Abstract:
A resilient insulating structure on the interior surface of a railway freight car body in contact with lading carried by the car and supporting at least a substantial portion of the lading carried by the car. The resilient insulating structure comprises a layer of polyurethane foam material having its outer surface secured to the inner surface of the metallic car body and an elastomeric inner liner secured to the inner surface of the polyurethane foam material. The polyurethane foam material forms an intermediate cushioning layer for the elastomeric inner liner and is of a thickness at least around 1 inch and may be as great as around 8 inches. The elastomeric inner liner is less than around 1/2 inch thickness and has a stiffness less than the stiffness of the foam material. Some of the energy created by forces exerted by the lading against the resilient insulating structure is dissipated by the deformation of the insulating structure with the remainder of the energy being transmitted to the railway car body through the insulating structure. Upon unusually high local stresses being exerted, such as from a tool or a workman within a car, the intermediate foam layer may be deformed permanently while the elastomeric inner liner in contact with the lading remains undamaged.
Abstract:
An insulated covered hopper railway car having a layer of rigid polyurethane foam applied on the outer surface thereof by spraying in place. An outer coat of a polyester resin is applied, such as by manual brushing, onto the outer surface of the polyurethane foam material on certain areas of the polyurethane foam material which are exposed to wear and abrasion, such as roof areas adjacent the walkway or running board and areas between the separate hatch covers. A layer of fibrous material, such as woven fiberglass, is then positioned on the coat of polyester resin. Then, the fibrous material is brushed and rolled to remove any air and to embed the material in the coat of polyester resin. The resin is then allowed to gel and cure which will be around 45 minutes at 77* F.