1 Copyright © 2007 by ASME 

Proceedings of the 2007 ASME Rail Transportation Division Fall Technical Conference 

RTDF2007 

September 11-12, 2007, Chicago, Illinois, USA 

RTDF2007-46013

IMPROVED TANK CAR SAFETY RESEARCH 

David Tyrell 

David Jeong 

Karina Jacobsen 

Volpe National Transportation Systems Center 

Cambridge, Massachusetts, USA 

Eloy Martinez 

Federal Railroad Administration 

Washington, DC, USA 

ABSTRACT 

Three recent accidents involving the release of hazardous 

material have focused attention on the structural integrity of 

railroad tank cars: (1) Minot, ND, on January 18, 2002; (2) 

Macdona, TX, on June 28, 2004; and (3) Graniteville, SC, on 

January 6, 2005. Each of these accidents resulted in fatalities. 

Research is being conducted to develop strategies for 

improving railroad tank cars so they can maintain tank integrity 

in severe accidents. A collaborative effort called the Next 

Generation Rail Tank Car (NGRTC) Project intends to use 

these research results to help develop improved tank car 

designs. Dow Chemical Company, Union Pacific Railroad, and 

Union Tank Car Company are the industry sponsors of the 

NGRTC Project. The Federal Railroad Administration (FRA) 

and Transport Canada participate in the NGRTC project 

through Memoranda of Cooperation. FRA and the Pipeline and 

Hazardous Materials Safety Administration intend to use these 

research results to support rulemaking. 

The approach taken in performing this research is to define 

the collision conditions of concern, to evaluate the behavior of 

current design equipment in these scenarios, and to develop 

alternative strategies for increasing the maximum impact speed 

for which tank integrity is maintained. 

The accident scenarios have been developed from a review 

of accidents and are intended to bound the range of main-line 

accidents that can lead to a release of hazardous material from a 

tank car. The accident scenarios and collision modes have been 

used to define car-to-car impact scenarios. These car-to-car 

impact scenarios define the conditions under which the 

commodity must be contained. The impact scenarios are being 

used to evaluate the integrity of current design and improved 

design tank cars. 

Full-scale impact tests are also being conducted, to help 

validate modeling of the baseline equipment. The models have 

been refined based on the test results. The models are now 

being applied to develop the improved equipment designs. 

This paper describes the overall research framework and 

provides an overview of the research done to date, as well as 

the planned efforts. 

INTRODUCTION 

The safe transport of hazardous materials (hazmat) is a key 

concern of the Federal Railroad Administration (FRA). 

Moreover, the objective of FRA-sponsored research is to 

maintain tank integrity under various loading conditions. Data 

from the FRA’s Railroad Accident and Incident Reporting 

System (RAIRS) show that the number of accidents per year 

with at least 1 car releasing hazardous materials has decreased 

significantly over the past 25 years (Figure 1). The decrease is 

attributed to improvements in tank car designs and to Federal 

regulations that instituted requirements for head shields, 

thermal protection, and double self couplers—each of which 

reduces the likelihood of rupturing a tank car during an 

accident. 

Year

1975 1980 1985 1990 1995 2000 2005

Number of accidents

0

20

40

60

80

100

Figure 1. Number of Accidents with at Least One Car 

Releasing Hazardous Materials 
 2 Copyright © 2007 by ASME 

Although accident statistics show that the rail industry’s 

safety performance has generally improved over the last few 

decades, three recent accidents involving the release of hazmat 

have focused attention on the structural integrity of railroad 

tank cars under extreme or accident loading conditions: (1) 

Minot, ND, on January 18, 2002 [1]; (2) Macdona, TX, on June 

28, 2004 [2]; and (3) Graniteville, SC, on January 6, 2005 [3]. 

Consequently, the focus of FRA tank car safety research shifted 

from maintaining tank integrity under normal tank car 

operating conditions (e.g., metal fatigue and crack propagation) 

to maintaining tank integrity under accident loading conditions. 

In order to evaluate tank performance in accident loading 

conditions, collision dynamics and structural response must be 

considered in addition to material behavior. Figure 2 shows a 

timeline of events related to railroad tank car safety since the 

Minot accident in 2002 to the present. 

An industry research and development effort began in 

2006, called the Next Generation Rail Tank Car (NGRTC) 

Project [4]. Dow Chemical Company, Union Pacific Railroad 

(UP), and Union Tank Car Company (UTLX) are the sponsors 

of this collaboration. In 2006, FRA and the Pipeline and 

Hazardous Materials Safety Administration (PHMSA) initiated 

a Notice of Proposed Rulemaking (NPRM) for transporting 

hazmat by railroad tank cars [5]. 

Government and industry-sponsored research is being 

conducted to develop strategies for improving railroad tank 

cars so they can maintain tank integrity for more severe 

accident conditions than current equipment. FRA and PHMSA 

intend to use these research results to support rulemaking, and 

the NGRTC Project intends to use these research results to help 

develop improved tank car designs. FRA and Transport 

Canada also participate in the NGRTC Project through 

Memoranda of Cooperation (MOC). The Volpe National 

Transportation Systems Center (Volpe Center) is providing 

technical support to FRA in the rulemaking process and the 

NGRTC Project. As described in the press release issued by 

FRA on January 16, 2007 [6]: 

[FRA Administrator Joseph H.] Boardman said the FRA 

has signed a Memorandum of Cooperation (MOC) with Dow 

Chemical Company, Union Pacific Railroad and the Union 

Tank Car Company to participate in their Next Generation Rail 

Tank Car Project. The agreement provides for extensive 

information sharing and cooperation between ongoing FRA 

and industry research programs to improve the safety of rail 

shipments of hazardous commodities such as toxic inhalation 

hazards and high-risk gases and liquids. 

 This paper describes the overall approach for this 

research, as well as the necessary tasks and the organizations 

which will perform the tasks. Companion papers describe 

ongoing modeling [7, 8] and full-scale testing [9], as well as 

tank car design strategies for improving protection of the 

commodity [10]. 

. 

August 2006

Dow, UP, and UTLX announce 

NGRTC project at 

FRA/PHMSA Public Meeting

2002 2003 2004 2005 2006 2007 2008

FRA/Volpe Tank Car Safety Research:

Damage Tolerance and Fatigue Crack Growth Extreme/Accident Loading Conditions

January 18, 2002

Minot, ND

August 2005

President signs 

SAFETEA-LU

January 16, 2007

FRA signs Memorandum of 

Cooperation with Dow, UP, 

and UTLX

December 14, 2006

FRA/PHMSA Public Meeting

Support for NPRM and NGRTC

January 6, 2005

Graniteville, SC

November 16, 2006

FRA/PHMSA initiate NPRM

May 31-June 1, 2006

FRA/PHMSA Public Meeting

March 30, 2007

FRA/PHMSA Public Meeting

June 28, 2004

Macdona, TX

April 26, 2007

Full-Scale Shell 

Impact Test 1

Figure 2. Timeline of Events Related to Railroad Tank Car Safety
 3 Copyright © 2007 by ASME 

Figure 3. Research Steps to Develop Improved Tank Car Design 

APPROACH 

The approach taken in performing this research is to define 

the collision conditions of concern, to evaluate the behavior of 

current design equipment in these scenarios, and to develop 

alternative strategies for increasing the impact speed associated 

with maintaining tank integrity in these scenarios. The 

evaluations of the current equipment and alternative strategies 

are being accomplished iteratively, with analytic models of 

increasing complexity. Full-scale impact tests are also being 

planned, in part to help validate modeling, as well as to directly 

compare the effectiveness of current and alternative equipment 

designs. Figure 3 shows a schematic representation of the 

research steps. 

Definition of Problem: Generalized Accident and 

Impact Scenarios

The accident scenarios involving hazardous material 

release from tank cars have been developed from a review of 

accidents. These are intended to bound the range of accidents 

that can lead to a release of hazardous material from a tank car. 

These accident scenarios include derailments and collisions, 

which are listed in Table 1, along with example accidents and 

the collision mode that results in lading loss. The accident 

scenarios and collision modes have been used to define car-tocar impact scenarios, which define impact conditions under 

which the commodity must be contained. The impact scenarios 

are used to evaluate the integrity of current and improved 

design tank cars. The performance of improved equipment is 

compared with the performance of baseline equipment in the 

impact scenarios. 

Table 1. Accident Scenarios of Concern 

Accident Scenario Collision Modes 

1 Derailment 

Minot, ND, January 18, 2002 

Head and Shell 

Impacts 

2 Train-to-Train Collision 

Graniteville, SC, January 6, 2005 

Override, Head 

and Shell Impacts 

Figures 4 and 5 show possible outcomes of extreme 

loading conditions for head and shell collision modes. Figure 4 

shows an example of a head puncture, which is a photograph of 

the chlorine tank car damaged in the train collision that 

occurred in Macdona, TX, on June 28, 2004. The denting and 

puncture of the tank car resulted from a collision with a flat car. 

Figure 5 shows an example of a shell puncture, which is a 

computer-generated image of the damage to the chlorine tank 

car in the train collision that occurred in Graniteville, SC, on 

January 6, 2005. The computer-generated image is produced 

from three-dimensional laser measurements taken from the tank 

car. Moreover, puncture of the tank shell is attributed to impact 

from a broken coupler. 
 4 Copyright © 2007 by ASME 

Figure 4. Head Puncture from Macdona Accident 

Figure 5. Shell Puncture from Graniteville Accident 

One of the research activities being performed by the 

Volpe Center on accident loading conditions is analysis of 

derailment dynamics to examine the gross motions of rail cars 

during a train derailment [7, 11]. Moreover, the models for 

derailment dynamics produce car-to-car impacts that resemble 

those in accidents. Figure 6(a) shows car motions (in plan 

view) at two instants of time from an idealized derailment 

simulation. The two particular instants of time show car-to-car 

impacts for imminent head and shell impacts, respectively, 

which are encircled in the figure. The model results indicate 

that such head and shell impacts within the train consist occur 

at about one-half of the initial train speed at the point of 

derailment. Figure 6(b) shows the generalized head and shell 

impact scenarios schematically. In each scenario, the tank cars 

are essentially full. In the head impact, the coupler of one tank 

car impacts the head of a second tank car. In the shell impact, 

the coupler of one tank car impacts the side (shell) of a second 

tank car. 

(a) Accident simulation (b) Generalized impact scenario

Figure 6. Generalized Car-to-Car Impact Scenarios 

For a prescribed closing speed, the generalized car-to-car 

impact conditions, illustrated in Figure 6, are used to develop 

energy absorption requirements for the tank car. The Volpe 

Center is using these generalized impact scenarios as design 

requirements to drive the development of the improved tank car 

conceptual design [10]. 

Baseline Analysis

In evaluating the performance of current equipment, a 

DOT 105 car is considered as the baseline tank car. Table 2 

lists the key attributes associated with a typical chlorine tank 

car. 

Table 2. Summary of Attributes for a Typical Chlorine 

Tank Car 

Commodity Chlorine 

Gross Weight 263,000 lb 

Tank Inside Diameter 100.625 inches 

Head Thickness (Material) 0.828 inch (TC-128B) 

Shell Thickness (Material) 0.777 inch (TC-128B) 

Jacket (Material) 0.119 inch (A1011) 

Internal Pressure 100 psi 

Outage 10.6% 

Nonlinear (i.e., elastic-plastic) finite element analysis of 

the baseline car is performed using commercial solvers, 

namely, ABAQUS and LS-DYNA. Such analyses have been 

used to evaluate the performance of the baseline car in a range 

of impact conditions. The key output of the finite element 

models is the force-indentation characteristic (see Figure 7) of 

the tank as it is struck by an impacting object, such as a coupler 

or wheel from an adjacent rail car. Moreover, the basis for 

evaluating the performance of various tank car designs is the 

energy to failure or the area under the force-indentation 

characteristic, which, in turn, is related to the impact velocity to 

cause failure through kinetic energy. That is, the velocity at 

which failure of the tank may be expected is proportional to the 

square root of the energy or area under the force-indentation 

curve. The specific point at which failure may occur on the 

force-indentation curve depends on several factors, such as size 

and shape of the impacting object and material properties. 
 5 Copyright © 2007 by ASME 

Energy

F

d

Elastic

Plastic

Failure

Possible

Failure

Unlikely

Failure

Likely

Figure 7. Generic Force-Indentation Characteristic 

Credibility and confidence in the finite element modeling 

are achieved through verification and validation studies. 

Results from static, nonlinear finite element analyses are 

compared to closed-form solutions for rigid-plastic 

deformations of cylindrical shells to verify the model 

development. Results from dynamic, nonlinear finite element 

analyses are compared to test data to validate the models. In 

this context, verification means that the mathematics of the 

models are being calculated correctly, while validation means 

that the physics are being modeled properly. 

Figure 8 shows the deformation of an ellipsoidal end cap 

or tank car head, calculated from closed-form and finite 

element analyses. The closed-form solution assumes rigidplastic material behavior and calculates axisymmetric 

deformation due to a concentrated load applied at the center. In 

the finite element analysis, elastic-plastic material behavior is 

assumed as the load is applied over a rectangular area at the 

center. Despite the differences in material behavior and applied 

load, the calculated deformations are nearly the same. 

Closed-Form Solution Finite Element Analysis

• Rigid-plastic material behavior

• Concentrated load

• Elastic-plastic material behavior

• Rectangular punch load

Figure 8. Deformation of Ellipsoidal Cap 

Figure 9 shows the force-indentation curves corresponding 

to the closed-form and finite element analyses. Despite the 

differences in assumptions, the curves are in close agreement. 

Moreover, the results shown in the two previous figures 

provide verification of the finite element analyses for head 

impact. Similar calculations have been performed to verify the 

analyses for shell impacts [9]. The analyses will be validated 

with data from full-scale and component tests. 

Center Indentation (inches)

0 5 10 15 20 25 30 35 40

F (ki )

0

100

200

300

400

500

Closed-Form Solution

Finite Element Analysis

Figure 9. Comparison Between Closed-Form Solution and 

Finite Element Analysis for Head Indentation 

The Volpe Center is applying the verified and validated 

analyses to examine the performance of baseline and improved 

tank car designs in a range of impact conditions. The baseline 

analysis results establish the reference for assessing potential 

improvements. The potentially improved designs are evaluated 

for the same conditions (e.g., the generalized head and shell 

impact scenarios) with the same analysis techniques, and the 

resulting differences in performance are compared. 

Full-Scale Testing and Analysis Refinement

A series of full-scale shell impact tests was performed at 

the Transportation Technology Center in Pueblo, CO, in 2007. 

The purpose of the shell impact tests is to establish the 

crashworthiness performance of existing tank cars. 

Figure 10 shows a flow chart of the activities required for 

the successful implementation of the full-scale tests. FRA 

coordinated with the Volpe Center to design these tests using 

simplified models. Dow Chemical collaborated with Applied 

Research Associates, Inc. (ARA) in developing more detailed 

simulation models that supported the Transportation 

Technology Center, Inc. (TTCI) in implementation of the tests. 

The Volpe analyses include closed-form and finite element 

analysis, which accounts for fluid-structure interaction, 

material failure and basic tank car geometry (no body bolster, 

stub sill, etc.) [9]. The simplified model was used to develop 

the test requirements and test design. These results provide the 

basis for more detailed tank car models. 
 6 Copyright © 2007 by ASME 

Simplified 

Analyses

FRA/Volpe

Detailed 

Analysis

Dow/ARA

Test Conduct

Dow/TTCI

Test Design

FRA/Volpe

Specification of 

Detailed Analysis

FRA/Volpe

Figure 10. Flow Chart of Activities Supporting Full-Scale 

Tests 

The detailed analysis model developed by ARA includes a 

detailed description of the car geometry, including the body 

bolster, stub sills, and fittings. These simulations are used to 

verify the test requirements, particularly the test speed. 

The test requirements include descriptions of the track, 

initial positions of equipment, impact speed, and measurements 

needed for comparison with the analyses. These measurements 

enable verification of the analyses, as well as measure the 

information needed to improve the analyses if the predications 

and test results disagree. 

A Test Implementation Plan (TIP) is needed for 

appropriate and safe implementation of the test. The TIP 

describes the test equipment, setup, instrumentation, data 

acquisition system, and conduct of the test, including safety 

procedures. 

Figure 11 illustrates the shell impact test scenario. The 

tank car was positioned with the centerline perpendicular to the 

tracks and supported by a fixed barrier on one side. The tank 

car contained clay slurry, which approximated a typical load of 

chlorine. The side of the tank car was impacted with a ram car 

traveling at an initial velocity. The ram car was a ballasted 

flatcar with an indenter protruding from the lead end. 

Both the ram car and tank car were instrumented with 

accelerometers, string potentiometers, strain gages, and 

pressure transducers to measure the impact forces experienced 

by the tank car, gross motions in three-dimensions of the ram 

car and tank car, the pressure gradient within the tank, and dent 

size and material strains of the tank car shell. High-speed 

digital video cameras were used to document the motions of the 

ram car and tank car, as well as the progression of the tank car 

deformation during the impact. Two tests of this arrangement 

have been conducted, one with a punch size too large to cause 

puncture and one with a punch size sufficiently small to cause 

puncture. In this way, the bounds of the ‘Failure Possible’ 

region shown in Figure 7 have been measured. 

On April 26, 2007, tank car shell impact test 1 was 

conducted [9]. A ram car traveling at 14 mph impacted the side 

of a stationary tank car with the characteristics listed in Table 2. 

The indenter of the ram car deformed the shell to a maximum 

dent depth of 26 inches, without puncturing the tank car shell. 

The face of the indenter was 23 inches wide and 17 inches 

high, approximately the cross-section size of a freight car draft 

sill. 

Figure 11. Schematic of Full-Scale Shell Impact Test 

Figure 12 shows still photographs from the high-speed 

cameras of Test 1. The three stills show the time at which (1) 

the indenter of the ram car makes contact with the tank car, (2) 

the maximum penetration of the indenter into the tank, and (3) 

the final dent size after the indenter has rebounded off the tank 

car. 

Figure 12. Stills from Test 1 
 7 Copyright © 2007 by ASME 

Figure 13. Stills from Test 2 

The simplified finite element analysis model closely 

predicted force-time histories in both of the shell impact tests 

[9]. The pre-test model for test 1 estimated the peak force 

within 10 percent of the measured test data, and the dent size to 

within 15 percent. The discrepancy results from the exclusion 

of the jacket in the modeled tank car and the assumption of 

conservative (minimum) material properties for the shell. As a 

result, the model estimates a somewhat larger dent at a slightly 

lower load than the test results, as shown by the data presented 

in Table 3. 

Table 3. Comparison Between Test 1 and Analysis 

Maximum 

Force (kips) 

Maximum 

Dent (inches) 

Test 1 Data 1290 26 

Finite Element Analysis 1170 30 

On July 11, 2007, tank car shell impact test 2 was 

conducted [9]. A ram car traveling at 15 mph impacted the side 

of a stationary tank. The indenter of the ram car punctured the 

tank car shell. The face of the indenter was 6 inches wide and 

6 inches high, approximately the cross-section size coupler 

shank. 

Figure 13 shows still photographs from the high-speed 

cameras of Test 2. The three stills show the time at which (1) 

the indenter of the ram car makes contact with the tank car, (2) 

the maximum penetration of the indenter into the tank, and (3) 

just after the indenter has punctured the tank car. 

The pre-test estimates closely matched the principal results 

for both tests [9]; however, the measurements have been used 

to refine the models and provide a high level of confidence in 

the evaluation of improved designs. These refined analysis 

techniques are being used with a high level of confidence to 

evaluate alternative improved designs. 

Development and Evaluation of Improved Design

The objective of FRA tank car research is to develop 

strategies for improving railroad tank cars so that tank integrity 

is maintained for more severe accident conditions than current 

equipment. As discussed above, the full-scale testing of 

conventional tank car equipment establishes a baseline 

representation of crashworthiness performance of tank car 

equipment currently in operation. Figure 14 shows the 

development of concepts for an improved tank car design. 

Each step incrementally generates more detail on improved 

concepts. 

Design Goals

Generation of 

Alternative 

Concepts

Rating and 

Ranking of 

Concepts

Concept 

Selection 

Preliminary 

Design 

Studies

Service, Manufacturing, 

Crashworthiness, 

etc.

Identify and 

organize 

concepts

Assess 

concepts’ 

potential for 

meeting 

requirements

Choose 

concept with 

most potential

Develop 

concept details

Figure 14. Schematic of Improved Design Development 

Table 4 lists the functions and associated features of the 

conceptual design. These functions are needed to meet the 

impact requirements of a head impact and shell impact. The 

conceptual design must perform four functions to meet the 

impact requirements: blunt the impact loads, absorb collision 

energy, strengthen the tank, and assure that any impact loads 

are first blunted and that a significant amount of energy is 

absorbed before the tank is loaded. 

Table 4. Improved Design Functions and Features 

Functions Features 

Blunted impact loads 

Collision energy absorbed 

Sacrificial structure that shields 

tank and absorbs energy 

Stronger tank Reinforcement of head and shell 

Control load path to tank Carbody supports service loads 
 8 Copyright © 2007 by ASME 

Head shields on current cars principally act to blunt the 

impact load. In essence, the shield makes the size of the 

impacting object appear larger to the tank, spreading the load 

over a greater area. By doing so, the energy required to rupture 

the tank is increased. The addition of an energy absorption 

component between the shield and the tank can further increase 

the energy required to rupture the tank. The energy absorption 

layer decreases the speed of the impact experienced by the 

tank. 

Strengthening the tank allows an energy absorption 

component to crush at a higher load. If the tank remains the 

main service load-bearing structure, then the potential for 

weldments to lead to fatigue failures is of concern. In such a 

case, bonding the stiffeners to head and shell is a potential 

option. If the service load-bearing structure is separate from 

the commodity tank, and the tank does not experience cyclic 

service loads, then the potential for fatigue failure is much 

lower. In such a case, directly welding to the head and shell 

may be a viable option. 

Accident history suggests that rupture can initiate 

anywhere on the tank. Ruptures are more likely at certain 

locations on the tank—below the beltline and at the ends of the 

cars. Some cars, however, appear to have been ruptured by 

impacts near the draft sill/body bolster and on the top. These 

accident results suggest that the entire car should be shielded 

and that collision energy should be absorbed before the tank is 

impacted. In order to accomplish this function, a separate 

carbody structure supports the service loads. 

Figure 15 shows a schematic of the features integrated into 

a conceptual design. Potentially, these features could be 

applied incrementally to existing designs, working from the 

inside out. The tank could be strengthened with bonded 

stiffeners alone. As described in a companion paper [10], such 

stiffeners have the potential to double the energy required to 

rupture the tank. A sacrificial structure for blunting the load 

and absorbing energy could be further added. The stiffeners 

and sacrificial structure could increase the energy required to 

rupture the tank by a factor of four for most impacts. Such a 

car would be at least somewhat more vulnerable near the draft 

sill/body bolster attachments, even if these attachments act as 

structural fuses and fail in a prescribed manner for prescribed 

loads. Impact loads that bypass the sacrificial structure could 

be introduced to the tank through the Achilles’ heel of the draft 

sill/body bolster. The external carbody would eliminate this 

vulnerability and result in the integrated conceptual design. 

For example, the continuous center sill design relieves the tank 

from bearing the in-train buff and draft forces and continues to 

be used in DOT 105A500W tank cars built for carbon dioxide 

service. 

While information is being shared, the design development 

activities supported by Dow Chemical are separate and distinct 

from the design development activities being conducted by the 

Volpe Center in support of FRA. In the process chosen by FRA 

and the Volpe Center, an overall strategy is evolved into a 

single concept with required functions and features. These 

features are then refined into detailed forms with preliminary 

design studies. This approach has been used to develop crush 

zones for passenger equipment [12, 13, 14], the state-of-the-art 

cab car end frame design [15], and improved locomotive 

crashworthiness features [16], as well as improved workstation 

tables [17], optimized commuter seats [18], and a conceptual 

design for inflatable structures for train operator protection 

[19]. 

Sacrificial Structure

Blunt Force and Absorb Energy

Carbody

Carry Service Loads

Reinforcement

Strengthen Tank

Design Integration

Service, Manufacturing, and Crashworthiness Goals

Figure 15. Preliminary Design Studies 

The crashworthiness components shown in Figure 15 are 

being individually evaluated and integrated together to achieve 

an improved tank car design. The improved conceptual tank 

car design is being further developed in support of FRA 

regulatory efforts to show that a tank car can retain its lading 

for head and shell impact with four times the energy as the 

impact for which the baseline tank car can retain its lading. 

Meeting this goal doubles the impact speed for which the 

integrity of the tank can be maintained. As described in 

references [8, 9], the impact energy and speed depend upon the 

height and width of the nose of the blunt punch. The relative 

increase in performance sought is the same for a wide range of 

nose sizes. 

Comparison of the conceptual design performance with the 

baseline performance results in the potential benefits of the 

improved conceptual design. The design development 

demonstrates the analysis and test techniques needed for 

assuring a level of performance in the generalized scenarios. 

The conceptual design illustrates the technologies that can 

contain the lading in the generalized scenarios at prescribed 

impact speeds. 

SUMMARY AND NEXT STEPS 

A framework has been developed for screening alternative 

strategies for increased tank car safety in train accidents. This 

framework acts as a roadmap for developing and evaluating 

potentially improved designs. As part of this framework, 

generalized head and shell impact scenarios have been 

developed. The baseline performance in the shell impact 

scenario has been evaluated with analyses and tests. The 

functions and features of an improved design have been 

identified. 
 9 Copyright © 2007 by ASME 

Current Volpe Center efforts are focused on developing a 

conceptual improved tank car design. Preliminary studies of 

available weight and space, strategies for blunting impact 

loads, means of energy absorption, and arrangements for 

strengthening the head and shell, as well as development of a 

carbody structure conceptual design, are also ongoing. A 

companion paper presents results to date of these preliminary 

design studies [10]. Component tests are tentatively planned to 

confirm (or refute) the results of selected substructure analyses 

being conducted as part of the conceptual design development. 

Recent accidents involving the release of hazmat, with 

consequent fatalities, have focused attention on the structural 

integrity of railroad tank cars. The research described in this 

paper is being conducted to develop strategies for improving 

railroad tank cars so they can maintain tank integrity in severe 

accidents. The NGRTC Project is using these research results to 

help develop improved tank car designs. FRA and PHMSA 

intend to use these research results to support rulemaking. 

ACKNOWLEDGMENTS 

FRA, Office of Research and Development, sponsored the 

work described in this paper. Ms. Claire Orth is the Chief of 

the Equipment and Operating Practices Division. Mr. 

Francisco Gonzalez is the FRA project manager for research on 

railroad tank cars. 

Mr. Grady Cothen, Deputy Associate Administrator for 

Safety Standards and Program Development, FRA, is leading 

the effort to develop tank car safety standards. The authors 

thank Ms. Jo Strang, Associate Administrator for Safety 

Enforcement, FRA, for her efforts to coordinate the standards 

development and tank car safety research. 

Ms. Michelle Priante, Mechanical Engineer, Volpe Center, 

coordinated the design of the full-scale tests, analyzed the 

collision dynamics of the tests, and is assisting in development 

of the improved conceptual design. Mr. Jeff Gordon, Senior 

Engineer; Ms. Yim H. Tang, Senior Engineer, Volpe Center; 

and Dr. Hailing Yu, Chenga Advance Solutions & Engineering, 

LLC; assisted in the design of the full-scale tests and performed 

the simplified finite-element analysis of the tests. Mr. Brandon 

Talamini, Senior Engineer; Mr. Michael Carolan, Mechanical 

Engineer; and Mr. Philip Mallon, Mechanical Engineer, Volpe 

Center; are coordinating the development of the improved 

conceptual tank car design. Finally, the authors would like to 

thank Professor A. Benjamin Perlman, Senior Engineer, Volpe 

Center, for his assistance through all aspects of this project. 

REFERENCES 

[1] National Transportation Safety Board, 2004: “Derailment 

of Canadian Pacific Railway Freight Train 292-16 and 

Subsequent Release of Anhydrous Ammonia Near Minot, 

North Dakota; January 18, 2002,” Railroad Accident 

Report NTSB/RAR-04/01. 

[2] National Transportation Safety Board, 2006: “Collision of 

Union Pacific Railroad Train MHOTU-23 with BNSF 

Railway Company Train MEAP-TUL-126-D with 

Subsequent Derailment and Hazardous Materials Release, 

Macdona, Texas, June 28, 2004,” Railroad Accident 

Report NTSB/RAR-06/03. 

[3] National Transportation Safety Board, 2005: “Collision of 

Norfolk Southern Freight Train 192 with Standing Norfolk 

Southern Local Train P22 with Subsequent Hazardous 

Materials Release at Graniteville, South Carolina, January 

6, 2005,” Railroad Accident Report NTSB/RAR-05/04. 

[4] Hutchinson, H. “Containing Risk,” Mechanical 

Engineering, Vol. 129/No. 6, June 2007, American Society 

of Mechanical Engineers, New York, NY. 

[5] Pipeline and Hazardous Materials Safety Administration, 

“Hazardous Materials: Improving the Safety of Railroad 

Tank Car Transportation of Hazardous Materials,” Notice 

of Public Meeting, Federal Register, Vol. 71, No. 222, 

Friday, November 17, 2006. 

[6] Federal Railroad Administration, “Development of New 

Federal Design Standards for Hazardous Materials Tank 

Cars to Benefit from Public-Private Partnership,” U.S. 

Department of Transportation, FRA02-07, Tuesday, 

January 16, 2007. 

[7] Jeong, D.Y., Lyons, M.L., Orringer, O., Perlman, A.B., 

2007: “Equations of Motion for Train Derailment 

Dynamics,” Proceedings of 2007 ASME Rail 

Transportation Division Fall Technical Conference, 

RTDF2007-46009. 

[8] Yu, H., Jeong, D.Y., Gordon, J.E., Tang, Y.H., “Analysis of 

Impact Energy to Fracture Un-notched Charpy Specimens 

Made from Railroad Tank Car Steel,” Proceedings of 2007 

ASME Rail Transportation Division Fall Technical 

Conference, RTDF2007-460xx. 

[9] Tang, Y.H., Yu, H., Gordon, J.E., Priante, M., Jeong, D.Y., 

Tyrell, D.C., Perlman, A.B., 2007: “Analysis of Full-Scale 

Tank Car Shell Impact Tests,” Proceedings of 2007 ASME 

Rail Transportation Division Fall Technical Conference, 

RTDF2007-46010. 

[10] Tyrell, D.C., Jacobsen, K., Talamini, B., Carolan, M., 

2007, “Developing Strategies for Maintaining Tank Car 

Integrity During Train Accidents,” Proceedings of 2007 

ASME Rail Transportation Division Fall Technical 

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[11] Paetsch, C.R., Perlman, A.B., Jeong, D.Y., 2006: 

“Dynamic Simulation of Train Derailments,” Proceedings 

of IMECE2006, 2006 ASME International Mechanical 

Engineering Congress and Exposition, IMECE2006-

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[12] Tyrell, D., Jacobsen, K., Martinez, E., “A Train-to-Train 

Impact Test of Crash Energy Management Passenger Rail 

Equipment: Structural Results,” American Society of 

Mechanical Engineers, Paper No. IMECE2006-13597, 

November 2006. 

[13] Martinez, E., Tyrell, D., Rancatore, R., Stringfellow, R., 

Amar, G., “A Crush Zone Design for an Existing Passenger 

Rail Cab Car,” American Society of Mechanical Engineers, 

Paper No. IMECE2005-82769, November 2005. 
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[14] Martinez, E., Tyrell, D., Perlman, A.B. , “Development of 

Crash Energy Management Designs for Existing Passenger 

Rail Vehicles,” American Society of Mechanical 

Engineers, Paper No. IMECE2004-61601, November 

2004. 

[15] Mayville, R., Stringfellow, R., Johnson, K., Tyrell, D., 

“Rail Vehicle Car Cab Collision and Corner Post Designs 

According to APTA S-034 Requirements,” American 

Society of Mechanical Engineers, Paper No. MECE2003-

44114, November 2003. 

[16] Tyrell, D., Severson, K., Marquis, B., Martinez, E., 

Mayville, R., Rancatore, R., Stringfellow, R., Hammond, 

R., Perlman, A.B., “Locomotive Crashworthiness Design 

Modifications Study,” Proceedings of the 1999 

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Electrical and Electronics Engineers, Catalog Number 

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Crashworthiness Performance,” American Society of 

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November 2005. 

[18] Severson, K., Tyrell, D., Rancatore, R., “Crashworthiness 

Requirements for Commuter Rail Passenger Seats,” 

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[19] Zolock, J., Tyrell, D., “Locomotive Cab Occupant 

Protection,” American Society of Mechanical Engineers, 

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