Bob is absolutely correct! For the unitiated, they are Multiple Unit connectors to which cables connect from one locomotive to another and will allow one locomotive's cab operating controls to control the other locomotives to which it is connected (a consist).
OK .. I'll buy that. NOW, what are all the hoses for? Usually 6-8 on each end? I thought they were mu connections?
The multiple unit (MU) electrical receptacles were "high mounted" on the GP-7s to help facilitate electrical connections with car body units. Most early full width car body units (F-3, F-7, FP-7, F-9, E-7, E-8, FA and FB units) had high mounted MU electrical receptacles. On these units the receptacles were near the nose headlight on A units, typically covered with a small door, on the front and near or above the top of the door at the rear and on B units. This permitted the use of a shorter "standard" length of MU jumper cable to connect any combination of unit types. More modern units standardized with low mounted MU stands just above the end walkways. Today almost all units have the MU receptacles mounted in the front pilot below the end walkways. Hope this helps. Thanks! Mark
This thread is a perfect example of what is so great about Frisco.org. Thanks guys collectively your the best! Bob Wintle Parsons, Ks.
Way to go BOBO very true. I now have more questions .... Main Reservoir Equalizing Hose ?? (holding tank or what?) Actuating Hose ?? (for actuating what?) Brake Cylinder Hose (maybe smart enough to figure this out) Sanding Pipe ( really??)
I went to Wikipedia and found lots of info on MU's. http://en.wikipedia.org/wiki/Multiple-unit_train_control Thanks much - guys
In the same manner that the electrical "jumper cable" combines the electric functions of each unit into one locomotive, the Main Reservoir Equalizing Hose, the Actuating Hose, and the Brake Cylinder Hose combines the air brake components of each unit into a single system. The pneumatic sand pipe(s) combined to make the sanders of each unit function as one. There are two sand lines on each unit, one forward and one reverse. They are connected so the the leading sander on each unit is controlled from the lead unit. Some locomotive sanders are controlled through the electric MU Jumper cables. The Main Reservoir Equalizing Hose combines the (generally two) main reservoirs on each unit and and the air compressor on each unit into a single system. See the attachment which was taken from the Frisco's "Train Handling Rules & Instructions for Controlled Train Dynamics". The Actuating Line is pressurized when the independent brake is baled-off. (the engine brakes are released while maintaining a set in the train.) The Brake Cylinder Hose is pressurized according to the amount of braking applied to the independent (locomotive) brakes. The air brake schedule of the locomotive detemines the number of these MU hoses. Some roads had ten or more hoses for a duplex set-up. This feature allowed units with a 24RL or 26L to mate with a units that had a 14EL, 6SL, or 6 BL schedule
Karl ... thanks very much. That is a really good diagram. I am gonna enlarge the diagram and print it out. Jessez, I had no idea that the braking system and air lines were that involved, even down to the sanders. All U guys .. thanku, thanku very much .. unnn-huh!
Sherrel, Check this link for the complete diagram of Diesel Locomotive Connections. http://www.frisco.org/vb/showthread.php?t=2874
Superb explanations, gentlemen. In spite of my internal-combustion aversion I read through and learned quite a bit. A good team effort. Best Regards,
