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Re: What does the freight/commute switch do on an SDP-45
Author: HUTCH 7.62
Date: 07-31-2013 - 17:23
Dr Zarkoff Wrote:
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> This was an SP modification. When put in the
> "Commute" position, the switch put the switch gear
> into parallel so you started out in parallel and
> never had forward or backwards transition during
> acceleration and deceleration. In "Frt" you had
> forwards and backwards transition. After this
> modification, the engines were known as
> troublemakers because of not loading sometimes
> after making backwards transition, particularly
> the 3208. The "fix" was to zip the throttle to
> idle and then back out to what ever position you
> were in.
>
> There was no HEP and no blended braking, unless
> you did it manually which was virtually unheard of
> in those days. The switch, being in the
> locomotive's electrical power system, had nothing
> to do with the air brakes.
I don't get exactly what you mean by transition.
-------------------------------------------------------
> This was an SP modification. When put in the
> "Commute" position, the switch put the switch gear
> into parallel so you started out in parallel and
> never had forward or backwards transition during
> acceleration and deceleration. In "Frt" you had
> forwards and backwards transition. After this
> modification, the engines were known as
> troublemakers because of not loading sometimes
> after making backwards transition, particularly
> the 3208. The "fix" was to zip the throttle to
> idle and then back out to what ever position you
> were in.
>
> There was no HEP and no blended braking, unless
> you did it manually which was virtually unheard of
> in those days. The switch, being in the
> locomotive's electrical power system, had nothing
> to do with the air brakes.
I don't get exactly what you mean by transition.
