Prototype Locomotive Operation

[TrainMaster1]

Hours of service was an meter that read how many amperes were running through the traction motors...it was never disengaged at any time since it could the difference of a long walk to a crew van plus some serious explaining in front of a trainmaster and division personnel.

This was commonly known also as the ammeter as well. It's real purpose was to monitor when you traction motors were in the red zone. This was an area where depending how far in the zone you were, in turn, meant how long it was until you would successfully melt or otherwise harm your traction motors. Red zoning creates a ton of heat on the motors and generally happens when the engine is below its lowest continuous rated speed and under heavy load. Think long coal train uphill. If the road did not power the train correctly, you find yourself asking an awful lot from the engines on your train. That is when you had to know how to work the throttle just right to make the hill and still have a viable engine on the other side.

Had nothing to do with how many hours the crew actually worked. Believe me guys were excellent at keep track of that and did not need a meter to let them know when it was time to end their day.

Nick

[Kali]

They relied on the driver for that over here - you were allowed an hour a day up to a point in the yellow zone on the ammeter ( unless it's an electric, it was good practice to run those in the yellow for some reason ). I'm not sure how strictly that rating was/is adhered to...

[mapitts]

The ammeter also works in DB mode too. Yes, you can burn up traction motors with the dynamic brakes as well as the DB resistor grids. Never could figure out how DB's worked with AC traction motors until I found out about DC pulsed injection. AC traction motors are probably the best thing to happen to railroads since they started to dieselize. They will take a lot more of a beating that a DC traction motor could even think about.

[gleno747]

I have a question. Do locomotives shut down after a certain amount of time of being in idle stage?

[Kali]

That will depend entirely on the engine, but until recently not if they were left alone. One of the US builders has added a sleep option, I suspect the europeans will follow suit ( one of the Siemens DMUs shuts half it's engines down in transit if they're not all being fully used ).

[mapitts]

No, they idle unless turned off. It takes a long time for a locomotive to warm up. Crank an ALCO 539 on a 30 degree day. You can run 8 hours and not get above 120 degrees if it is cold. I have seen that happen even with the radiator shutters closed. Better off letting it idle. Cranking a locomotive from a cold start is a little different. When it is cold not all of the cylinders will fire. This causes over fueling and a condition known as a wet exhaust manifold. Wet with diesel fuel. When it warms up and the fuel reaches it's flash point, the exhaust manifold, turbo ( if it has one ) and stack flame out. There is a device called Hot Start that will crank a locomotive and let it warm up in cold weather. When it reaches a certain water temperature, it will shut it off. I know CSX has that installed on some units. Mostly GP-38's & GP-40's. They are the most common used for switching setting who knows where. Most locomotives just idle all the time when not in use in the winter time. A locomotives engine is not designed for antifreeze. Several years back NS crews were instructed to not use DB when stopping to only use the train line brakes to conserve fuel. They were also instructed to shut all of the units in their lash up down if they were going to idle more than 30 minutes.