Inclined vehicles

If a level railway track starts to rise or fall, a passing vehicle has to be aligned to the resulting curve. This is done by defining two points of contact between the vehicle (its wheels) and the track. The connecting line between these points defines the inclination to be used for the vehicle body.

If two single axes or two bogies exist, the real points of contact are used or the central locations of the bogies are assumed as virtual points of contact. But if irregular wheel arrangements exist or the vehicle consists of different partial bodies like steam locomotives with separate tenders or the "three-room-appartment with wheels" E 91, this method will not succeed. Here, additional information is necessary to calculate the appropriate points of contact for correct inclinations.

For this, the vehicle bitmap has an additional bottom line with control pixels added as shown in the illustrations alongside.

The control line, containing locations for points of contact as well as for boundary points, can be recognized by the existence of a black pixel at the right lower corner of the bitmap (3). Individual black pixels within the control line identify points of contacts, where the straight connecting line between such two points (to be drawn virtually along the track profile) defines the inclination for the vehicle body (in the illustrations alongside, the single inclination region between two points of contact is marked with (4)).

If a vehicle body is overhanging (i.e. its edges are outside of the region between the points of contact), the inclination for the outside parts (marked with (5)) is not altered relative to the inside part of the vehicle body. The overhang is delimited either by the boundary of the vehicle or by an adjacent partial body of the same vehicle which has its own inclination. In the latter case, the boundery between these two bodies is marked by a boundary point within the control line which consists of two concatenated black pixels.

If the bitmap contains two side views of the vehicle, only the information for the left part is needed. For the right part, the program uses the mirrored information.