The traditional method for accessing bogies was to lift the car body off the bogies by use of an overhead crane or cranes as shown in the left hand photo below. Each vehicle to be lifted has to be separated from its fellows in the train and dealt with separately. If one car in a set is defective, it has to be uncoupled and pushed into the shop for lifting. To access the bogies, the overhead crane is used to lift one end while the bogie is rolled clear and then the body is lower onto stands. Then the other end is lifted, the bogie rolled clear and the body lowered onto two more stands. Motors, wheels and other items can then be worked on or removed from the bogie as necessary. Naturally, this takes up a lot of track space in the shop and requires time spent on separating the vehicle from the train and then from its bogies. For overhauls, the bogie may be removed to a special area where it is placed on stands for stripping and refitting work.
A quicker lifting method is to use two cranes which lift both ends of the car body together and free both bogies at the same time. The body can then be removed to another part of the workshop for maintenance.
 Car being lifted in a workshop by a pair of overhead cranes |  |
Jacks are the usual method of lifting nowadays. Vehicles can be lifted individually or, if a fixed formation is used for normal service, more recent practice has been to lift the whole train set. This is done by synchronised jacks. The jacks are linked by control cables and controlled by one person from a control desk. The big advantage of this system is that you don't have to break up the train into individual cars to do the work on one vehicle. The time saved reduces the period the train is out of service.
Underfloor jacks are also becoming more popular as shown below.
 Workshop with underfloor jacks |  Car lifted with underfloor jacks. |
Again, the lifting system is synchronised to allow several cars to be lifted at the same time if necessary. This is quicker then uncoupling each vehicle, especially if there is only one requiring attention.
Rolling stock can be lifted on a track where there is no pit, especially if there is a need to exchange a piece of underfloor equipment. A fork lift truck can be used to do this if there is enough room at the sides of the trains for it to manoeuvre. Otherwise a small scissors lift table can be used. In all cases, it is essential to ensure that the floor will take the weight of the train raised on jacks. Most modern rolling stock is designed to be lifted with its bogies still attached so that exchange of one piece of underfloor equipment can be carried out on a lifted train without disturbing any other cars.
Bogie Drops
Bogie Drops
 Bogie drop table |  Bogie being lowered |
heightAnother system used in some shops is the bogie drop. The train is run over the lifting road, which has a pit and is positioned so that the bogie to be removed is located over a special section of track. The bogie requiring removal is disconnected from the train, using the pit for access. The car bodies are then lifted, leaving the disconnected bogie on the track. The section of track where the bogie is located can now be lowered into a basement area and the bogie removed and replaced by a fresh one.
heightA variation of this system has the train lifted by raising the sections of track under the bogies. The car bodies are then supported by stands placed under them and the bogies to be changed are disconnected. Once free, they are lowered to floor level and serviced or exchanged for new bogies. Turntables can be installed to assist in the removal of the bogies to other maintenance areas.