Overview
“Bimodal” trains are a part of the well known combined, rail-road transportation system. The advantage of the bimodal idea is that this method of transportation completely eliminates vertical movements of loading units during terminal operations. Loading units (semi-trailers in the road mode) form the train after being attached through adapters to freight bogies. In the structure of the train there are front, rear and intermediate bogies equipped with single and double adapters.
The Polish prototype of the bimodal train was presented for the first time in Poznan, during the International Fair in 1994. The lack of information concerning safety of braking of bimodal trains longer than three wagons was the main motivation for modelling and investigation of long bimodal trains.
So far, the dynamic behaviour of braking bimodal train running on curved track and equipped with adapters, has not been investigated.
Results obtained from simulations in the ADAMS/RAIL package provide with reliable information concerning safety of a long bimodal train (19 coupled car bodies utilising coupling devices). According to this information we can say that two of the main criterions for the judgement of bimodal freight cars with respect to derailment (Nadal and Weinstock) were performed.
The simulations were performed using AdamsRail software, specially designed for simulation of general multibody systems. AdamsRail enables modelling the system, then automatically generates the equations of motion and prepares the numerical results to analyses and visualisation.
Funding
Results
In the realised research project the investigation method, according to the safety of long bimodal trains, was described scientifically and examined on straight and curved tracks. A modern simulation tool was used to model and calculate the objects, which consist of 53 units: 2 locomotives and 51 freight wagons. The model of the long train was composed of classical and bimodal cars.
The simulations were performed using AdamsRail software, specially designed for simulation of general multi-body systems. The general non-linear wheel-rail contact model, the model of coupling devices and model of pneumatic braking system were utilised during simulations. Results obtained from simulations provided reliable information, according to the assessment of long bimodal trains with respect to measuring the safety against derailment, in extreme conditions (acceleration and braking the train).
Technical Implications
The results can be utilised in scientific-research centres, interested in development of modern, rail-road transportation means (especially bimodal transportation system). A considerable part of the results was introduced into the specialization of “Vehicles” in “SiMR” department, of Warsaw University of Technology.
Policy implications
These results may be very important for potential users (rail enterprises) in the near future, because transport of goods by bimodal train belongs to the “Just in Time” system of transportation, very profitable from economic point of view.