These locomotives have a higher tractive effort than standard DC-traction locomotives. The larger than usual longitudinal tractive and braking forces transmitted through the track structure to railway bridges has caused some concern in the industry. The forces and stresses in typical bridges that are caused by AC-traction locomotives are currently under investigation. A number of analytical studies on common types of railway bridges are currently under way. In the near future, an experimental study of a railway bridge subjected to AC-traction locomotive loadings is planned.
Further utility is gained from the finite element modeling of the track structure.
In general, most studies of the longitudinal loads in track structures caused by passing trains have tended to concentrate on more localized effects. The currently developed models employ modern finite element techniques which allow researchers and practicing engineers to better simulate actual loading and response conditions in the field.