 On the trailer cars, the trucks are similar to those of ordinary passenger cars, but have shorter frames.They lack axlebox guides (the longitudinal movements of the axles relative to the truck frame are limited solely by the suspension springs themselves), the springs are softer, the central pivot is made of 3 segments (which gives it a degree of flexibility), and the axlebox suspension friction shock absorbers are mounted inside the springs (on the power car trucks, they are mounted outside).The leading truck of the driving trailer has brackets for mounting the cab signal receiver coils.