For many design purposes, it is sufficient to regard trains as simple cylindrical blockages moving at constant speed through the tunnel system. In ThermoTun, simple trains such as this are usually defined by their length, cross-section and frictional resistance alone.
When desired, "simple" trains can be given more than 20 characteristic properties defining their geometry, resistance, power, conventional and regenerative braking, temperature, thermal capacity, on-board services, aerodynamic sealing and even the compressibility of the train body itself. However, you give only as much detail as you wish. The software takes care of the rest.
More complex trains can be formed as a line of wagons, each of which can be assigned as many of the above properties as you wish. There are ample copying facilities so this is not a major task. The process of telling ThermoTun what you want is almost certain to be far quicker than the process of deciding what you want in the first place.
Each train can be assigned its own speed characteristic. This can be prescribed a-priori as a function of time or distance or it can be deduced from prescribed traction power. Often, the train speed may be regarded as constant during entry, travel and exit. Nevertheless, accelerations and decelerations are commonly important, especially in underground railways.
