Innovative Safety Systems for Rail Vehicles: A Case Study

Sharma & Associates (SA) is a company that provides engineering solutions to the railroad industry. They specialize in railway mechanical and infrastructure engineering, as well as mechanical engineering projects in the automotive and consumer electronics industries. Since 1995, SA has delivered safe, effective, and efficient solutions to its customers, which include the Federal Railroad Administration (FRA), the Association of American Railroads (AAR), railroads and transit agencies, rail car builders, and rail car component manufacturers. SA also works with the National Transportation agency (VOLPE), a part of the U.S. Department of Transportation, which helps the transportation community anticipate emerging problems with technical, operational, and institutional issues.

Train collisions, though not common, can have devastating impacts, especially on the often unprotected rail engineer. The interior of the front rail car is built to withstand a moderate to severe impact, but the engineer console is virtually unprotected, leaving the engineer vulnerable to potentially life-threatening impact injuries. Sharma & Associates (SA), a provider of engineering solutions to the railroad industry, initiated research into creating an Engineer Protection System (EPS) concept. However, SA was not familiar with the necessary safety requirements, available systems, or overall performance tuning of impact environments and needed a partner to help develop the new system. The EPS had to meet specific criteria: it could not be triggered by the engineer and could not interfere with the engineer exiting the control car.

SA enlisted the help of Altair ProductDesign for the project. Altair's first task was to create accurate finite element (FE) models of the interior of a standard rail operator's cabin using HyperWorks pre-processor, HyperMesh. They then brought in a human dummy model into the environment and positioned it into the engineer’s seat facing the control panel. Altair’s crash specialists experimented with a wide variety of airbag types, sizes, positioning, and flow rates, along with developing a new deformable knee bolster to absorb impact forces during a crash. The EPS system that the team developed used an automobile passenger style airbag system in combination with a crushable knee bolster to keep injuries to a minimum, while also meeting compartmentalization, egress, and functionality requirements for an unbelted occupant. The development effort used analytical modeling at the system and sub-system levels, in combination with a series of quasi-static and dynamic sled tests using HyperWorks’ RADIOSS solver, to develop and demonstrate system level performance.

• The project demonstrated the feasibility of developing a protection system that can effectively protect cab engineers by applying modern occupant protection technologies, through the use of state-of-the-art analytical techniques and test methodologies. The EPS system is designed and ready to be installed in current rail control cars and is adaptable to work with new designs. It is currently waiting to be used and implemented by rail manufacturers to increase the safety for their engineers from secondary impact. The partnership between SA and Altair continues to be a strong one with SA continuing the use of HyperWorks and Altair ProductDesign services when necessary.

• All performance targets for the EPS were met
• The new safety system added minimal cost and weight to the rail car
• The system does not hinder the engineer from exiting the cab