ) 2

2

crit 1-

KE(t/b)

ν

σ =

where σcrit = Critical stress for buckling 

E = Material modulus (for steel–29 Mpsi) 

ν = Poisson’s Ratio 

t = Plate thickness 

a = length of the plate 

b = width of the plate 
10

The empirical constant K is a function of the ratio of width and length of the plate. Tabulated 

values are available in Young (1989). Both the GE and EMD roof panels are roughly square. As 

given by Young, K is 7.7 for a square plate (a/b=1). 

With the critical stress determined, multiplying the critical stress by the facing area of the plate 

provides the critical load. With the cutout for the hatch, the effective area of the roof is reduced 

to the area around the hatch itself. For each of the locomotives studied, this is the width of the 

roof panel less the width of the hatch, applied over the length of the hatch. 

This analysis neglects the effects of the longitudinal stiffeners running along the cab roof. As 

such, it is conservative. 

The design process considered likely changes to the roof structure for both a GE and an EMD 

locomotive. Figure 2 shows the roof structure of the GE AC4400 with and without the hatch 

opening. Figure 3 shows the equivalent changes for the EMD SD70MAC. These two 

locomotive designs represent the structures currently under test by the researchers as part of an 

ongoing study into crashworthiness of freight locomotives. 

Figure 2. Roof structure for GE AC4400 

Figure 3. Roof structure for EMD SD70MAC 
11

Table 1 shows a comparison of areas and buckling loads for the cab roofs (both SD70MAC and 

AC4400). 

Table 1. Estimated buckling area of locomotive roof 

EMD SD70MAC GE AC4400 

Original Modified Original Modified 

Area (in2) 12.56 8.8 14.04 7.9 

Critical Buckling Stress (psi) 1,944 1,590 4,418 5,053 

Critical Buckling Load (lb) 41,686 38,128 36,873 40,273 

Based on these calculations, the overall strength of the roof does not appear to be greatly 

changed by the addition of the roof hatch opening. As noted before, this analysis neglects the 

effects of the longitudinal stiffeners running along the hatch roof. An additional stiffener added 

to the original structure in both designs framed the hatch opening (see Figure 2 and Figure 3). 

This added stiffener should ensure that the new structure is stronger than the original design. 

Once specific loading and design criteria are set, a more detailed analysis may be necessary to 

verify the actual buckling strength of the structure. 

2.3 Design of the Prototype Hatch System 

The roof hatch system consists of two elements, the escape hatch and the hand/footholds. The 

following subsections describe each of these subsystems individually. 

2.3.1 Escape Hatch Design 

The basic escape hatch must fill the rectangular opening in the cab roof, be operable from both 

inside and outside the cab, and, ultimately, seal against weather. The prototype design addresses 

all of these issues, although the current design would not be completely weather tight. In 

addition, the design of the prototype allowed for its integration into the wooden mockup frame. 

It would, however, require only small changes to adapt it to an actual locomotive. Figure 4 

shows the conceptual design. 

In practice, an extruded neoprene rubber gasket seals the space between the hatch panel and the 

frame. For clarity, the seal does not appear in the figures. 
12

Figure 4. Conceptual design of the emergency escape hatch 

2.3.2 Frame Design 

The design of the frame mimics the rectangular opening used in the roof evaluations. The free 

area is 21.8-in wide by 29.5-in long. A steel frame weldment, with integrated points for the 

latches, defines the opening. Figure 5 shows the hatch and frame. For clarity, the inner hatch 

frame is not part of this illustration. In practice, the open space in the hatch would contain an 

acoustic dampening material to reduce noise transmission through the hatch. 

Figure 5. Hatch and exterior frame 

2.3.3 Mechanism Design 

The operating mechanism is an integral part of the hatch assembly. The exterior structure of the 

hatch is a steel assembly consisting of an upper panel, a lower enclosure, and steel bezel to cover 

the mechanism. 
13

Turning a handle on either the interior or exterior of the cab disengages the latching mechanism. 

Both handles are tied to a common shaft, which in turn is tied to the actuator plate. Two nonmetallic bearings guide the shaft rotation. A round guide plate ties the bearings to the hatch 

structure. O-rings provide a seal for the outer guide plate and outer end of the shaft. Figure 6 

shows the handle assembly. Tie rods join the actuator plate to the latches. A single latch is at 

each end of the hatch. Along the sides of the hatch, two latches are joined by a common bar so 

that they can actuate simultaneously. Figure 7 shows the mechanism schematically. 

Figure 6. Handle assembly Figure 7. Mechanism schematic 

The latches pass through openings in the lower enclosure frame. Figure 8 shows this frame, 

along with the latch components. These openings coincide with the latching points in the outer 

locomotive frame. Figure 9 shows a detail of the end latch. 

Figure 8. Lower enclosure frame Figure 9. Latch details 

Turning a handle approximately 40° in either direction releases the hatch from the opening. 

Removal requires an outward push. 
14

2.3.4 Hand/Foothold Design 

The basic hand/foothold design is similar in approach to the hatch. The basic structure of the 

mechanism is a steel outer frame intended for integration into the wood-framed roof of the 

mockup. This approach allows the basic design to be adapted to an actual locomotive frame with 

a minimum of changes. 

As shown below in Figure 10, the hand/foothold hinges into the external frame so that it can be 

held flush to the interior cab roof when not in use. The rung itself is a single steel bar, 1 in. in 

diameter and approximately 11-in long. When stowed, it is held in place by a detent pin. When 

needed, pulling outward on the rung deploys the hand/foothold. This overcomes the detent 

force, allowing the rung to swing downward as shown in Figure 11. Two angular braces fold out 

with the rung to provide added support. 

Figure 10. Hand/foothold, stowed Figure 11. Hand/foothold, deployed 

 

The hand/foothold design assures that it is usable in either the deployed or stowed condition. If 

the hand/foothold is jammed in the stowed condition, sufficient space still exists around the rung 

to allow grasping or standing if need be. 

2.4 Prototype Construction 

Local machine shops manufactured the hatch system in accordance with fabrication drawings. 

The structural elements consist of welded sheet metal. The mechanism is a combination of 

custom-machined parts and commercial off-the-shelf hardware. Although the design process 

involved some effort to keep the costs of the prototype low, the designers did not try to minimize 

the overall manufacturing costs for the system. Since some redesign would likely be required 

after functional testing, cost reductions in the design were beyond the scope of this phase. 
15

2.4.1 Prototype Hatch 

The prototype hatch is a welded steel frame that supports the removable door panel. The panel 

itself consists of a welded steel outer shell, an integrated latching mechanism, and a cover panel. 

Tie-rods couple the latches to the rotating mechanism. 

The series of photographs that follow show the hatch with the cover plate removed so that the 

mechanism can be more easily seen. 

Figure 12 shows the center rotary mechanism. In this photo, the mechanism is slightly skewed 

from the latched condition. Four tie-rods can be seen leading from the square actuating plate to 

the latch cams. In the latched condition, the mechanism is a point of minimum mechanical 

advantage. In this way, the device operates into increasing mechanical advantage as it is opened. 

When first assembled with a neoprene foam weather gasket in the hatch panel, the reactive 

pressure exerted by the gasket force was sufficient to force the hatch open. To correct for this, 

four detents in the bearing plate (round metallic plate visible in Figure 12) lock the mechanism in 

the latched position. With the detents installed, it requires approximately 10 lb of force to 

actuate the mechanism and overcome the detents. In Figure 13, the mechanism is in the open 

condition. 

Figure 12. Latching mechanism near the 

closed position 

Figure 13. Latching mechanism in the open 

position 

Along the long axis of the hatch panel, two latch cams are actuated from a single point, as shown 

in Figure 14. The tie-rod attaches to a central point along a latching bar. The bar is welded to 

the latch cams at each end and pivots about a single axis. In this way, the side latches operate 

both cams simultaneously. 
16

Figure 14. Side latch cams and latching bar 

Figure 15 shows an end panel latch cam from inside the hatch. The cam is in the latched 

position. The top end of the cam attaches to a tie-rod through a rod-end bearing that provides 

angular freedom along with rotary motion. Figure 16 shows a view of the cam from the outside 

of the hatch. In this condition, the cam protrudes through the hatch and would lock itself to a 

similar opening in the frame. 

Figure 15. Latch cam in the latched 

condition, interior 

Figure 16. Latch cam in the latched 

condition, exterior 

As the mechanism rotates, it pulls the cam back from the side of the hatch, allowing the entire 

latching surface to recede into the inner frame, as shown in Figure 17. Figure 18 shows an 

external view of this. In this condition, the entire latch face is withdrawn into the hatch panel, 

allowing the hatch to be freely removed from the frame. 
17

Figure 17. Latch cam in the open position, 

interior 

Figure 18. Latch cam in the open position, 

exterior 

2.4.2 Prototype Hand/Footholds 

The prototype hand/footholds use the same welded steel construction as the hatch. The outer 

frame supports a movable rung. The frame is seam welded along the upper corners and closed at 

the back. A series of holes drilled along the perimeter provides a means of mounting the frame 

to the wooden locomotive cab mockup. In practice, the frame would be welded into the cab roof 

structure. 

The rung pivots at the lower corner such that in the stowed condition, it resides in the center of 

the box. A detent pin holds the rung stowed, and pulling on the rung will cause it to open when 

needed. 

The following photographs show the hand/foothold. Figure 19 shows the hand/foothold in the 

stowed condition. The mounting holes are visible along the lower edge. 

Figure 19. Hand/foothold in the stowed condition 
18

Figure 20 shows the detail of the rung. In the stowed position, the outer surface of the rung is 

flush with the frame of the box. This provides sufficient space around the rung for grasping or 

standing should the rung become jammed as the result of an accident. In practice, it might be 

necessary to recess the rung slightly, which can be controlled by the placement of the detent pin. 

Figure 20. Stowed rung detail 

Figure 21 shows the rung in the deployed position. When open, the edges of the rung support sit 

on the side of the box to help support the climbing load. Given the construction of the frame and 

rungs, the designers felt that the overall load capacity was sufficient to allow for climbing 

without additional support. For that reason, the designers eliminated the diagonal braces of the 

original design. 

Figure 21. Hand/foothold in the deployed condition 

Figure 22 shows the tip of the detent pin. Figure 23 shows the corresponding socket in the rung 

support. The detent pin is actually a spring-loaded steel ball, locked into a threaded housing. A 

tapped hole in the side panel of the box provides a means of adjusting the locking load on the 

rung. Functional testing indicated that the rung could be actuated with a force of 18 lb. This is 

equivalent to a 6.5–g vertical acceleration of the 2.75 lb rung. In general, this is well below the 

common accelerations seen in normal operation. It is also well within the capability of a 

crewmember to operate in the event of an accident. 
19

Figure 22. Detail of locking detent pin Figure 23. Detail of detent socket 

2.5 Alleviation of Noise due to Roof Hatch 

The small outward projection of the removable roof hatch might cause the noise level inside the 

locomotive cab to increase to some extent when the locomotive is at running speed. The 

following factors are the likely sources of this additional noise: 

a) Vibration of the hatch in its installed position or chattering of the metallic linkages 

employed for the hatch release mechanism. 

b) Turbulent airflow past the projected surface of the hatch above the roof surface. 

c) Any external noise transmitted through gaps between the hatch cover and the cutout. 

Keeping the basic comfort of the crew in mind, simple but effective solutions offer the potential 

to eliminate any further rise in noise level inside the cab beyond the existing operational noise 

level in the absence of the removable roof hatch. 

a) Vibration of the hatch in its installed position or chattering of the metallic linkages 

employed for the hatch release mechanism 

The present design of the removable hatch cover incorporates thick rubber gaskets in the 

underside of the hatch. These gaskets eliminate metallic contact between the cutout of the 

roof and the hatch, especially when it is latched in closed position. Threaded connections 

permit adjustment of the length of the linkages of the hatch. Therefore, any slackness in 

them should be adjustable. In order to avoid any likely chatter due to resonant vibration 

caused by the excitation of the locomotive chassis while traveling at high speeds, however, 

acoustic (sound absorbing) materials readily available in the form of tiles or quilts should be 

packed into the gap between the hatch cover and the linkages. This would help dampen the 

vibration of linkages, if any. 

b) Turbulent airflow past the projected surface of the hatch above the roof surface 

The present design of the roof hatch cover projects slightly above the locomotive roof 

surface. When the locomotive runs at higher speeds, this would act as a bluff body and is 

likely to produce a turbulent flow past the hatch cover and may transmit a wheezing sound 
20

inside the cab. To overcome this source of noise, smooth aerodynamically shaped wedge 

blocks made of neoprene rubber will be permanently bonded along all four edges of the roof 

hatch cutout to make the air flow past the projecting hatch cover. Additionally, packing the 

underside of the hatch cover with acoustic materials would further diminish any noise from 

outside the roof going into the cab. 

c) Any external noise transmitted through gaps between the hatch cover and the cutout 

The use of a strong neoprene rubber gasket around and in the underside of the hatch cover 

should eliminate any gap between the cover and the cutout. Therefore, the hatch cover in 

closed condition is expected to make this opening both water and air-tight and hence 

preclude any transmission of noise. The additional use of sound absorbing material at the 

cutout in the underside of the hatch cover in its latched condition should inhibit noise 

transmission of any kind through the roof hatch. 

If the above precautions are a part of the design and fabrication of the removable roof hatch, then 

the present noise level inside the locomotive cab should remain unchanged. 

2.6 Emergency Lighting 

Crew egress from a locomotive cab in an emergency situation can be critically dependent on 

adequate interior lighting. In nighttime conditions or in a smoke-filled environment, lighting and 

related luminescent materials would facilitate the identification of egress routes and apparatus, as 

well as improve the chances for crew survivability. 

2.6.1 Emergency Lighting Requirements/Standards 

Because an escape hatch is a new concept for freight locomotives, no current lighting standards 

exist. Lighting standards in other transportation modes and other industries, however, do exist. 

Compiling and analyzing these standards provides boundaries for the level of lighting needed to 

effectively mark the emergency exit. 

Many organizations have developed standards for emergency lighting levels (see Table 2). 

Although these standards vary in their recommended levels of illumination at points of egress in 

emergency situations, most ranged from 5–20 lux or 2–20 mcd/m2

. These guidelines generally 

provide for enough light at floor levels to allow passengers to find their way to an exit in a 

darkened environment. 
21

Table 2. Emergency lighting standards 

Standard For Emergency 

Lighting Application Illumination 

Illumination 

Period 

Electrically powered systems as low 

level lighting on passenger ships–

All active parts 

Minimum of 10 cd/m2

Electrically powered systems as low 

level lighting on passenger ships–

Point source in miniature 

incandescent lamps 

150 mcd mean spherical 

intensity 

International Marine 

Organization (IMO) 

Resolution A.752 

Electrically powered systems as low 

level lighting on passenger ships–

Point source emitting diode systems 

Minimum peak intensity 

of 35 mcd 

60 min 

European Standard 1838 Horizontal luminance on the floor 

along the center of an escape route 

Not less than 1 lux 

NFPA 101: Life Safety 

Code 

Along the floor of the escape route 10 lux initially, with a 

minimum of 1 lux 

90 min 

Canadian Railway Act–Part 

XIV; Division 300.05 

In areas where employees pass 

while carrying out procedures 

35 lux (3 fc) No specified 

length of 

time 

Minimum luminance at vehicle 

egress points at floor level 

20 lux 

Minimum luminance on emergency 

equipment provided to assist in 

egress from a vehicle 

20 lux 

United Kingdom Rail Safety 

Standards Board Railway 

Group Standard GM/RT 

2176 

Minimum luminance on an escape 

route at floor level 

5 lux 

90 min 

2.6.2 Approach 

The method of lighting specific to a locomotive cab should stem from what is needed in the most 

adverse conditions. In a worst-case scenario locomotive accident, crewmembers would be 

disoriented and injured. A nighttime wreck would result in a dark, smoke-filled cab with no 

power. Although the cab environment is a relatively confined space, about 9.5 x 7.5 ft, and is 

overly familiar to train crews, locating the exit in this condition would prove very difficult. The 

primary objective, therefore, was to determine the best method for illuminating the egress system 

under this worst-case scenario. 

The lighting system employs two different techniques. One technique emphasizes the luminance 

contrasts of the details of the escape system. Starting at the handle of the hatch and working 

outward, reflectance levels were alternated by using colored paint. More specifically, the handle 

of the hatch was left gray–a low reflectance color–while the recessed portion in the center of the 

hatch was painted white–a high reflectance color. The rest of the escape hatch apart from the 

recess was again painted gray, to contrast with the white recessed area. The rationale behind this 

approach is that the human visual system is designed to detect luminance contrasts, so the higher 

the luminance contrast, the more likely it is to be seen, particularly at very low light levels. The 

design team used the same strategy for the hand/footholds. 

A second technique employed was providing emergency lighting for the escape hatch and the 

hand/footholds. Determining the method of illumination involved consideration of a number of 

factors. Detailed analysis of cost, maintenance, visibility, reliability, available space, vibration, 
22

and temperature determined the best possible material for use in a locomotive cab. 

2.6.3 Candidate Technologies 

The following technologies currently exist in emergency vehicle lighting systems used in 

aircraft, helicopters, and civilian transportation systems (including railroads) throughout the 

world: 

• Incandescent (filament bulbs) 

• Fluorescent (mercury-based vapor excited by an AC or DC source) 

• Halogen (filament bulbs) 

• Light emitting diodes (LED) 

• Electroluminescent (phosphor-based compounds excited by a DC or AC power supply) 

• Self-luminescent (phosphorous-coated capsule excited with Tritium gas) 

• Photoluminescent (silicate and alkaline aluminate-based compounds; zinc chromate and 

strontium aluminate) 

• Chemiluminescent (hydrogen peroxide mixed with oxalix phthalate that charges a 

fluorescing dye, which releases light) 

Investigation of the qualities of these materials and consideration of the requirements and 

concerns of lighting the cab led to the selection of photoluminescent materials. These materials 

are inexpensive, reliable, easy to install, and virtually maintenance free. Vibration would not be 

an issue because no battery packs or other pieces are required. The materials are typically flameretardant and designed to withstand salt spray mist, water, and cleaning agents. 

The potential drawbacks of using photoluminescent materials are that (1) initial afterglow 

luminance is highly temperature dependant (e.g., afterglow luminance generally increases and 

decreases with temperature), (2) they require sufficient levels of incident light in order to fully 

saturate, and (3) the light could potentially be a distraction to operators driving under nighttime 

conditions. Considering that these materials will be placed on the interior of the locomotive cab, 

however, cold temperatures would not be an issue. Furthermore, installing an LED light source 

with a peak emission around 400 nanometer would make it possible to continuously energize the 

photoluminescent materials while producing very little visible light in the cab. The need exists 

for further research to determine if photoluminescent lighting will hinder driving abilities at 

night. 

Recent research has produced new inorganic compounds whose photometric characteristics 

greatly exceed those of the conventional zinc sulphide compounds. Strontium aluminate 

compounds, available in flexible vinyl and rigid PVC sheets, offer much brighter (15 times) and 

longer lasting photoluminescence. They can be formulated to produce a range of colors. These 

products generally exceed existing photoluminescent lighting standards (see Table 3). 
23

Table 3. Photoluminescent lighting standards

Standard For 

Photoluminescent 

Lighting Application Illumination 

Illumination 

Period 

APTA SS-PS-002 Standard emergency signage for egress/access of 

passenger rail equipment 

not specified 

15 mcd/m2 IMO Resolution A.752 Photoluminescent systems as low location lighting 10 min 

on passenger ships after the removal of all external 

illumination sources >2 mcd/m2 60 min 

17 mcd/m2

 10 min 

4 mcd/m2

 30 min 

1.7 mcd/m2

 60 min 

DIN 67 510 For the purpose of egress, photoluminescent 

material must provide certain luminance at certain 

times 

0.3 mcd/m2

 240 min 

20 mcd/m2 ASTM E 2073-00 Standard specification of photoluminescent safety 10 min 

markings 

2.8 mcd/m2

 60 min 

2.6.4 Implemented Approach 

The researchers placed peel-and-stick versions 

of both zinc sulphide and strontium aluminate 

materials along the recessed walls of the hatch 

and hand/footholds in the mockup. They also 

placed exit signs made of these materials on the 

flat surface of the hatch, above and below the 

hatch handle (see Figure 24). All participants 

in the usability testing said they could see the 

photoluminescent materials very well in the 

dark, and all rated the strontium aluminate as 

being brighter than the zinc sulphide. A rough 

cost estimate of the strontium aluminate 

material is between $25 and $35 per thousand 

in2

. 

One concern mentioned earlier was whether 

strontium aluminate would be so bright as to be 

distracting during nighttime operation. 

Usability test participants felt that this would 

not be the case. 

Figure 24. Photoluminescent materials on 

sides of recessed areas 

Photoluminescent material is the most appropriate lighting source to use in a locomotive cab 
24

environment. It provides for a low-cost, low-maintenance, high-visibility, and high-reliability 

solution, without being a distraction during normal operation. An in-locomotive, onsite test with 

the manufacturer’s product wherever possible and certified photometric test reports can provide 

assurance that the appropriate amount of light diffuses in a dark or smoky environment. A need 

exists for further research to determine if the stronger photoluminescent materials will be a 

nuisance during nighttime train operation. 

2.7 Prototype Hatch System 

A full-size mockup of a freight locomotive cab provided the means to evaluate the overall utility of 

the egress concepts developed under this program. The mockup is a wood-framed, plywoodsheathed structure representing a composite locomotive cab. The cab dimensions reflect sizes 

common to both GE and EMD locomotives currently in service. The cab interior is 9.5 ft wide, 

6.5 ft from floor to ceiling, and 7.5 ft from the operator’s console to the rear wall. In its current 

configuration, there is no rear wall, thus allowing improved viewing and access during testing. The 

mockup construction provided openings for a roof hatch, hand/footholds, and grab irons in place. 

Currently, the mockup represents the basic configuration of the operator’s station, roof, windshield, 

chair, and hood, and it does not include the front doors or electrical switching panels. The research 

team assembled the mockup on its side, which simulates a 90° rollover derailment, allowing 

evaluation of the egress system. Figure 25 shows an exterior view of the mockup, and Figure 26 

shows an interior view. 

Figure 25. Mockup of toppled locomotive cab with egress system 
25

The hatch itself is a steel assembly consisting of an upper panel, a lower enclosure, and an internal 

latching mechanism. The overall assembly weighs approximately 40 lb. The hatch releases from 

the opening when the handle turns approximately 40° in either direction. An outward push on the 

hatch panel frees it from the opening. The mechanism has a cover with appropriate placards for its 

use applied to the surface. The signage is informative to persons unfamiliar with its use, so they 

could readily identify the device, operate the hatch, and clear the opening for egress. 

Photoluminescent strips provide illumination of both the hatch and the hand/footholds. Two grab 

irons fixed to the cab’s exterior will aid the exiting crewmembers and rescue personnel in entering 

the locomotive. The grab irons are 22 in long and are of a 1-in diameter. Figure 25 illustrates the 

vertical placement of the grab irons on either side of the roof hatch when the locomotive is in a 

toppled condition. 

Figure 26. Interior view of cab mockup with hatch system 

27

3. Usability Testing 

The objective of the usability testing was to examine the functionality of the proposed 

emergency egress roof hatch system (roof hatch, hand/foothold, and grab iron designs) for a 

locomotive cab. Many transportation vehicles, such as buses, airplanes, and boats, have 

successfully utilized roof hatches for egress/access for many years; however, the effectiveness of 

a roof hatch design for locomotive egress was unknown. 

Specifically, the purpose of this usability evaluation was to obtain both quantitative and 

qualitative feedback as to the effectiveness of the locomotive roof hatch system. Railroad 

locomotive engineers and conductors, as well as emergency rescue personnel, participated in the 

tests to determine if they could safely enter and/or exit the cab in the event of a locomotive tipover. 

3.1 Use of Human Research Participants 

An Institutional Review Board (IRB) convened by Dunlap and Associates, Inc. conducted a 

human subjects review of the study design, protocol, and materials to be used in the usability 

study. The IRB consisted of individuals with expertise in research involving human subjects. 

The IRB found no risk to human participants in the proposed research design and consequently 

approved the research plan for the usability study on September 4, 2003. 

3.2 Participant Recruitment 

Because the knowledge base, physical characteristics, responses, and actions of a typical user are 

of the highest interest during usability testing, actual qualified locomotive crewmembers and 

current emergency response personnel were eligible to be research participants. The researchers 

coordinated with local United Transportation Union and Brotherhood of Locomotive Engineers 

representatives to identify six volunteers for this research. In order to obtain data and feedback 

from an emergency crew perspective, the researchers recruited five volunteers from the local 

Fitchburg, MA, Fire Department. The following were the criteria to identify candidate 

participants: 

• Only current engineers or conductors were eligible to participate. 

• Train crew candidates all had at least 1 year (yr) of road freight experience. 

• Emergency response participants were actively employed with a local fire department. 

• All candidates were in good health and fit for duty. 

A researcher contacted potential train crew participants to request their participation in the 

project. The researcher told candidates that participation was voluntary, confidentiality would be 

maintained, and each volunteer would be compensated $60 by the research team for his/her 

involvement in the study. The researcher scheduled individuals willing to take part in the 

experiment for a 45-min time block at their convenience. 

The research team recruited a group of rescue personnel separately from a local fire department 

for participation in the study. A block of 4 hours (h) was arranged with the crew to run through a 

variety of rescue scenarios. Compensation for fire crewmembers was at their standard hourly 
28

rate. 

3.3 Experimental Study 

3.3.1 Pre-Experimental Preparations 

Each participant began with pre-experimental preparations. The researcher explained that the 

purpose of the study was to assess the effectiveness of a new roof hatch egress system for use in 

locomotive accidents. Next, he/she was given an Informed Consent form to read and sign (see 

Appendix A). 

The experimenter then answered any questions that the participant may have had regarding his or 

her participation in the study and the material covered by the Informed Consent form. Upon 

agreeing to participate and signing the Informed Consent form, the experimenter gave train crew 

participants a brief background survey that solicited age, gender, height, weight, job title, and 

experience. The experimenter also explained that, although the speed with which the participant 

could enter and/or exit the locomotive was of interest, it was secondary to the participant’s safety 

and his/her evaluation of the hatch system. 

At the conclusion of the pre-experimental preparations, the experimenter asked the subject if 

he/she had any questions about the material just covered or the upcoming procedure. The 

experimenter then escorted the participant to the locomotive mockup. 

3.3.2 Experimental Design 

The experimental design for testing the effectiveness of the roof hatch system was a 3x2 repeated 

measures design, where independent variables were injury type (no-injury, broken arm, broken 

leg) and visibility [high visibility (natural light) and low visibility (photoluminescent light)]. 

Because evaluation of visibility required only one trial for each participant, it was not necessary 

to fully cross all conditions (and run participants through darkened scenarios more than once). 

The ordering of participant trials was counter-balanced to control for any effects of learning. 

Height and weight of participants were factors that were analyzed after the fact, but definition of 

the experimental groups did not use these factors. 

3.3.3 Test Facility 

The hatch itself is a steel assembly consisting of an upper panel, a lower enclosure, and an internal 

latching mechanism. The overall assembly weighs approximately 40 lb. The hatch releases from 

the opening when the handle turns approximately 40° in either direction. An outward push releases 

the hatch panel from its frame. Once pushed away from the locomotive, a tether line system 

removes the hatch from the opening and surrounding area. The tether line is a safety measure to 

move the falling hatch away from the egress area during usability testing. 

The tether line is a cable attached to the emergency hatch. From the hatch, the cable runs 

through a pulley system and is connected at the opposite end to a counter weight. As the hatch 

begins to fall to the ground, the cable pulls the hatch away from the egress area. At the same 

time, the counter weight slows down the descent of the hatch and allows the hatch to softly come 

to rest on the ground, a safe distance from the participants. In this position, neither hatch nor 

tether line is an obstacle to the participants. Figure 27 through Figure 30 show the tether line 
29

safety system installed for the falling hatch. 

3.3.4 Test Procedure 

Crew participants began their trials inside the locomotive cab. To simulate an accident scenario 

and possible disorientation, crew participants put on a blindfold, as the researcher assisted in 

turning the individuals around twice before sitting them down on the floor of the locomotive cab. 

Next, the researcher asked each subject to remove the blindfold, exit through the hatch, and 

lower himself/herself to the padded floor. No further instruction was given at this time, as it was 

important to determine if crewmembers would be able to exit effectively without receiving 

special egress training. The researcher asked each participant to exit several times, simulating 

different physical (injury type) and environmental (visibility) conditions. 

Types of injuries that were simulated included a broken arm and a broken leg. This was 

accomplished by asking participants to either place their dominant hand in their pocket or behind 

their back (broken arm scenario), or to avoid using one leg (broken leg scenario) as they exited 

the cab. 

Visibility was altered from high visibility to low visibility to simulate both daytime and 

nighttime conditions. The nighttime scenario was achieved by simply covering all open areas of 

the mockup with a dark tarp, to keep any light from entering the cab, while the daytime or highvisibility scenario was simply performed under ambient daylight. Photoluminescent materials 

placed in the recessed areas around the hatch and hand/footholds facilitated simulations of 

nighttime egress. This provided enough light for participants to clearly view the hatch and 

hand/footholds, and dimly lit the interior. Once the participant removed the hatch, natural light 

filled the cab, allowing complete visibility to aid in exiting. 

After each trial, participants filled out a subjective survey form (post-scenario survey, see 

Appendix B) in which they rated a number of features of the roof hatch system. These questions 

pertained to ease of exit, visibility of the hatch/foothold/grab irons, amount of force exerted to 

open the hatch, overall effectiveness of the system, and possible improvements. The survey 

consisted of five-point Likert scales, categorical responses, and open-ended questions. After the 

crewmembers finished all trials, they provided comments and/or suggestions regarding the grab 

irons, hatch, hatch markings, and hand/footholds. The researcher recorded these suggestions, 

along with the subject’s time to exit on a data sheet (see Appendix C). 

Emergency response personnel performed several trials. The first crew consisted of two 

rescuers, then three, four, and five, respectively. This was done to determine the number of 

rescuers that would likely be required in a roof hatch rescue. In all cases, they began their trial 

outside the locomotive cab, dressed in full rescue gear, with all necessary equipment on hand. 

The researcher simply instructed them to enter the cab, place an injured person on a body-board, 

and exit the cab with the injured person. All trials took place in high-visibility conditions 

(daylight), as emergency workers should always be equipped with means of lighting. A trial was 

stopped if the researcher determined that more crewmembers were necessary to remove the 

victim from the cab. 

Following these trials, emergency response participants filled out a subjective survey form (postscenario survey, see Appendix B) similar to that filled out by crew participants. After 

completing this form, the researchers asked participants to give comments and/or suggestions 
30

Figure 27. Hatch is attached to a tether line Figure 28. Tether line is run through a pulley system

Figure 29. Pulleys remove hatch from egress path Figure 30. Counter weights allow hatch to settle gently
31

regarding the grab irons, hatch, hatch markings, and hand/footholds. The researcher recorded 

these comments, along with the participants’ time to enter and exit, on a data sheet (see 

Appendix C). 

In all instances, video recording documented the participant’s performance. This in no way 

jeopardized the confidentiality of the participants and was done simply to capture each 

performance in the event it required referencing at a later time. The collection of these data 

during the experiment did not interfere with the tasks of the volunteers. Two researchers were 

present at all times to monitor for participant safety. 

3.4 Results 

Separate subsections below describe the results of the train crew and emergency responder 

usability tests. 

3.4.1 Train Crew 

Six train crewmembers, four conductors and two engineers, participated in the usability testing. 

The average crew member was 40.8 yr old, 5 ft 11 in, weighed 191.6 lb, and had 20 yr of 

experience. The largest participant was 6 ft 1 in and weighed 215 lb, while the smallest 

participant was 5 ft 10 in and weighed 180 lb. 

As anticipated, the no injury condition resulted in the quickest escape time. Participants were 

able to use both arms and legs to access the hand/footholds and grab irons to quickly extricate 

themselves from the cab. It took subjects only slightly longer to escape in a darkened 

environment. All participants reported that the photoluminescent materials placed on and around 

the hatch and hand/footholds provided adequate escape route lighting. Escaping with a 

simulated leg injury took somewhat longer, as participants were asked not to use the leg to stand 

up or to bear any weight. These subjects were able to use the hand/footholds to hop up to the 

hatch opening and were then able to reach outside the cab and get hold of the two grab irons. 

This was enough to allow the participants to pull themselves out. The simulated arm injury 

seemed to cause the greatest problem for participants. This is probably because most 

participants, four of six, chose a head first approach to exit through the hatch. These subjects 

used one arm to take hold of a grab iron and then pulled the rest of their bodies through the 

opening. Nonetheless, under all conditions, escape time was under 30 s (see Table 4). 

Table 4. Average time for train crew participants to exit locomotive 

Scenario Average exit time (s) Ease of exit rating 

No injury 16.93 4.0 

In darkness 19.60 NA 

Leg injury 23.83 3.1 

Arm injury 27.78 2.3 

Participants’ subjective ratings on ease of exit with various physical injuries correspond with 

actual exit times, with no injury, leg injury, and arm injury, receiving ratings of 4.0, 3.1, and 2.3, 

out of 5 (extremely easy), respectively. Ease of exit rating in darkness is assumed to be equal to 
32

Figure 31. Interior and exterior views of crewmember egress 

that of the no injury condition, since the intended meaning of this rating is how physically easy it 

is to exit. 

3.4.2 Emergency Rescue 

Rescue groups of two, three, four, and five attempted to extricate a simulated victim from the 

cab. The victim for all trials was a 5 ft 11 in male weighing 230 lb. A two-person crew could 

not safely remove the victim through the cab hatch. The crew managed to lift the victim up to 

the hatch and rest the backboard in the opening but was unable to remove him safely. A threeperson crew utilized all three people to lift the victim up to the hatch opening; then, after one 

rescuer exited the hatch, the remaining two slid the victim out on the backboard, face-up, to the 

rescuer on the outside. The rescuer on the outside then held the victim vertically on the 

backboard until the remaining rescuers could exit the cab and assist in lowering the victim safely 

to the ground. The four-person crew used a similar method of removing the victim, sending 

three rescuers inside the cab to lift the victim, while one remained on the outside. After the lift, 

one rescuer climbed out, and the remaining crewmembers slid the victim out of the hatch to the 

two rescuers on the outside. The two rescuers on the outside once again held the victim 

vertically on the backboard until the remaining rescuers could exit and assist in lowering the 

victim safely to the ground. Finally, the five-person crew used the same method for removing 

the victim, but instead sent four rescuers into the cab for lifting, before one climbed out. Once 
33

again the remaining crew slid the victim out to the rescuers on the outside, and the rescuers on 

the cab exterior held the victim vertically until the rest of the crew exited the cab and assisted in 

lowering the victim to the ground (see Table 5 for times). Figure 32 shows one of the teams 

removing an injured crew member. 

Table 5. Time for rescue personnel to extricate victim from cab

 Crew Size 

 2 3 4 5 

Total Time to Enter 

and Exit (min:s) 

8:001 8:40 8:37 9:00 

Successfully Removed 

Victim? 

No Yes Yes Yes 

1

 Total time for two-person crew to enter locomotive and lift victim up to hatch opening 

Increasing the number of rescue personnel beyond three did not seem to improve rescue time. 

Based on participants’ feedback, however, additional personnel did make it easier to remove the 

victim. 

Figure 32. Views of emergency personnel entrance, victim preparation, and extrication

3.4.3 Train Crew Subjective Data 

All participants used the hand/footholds, with the bottom foothold being used most often. Four 

of the six participants simply stepped into the recessed areas without folding out the hand/foot 

bars in their first trial, stating that they did not realize they folded out. Some of these individuals 

stated that the hand/footholds may not be necessary, and that in an emergency situation, they 
34

may not take the time to fold them out. Using the fold-out is necessary, however, when using the 

hand/foothold above the hatch opening because it is the only thing to grab. Overall, subjects 

rated the hand/footholds as extremely easy to use and relatively effective in their placement. 

Participants rated the hatch as very straightforward to use and physically very easy to open and 

push out. 

All participants used grab irons, located on the cab’s exterior, but many participants suggested 

additional grab irons or changes in their current location. Five of six participants stated that they 

would like a grab iron placed horizontally above the hatch opening, providing them with a better 

place to grab onto upon exit. Two participants suggested diagonally slanting grab irons above 

the top corners of the hatch. 

In the darkened scenarios, participants rated the hatch as being very easy to see, stating the 

photoluminescent materials worked very well in lighting the area. Hand/footholds received only 

a mediocre rating for visibility. One subject stated that the first thing he saw was the bright glow 

of the hatch, and he just went toward it, without noticing anything else. 

3.4.4 Emergency Personnel Subjective Data 

Emergency personnel rated the hatch as very straightforward to use and extremely easy to open 

and lift away from the opening. In fact, after the first two trials, the rescue crew propped the 

hatch against the side of the locomotive mockup, using it as a stepping stool to boost themselves 

into the opening and to step down onto when exiting. 

Participants gave the placement of the grab irons only a mediocre rating for entry. One rescuer 

attempted to hold one of the irons and swing feet first into the opening, only to have his grip 

slide down the vertical grab iron. Rescuers stated that placing grab irons above and below the 

hatch, however, would likely interfere with getting out. They suggested that having a foothold 

on the exterior of the locomotive would help dramatically with entry. 

Another suggestion was to add texture to the grab irons to provide better grip. 

Rescuers rated the placement of the grab irons somewhat higher for exiting the cab. They 

seemed to exit a bit easier and stated that the grab irons provided good leverage for getting out. 

Rescuers were very pleased with the design of the hand/footholds. They rated them as extremely 

straightforward and easy to use, and most were pleased with their placement as well. More than 

one rescuer stated that the pull-down stepping bars made the steps easier to use with their large 

fire boots, as opposed to simply stepping into the recessed well. 

Overall ease of entering and exiting the cab received a mediocre rating from the rescuers. Two 

factors resulted in this rating. First, participants had a difficult time entering the cab without an 

exterior foothold or other device to allow them to boost themselves into the hatch opening. 

Second, rescuers stated that the current size of the hatch was adequate but sometimes made it 

difficult to enter or exit in full turnout gear (including an oxygen tank on their back). One 

participant said that if the hatch was as large vertically as it is horizontally, it would make the 

rescue crew’s job easier. 

3.5 Discussion 

Overall, the design of the hatch escape system was effective in its purpose. It allowed for a safe 
35

and efficient escape for train crewmembers and was sufficient in permitting rescuers to 

successfully retrieve an injured victim from inside the cab using a backboard. The hatch and 

hand/footholds were very straightforward and easy to use, while the grab irons provided 

adequate holds to assist with entry and exit. Photoluminescent materials also successfully 

illuminated the escape route during darkened conditions. 

Both train crew and rescue personnel had suggestions for improving the egress system. The 

following suggestions were made: 

• Hatch/Opening

Rescuers had two suggestions regarding the hatch. First, they stated that bigger is better 

regarding their interests. Specifically, they would like the opening to be as large vertically as 

it is horizontally. A larger opening would allow easier entry and egress. One point to 

consider here, however, is that the larger the opening gets, the larger and heavier the hatch 

becomes. The second suggestion related to night rescue. Rescuers stated that 

photoluminescent or retroreflective materials around the exterior of the hatch would provide 

clear visibility to the rescue route. 

• Hand/Footholds 

A few of the train crew participants said they did not realize the bars in the recessed areas 

folded out. With entire work days spent in the cab environment, however, crewmembers 

would be well aware of this function. Other train crew participants stated that the folding bar 

may not be necessary for the hand/footholds and that the recessed area may be enough by 

itself. These participants did, however, grab the folding bar above the hatch to pull 

themselves toward the opening. Because of the necessity of the folding bar above the hatch, 

it means the hand/footholds below the hatch should also be fitted with folding bars, in the 

event the locomotive rolls over on its opposite side. Rescue workers stated that the folding 

bar was useful because of their large fire boots. One concern of a train crewmember was that 

over time, the folding bars would become loose and make constant noise throughout normal 

operation. He suggested replacing the folding bar with a fixed bar to avoid this issue. 

• Grab Irons 

The primary suggestion from train crew participants was that a grab iron placed horizontally 

above the hatch would make exiting the cab easier. This would of course require one to be 

placed below the hatch as well, in the event the cab tipped on its opposite side. The rescuer’s 

comments were counter to this, however, suggesting that grab irons above or below the hatch 

might hinder one’s exit. Rescuers instead suggested perhaps placing small horizontal grab 

irons above-left and above-right, as well as below-left and below-right of the opening, 

allowing for an overhead grab, but not impeding an entry or exit. Another suggestion was to 

replace the vertical grab irons on either side of the hatch with diagonal grab irons in each 

corner. This may also allow for an overhead grab without hindering entry or egress. A final 

suggestion was to add texture to the grab irons for improved grip. 

37

4. Removable Windshield 

The collision or derailment of a locomotive can result in structural damage to the cab or cause 

the locomotive to roll onto its side. This can block the egress routes used during normal 

operation from the cab. Primary emergency egress can be accessed through a roof hatch as 

described in the previous section. Secondary emergency egress options include a locomotive 

windshield that can be removed from the cab interior by the crew and removable hinges on the 

rear door of the cab. This section discusses development of the removable windshield. 

4.1 Current Windshield Design 

Two basic types of windshields are currently used in locomotives: frame mounted and nonframe mounted. Frame mounted windshields are typically found in newer model locomotives 

manufactured by GE. The GE windshield dimensions are approximately 52 in by 17 in. With a 

framed windshield, the glazing manufacturer inserts the glazing into a frame assembly with a 

gasket. Then, the installer places the entire frame assembly, with glazing and gasket, into the 

locomotive windshield frame. With the non-framed windshields, typically found in EMD 

locomotives, the glazing installs directly into the locomotive windshield frame with a gasket. 

The dimensions of a windshield of an EMD SD70MAC are approximately 57 in by 19 in. 

Figure 33 and Figure 34 show an example of a framed windshield. Figure 33 shows an 

assembled GE windshield frame including gasket and glazing. Figure 34 shows a closeup view 

of the frame assembly. The entire frame assembly shown in these figures goes into the 

locomotive windshield frame. In Figure 34, the arrow on the right side of the image points to 

one of the screws that are used to fasten the assembly to the locomotive. The arrow on the left 

side of the image points to the weather stripping material used to create a tight fitting seal 

between the assembly and the locomotive. Figure 35 shows a section of a framed windshield 

showing details of assembly including the glazing and gasket. 

Figure 33. GE windshield frame assembly 
38

Figure 34. Closeup view of GE windshield assembly 

Figure 35. Detail sectional view of framed windshield assembly 

Non-framed windshield installations use only a gasket to hold the glazing into place. The section 

view in Figure 36 is an example of a non-framed windshield gasket currently used for normal 

operation. The gasket section shown does not include emergency egress modifications. The 

installer pushes the small fins on either side of the gasket upward and inward against the main 

body of the gasket to insure a tight fit against the locomotive frame. The curved void at the 

bottom of the gasket also helps to provide a tight fit by allowing the gasket to compress to the 
39

same width as the windshield frame. Once the gasket is in the frame and the glazing is in the 

gasket, the zip flap folds closed and locks into place, applying a pressure against the glazing to 

complete the installation. Figure 37 is a sketch that illustrates the non-framed windshield 

assembly after installation into a locomotive windshield frame. A cut in the gasket at a critical 

location detaches the zip flap, thus allowing the removal of the glazing outward for emergency 

egress. 

Figure 36. Sectional view of a gasket currently used in locomotive windshields 

Figure 37. Sectional view of non-framed locomotive windshield assembly 
40

4.2 Candidate Designs for a Removable Windshield 

Windshield removal from the cab interior requires cutting the gasket on the windshield assembly. 

After cutting the gasket, the glazing can be removed from the windshield frame. The initial 

concept for emergency egress through the windshield used a tensioned wire to fold and deform 

the gasket to an altered position and allow removal of the glazing. Experiments with conceptual 

scale models to investigate the folding method determined that the wire tends to cut and tear 

rather than fold the gasket. Based on these findings, the researchers evaluated the following 

candidate cutting methods: 

• Single Loop Folding Wire 

• Single Loop Cutting Wire 

• Double Loop Cutting Wire 

• Single Loop Wire with Cutting Blade 

The design used for cutting the gasket applies to both the framed and non-framed windshields. 

The non-framed windshield, however, provides a less difficult platform to develop this egress 

system. Therefore, the prototype locomotive windshield for this research was based on a nonframed windshield assembly. 

4.2.1 Single Loop Folding Wire 

This concept requires modification of the windshield gasket geometry so that a wire, when 

pulled, can bend the outer edge of the gasket. During installation, a single loop of wire is 

embedded within the modified windshield gasket. The standing end of the wire remains fixed 

while the running end is free to move during emergency actuation. Since the gasket loops 

around the windshield, the loop tries to decrease in size with a hoop tension when pulled. As the 

wire loop reduces in size, it pulls on a fold added to the gasket. The gasket deforms and bends 

into a position that no longer holds the glazing firmly in place but allows the gasket and glazing 

to be pushed out of the windshield frame. Figure 38 shows a sketch of the modified gasket in a 

normal operating position for the folding method. Figure 39 shows the conceptual sketch of the 

gasket after emergency activation when the gasket has folded. 

Figure 38. Single loop folding wire, normal 

position 

Figure 39. Single loop folding wire, 

released position 
41

4.2.2 Single Loop Cutting Wire 

The single loop cutting wire was the initial concept that appeared to be the most feasible option 

for removing the window gasket from the cab interior. As with the folding concept, the gasket 

has an embedded wire and a modified geometry to facilitate the removal procedure. Instead of 

folding the gasket, however, the wire severs the gasket, allowing removal of the glazing for 

egress. One end of the wire is free to move while the other end remains fixed to create an inward 

hoop tension in the wire. Figure 40 shows the schematic travel path of the wire as it cuts through 

the gasket. As tension increases in the wire, the gasket begins to fail at the first corner opposite 

to the direction of wire retrieval. After the wire cuts the gasket at the corner, it cuts the two sides 

adjacent to the corner. Continued retrieval of the wire causes additional cutting of the gasket 

until the glazing is free to be removed from the windshield frame. 

Figure 40. Schematic retrieval path of a single loop cutting wire 

The gasket currently in use on locomotive windshields (Figure 36) requires geometry 

modifications to function properly for the single loop wire cutting method. Figure 41 shows the 

slight changes in geometry required. The important change in the geometry is to increase the 

length of the slot below the folding flap. The small diameter wire is embedded into the gasket at 

the end of the slot and rests there passively until needed. This method also requires an upward 

curve at the end of the slot. The curve will prevent the wire from sliding up toward the fold in 

the flap and will concentrate the stress on the proper location of the gasket. Figure 42 shows a 

sectional view of the gasket that illustrates the normal operating position of the single loop 

cutting wire installed with the glazing. 
42

Figure 41. Sectional view of the gasket with modified geometry 

Figure 42. Sectional view of the assembled gasket with single loop cutting wire 

As the wire cuts through a critical section of the gasket, the folding flap portion of the gasket 

detaches from the remainder of the gasket. During the cutting procedure, the wire that has 

already cut the gasket slides along the exterior surface of the glazing, as illustrated in Figure 43. 

With the gasket cut, the folding flap no long restrains the glazing, which is then easily 

removable, as shown in Figure 44. 
43

Figure 43. Sectional view depicting cutting 

action of single loop wire 

Figure 44. Sectional view showing the 

severed gasket 

4.2.3 Double Loop Cutting Wire 

Similar to the two methods previously discussed, the double loop cutting wire utilizes a wire 

embedded in the gasket and installed around the windshield. In addition, one end of the wire 

remains fixed while the other end of the wire is free to move. When the wire is tensioned during 

this method, however, the wire does not apply an inward force to bend or cut the gasket. Two 

wire loops around the windshield. Under tension, the loop doubles back on itself, creating a 

rolling bight that cuts the gasket. Figure 45 shows the schematic retrieval path of the wire. 

Figure 45. Schematic retrieval path of double loop cutting wire 
44

Conceptual testing of this method showed that less force in the wire is required to cut through the 

gasket as compared to the single loop method. The advantage of reduced force, however, is 

offset by an increased amount of wire length required to be pulled during its retrieval. 

The fixed end of the wire rests on the interior side of the gasket close to the glass while the 

running end is on the external side of the gasket. The installation process includes insertion of 

the cutting wire around the glazing side of the zip strip to create the double loop. The sketch on 

the left side of Figure 46 shows the double loop cutting wire assembly during normal operation, 

before the gasket is cut. The sketch on the right side of the figure shows the gasket with the 

critical section cut allowing emergency removal of the windshield. 

 Figure 46. Sectional view of gasket before and after cutting by the double loop wire 

4.2.4 Single Loop Wire with a Cutting Blade 

The final candidate gasket design for an easily removable windshield is the single loop wire with 

a cutting blade. As with the other methods, the gasket surrounding the glazing has an embedded 

wire. With this option, the wire is not required to fold or cut the gasket. Instead, the end of the 

wire has a cutting blade. As the wire is retrieved, it pulls the blade and cuts the critical section of 

the gasket in its path. A shim guide is important with this cutting method to facilitate the wire 

retrieval and to keep the blade at a proper orientation and cutting angle. The wire connects to the 

base of the blade at a cylindrical shank. The blade shank and wire are installed into the shim 

guide with only the blade exposed and extending out to cut the critical gasket section. Figure 47 

shows a sectional view of the assembled gasket with single loop wire in normal position, before 

cutting the gasket. After the critical section of the gasket is cut away by the blade, the 

windshield glazing is free and can be pushed out of the frame for emergency egress. Figure 48 

shows the severed gasket after the blade has cut through the critical section. 
45

Figure 47. Sectional view of the assembled 

gasket with single loop wire 

Figure 48. A view of the severed gasket 

after cutting at critical section 

4.2.5 Selection of Candidate Design for Removable Windshield 

The following attributes were the basis for comparison and selection of an option for a prototype 

design: 

• Operational simplicity 

• Functional reliability 

• Cost 

• Effort for retrofit in existing locomotives 

• Time for deployment 

Table 6 contains the ratings for candidate designs with respect to these factors. Based on this 

analysis, the single loop cutting wire was the preferred concept. The single loop method 

required a new gasket design with a modified geometry. Figures 36 and 41 show a sketch of the 

currently used gasket and the gasket modified for the single loop cutting method, respectively. 

Preliminary tests of the single loop cutting method with the existing gasket material identified 

problems with this concept. Although the current gaskets did not have a modified geometry, it 

was apparent after several tests that the single loop wire method would not sever a rubber gasket. 

Therefore, cutting the gasket required either a modified single loop cutting method or a 

completely separate method. 

Preliminary testing of the double loop cutting wire showed that the method was effective at 

cutting the gaskets with varying thicknesses and various sized wire diameters. The double loop 

cutting method eventually proved successful in the prototype windshield frame and on the 

wooden mockup locomotive. The next section discusses the specifics of development for the 

single and double loop cutting methods for severing the windshield gasket. 
46

Table 6. Comparison of performance attributes for removable windshield concepts 

Concept 

Operational 

Simplicity Reliability Cost 

Retrofit 

Effort 

Time for 

Deployment 

Single Loop 

Folding Wire Bad Bad Good Good Medium 

Single Loop 

Cutting Wire Good Good Good Good Medium 

Double Loop 

Cutting Wire Medium Good Medium Medium Medium 

Single Loop 

Wire with 

Cutting Blade 

Medium Medium Bad Medium Medium 

4.3 Design of Double Loop Cutting Wire 

4.3.1 Limitations of the Single Loop Method 

As described above, efforts to develop a method to cut a gasket with a wire began with the single 

loop cutting method. The single loop method proved unsuccessful because friction between the 

wire and the gasket dissipates some of the force. The remainder of the force is transmitted 

inward at the first windshield corner, as designed. As the tensile load increases in the wire, 

however, the wire fails and breaks before reaching a load great enough to begin the severing of 

the gasket. Instead of a concentrated load, the inward force of the wire distributes along the 

curve of the 4-in radius locomotive windshield. 

Additional tests with the single loop method used various sized wire diameters ranging from 

0.018 in to 0.038 in. Additional testing involved decreasing the thickness of the gasket. At the 

location where the wire will cut the gasket, the current minimum dimension specified by the 

windshield manufacturer is 0.03 in. Even with the reduced gasket thickness of 0.015 in (half of 

the minimum required thickness), the cutting wire still could not sever the gasket. 

4.3.2 Twin Double Loop Method 

The initial process of selecting a concept to release the windshield glazing identified the double 

loop method as an attractive second choice (see Table 6). The double loop, however, seemed too 

complicated as the rolling bight of the wire needed to travel most of the circumference of the 

windshield. Reconsidering this concept, researchers modified the double loop design to include 

two separate loops (twin double loops). Twin double loops of cutting wire embedded in the 

gasket, each cut half the length initially assigned to the single wire double loop method. Figure 

45 shows the travel path of the cutting wire in the single wire design. Figure 49 shows the travel 

paths of cutting wires for the twin double loop. 
47

Figure 49. Sketch of retrieval path for twin double loop cutting wire method 

Using twin double loop cutting wires simplified the double loop method. Testing the single wire 

double loop method on the prototype windshield identified two problems. The first was having 

the rolling bight negotiate the corners of the windshield. The second problem with the single 

wire method is the large length of wire that must be pulled through the gasket and around the 

windshield. 

As the wire of the double loop method approaches a windshield corner, it has a tendency to leave 

the desired cutting path and prevents cutting the gasket. Modifying the geometry of the gasket 

addressed this problem. A modification to the gasket geometry provided for a larger slot to help 

maintain the proper position of the cutting wire, as shown in Figure 41. However, using a twin 

double loop system requires each loop to cut through only one corner. The single wire version of 

the double loop method requires two corners to be cut by the wire. 

The second problem experienced with the single wire method is the long length of gasket that 

must be cut to release the glazing. The dimensions of the non-framed windshield, such as the 

one in an EMD SD70MAC, are approximately 57 in by 19 in. Prototype testing shows that 

cutting three of the four sides will release the glazing. Therefore, using the single wire method, a 

single wire must cut a gasket length of 95 in (19 in + 57 in + 19 in). With the twin double loop 

method, each of the two cutting wires must cut one short side (19 in) and half of one long side 

(28.5 in) or a total of 37.5 in. Reducing the length for each of the twin loop wires is significant 

to successfully cutting enough length of gasket to release the glazing. 

The force to actually cut the gasket with the rolling bight of the double loop method is minimal 

as compared to the friction force created between the wire and the gasket. As the embedded wire 

is pulled through the gasket, a friction force develops. The accumulated friction force is greater 

at the corners. With the non-twin method, more than twice as much wire exists to contact the 

gasket and two corners included in the cutting path. 

With the twin loop method, each loop is responsible for cutting half of the gasket on the top of 

the windshield, the top outer corner, and the entire length of the small vertical side of the 

windshield for a total of about 48 in (see Figure 49). The twin loop system uses the strength of 

two wires to resist about the same frictional force encountered with the single wire system. The 
48

single wire system failed frequently during prototype testing. Using the twin loop system offers 

a successful solution to this problem. 

After the twin loops of wire cut the gasket, the remaining intact gasket is the long bottom section 

and part of the bottom corners. Prototype testing shows that with this amount of gasket cut, the 

bottom length of gasket acts as a hinge, and the glazing is easily pushed from the windshield 

frame. 

4.3.3 Gasket Geometry Final Design 

The final gasket geometry design includes modifications to accommodate the twin loop method 

for cutting the gasket. The design is similar to that used for the single loop method. 

4.3.4 Cutting Wire 

Wires with diameters ranging from 0.018 in to 0.038 in could cut the gasket during preliminary 

testing of the gasket cutting. The only size wire, however, that will work with repeated success 

while the windshield is assembled is a wire with a diameter around 1/32 in. Wires with a smaller 

diameter will fail due to the decrease in tensile strength. With larger diameter wires, the wires 

that make up the strand become coarse and abrasive. As the wire cuts the gasket around the 

corner of the windshield, the coarse strand catches on the glazing. The additional friction 

developed against the glazing (in addition to the force required to cut the gasket) is large enough 

to cause the larger wires to fail. The cutting wire that is used is a 1x7 (1 strand with 7 wires per 

strand) galvanized steel multipurpose wire rope with a diameter of 1/32 in and a breaking 

strength of 185 lb. 

4.3.5 Actuator System 

The twin double loop method requires a system to simultaneously retrieve both wires with one 

actuator. As shown in Figure 49, the twin loop configuration requires the retrieval of two wires 

from two separate locations. Wire sleeves installed between the windshield frame and a winch 

guide the wires onto one winch, as shown in the sketch in Figure 50. 

A fabricated windshield frame provided a means to perform usability testing of the removable 

windshield. The image in Figure 51 shows one side of the mockup windshield frame and the 

actuator for wire retrieval. The installed windshield glazing has a modified gasket. The black 

tubing shown is a sleeve for the cutting wires. The wire sleeves are the same as those used for 

the braking and shifting wires on most recreational bicycles. Figure 51 shows the sleeve exiting 

the windshield frame and guiding the cutting wire to the winch. 

Figure 52 shows another view of the wire sleeve as it exits the windshield frame. The cutting 

end of wire to be retrieved onto the winch runs within the sleeve. The exposed steel wire 

attached to the bolt shown in the figure is the fixed end of a double loop. 
49

Figure 50. Sketch of wire retrieval actuator system 

Figure 51. Wire sleeve from windshield frame to winch 

 
50

Figure 52. Wire sleeve for cutting wire 

The wire sleeves add a great advantage to the emergency egress system by allowing the retrieval 

of two wires from two separate locations. In addition, the sleeves allow the freedom to install a 

manual or electric winch anywhere in the locomotive rather than being restricted to keeping the 

winch close to the windshield frame. A termination block allows the wires to be pulled through 

the sleeves and onto the winch. Figure 53 shows a manual winch attached to the custom built 

termination block. The two arrows in the figure point to holes in the front of the termination 

block that will receive the cutting wires and sleeves. Each hole has a large diameter on the front 

of the termination block. The hole decreases in diameter on the back side of the block. 

Changing the diameter of the hole allows both the wire and sleeve to enter the block but allows 

only the wire to exit the block and spool onto the winch. 

The manual winch used to retrieve the cutting wire for usability testing and shown in the figures 

above is a one speed, spur gear hand winch. The winch has a capacity of approximately 600 lb. 

The gear ratio of the winch is 3.1:1, the spool diameter is 2 in; and the handle length is 6 in. The 

accumulated mechanical advantage is 6 in/2 in x (3.1) or about 9.3:1. Figure 54 shows the 

assembled wire retrieval system. The wires covered with the protective sleeves enter the 

termination block at one side. The winch pulls the wires from the sleeves at the other side of the 

termination block. 
51

Figure 53. Termination block and winch Figure 54. Winch pulling wires from sleeves 

through termination block 

4.4 Usability Assessment 

Usability testing employed a prototype windshield installed in the cab mockup. A mockup 

locomotive windshield frame was fabricated based on the dimensions of the GM EMD 

locomotive test article located at the Foster-Miller Locomotive Testing Facility in Fitchburg, 

MA. The prototype system consists of the steel windshield frame, 0.5-in thick polycarbonate cut 

to match the size of the glazing used in the locomotive, and the modified gasket with cutting 

wire. Figure 55 shows a photograph of the mockup windshield frame. The wooden mockup 

locomotive is in the background of the picture. Figures 56 and 57 show the steel mockup 

windshield frame mounted into the wooden locomotive from the exterior and interior, 

respectively. 
52

Figure 55. Steel mockup windshield frame installed in mockup 

Figure 56. Exterior view of windshield frame mounted in mockup locomotive 
53

Figure 57. Interior view of windshield frame mounted in mockup locomotive 

The wire sleeves are utilized in the mockup locomotive. As the running end of the wire exits the 

gasket and passes through the frame, the sleeve protects the wire from chafing against the steel 

frame. The fixed end of the wire exits the frame without a sleeve (Figure 58). In addition, by 

using the wire sleeves, the winch has the flexibility to be located anywhere within the cab. To 

demonstrate usability, the prototype emergency windshield was installed into the overturned 

wooden mockup. A small section of the roof panel was added to the mockup locomotive to 

provide a mounting location for the winch. Figure 59 shows the winch mounted in the overhead 

console of the mockup locomotive. The prototype windshield with a steel frame is on the left as 

shown in the picture. The photograph is rotated 90° to show the orientation of the cab during 

normal operations, without a rollover. Figure 60 shows the winch installed overhead in the 

rollover orientation, as is the current condition of the wooden mockup locomotive. The view in 

Figure 60 shows the wires exiting the termination block as they are spooled onto the winch. In 

addition, this figure shows the wire sleeves exiting the other side of the termination block, 

curving around toward the overhead roof panel, and running to the openings in the windshield 

frame. The paths of the wire sleeves are present in the wider view in Figure 57. 
54

Figure 58. Fixed wire and running wire within sleeve exiting windshield frame 

Figure 59. Winch located in overhead console of mockup locomotive 
55

Figure 60. Winch installed overhead, oriented in rollover position 

Turning the winch handle actuates the emergency windshield egress system. As the handle 

turns, wire travels through the wire sleeve and spools onto the winch. The twin double loops 

close onto each other as designed to cut the gasket (Figure 49). The loops simultaneously cut the 

gasket on each side of the windshield (Figure 49). The cutting rate of the two loops is identical 

as they are both retrieved onto the same winch. Once the wire is retrieved to the winch, the 

gasket on both short sides and one long side of the windshield is cut. The only part of the gasket 

that remains intact is along one of the long sides of the windshield. Figure 61 shows a gasket 

severed by the wire. With one intact gasket edge acting as a hinge, a crewmember can push the 

glazing from the windshield frame. Figure 62 shows a series of pictures that illustrate 

emergency egress from the mockup locomotive windshield. 

Figure 61. Gasket after being severed by wire 
56

Figure 62. Removal of glazing after cutting the windshield gasket 

4.5 Prototype Evaluation 

The prototype emergency windshield system was successfully demonstrated in the laboratory. In 

addition to usability, the researchers reviewed the design for installation and manufacturing cost. 

4.5.1 Force Requirements 

Prototype testing indicates that peak wire force occurs when initiating the cut. Once the wire 

begins to cut through the gasket, continued retrieval of the wire requires a much lower force. 

During prototype testing, a torque wrench measured the force required to initiate the gasket 

cutting and the force required after the initial cut. The torque required to initiate cutting was 10 

ft-lb. The torque required to maintain cutting drops to 4 ft-lb after the initial peak. The handle 

of the winch is 6-in long; therefore, the force required at the winch handle to initiate and 

maintain the gasket cutting is approximately 20 lb and 8 lb, respectively. 

4.5.2 Egress Time 

The time required to exit the locomotive cab is relevant to crew safety during an emergency. 

Prototype testing indicates that the time required to cut the gasket and push out the windshield 

was approximately 50 s. This is an acceptable emergency egress time. 
57

4.5.3 Costs 

Cost estimates for implementation of the removable windshield system are based on component 

and labor costs. Costs for the prototype system provide a basis for the estimates. The cost to 

retrofit an existing locomotive would likely be greater than that to install the system during new 

construction. Therefore, to be conservative, the authors assumed retrofitting costs for the 

estimates. The material and labor costs required to retrofit an existing locomotive total less than 

$1000 per windshield, as itemized in Table 7. 

Table 7. Costs to retrofit a locomotive with removable windshield 

Description (Parts/Tasks) Labor Material Total 

Gasket n/a $45 $45 

Cutting wire n/a $10 $10 

Wire sleeve n/a $30 $30 

Termination block $180 (3 h @ $60) $35 $215 

Winch n/a $40 $40 

Installation: 

Remove windshield glazing and gasket, drill access 

holes through windshield frame, embed wire into 

gasket, install glazing and wired gasket into frame, 

feed wires through wire sleeves, mount winch and 

termination block in locomotive, connect ends of 

wire sleeve to windshield frame and termination 

block, fasten wires to winch 

$600 (12 labor-h @ $50) n/a $600 

Total estimated cost per windshield $940 

59

5. Removable Door Hinge 

This section describes the removable door hinge for the locomotive rear door, one of the two 

secondary egress methods. The design of this innovative door hinge attachment facilitates 

removal of the cab rear door when deformation of the cab and the door frame prevent normal 

operation of the door. The design requirements were that (1) the mechanism should be simple 

and easy for the crew to engage from inside the cab, (2) all the components should be sturdy to 

last the life of locomotive, and (3) emergency rescue personnel should be able to easily remove 

the hinge pins from the exterior of the cab. Construction of a prototype door assembly for the 

GE AC4400 locomotive with the hinge design described below allowed for proof-of-concept 

evaluation. 

5.1 Existing Rear Door Hinge Attachment 

The current design practice for the modern locomotive rear door employs either two-hinge or 

three-hinge construction. Generally the rear door opens outward, for both narrow nose and wide 

nose freight locomotives. Figure 63 shows the interior view of a cab rear door of a GE AC4400 

locomotive in the open position. This figure shows that the hinge line is outside the cab and one 

leaf of each hinge is welded to the cab structure. The other leaf of each hinge attaches to the rear 

door with two fasteners, which are spot-welded from inside the cab. Some free space is available 

on the inner side of the door and could incorporate this secondary egress mechanism. 

Figure 63. Interior view of the existing locomotive rear door at a test facility 

5.2 Design Concept 

Figure 64 schematically shows the conceptual design for the emergency door hinge release 

mechanism. A single fastener bolt holds the door side leaf of each hinge firmly in place inside a 

machined slot in the hinge mounting block. The machined block is welded to the edge of the 

door panel, and the leaf of the hinge is assembled under spring loaded condition with the help of 

four compression springs held in blind holes of the block. The fastener-nut is tightened from 

inside the door over the sliding bar with machined key-hole slots. The emergency hinge release 
60

handle attaches to the sliding bar with a pin joint for simultaneous release of both fastener nuts, 

which in turn release the hinge leaves. The detachable hinge system is installed into position 

with the door as a subassembly. While carrying out this subassembly, care should be taken to 

ensure proper alignment between the centerlines of the acorn fastener nuts and the key-hole slots 

on the sliding bar. Some locomotives, like the GE AC4400, have three hinges, while other 

locomotives, like the GM EMD SD70MAC, have two hinges to support the weight of the rear 

door, as well as to maintain proper seal compression on the hinge side of the rear door. 

Addressing this issue effectively requires two stronger and sturdier hinges than those presently 

used in either type of locomotives. 

Figure 64. Conceptual design for locomotive rear door hinge release mechanism 

Under emergency egress conditions, the crew inside the cab could activate the door hinge release 

mechanism by removing the locking pin from the handle keeper and pushing down the release 

handle located at the inner side of the door. The actuation of this handle would make the sliding 

bar move upward. When the fastener nut positions coincide with the large diameter key-hole 

slots, the tension on the bolts releases, and the hinge leaves outside of the door swing outward, 

thereby disengaging the fastener bolts. The crew could then push the hinge side of the door out 

of the way and escape. 

If the crew is injured or for some other reason is unable to exit on its own, the emergency rescue 

team may approach the cab from outside. With the knowledge of the specially designed 

removable hinge-pins (see 5.3.4), the team can easily remove the pins, separate the two leaves of 

the hinges, and remove the door to evacuate the crew to safety. 
61

5.3 Design of Rear Door Hinge Release Mechanism 

The hinge release mechanism consists of two hinge mounting blocks, two hinges, a sliding bar 

with two slotted key-holes, and a hinge release handle along with associated attachment brackets, 

fasteners, and compression springs. In addition, providing easily detachable hinge pins 

facilitates access by the emergency rescue team from outside the cab. 

5.3.1 Hinge Mounting Block 

The main component of the hinge release mechanism is the hinge mounting block. This block 

must be designed and fabricated with steel so that its thickness dimension properly matches the 

hinge side thickness variation of the rear door panel construction of both GE AC4400 and GM 

EMD locomotives. Based on this consideration, the mounting block has two distinct thickness 

zones, as shown in Figure 65. Each rear door in the locomotive requires two blocks. Each block 

has one through-the-thickness hole for a steel fastener bolt and four blind holes for holding in 

position four stiff compression springs. These springs will throw back the hinge leaf once the 

fastener nut is released from inside the door panel. The hinge leaves support the weight of the 

door. These hinge leaves sit in the matched groove made on the mounting blocks. The fastener 

bolt simply holds the hinge leaf tightly in position until it is released from inside. The fastener 

bolt therefore experiences only tensile force due to tightening of the acorn nut and does not carry 

any bending load due to the weight of the door. To prevent corrosion due to long exposure to the 

elements, all the steel components of the door hinge release mechanism should have an 

anticorrosive treatment before subassembly of the rear door. 

Figure 65. Hinge mounting block 
62

5.3.2 Sliding Bar with Slotted Key-Holes 

One 1⁄4-in thick flat steel bar at the inner side of the door facilitates simultaneous release of the 

fastener nuts of the hinges on operation of the emergency hinge release mechanism. This bar has 

large size key-hole shaped cutouts at precise positions that match the relative position of the 

hinges on the rear door of the locomotive. The bar is guided to move only in the vertical (up or 

down) direction and not sideways. Figure 66 shows the sliding bar. 

A pin joint connects this sliding bar to a lever or release handle. When engaged, the release 

handle makes the sliding bar move up vertically so that the fastener nuts, which are normally 

tightened on the narrow slot of the key-hole, slide into the large circular hole (oversized for the 

diameter of the fastener nut). The spring action of the four compression springs, located inside 

blind holes under the hinge leaf, pushes outward on the hinge leaf. 

Figure 66. Details of the sliding bar used in hinge release mechanism 

5.3.3 Hinge Release Handle 

A handle made of flat steel bar, which is located at the inside of the locomotive rear door, 

activates the emergency hinge release mechanism. This handle is attached at one end to the 

sliding bar with a slotted key-hole with the help of a pin joint. A pivot arrangement, about which 

it can rotate in order to move the sliding bar up for the release of hinges, strongly supports the 

lever. The handle design offers a large mechanical advantage, which means that the crew would 

have to exert a small force at the free end of this lever to activate the hinge release mechanism. 

The force to be applied to this lever depends on the torque with which the fastener nuts located 

on the sliding bar are tightened to ensure rigidity of the door support. In order to prevent any 

accidental or inadvertent movement of the release handle during normal operation of the 

locomotive, a handle keeper block, along with associated hardened and spring-loaded locking 

pin, is part of the design. Figure 67 depicts the exterior view of a door hinge in the assembled 

position and attached to the release mechanism inside with a single sturdy fastener bolt. Figure 

68 provides a closeup view of the release handle attachment to the sliding bar. 
63

Figure 67. Exterior view of a hinge 

subassembly attached to the release 

mechanism with one sturdy fastener bolt 

Figure 68. Closeup view of the release 

handle attachment to the sliding bar 

5.3.4 Door Hinge with Detachable Pin 

The locomotive rear door hinges, presently employed in different types of locomotives, have 

small size leaves of relatively low thickness (about 0.125 in). These hinges appear strong 

enough to support the weight of the door over the cab’s lifetime, despite rough usage. The 

precise alignment required for simultaneous disengagement of the hinge leaves necessitates the 

use of two sturdier steel hinges of relatively larger size and higher leaf thickness. 

In view of the requirement of this innovative design that the leaves of the two hinges must 

support the weight of the door, the selected hinges must be relatively large and sturdy. For this 

reason, the design uses 0.25-in thick, 4.0-in height, and 4.0-in wide (each leaf) steel hinges. The 

hinge pin diameter is 0.5 in. One leaf of each hinge attaches to the door with one sturdy steel 

fastener bolt of 0.375-in diameter. During the door subassembly, the fastener bolt in the 

assembled state compresses four compression springs by 0.25 in inside the blind holes 0.5-in 

deep, located on the exterior part of the hinge block. Welding of the other leaf of each hinge to 

the body of the cab occurs at the time of final door assembly as is currently done. 

Hinge pins that are easily removable from the cab exterior will facilitate access by emergency 

responders. These hinge pins are made of round cylindrical steel bars with a machined cap at 

one end. The other end of each hinge pin has a 0.3125-in diameter reamed hole. A pin-insert of 

0.313-in diameter and 0.5-in length with a built-in cap of 1.25-in diameter fits into the reamed 
64

hole in the hinge pin with interference. An additional step has been provided in this pin-insert 

just underneath the cap with a diameter of 0.625 in and a length of 0.25 in. Using a crow bar or 

any other narrow-tipped tool, the emergency response team can easily remove the hinge pins. 

The other end of the hinge pin has a built-in cap of 1.125-in diameter. The small pin-insert fits 

into the top end of each hinge pin with interference-fit after assembly of the two leaves of the 

hinge. Dipping the small pin-inserts in liquid nitrogen (available in small portable bottles or 

cylinders) for about 15 min before insertion into the reamed holes of the hinge pin eases the 

insertion. Under normal ambient temperature conditions, the hinge pins will expand to attain 

press-fit condition and will function as if the hinge pin is fitted with rigid end caps. Figure 69 

shows a photograph of two sample hinge pins, one in partially assembled position and the other 

with its small pin-insert in detached condition. 

Figure 69. Hinge pins and the interference fit small pin-inserts with cap 

In emergency conditions, the rescue team would need only a small crow bar or a similar narrowtipped tool to forcibly dislodge the pin-insert from the hinge pin and then hammer down the 

hinge pin with the same tool, so as to separate the leaves of the door hinges to enter inside the 

cab. 

5.4 Considerations for the Modification to Locomotive Rear Door 

Incorporating removable door hinges will require minor modifications to the existing rear door 

design and fabrication process. Building the new doors with the proposed emergency egress 

features uses the smallest number of modifications possible. Most of the standard parts, like 

compression springs, nuts, and bolts, are commercially available. 

The rigidly fixed steel hinges of the rear door in the present design require modification to be 

mechanically detachable for emergency egress. One alteration to the rear door fitting is to make 

provision for two relatively larger and sturdier hinges in place of three small hinges presently 

employed in GE-AC4400 locomotives. In GM EMD locomotives, the two relatively smaller 

hinges must be replaced with two sturdier ones, as proposed here. Installing the two new hinges 

near the top and bottom parts of the rear door requires two cutouts to accommodate the hinge 

mounting blocks (shown in Figure 65). The steel blocks are welded to the door panel at the 

cutouts, and a sturdy fastener bolt clamps one leaf of each hinge to the block. 
65

5.5 Proof of Concept 

A fabricated rear door with the hinge release mechanisms provided the means to evaluate the 

functionality of the hinge system. The door specifications are those of a GE AC4400 

locomotive. The researchers installed the door and hinge release mechanism on a simple test rig 

that simulated a rear door frame. Figure 70 shows the exterior view of the door and hinge 

system in the test rig. The proof-of-concept evaluation involved verifying the functionality of 

the removable hinges from the simulated cab interior and exterior. Additional figures illustrate 

the results of this evaluation. 

Figure 70. Exterior view of an assembled rear door on the test rig 

Figure 71 shows a closeup view of one assembled door hinge, as seen from outside the cab. 

Figure 72 shows the interior view of the door with most of the components of the hinge release 

mechanism in assembled condition. Installation of the handle keeper occurred after the 

photograph was taken. 
66

Figure 71. A closeup view of one hinge in assembled condition 

Figure 72. Interior view of the rear door with hinge release handle in assembled condition 
67

As described earlier, the two sturdy leaves of two hinges support the weight of the door. The 

fastener bolts clamp the hinge leaves into the machined groove of the hinge mounting blocks. 

The fastening acorn nuts sit on the narrow slot of the keyhole in the sliding bar. During 

installation, use of a torque wrench assures that this nut is properly tightened, as shown in Figure 

73. 

Figure 73. Closeup view of an acorn nut assembled on the narrow slot of the key-hole in 

the sliding bar 

Figure 74 shows an interior view of the door and the initial actuation of the hinge release 

mechanism. Figure 75 illustrates the final position of the hinge release lever on completion of 

the actuation. Figure 76 shows a closeup view of the disengaged fastener nut inside the circular 

key-hole, and Figure 77 shows an exterior view of the popped out fastener and the hinge leaf. 
68

Figure 74. Interior view of the door 

showing the actuation of hinge release 

handle 

Figure 75. Final position of the hinge 

release handle after actuation 

Figure 76. Interior closeup view of the released fastener nut 
69

Figure 77. Exterior view of the fastener bolt and hinge leaf released from the hinge 

support block 

Figure 78 shows the exterior view of the hinge support block after detachment of the hinge leaf. 

Under accident conditions, on release of both the fastener bolts and the hinge leafs, the 

crewmembers can easily separate the cab rear door from the two hinges and then leave the cab 

through the rear door opening. 

Figure 78. Closeup exterior view of a hinge support block after detachment of the hinge 

leaf 

Figures 79 and 80 illustrate the procedure for external removal of the door. Figure 79 shows the 

method to be followed for removal of the interference fit insert to the hinge pin. The rescue team 
70

needs to use only a small crow bar or any other tool with a narrow tip to disengage the insert atop 

the hinge pin as shown in Figure 79. Finally, Figure 80 shows the hinge pin removal from the 

door hinge. With both the hinge pins removed, the rescue team can move the hinge side of the 

door out of the way, enter the cab, and carry the crew to safety. 

Figure 79. Removal of the pin-insert from 

the hinge pin 

Figure 80. Removal of the hinge pin before 

separation of the rear door 

5.6 Long-Term Functionality and Maintenance Considerations 

In principle, the emergency egress mechanisms incorporated into a locomotive cab are for use 

only in the event of an emergency arising out of an accident or crash that leads to normal cab 

entry and exit routes being blocked or disabled. Since railroad locomotives are in service for 20 

to 30 yr, long-term functionality and routine maintenance are concerns. Therefore, the 

components of the rear door hinge release mechanism are rugged and heavy duty. 

Exterior components exposed to the elements require anticorrosive treatment consistent with 

current practice for locomotive construction. This together with periodic preventive mechanical 

maintenance should ensure long-term functionality of the rear door hinge release mechanism. 

Installing a prototype system into an operational locomotive is the appropriate way to evaluate 

the system’s performance under normal operating conditions. This may be a part of a future 

program. 

Regarding the frequency and cost of required maintenance, the existing routine maintenance 

schedule for the mechanical components of the locomotive should suffice. The extra effort 

necessary to maintain these components would include using a torque wrench to check the 

tightness of the two acorn nuts assembled with a lock washer. These nuts may need resetting to 

the prescribed torque value, followed by light lubrication of the hinges in metallic components 

assembled inside the door. The estimated time to accomplish the above maintenance should not 

be more than an hour during scheduled routine maintenance of the locomotive. As a fail safe 

approach, however, it is recommended that once a year, the hinge release mechanism be 

activated during the mechanical maintenance and all the components be reassembled after a 

thorough cleaning of all parts. This process would involve two technicians and no more than 

2 h. 
71

6. Key Findings and Recommendations 

Construction of the prototype hatch egress system and subsequent usability testing demonstrated 

the feasibility of this approach as a viable means of emergency egress from a locomotive cab. 

Similarly, the design and construction of proof-of-concept prototypes for the removable 

windshield and removable rear door hinges illustrated the engineering feasibility of these 

concepts. This section presents the key findings of the developmental work and suggests how 

future research can further these concepts toward incorporation in road freight locomotives. 

6.1 Key Findings 

Since the focus of this work was on three separate egress options, the following describes the 

findings separately with respect to each option. 

• Hatch system–The hatch system, including the hand/footholds and complementary 

photoluminescent lighting, is usable by both crewmembers and emergency responders as 

designed. The system provides a viable means of exit for crewmembers following a 

crash. Similarly, emergency responders demonstrated that they could successfully 

remove an injured crew member via the hatch. Based on the usability tests, an exterior 

foothold would be a beneficial addition as it would aid emergency responders in entering 

through the hatch. Before installing the hatch system in a working locomotive, however, 

several engineering design issues merit exploration. The hatch requires testing to 

establish resistance of its seal to air and water leaks. In addition, the hatch requires a 

separate test to evaluate the effect of vibration on the latching mechanism. 

• Removable windshield–The double cutting loop method for removing the windshield 

from the cab interior appears feasible. The proof-of-concept test found that, using this 

method, a crewmember can remove the windshield without excessive force in a matter of 

minutes. The installation process used for the proof-of-concept testing, however, was 

time consuming. In addition, if the cutting wire was not carefully placed in the gasket 

groove, the wire would not function properly. This egress option may be relatively 

inexpensive to install on current locomotives because it requires only substitution of a 

modified gasket, available at the same cost as current gaskets. 

• Removable door hinges–The hinge release mechanism, initially intended for all three 

door hinges, appears to function properly when the door has only two hinges. The design 

appears suitable for retrofit on existing doors. Additional testing and installation in a 

working locomotive will determine if the day-to-day use of the door will compromise the 

functionality of the release mechanism. 

6.2 Recommendations for Future Research 

The results of the research described in this report suggest areas for further research relative to 

improved emergency egress for locomotive crews. The following discusses these areas. 

Refine hatch system design 

The results of the usability tests suggest several potential refinements in the hatch system design. 

The issues that merit investigation include alternate placement of the exterior grab irons, the size 
72

of the opening, exterior hand/footholds to facilitate entry, and exterior markings to aid 

emergency responders in locating the hatch. The photo luminescent lighting might prove to be a 

distraction to the train crew during nighttime operation. Testing in a road locomotive would 

determine whether or not this will be problematic. 

Several engineering design issues also remain to be explored. Testing of the hatch seal for its 

ability to prevent either air or water leaks has not yet occurred. Noise insulation must also be 

added so that the noise level in the cab does not increase. Over time the vibration of the 

locomotive may compromise the performance of the latching mechanism. This potential 

problem requires investigation. 

Test hatch system and secondary egress equipment under partial rollover condition 

To date, tests of the prototype egress equipment have involved either an upright locomotive or a 

90° rollover. Since a locomotive may become partially toppled, perhaps at 45°, following a 

crash, it is desirable to assess the functionality of the hatch system and the secondary egress 

equipment in this configuration. These tests will require a special test fixture that rotates the 

mockup. 

Conduct usability tests for removable windshield and door hinges 

Usability testing to date has focused on the hatch system. Both the removable windshield and 

the door hinge system require the same type of assessment. As was done with the hatch system, 

both locomotive crewmembers and emergency responders should be participants in these 

usability tests of the door hinges. Since the removable windshield is designed for use by 

crewmembers, only these individuals will participate in the usability test. 

Conduct usability tests under partial rollover condition 

Once the hatch system and the secondary egress equipment have performed satisfactorily in a 

partial rollover configuration, additional usability tests will be possible for this scenario. 

Obtain and incorporate industry feedback 

Locomotive builders, the railroad industry, railroad labor, and FRA all have an interest in 

emergency egress. Deployment of any of the three emergency egress concepts requires review 

and acceptance from all four groups. At this point in the development of the three concepts, it is 

important to get feedback from each group and refine the designs to address their concerns. 

Meetings with each stakeholder group can provide a forum to discuss a range of issues, such as 

operability in critical or hazardous situations, the cost impacts to install and maintain the 

equipment, structural considerations, and necessary changes to installation and maintenance 

procedures. 

Validate functionality of windshield and hinges under accident conditions 

The intended use of the removable windshield and removable door hinges is under accident 

conditions. Testing can validate the functionality of these devices under these conditions. A 

crash test will validate that the modified gasket does not cause the window to release as the result 

of a crash and that the window can be released from the cab interior following a crash. Similarly 

a crash test that involves structural damage to the rear door frame will validate the utility and 

functionality of the hinges. 
73

Examine retrofit to existing equipment 

The hatch system was designed for installation in a new locomotive. Installation in existing 

equipment may also be feasible, but this possibility remains to be examined. The primary issue 

appears to be relocation of wiring harnesses currently in the roof and any equipment, such as 

global positioning systems, installed on the roof. In terms of the removable windshield and the 

removable door hinge, these are likely to be less problematic when installed on existing 

locomotives. Assessing the feasibility of retrofitting each of the three innovative egress devices 

requires consideration of both structural and cost issues. Consideration of cost includes material 

and installation expense, as well as periodic maintenance over the life of the equipment. 

Investigate smart technologies to enhance egress options 

Advances in Intelligent Transportation Systems and sensors offer the technology to create 

systems that automatically detect and self-actuate in the event of a crash. By drawing on 

available components and systems, application of these smart technologies to the locomotive 

environment should require minimal development. Concepts that merit exploration include: 

• Communication system that automatically notifies the dispatcher and emergency rescue 

personnel of the crash. 

• Exterior warning lights to assist rescue personnel in locating the locomotive at the crash 

site. 

• Automatic dislodging of the side window for egress in the presence of smoke. 

• Automatic release of masks with fresh air flow for crew survivability in the event of 

smoke in the cab. 

75

7. References 

Carter, J., Gertler, J., Acton, S. & Kokkins, S. (2003). Evaluation of Concepts for Locomotive 

Crew Egress. (DOT/FRA/ORD-03/07). Washington, DC: Federal Railroad Administration. 

Federal Railroad Administration Office of Safety. (1996). Locomotive Crashworthiness and 

Cab Working Conditions, Report to Congress. Washington, DC: Federal Railroad 

Administration. 

Kokkins, S.J. (2002). Locomotive Crashworthiness Research: Locomotive Crew Egress 

Evaluation. (DOT/FRA/ORD-02/03). Washington, DC: Federal Railroad Administration. 

Young, W.C. (1989). Roark’s Formulas for Stress and Strain, 6th edition. New York: McGraw 

Hill. 

77

Appendix A. 

Informed Consent 

- INFORMED CONSENT - 

PARTICIPATION IN A RESEARCH STUDY 

You have been asked to participate in a research study. In this document we explain the nature 

of your participation, describe your rights, specify how your experimental data will be treated, 

and obtain your consent for participation. 

1. Overview of the Study 

Title: Usability of a roof-mounted escape hatch system as means of egress from a toppled 

locomotive. 

Sponsor: Federal Railroad Administration (FRA), Office of Research and Development, 1120 

Vermont Ave. NW, Washington, DC 20590. 

Organization Performing the Research: Foster-Miller, Inc., 350 Second Avenue, Waltham, MA 

02451. 

Investigators: Judith Gertler (Principal Investigator), Alex Viale (Co-Investigator), Sarah Acton 

(Co-Investigator) 

2. Purpose 

The purpose of your participation in this study is to help Foster-Miller evaluate a new roofmounted escape hatch system as a means of egress from a toppled locomotive. You will be 

asked to exit (enter and exit if you are an emergency response person) the locomotive quickly 

and safely, and lower yourself to the ground. You will be asked to repeat this task under a 

number of different conditions. While we are seeking information regarding the amount of time 

it takes you to exit (enter and exit for emergency response crew) the locomotive, we are mainly 

concerned with your safety, and the usefulness of the system, as well as any suggestions you may 

have for improvements. 

3. Procedures 

1. Timeline: Your participation in this study will last approximately 45 minutes. 

2. Requirements for participation: As a participant in the study, you will be asked to do the 

following after signing the Informed Consent: 

(a) First, you will be asked to complete a brief background survey that asks your age, gender, 

height, weight, job title, and years of work experience. Such information, as it relates to you, 

will be kept confidential pursuant to the confidentiality section below. Please do not write your 

name on this document. 

(b) Next, you will be briefed on what you can expect from participating in this study. 

(c) You will then be escorted to the locomotive mockup. In order to simulate an accident 

scenario, and possible disorientation, we will ask you to put on a blindfold, and a researcher will 
78

assist you with turning around twice and sitting you down on the floor of the cab. Next, you will 

be asked to remove the blindfold, escape through the roof hatch, and lower yourself to the 

ground. You will be asked to perform this task under a number of different conditions. At all 

times, your performance will be recorded with the use of video taping equipment. This will 

in no way jeopardize your confidentiality, and is simply done in order to capture each 

performance in the event it requires referencing at a later time. Remember, that although we are 

interested in how efficiently you can exit the locomotive, your first priority should be to perform 

this task safely. 

(d) At the conclusion of each trial, you will be asked to complete a brief survey that contains 

questions pertaining to your tasks. You will also be asked to complete an exit survey, soliciting 

your suggestions for improvements to the hatch system. 

4. Risks and Procedures for Termination of Participant 

Due to the careful planning and ergonomic design of the roof-hatch, tether line safety system, 

hand/footholds, grab irons, and the use of photoluminescent egress materials, no injuries are 

anticipated while participating in this study. However, there is always the slightest chance for 

injury. Possible injuries may relate to: disorientation, bumping into something in the lowvisibility (darkness) scenario, bumping one’s head upon entrance or exit of the hatch; losing grip 

of the grab irons and landing on the ground; or turning an ankle when lowering oneself onto the 

ground. If you sustain any type of injury, or feel any discomfort whatsoever, you may 

discontinue your participation at any time by simply telling the experimenter you wish to stop. 

Further, the investigators will monitor your activity throughout each trial, and will be in 

immediate proximity to you at all times (one researcher inside the locomotive cab, and one just 

outside the cab). Investigators will look for any signs of injury or discomfort and will stop the 

trials immediately if any of these signs present themselves. In the unlikely event you are 

injured, we will transport you to the nearest hospital emergency room, or call 911 (if 

necessary), but you are responsible for the treatment and care of said injury and agree to 

release us from any responsibility related to said injury. 

5. Benefits 

You will benefit from the study by taking part in an investigation that may improve the safety of 

locomotive operations, which ultimately may result in a reduction in fatalities, injuries and 

associated costs. After the study has been completed and the results are analyzed, a final report 

will be provided to the Office of Research and Development of the Federal Railroad 

Administration. You may view the report by contacting any of the Foster-Miller investigators 

for a copy of the report. Contact information is provided at the bottom of this form. 

6. Compensation 

There is a $60 compensation for your participation in this research. This will be awarded to you 

upon completion of all tasks, or in the event you wish to withdraw from the study due to an 

injury you sustained during your participation. 

7. Confidentiality 

We will be collecting a variety of data as part of your participation in this study today. These 

data include paper-based questionnaires and performance data, and a video recording of your 

performance. As a participant in this study, you will be assigned a unique identification number 

which is known only to you and the investigators from Foster-Miller, Inc. We will use this 
79

unique identification number to match your performance data with the paper-based forms that 

you fill out and the video recording of your performance. Your name will not be recorded 

anywhere except on this consent form and a spreadsheet that Foster-Miller will use to manage 

the study. All of these data will be maintained by Foster-Miller, Inc. and will be kept strictly 

confidential. In the event of any publications or reports on this study, your identity will not be 

disclosed. We will not provide any information on your participation to the Federal Railroad 

Administration (FRA), Brotherhood of Locomotive Engineers (BLE), United Transportation 

Union (UTU), or any other party to the extent permitted by law. 

8. Research-Related Injury Coverage 

Your participation in this research study should not result in any physical discomfort or injury to 

you. Again, in the unlikely event you are injured, we will transport you to the nearest 

hospital emergency room or call 911 (if necessary), but you are responsible for the 

treatment and care of said injury and agree to release us from any responsibility related to 

said injury. 

9. Voluntary Participation 

Your participation is voluntary and you may withdraw from participation in the study at any time 

by simply telling the experimenter you wish to stop. All information collected will still be held 

strictly confidential. 

10. Questions 

You may contact the Foster-Miller investigators at any time with questions you have about the 

study or the conditions of your participation as a research participant. The investigators are: 

 Judith Gertler Principal Investigator 781-684-4270 

 Alex Viale Co-Investigator 781-684-8444 

 Sarah Acton Co-Investigator 781-684-4281 

11. Consent and Signature 

I have read and understand the requirements of my participation in this study as described in this 

Informed Consent, as well as my rights to refuse to participate or to stop participating at any 

time. I am fully aware that my participation will be recorded on video tape and expressly 

consent to such recording. I understand the possible risks and discomforts I may experience and 

the possible benefits to me and to others as a result of this research. I also understand that the 

information collected about me will be kept confidential. Any questions I had have been 

answered, and I agree to voluntarily cooperate and participate in good faith. 

Name (print): _______________________________________ 

Signature: __________________________________________ Date: ____________ 

Signature of witness: __________________________________ Date: ____________ 
80

 Background Survey 

Unique ID: Date: 

1. Gender (circle one): Male Female 

2. Age: 

3. Height: _______________ 

4. Weight: ______________ 

5. Job Title: _____________________________________ 

6. Number of years experience at this type of work: 
81

Appendix B. 

Post-Scenario Survey

(Emergency Response Personnel) 

ID#_______ Date_______ 

Instructions: 

To help us in making future decisions about the design of the hatch system, please take a few minutes to 

complete the following survey. Some questions will ask you to respond using a five-point scale. Please 

select and circle one of the five numbers on the scale that best corresponds to your response. 

Descriptions of each number are provided directly underneath the scale. We will use these results to gain 

additional insight into hatch system design. If you have any questions, please do not hesitate to ask the 

researcher for assistance. Thank you! 

 1. How difficult or easy was it to determine how to open the roof hatch? 

 1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

 2. How difficult or easy was it physically to open the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

 

 

 3. How difficult or easy was it to enter the cab through the roof hatch?

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

4. Did you use the grab irons (on the outside of the locomotive) to help you 

 enter the locomotive? 

 No ______ Yes ______

 

If you used any of the grab irons, how ineffective or effective was their 

placement? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither ineffective somewhat extremely 

 ineffective ineffective or effective effective effective 

 Please explain your answer: 
82

5. How difficult or easy was it to determine how to operate the hand/footholds? 

 1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

6. Please check off which hand/footholds you used (if any) during entrance 

 entrance and exit. 

 

Entrance Exit

 Highest hand-foot-hold (above the hatch) 

 Middle hand-foot-hold (just below hatch) 

 Lowest hand-foot-hold (very bottom) 

 

If you used any of the hand/footholds, how ineffective or effective was their 

placement? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither ineffective somewhat extremely 

 ineffective ineffective or effective effective effective 

 Please explain your answer: 

7. How difficult or easy was it physically to maneuver the hand/footholds into a 

usable position? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

8. How difficult or easy was it to exit the cab through the roof hatch (with 

 full gear and an injured person)? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 
83

9. Did you use the grab irons (on the outside of the locomotive) to help you 

 exit the locomotive, and/or lower yourself to the ground? 

 

 No ______ Yes ______

 

If yes, how ineffective or effective was their placement? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither ineffective somewhat extremely 

 ineffective ineffective nor effective effective effective 

 

 Please explain your answer: 

10. Overall, do you feel that this new system is an effective way of entering a 

toppled locomotive? 

 No_____ Yes_____ 

11. Overall, do you feel that this new system is an effective way of exiting a 

toppled locomotive (with full gear and an injured person)? 

 No_____ Yes_____ 
84

Post-Scenario Survey 

(Crew Survey – Light 1st, Dark 2nd, Part I) 

ID#_______ Date_______ 

Instructions: 

To help us in making future decisions about the design of the hatch system, please take a few minutes to 

complete the following survey. Some questions will ask you to respond using a five-point scale. Please 

select and circle one of the five numbers on the scale that best corresponds to your response. 

Descriptions of each number are provided directly underneath the scale. We will use these results to gain 

additional insights into hatch system design. If you have any questions, please do not hesitate to ask the 

researcher for assistance. Thank you! 

1. How difficult or easy was it to determine how to operate the hand/footholds? 

 1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

2. Please check off which hand/footholds you used (if any) during exit: 

 

Highest hand-foot-hold (above the hatch) 

Middle hand-foot-hold (just below hatch) 

Lowest hand-foot-hold (very bottom) 

 If you used any of the hand/footholds, how ineffective or effective was their 

placement? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither ineffective somewhat extremely 

 ineffective ineffective or effective effective effective 

 Please explain your answer: 

3. If you used any of the hand/footholds, how difficult or easy was it physically

to maneuver them into a usable position? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

4. How difficult or easy was it to determine how to open the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 
85

5. How difficult or easy was it physically to open the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

6. How difficult or easy was it to exit the cab through the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

7. Did you use the grab irons (on the outside of the locomotive) to help you 

 exit the locomotive, and/or lower yourself to the ground? 

 

No ______ Yes ______ 

 If yes, how ineffective or effective was their placement? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither ineffective somewhat extremely 

 ineffective ineffective or effective effective effective 

 

Please explain your answer: 

8. Overall, do you feel that this new system is an effective method of 

 exiting a toppled locomotive? 

 No_____ Yes_____ 

 

9. Do you feel that the roof hatch, hand/footholds, or grab irons would, in 

 any way, interfere with the normal everyday operations of the locomotive? 

 No______ Yes______ 

 If yes, how so: 
86

Post-Scenario Survey 

(Crew Survey cont... – Light 1st, Dark 2nd, Part II) 

ID#_______ Date_______ 

1. How visible were the hand/footholds (during the darkened condition)? 

 1--------------------------2--------------------------3--------------------------4--------------------------5 

 not visible not very visible neither invisible somewhat visible extremely visible 

 at all or visible 

2. How visible was the roof hatch (during the darkened condition)? 

 1--------------------------2--------------------------3--------------------------4--------------------------5 

 not visible not very visible neither invisible somewhat visible extremely visible 

 at all or visible 

3. How visible were the operational instructions of the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 not visible not very visible neither invisible somewhat visible extremely visible 

 at all or visible 

4. If you attempted different methods of exiting the locomotive (head-first / 

 both feet-first, one leg at a time), which method did you find the most 

 effective? 

 Head First _______ Both Feet First _______ One leg at a time _______ 

5. Overall, do you feel that this new system is an effective method of 

 exiting a toppled locomotive? 

 No_____ Yes_____ 
87

Post-Scenario Survey 

(Crew Survey - Dark 1st, Light 2nd, Part I) 

ID#_______ Date_______ 

Instructions: 

To help us in making future decisions about the design of the hatch system, please take a few minutes to 

complete the following survey. Some questions will ask you to respond using a five-point scale. Please 

select and circle one of the five numbers on the scale that best corresponds to your response. 

Descriptions of each number are provided directly underneath the scale. We will use these results to gain 

additional insights into hatch system design. If you have any questions, please do not hesitate to ask the 

researcher for assistance. Thank you! 

1. How visible were the hand/footholds? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 not visible not very visible neither invisible somewhat visible extremely visible 

 at all or visible 

2. How difficult or easy was it to determine how to operate the hand/footholds? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

3. Please check off which hand/footholds you used (if any) during exit: 

Highest hand-foot-hold (above the hatch) 

Middle hand-foot-hold (just below hatch) 

Lowest hand-foot-hold (very bottom) 

 If you used any of the hand/footholds, how ineffective or effective were their 

placement? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither ineffective somewhat extremely 

 ineffective ineffective or effective effective effective 

 Please explain your answer: 

4. If you used any of the hand/footholds, how difficult or easy was it to 

physically, to maneuver them into a usable position? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

5. How visible was the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 
88

6. How visible were the operational instructions of the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

7. How difficult or easy was it to determine how to open the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

8. How difficult or easy was it physically to open the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

9. How difficult or easy was it to exit the cab through the roof hatch? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither difficult somewhat extremely 

 difficult difficult nor easy easy easy 

10. Did you use the grab irons (on the outside of the locomotive) to help you 

 exit the locomotive, and/or lower yourself to the ground? 

 

 No ______ Yes ______ 

 If yes, how ineffective or effective were their placement? 

1--------------------------2--------------------------3--------------------------4--------------------------5 

 extremely somewhat neither ineffective somewhat extremely 

 ineffective ineffective or effective effective effective 

 Please explain your answer: 

11. Overall, do you feel that this new system is an effective method of 

 exiting a toppled locomotive? 

 No_____ Yes_____ 

12. Do you feel that the roof hatch, hand/footholds, or grab irons would, in 

 any way, interfere with the normal everyday operations of the locomotive? 

 No______ Yes______ 

 

 If yes, how so: 
89

Post-Scenario Survey 

(Crew Survey cont... - Dark 1st, Light 2nd, Part II) 

ID#_______ Date_______ 

1. If you attempted different methods of exiting the locomotive (head-first, both 

 feet-first, one leg at a time), which method did you find the most effective? 

 

2. Overall, do you feel that this new system is an effective method of 

 exiting a toppled locomotive? 

 No_____ Yes_____ 

91

Appendix C. 

Data Sheet 

 (Emergency Response Personnel) 

ID#_______ Date_______ 

1. Time to enter and exit

Lighted 

Condition 

Time (2 people): 

Time (3 people): 

Time (4 people): 

Time (5 people): 

2. Researcher Comments

 Condition 1: 

3. Comments or suggestions regarding the grab irons? 

4. Comments or suggestions regarding the hatch? 

5. Comments or suggestions regarding the hatch markings? 

6. Comments or suggestions regarding the hand/footholds? 
92

Data Sheet 

(Crew Personnel) 

ID#_______ Date_______ 

1. Time to exit 

Condition 1 Condition 2 Condition 3 Condition 4 

Time 

2. Researcher Comments

 Condition 1: 

 Condition 2: 

 Condition 3: 

 Condition 4: 

3. Participant Comments

a. Comments or suggestions regarding the grab irons? 

b. Comments or suggestions regarding the hatch? 

c. Comments or suggestions regarding the hatch markings? 

d. Comments or suggestions regarding the hand/footholds? 
93

Appendix D. 

Description of Training Video 

Foster-Miller produced a training video designed to prepare emergency responders to respond to 

a locomotive wreck. The title of this video is “Locomotive Emergency Response Operations.” 

The video helps emergency responders to: 

• Understand the railroad transport system. 

• Assess their coverage area for special risks. 

• Approach a site and enter a locomotive after an accident. 

• Extricate the crew. 

The video explains that a railroad is divided into territories, each under the jurisdiction of a 

dispatcher, who manages that territory from a dispatching center. Signal systems and dark 

territory are also explained. Emergency responders are encouraged to become familiar with the 

railroad operations in their coverage area and to identify any special situations such as bridges, 

tunnels, and track, in difficult to access areas. The various parts of the locomotive—such as the 

fuel tank, high pressure hoses, traction motors, and emergency shut off switches—are illustrated. 

The video suggests the steps to take in responding to a crash and how to approach the site and 

enter the cab. Techniques for extricating the crew are demonstrated in the video. The video 

concludes with an actual worst-case scenario and how the emergency responders managed the 

situation. 

Three handouts accompany the video: (1) checklist of things to do when approach the site, (2) 

checklist of things to do when entering the locomotive, and (3) instructions on railroad flagging 

procedures. 

95

Abbreviations/Acronyms 

AC alternating current 

APTA American Public Transit Association 

ASTM American Society for Testing and Materials 

cd/m2 candela per square meter 

DC direct current 

DIN Deutsches Institute für Normung eV (German Institute for Standardization) 

EMD General Motors Electromotive Division 

fc foot-candle 

FRA Federal Railroad Administration 

ft foot (feet) 

ft-lb foot-pound 

GE General Electric 

h hour 

IMO International Maritime Organization 

in inch 

IRB Institutional Review Board 

LED light emitting diode 

mcd/m2 millicandella per square meter 

min minute 

NFPA National Fire Protection Association 

PVC polyvinyl chloride 

yr year