Select A Power

Hello Everyone,

Does anyone know what the Select A Power Decal on the sides of some Conrail locomotives refer to?

If this question has been answered before please let me know.


Eric

Eric Kreszl wrote:Hello Everyone,

Does anyone know what the Select A Power Decal on the sides of some Conrail locomotives refer to?

If this question has been answered before please let me know.


Eric

http://crcyc.railfan.net/locos/ge/7c30a/c307aproto.html

All Conrail C30-7A's are also equipped with Harmon Select-A-Power, which is noted in a decal on the cab either above or below the 'C30-7A' locomotive class. Harmon Select-A-Power is an add-on fuel-saving electronic device. When a train doesn't need all its units to be online, this device allows an engineer to take trailing units off line one by one until only the lead unit is active. Units can also be reactivated as needed. When a unit is offline, it produces power of throttle position #1.

scotty269 wrote:

Eric Kreszl wrote:Hello Everyone,

Does anyone know what the Select A Power Decal on the sides of some Conrail locomotives refer to?

If this question has been answered before please let me know.


Eric

http://crcyc.railfan.net/locos/ge/7c30a/c307aproto.html

All Conrail C30-7A's are also equipped with Harmon Select-A-Power, which is noted in a decal on the cab either above or below the 'C30-7A' locomotive class. Harmon Select-A-Power is an add-on fuel-saving electronic device. When a train doesn't need all its units to be online, this device allows an engineer to take trailing units off line one by one until only the lead unit is active. Units can also be reactivated as needed. When a unit is offline, it produces power of throttle position #1.

Thanks for the info.

Eric

Many Conrail locomotives in the past were equipped with Harmon fuel savers. The engineer on the operating unit could cut
power on as many trailing units as he desired to in order to save fuel while providing for adequate power where the grades
were not severe and fewer than the assigned units would adequately maintain the running times.
Use of this feature did NOT isolate the trailing units but rather reduced traction power to first notch power on the trailing
units at were not needed for full power. They were also on the line for dynamic brake use if it was needed without any
further action by the engineer. The theory of first notch power for units so selected by the engineer was to provide enough
power to carry the weight of the engine.
My opinion of this device was that it was a good feature for saving fuel and often it helped in train handling as well.
The only time I would not use the device was in extremely cold weather and I seem to recall that the railroad had instructions
regarding the use in cold weather.
With proper use, these devices could pay for themselves over a period of time.
Noel Weaver

When I hired in 1990 the select-a-power system was almost never used. The control panel for these was a series of buttons and lights lined up that you touched to add or delete units. All the engineers said it was a pain in the ass ,never worked or caught on for one reason or another. I think the Altoona area might have used this system more than other divisions? Seems in the 1980's this system peaked on Conrail.

Noel Weaver wrote:The only time I would not use the device was in extremely cold weather and I seem to recall that the railroad had instructions regarding the use in cold weather.
Noel Weaver

I'm thinking in low temps the viscosity of lube oil & fuel could stall out the engine vs keep at notch 1 power output.

- A

Of the 5 General Electric U-30-Bs that McHugh Bros. New Hope & Ivyland RR got from ConRail for themselves and The Shore Fast Line, 1 came with Harmon Select A Power. It allowed selection of any of 8 units in a consist.

TREnecNYP wrote:

Noel Weaver wrote:The only time I would not use the device was in extremely cold weather and I seem to recall that the railroad had instructions regarding the use in cold weather.
Noel Weaver

I'm thinking in low temps the viscosity of lube oil & fuel could stall out the engine vs keep at notch 1 power output.

- A

nope. first notch is still idle. if the reverser is centered, and units are equipped, they will run at a "low idle" speed, otherwise they run at "service idle" speed, in idle and run/notch 1. fuel runs through a heater anyways, and excess warmed fuel is returned to the tank, at any speed. lube oil doesnt really matter. it's 30 weight, and doesnt get that thick, until you get into single digits or below, if the engine isnt running.