When diesels are running in mu the throttle and breaking are controlled thru cables connected to each engine.
How are throttle and breaking controlled to helper diesels when they are mid train or end of train?
If in mid train or end of train and its a true helper then there will be an engineer and either a conductor or brakeman ( certain railroads have work rules which determine the class of service) and they will run the locomotives.
If it is Distributed power. Everything is controled by the engineer in the lead motor.He can either run them in synch with the leader ( just like they were all mu'ed) or he can run them independently.
Hope this helps, FYI there is an area in the trains forum that talks about locomotives. If you have any more questions give a shout.
Yes we are on time but this is yesterdays train
Thanks for your answer. Maybe I wasn't clear. How do the controls get to the engines in distributed power. They're not connected by cable. Is it by radio or what?
Thanks again
Some RR's set up helper engines to be controlled by radio as far back as the 1960's, such as the NP. Some of the early attempts didn't work too well, and in a few cases the crew lost control of the helpers. In recent years it's been much more reliable.
Yes it is basiclly by radio in modern DP. There was the Harris box version ( used on the Santa Fe power we had and in my opinion it was JUNK!!) and Integrated which is what all new power has.In concept its like arming a FRED ( obviously with a few more steps but same kinda concept)You set up the rear ( or mid train DP) like its a trailing unit. All controls except actuating are controled from the head end.
NP and Southern IIRC had the Locotrol mid train helper set up. Wasnt it old B units that had all the radio control equipment placed in them?
Dp is very reliable but sometimes we do get communication loss. Some spots its an all the time thing ( places where your in a canyon or have hills and the like)and you just deal with it.
Wasn't the Clinchfield steamer equipped with stand to operate diesel helper rather than double head with two crews?
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Thanks, you've been very helpful. I appreciate it.
Not just on the Clinchfield, SP 4449, the now retired Frisco 1522 are two that i'm aware of as being equipped with a control stand for diesel MU. There could be others. Baldwin was developing a steam throttle MU at the time the steam era ended, no prototypes were ever produced.
The Clinchfield ten-wheeler had a tonnage rating of only 200 tons, two F7 B units were modified to assist, thus no engineer was present.
Dave
IIRC there was some early (1960's) Distributed power equipment that relied on a sensor on the front pointing DPU locomotives drawbar to activate the throttle i.e when the cars in front pulled on the Engine's coupler the loco throttled up and when the coupler slacked off the unit throttled down. The idea of this was to allow any locomotive to operate on the front end of the train without having to have the RC equipment installed. Obv. this was far less responsive performance- wise than Radio Controlled DPU equipment. I believe L&N may have used this type of system...
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That's interesting, I didn't know that. Thanks for the answer
Sounds like you're an engineer. Thanks for the insight, it was very interesting
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