Pantographs
The two pantographs of type DSA 350 SEK (recognisable as half-pantographs, as opposed to the diamond-shaped full pantographs) were originally developed by Dornier, and built in Berlin-Hennigsdorf. Today, the firm Stemman-Technik GmbH in Schüttdorf are manufacturing and distributing these units. They weigh 270 kg (600 lb).
The pantographs are screw-mounted to the roof at three points. Pantograph 1 is connected directly through the roof to the main control switch in the engine room; pantograph 2 is connected via a cable splice running along the side wall of the engine room to the main switch. The contact shoes are outfitted with a monitoring system in case of contact shoe breakage. Inside of the contact shoe, which is made of graphite, runs an air channel, which is overpressurised. In case of breakage, the air escapes, causing the pantograph to automatically retract, preventing possible damage to the overhead contact wire.
The pantographs are raised using compressed air, which is provided at 5 bar (500 kPa/73 psi) to the lifting cylinder. Raising the pantograph takes 5 seconds, while retraction takes 4 seconds. The contact shoe pushes against the contact wire with adjustable pressure of between 70 and 120 N (16 and 27 lbf). The driver controls the pantograph via a push button on the driver's desk (Up, Down, and Down + Sanding for emergency cases are the settings). The choice of which pantograph to use can be left up to the locomotive by the driver, which would automatically use the back pantograph in the direction of travel, or, in double heading, where two locomotives are coupled, it would be the front pantograph on the front locomotive, and the back pantograph on the back locomotive. Otherwise the driver, using a switch located on the battery control table in driver's cab 1, may raise one or the other, or both together. This is primarily an advantage during shunting/switching operation, where otherwise the change from one driver's cab to the other would mean the automatic switching from one pantograph to the other. In cases where the pantograph is being switched, the unit that was in the down position is lifted first, and once it is successfully pushed up against the contact wire, the pantograph that was in service is lowered.
The compressed air for the lifting and lowering of the pantograph, as well as for the contact shoe monitoring system, are supplied via two teflon-coated hoses on the roof, which have to withstand the 15,000 volts of contact wire voltage.
Read more about this topic: DBAG Class 101