6913G626Q300026 SOW Phase II Wheelchair Sled Testing.pdf

RFQ No. 6913G626Q300026

STATEMENT OF WORK

Sled Tests to Evaluate a Universal Docking Interface Geometry (UDIG) Wheelchair Tie-down and Occupant Restraint System (WTORS) with ATD in a Simulated Train

Collision

1 Introduction The US Department of Transportation Volpe National Transportation Systems Center (Volpe Center) supports the Federal Railroad Administration (FRA) by conducting research to improve occupant protection for passenger rail cars. Research is ongoing to evaluate collision safety for passengers seated in wheelchairs. The FRA initiated the research in response to recommendations by the Rail Vehicle Access Advisory Committee (RVAAC) to increase the longitudinal space provided for wheelchair users from 54 to 59 inches, so that they could more easily maneuver their wheelchairs into the allotted space on a train. There is a concern, based on tests and analyses of passengers seated in various seating configurations, that larger longitudinal spaces may increase the risk and severity of passenger injuries during a train accident.

Train passengers seated in wheeled mobility devices (WhMDs) may be exposed to greater hazards than passengers seated in fixed passenger seats during an accident. The WhMDs can be heavy, as much as 440 pounds for some powered devices. An unsecured WhMD can act like a heavy projectile during a train accident, compounding the secondary impact forces experienced by an occupant in a train collision. Effective securement of WhMDs and compartmentalization of passengers seated in WhMDs can improve collision safety for wheelchair users and nearby passengers.

The testing described in this SOW is a continuation of tests conducted by the University of Michigan Transportation Research Institute (UMTRI) in December 2024. UMTRI performed the previous series of tests using a 50th percentile Hybrid III male (H3-50M) anthropomorphic test device (ATD) seated in a surrogate test wheelchair, which is defined in voluntary industry standard ANSI/RESNA WC18 [1]. In the baseline case, a two-person transversely mounted passenger seat compartmentalized the ATD and surrogate wheelchair. The other two tests utilized a three-point seat belt and two different wheelchair securement systems.

The series of tests described in this statement of work will evaluate additional wheelchair securement, ATD, and occupant restraint configurations to assess the effectiveness of UMTRI’s wheelchair tie-down and occupant restraint system (WTORS), which complies with universal docking interface geometry (UDIG) specifications in Rehabilitation Engineering Society of North America (RESNA) and International Standards Organization (ISO) wheelchair transportation safety standards [1, 2, 3].

2 Background During a train collision, an unrestrained, forward-facing occupant continues to travel at the speed of the train prior to the train collision, until he or she impacts an interior fixture, such as an adjacent seat, workstation table, bulkhead wall, etc. The occupant’s impact with their surroundings is referred to as a secondary impact.

Depending on the deceleration of the train during the collision, the interior configuration, and the rigidity of the impacted structure, secondary impacts can cause significant injuries and sometimes fatalities [4, 5, 6]. Through accident investigations, FRA identified rigid seats and thin, rigid workstation tables as causal mechanisms of serious secondary impact injuries. FRA also identified low back seats and certain seating configurations as causal mechanisms for a loss of compartmentalization. Compartmentalization is an interior design strategy that aims to contain occupants between rows of seats or between seats and tables during a collision, preventing occupants from traveling over seats and impacting other passengers and more hostile interior fixtures. As a result, they sponsored research to develop seats and tables that improve compartmentalization and minimize secondary impact injuries. The FRA has worked with the rail industry to develop improved regulations and safety standards for seats and tables to better protect train passengers from secondary impacts.

Passengers travelling in WhMDs are not required to secure their WhMDs or use seatbelts during rail transportation in the US. As accessibility improves in rail transportation, exposure of passengers traveling in wheelchairs to accident conditions may increase. The FRA has sponsored anthropomorphic test device (ATD) experiments in passenger rail cars during a full-scale train-to-train impact test to evaluate the risks associated with passengers seated in the following configurations: rear-facing in an unrestrained manual wheelchair, rear-facing in a secured surrogate wheelchair with lap-and-shoulder belt, and forward-facing in a secured wheelchair with a lap-and-shoulder belt [7]. In each experiment, the ATD injury measurements for the head, neck, chest, and femurs were well below the maximum injury assessment reference values (IARVs), i.e., performance requirements, specified in the American Public Transportation Association (APTA) Standard for Passenger Seats in Passenger Rail Cars, APTA PR-C&S-S-016-99, Rev. 3.1 (abbreviated as APTA S-016 in this document) [8].

Despite the positive test results, members of the WhMD-user community have expressed reservations about using WTORS if they cannot be secured and unsecured without assistance. The next series of tests performed at UMTRI in Dec 2024 only utilized WTORS that could be used independently. The WTORS sled tests also resulted in ATD injury measurements that were well below the maximum IARVs in APTA S-016. In the baseline experiment with an unsecured surrogate wheelchair and an unrestrained H3-50M ATD, the ATD impacted the back of the passenger seat, between the two seatbacks, as shown in Figure 1. The surrogate wheelchair and ATD were centered behind the two-passenger seat. During the secondary impact, the ATD’s knees impacted both seatbacks, causing the two seatbacks to spread apart slightly, creating sufficient space for the ATD’s head. On rebound, the seatbacks returned to their original position, compressing the neck of the ATD and trapping it between the two seatbacks. The H3-50M ATD used in the test was designed to assess neck injuries associated with automotive frontal impacts and might not correctly indicate the risk of neck injury associated with such an impact. The injury measurements for the head, chest, and neck were higher than those in the two WTORS experiments, but still lower than the IARVs. However, the femur load exceeded the IARV. The head and neck injury criteria likely would have been higher if the ATD’s head had impacted the seatback directly.

Figure 1. Post-test photo of unsecured wheelchair and unrestrained ATD

3 Objective The objective of the sled tests described in this document is to test additional wheelchair and ATD configurations, evaluate the effectiveness of UMTRI’s UDIG WTORS, and compare the results to the UMTRI sled tests performed in December 2024. The test conditions and performance requirements are based on those specified in the forward-facing human injury test in Section 3.2.1 of APTA S-016, provided as Attachment 1 to this document.

The testing planned in this research effort must include the UMTRI UDIG WTORS, a surrogate wheelchair, either a ballasted surrogate wheelchair to simulate a heavy-duty power wheelchair, or an actual heavy-duty power wheelchair, an H3-50M ATD, and a Hybrid III 95th percentile male (H3-95M) ATD. In addition to evaluating different wheelchairs and ATDs, a baseline test must also include an unsecured wheelchair, an unrestrained forward-facing ATD, and a rail passenger seat to evaluate a modified baseline case in which the ATD impacts one of the seatbacks directly, to prevent the ATD from getting stuck between the seatbacks. A test must also be performed using the UDIG wheelchair securement, but without the occupant restraint system. This configuration is akin to a passenger seated in a fixed seat, which would prevent the wheelchair from inflicting harm on the wheelchair user and nearby occupants.

There is limited experience with wheelchair securement and occupant restraint on North American passenger rail service. Testing is needed to assess the effectiveness of wheelchair securement and occupant restraint systems designed for use in automobiles and determine if they provide a viable protection strategy for accident conditions on passenger trains. The effectiveness of occupant compartmentalization, i.e., with no wheelchair securement or occupant restraint, must also be evaluated and compared.

4 Scope The scope of this SOW is to conduct three to five sled tests to evaluate the effectiveness of multiple configurations and occupant protection strategies in a simulated train collision. Each test must use either a H3- 50M or a H3-95M ATD. In one set of tests, the contractor will seat the ATD in a forward-facing surrogate wheelchair weighing 187 lbs [1]. In another set of tests, the contractor will seat the ATD in a forward-facing heavy-duty power wheelchair or surrogate wheelchair ballasted to weigh between 300 and 440 lbs while maintaining a center of gravity representative of a commercial heavy-duty power wheelchair. The contractor must supply all the wheelchairs necessary for testing. Some tests will use a two-person rail passenger seat, provided by the government, with shipping and installation provided by the contractor.

The securement/restraint systems to be tested are:

• System A – Compartmentalization provided by a commercially available passenger seat (acquired by the government and provided to the contractor), with no wheelchair securement or occupant restraint systems.

• System B – Wheelchair securement only provided by a UDIG wheelchair tie-down system developed by the University of Michigan Transportation Research Institute (UMTRI) [9], which complies with RESNA and ISO wheelchair transportation safety standards [1, 2, 3] (to be acquired by the contractor).

• System C – Wheelchair securement and occupant restraint system provided by a UDIG wheelchair tie-down and occupant restraint system (WTORS) developed by the University of Michigan Transportation Research Institute (UMTRI) [9], which complies with RESNA and ISO wheelchair transportation safety standards [1, 2, 3] (to be acquired by the contractor).

The parameters for each test are identified in the sled test matrix in Table 1 and Figure 2, below. A schematic of the baseline compartmentalization test (System A) and the wheelchair securement system only (System B) is depicted in Figure 2. A passenger seat is not required for tests with the full wheelchair securement and occupant restraint system (System C).

Table 1. Test matrix

Test

WTORS ATD

Wheeled Mobility Device

Passenger seat?

Orientation of seat?

CLIN Notes

1 A H3- 50M

Surrogate Wheelchair

Y/forward-facing 0100

ATD positioned behind aisle seatback; compare results to Phase I Test 3 with ATD centered between wall and aisle seatbacks (compartmentalization/injury test).

2 A H3- 95M

Surrogate Wheelchair

Y/forward-facing 0100

ATD positioned behind aisle seatback, as in Test 1, above (compartmentalization/seat integrity test).

3 B H3- 50M

Surrogate Wheelchair

Y/forward-facing 0100

ATD positioned behind aisle seatback (compartmentalization/injury test).

4 C H3- 95M

Power Wheelchair N 0200

Commercial heavy-duty power wheelchair or ballasted surrogate wheelchair weighing 300-440 lbs.

5 C H3- 50M

Power Wheelchair N 0200

Commercial heavy-duty power wheelchair or ballasted surrogate wheelchair weighing 300-440 lbs.

Figure 2. Schematic of test configuration

If so desired by the donor/provider of seat(s) and/or securement/restraint systems, the contractor must endeavor to protect and prevent disclosure of proprietary information related to the provided equipment. The test report must not specifically identify the manufacturers of the equipment provided and used in each experiment, unless allowed by the manufacturer. Photos of the seats and restraint systems will be included in the report.

5 Tasks The contractor must perform the following tasks:

TASK 1 – TASK MANAGEMENT PLAN

The contractor must develop a management plan that describes the plan to complete the work required in Section 5. This plan must include a milestone chart describing the schedule for initiating and completing each of the tasks, resources required to complete each task, and periodic meetings to coordinate test plans with the contracting officer’s representative (COR), FRA sponsor, WTORS manufacturer, and seat manufacturer. The management plan will be reviewed and approved by the COR.

TASK 2 – TEST IMPLEMENTATION PLAN

The contractor must develop a detailed test implementation plan (TIP) describing how the sled tests will be conducted, including a description of the test setup, test sled, mounting of equipment to the test sled, instrumentation, and data acquisition. The contractor must determine if any special fixtures or interface plates are needed to attach the wheelchair securement, ATD restraint systems, and passenger seat to the test sled. The contractor should reference sections in APTA-PR-CS-S-016-99, Rev. 3.1 where appropriate. The TIP must be developed in coordination with the COR. The TIP must be descriptive enough to conduct the sled tests and include:

• Planned layouts for the wheelchair and ATD restraint systems (and passenger seat, where applicable) in each test along with necessary dimensions for installation and test setup

• Description of test conditions and pre- and post-test documentation

• Description of test instrumentation, data post-processing, and high-speed video system

A draft TIP must be submitted to the COR at least 14 days before the planned test date. The final TIP is subject to approval by the COR before the execution of the sled test.

TASK 3 – SHIP PASSENGER SEATS

Coordinate and procure shipment of three rail passenger seats from seat manufacturer to test facility.

TASK 4 – CONDUCT CALIBRATION TEST RUN(S)

In advance of testing, the contractor must conduct a test run(s) with a ballasted test sled to demonstrate that that specified acceleration pulse can be achieved, ideally within the allowable parameters of section 5.3.9.2 of the SAE AS8049 Standard [10].

TASK 5 – CONDUCT THREE DYNAMIC SLED TESTS

The COR and any designated representatives must have the option of attending each test. The equipment providers must have the option of attending the test(s) of their equipment. The contractor must work with the COR to determine a mutually agreeable test date.

TEST CONDITIONS

In the base contract (CLIN 0100), the contractor must conduct three dynamic sled tests based on the test matrix in Table 1, as described in the TIP. In the contract option (CLIN 0200), two additional dynamic sled tests must be conducted, if the option is exercised. The contractor must acquire and install the equipment necessary for each test. The contractor must prepare the data acquisition system, required lighting, and high-speed video cameras.

The contractor must position the ATD according to the requirements in APTA PR-CS-S-016, Rev 3.1. The contractor must define, set-up, and conduct pre-test checks on the instrumentation and camera triggers. The contractor will be responsible for documenting all aspects of the test, including pre- and post-test photos and high-speed videos. Each test must be conducted using a crash pulse that is equivalent to an 8g, 250 ms crash pulse as shown in Figure 2. The crash pulse must comply with the requirements established in SAE AS8049, Section 5.3.9.2 and Appendix A, modified as necessary according to the test implementation plan developed in Task 1.

Figure 3. Crash Pulse

Each test must use a H3-50M ATD. The adjustment, positioning, and care of the ATDs must be in accordance with SAE AS8049.

The contractor must analyze and organize the videos, measurements, and data to prepare a test report as part of this effort. Where appropriate, the test report must include:

1. Test number

2. Test date

3. Summary of test setup and wheelchair and ATD restraint systems

4. Table of measured injury criteria for H3-50M ATD

5. Evaluation of test outcomes, including ATD injury results and ATD containment/compartmentalization, performance of WTORS, and any equipment failures

6. Plots of the processed data signals

The contractor must provide the following equipment:

- H3-50M ATD as defined in 49 CFR Part 572 Subpart E

- H3-95M ATD (uninstrumented)

- Surrogate wheelchair that complies with the requirements in RESNA WC-4:2017 – American National

Standard for Wheelchairs Volume 4: Wheelchairs and Transportation Section 18, Annex E

- Surrogate wheelchair ballasted to weigh between 300 and 440 lbs while maintaining a center of gravity representative of a commercial heavy-duty power wheelchair, or a commercial heavy-duty power wheelchair.

- UMTRI-developed WTOR system including lap and shoulder belt, that complies with the requirements in RESNA and ISO wheelchair transportation safety standards [1, 2, 3]

The government will provide the following equipment:

- Three rail passenger seats, with necessary hardware to secure seats to the test sled

DATA COLLECTION AND DOCUMENTATION

Instrumentation – The H3-30M ATD must be instrumented to measure data per 49 CFR 572. The instrumentation requirements are summarized below in Table 2. Targets must be applied to the ATD, passenger seat, wheelchair, and test sled, in locations determined by the contractor and the COR for the video evaluation of the wheelchair and ATD kinematics.

Table 2. Instrumentation requirements for each sled test

ATD/Object Transducer Measurement Channel Count

ATD Triaxial accelerometer Head (x, y, z) acceleration 3 ATD Triaxial accelerometer Chest (x, y, z) acceleration 3 ATD Rotary potentiometer Chest (x) displacement 1

ATD 6-axis load cell Upper neck forces (Fx, Fz) and extension/flexion moment (My) 3

ATD Uniaxial load cell Femur, left, axial load (Fz) 1 ATD Uniaxial load cell Femur, right, axial load (Fz) 1 WTORS Four Triaxial load cells Reaction load (x, y, z) at WTORS 12 Sled Accelerometer Sled (x) acceleration (redundant) 2 Total 26

Test measurements – The following forces and accelerations must be measured and processed for the H3-50M and ATD and test sled, in accordance with SAE J211/1 [11] and SAE J1727 [12]:

- Triaxial head acceleration-time history

- Triaxial chest acceleration-time history

- Axial left and right femur force-time history

- Upper neck extension/flexion bending moment

- Upper neck axial force, Fz

- Upper neck shear force, Fx

- Triaxial WTORS load cell force-time histories

Injury Criteria –The injury criteria in Table 3 must be computed in accordance with 49 CFR 571.208, SAE J211 [11], and SAE J1727 [12], where applicable, and compared to the corresponding injury assessment reference values.

Table 3. Human Injury Assessment Reference Values for the H3-50M ATD

Injury Criteria H3-50M

ATD

Head Injury Criterion 15ms (HIC15) 700

Neck Injury Criterion (Nij) 1.0

Peak Upper Neck Axial Tension FZ, kN 4.17

Peak Upper Neck Axial Compression FZ, kN -4.0

Resultant Chest Acceleration, 3ms Exceedance, g 60

Peak Femur Axial Force FZ, kN 10

Even though neck injury criterion (Nij) IARVs are all listed as 1.0, the intercepts (also referred to as constants) used to calculate Nij are not the same for the different sized ATDs. Equation 1 shows the Nij equation, and Table 4 shows the Nij intercepts (constants).

Equation 1. Neck Injury Criterion (Nij)

𝑁𝑁𝑖𝑖𝑖𝑖 =

𝐹𝐹𝑍𝑍

𝐹𝐹𝑍𝑍𝑍𝑍

𝑀𝑀𝑂𝑂𝑂𝑂,𝑌𝑌

𝑀𝑀𝑌𝑌𝑌𝑌

Table 4. Nij Intercepts (Constants)

Nij Constant H3-50M ATD

FZC, when FZ > 0 6.806 kN

FZC, when FZ < 0 -6.16 kN

MYC, when MOC,Y > 0 310 N-m

MYC, when MOC,Y < 0 -135 N-m

SAE J1727 has further information on how to compute the upper neck extension/flexion moment about the occipital condyle (MOC,Y).

Test data format – The contractor must provide the COR with raw and processed ASCII data files from the instrumentation listed above in Table 2. The qualification/calibration documentation from the instrumented ATD must be provided upon request.

Video – The contractor must provide the COR with processed digital high speed video files from each experiment. The digital videos must be captured using three high-speed cameras (overhead, views from each side) to evaluate the ATD kinematics and compartmentalization.

Chalk – The ATDs must be chalked in areas where the contractor expects the ATD to contact an impacted seat.

Photographs – Pre- and post-test still digital photographs of the test configuration must be taken. At a minimum, pre- and post-test photographs of the test sled must be taken from all four sides, as well as close-up photographs of the wheelchair and ATD restraint systems and passenger seat to document any damage.

TASK 6 - DATA PROCESSING

After the tests, the contractor must process the test data to produce the results described above. The contractor must describe any data filters and data processing algorithms applied to the test data, and submit all test videos, photos, and test measurements to the COR electronically.

TASK 7 - TEST REPORT

The contractor must prepare draft and final test reports that include a written description of the test setup and implementation, data measured, and test results, including graphs of all the measurements taken and evaluation of WOTRS and rail passenger seat to limit forces and decelerations experienced by the ATDs. The FRA technical report template in MS-Word (provided as Attachment 2 to this document) must be used to write the report. The test report must be Section 508-compliant and follow the guidelines in the attached PDF document (provided as Attachment 3 to this document).

6 SCHEDULE OF DELIVERABLES

Table 5. Schedule of Deliverables for CLIN 0100

Task # Deliverable/Event Deliverable Format

Delivered to: Due Date

1 Test management plan MS Word or

PPT

COR 4 weeks1

2 Test implementation plan MS Word COR 8 weeks1 3 Ship passenger seats to test facility N/A N/A 10 weeks1 4 Conduct calibration test run(s) MS Excel or

ASCII

COR 12 weeks1

5 Conduct sled tests 1-3 N/A N/A 14 weeks1 6 Electronic data files from tests 1-3:

Test videos Test photos Processed Test Data

MP4

JPG

MS Excel or

ASCII

COR 2 weeks2

7 Test Report, Draft MS Word COR 6 weeks2 7 Test Report, Final MS Word COR 10 weeks2

Notes:

1. After CLIN 0100 award

2. After completion of sled tests 1-3 in Task 5

Table 6. Schedule of Deliverables for Contract Option CLIN 0200

Task # Deliverable/Event Deliverable Format

Delivered to: Due Date

5 Conduct sled tests 4 and 5 N/A N/A 4 weeks3 6 Electronic data files from tests 4 and 5:

Test videos Test photos Processed Test Data

MP4

JPG

MS Excel or

ASCII

COR 2 weeks4

7 Amend CLIN 0100 Test Report, Draft MS Word COR 4 weeks4 7 Amend CLIN 0100 Test Report, Final MS Word COR 6 weeks4

NOTES:

3. After Option CLIN 0200 award

4. After completion of sled tests 4,5 in Task 5

The contractor must electronically submit all deliverables to the COR via email or other electronic data transfer method.

The contractor must promptly notify the COR about technical, scheduling, or financial problems encountered and seek guidance.

7 PERIOD OF PERFORMANCE

The period of performance for the work in this purchase order is 12 months from the date of contract award.

8 REFERENCES

[1] American National Standards Institute/Rehabilitation Engineering and Assistive Technology Society of North America [ANSI/RESNA], 2017, ANSI/RESNA WC-4:2017: Volume 4: Wheelchairs and Transportation, Section 18.

[2] ISO (2022). 7176-19: Wheelchairs Used as Seats in Motor Vehicles. International Standards Organization.

[3] ISO (2012). 10542-1: Wheelchair Tiedowns and Occupant Restraint Systems. International Standards Organization.

[4] Parent, D., Tyrell, D., Perlman, A.B., "Crashworthiness Analysis of the Placentia, CA Rail Collision," Proceedings of I-Crash 2004, International Crashworthiness Conference, San Francisco, California, July 14-16, 2004.

[5] Parent, D., Tyrell, D., Jacobsen, K., and Severson, K., "Crashworthiness Analysis of the January 26, 2005, Glendale, California Rail Collision," American Society of Mechanical Engineers, Paper No. JRC2011-56132, March 2011.

[6] Tyrell, D., Severson, K., Jacobsen, K., Carolan, M., Lapre, P., Whelan, C., Schuster, J., Sandler, M., and Marceau, P., “Passenger/Freight Train Collision September 12, 2008, Chatsworth, CA: Main Report and Appendices,” U.S. Department of Transportation, DOT/FRA/ORD-17/20, September 29, 2017.

[7] Gordon, J., Severson, K., and Eshraghi, S., “Train-to-Train Impact Test: Wheelchair Securement Experiments,” Report No. RR 22-27, Federal Railroad Administration, September 2022.

[8] American Public Transportation Association, "APTA PR-CS-S-016-99, Rev. 3.1 - Standard for Passenger Seats in Passenger Railcars," Washington, D.C., October 2023.

[9] Klinich, K. D., Manary, M. A., Boyle, K. J., Orton, N. R., Hu, J.; “Development of an Automated Wheelchair Tiedown and Occpant Restraint System”, DOT HS 813 275, University of Michigan, Transportation Research Institute, October 1, 2022.

[10] SAE, "Performance Standard AS8049E - Performance Standard for Seats in Civil Rotorcraft, Transport Aircraft, and General Aviation Aircraft," May 2025. [Online]. Available: https://www.sae.org/standards/as8049e-performance-standard-seats-civil-rotorcraft-transport-aircraft-general-aviation-aircraft/.

[11] SAE, "Recommended Practice J211/1 - Instrumentation for Impact Test - Part 1 - Electronic Instrumentation," August 2022. [Online]. Available: https://www.sae.org/standards/j2111_202208-instrumentation-impact-test-part-1-electronic-instrumentation/.

[12] SAE, “Recommended Practive J1727 – Calculation Guidelines for Impact Testing,” February 2015. [Online].

Available: https://www.sae.org/standards/content/j1727_201502/.

https://www.sae.org/standards/as8049e-performance-standard-seats-civil-rotorcraft-transport-aircraft-general-aviation-aircraft https://www.sae.org/standards/as8049e-performance-standard-seats-civil-rotorcraft-transport-aircraft-general-aviation-aircraft https://www.sae.org/standards/j2111_202208-instrumentation-impact-test-part-1-electronic-instrumentation/ https://www.sae.org/standards/j2111_202208-instrumentation-impact-test-part-1-electronic-instrumentation/ https://www.sae.org/standards/content/j1727_201502/