From: grr@cbmvax.commodore.com (George Robbins)
Newsgroups: rec.railroad
Subject: Re: Diesel vs. Electric Locomotive Maintenance
Date: 13 Oct 92 07:16:20 GMT
Reply-To: grr@cbmvax.commodore.com (George Robbins)
Organization: Commodore, West Chester, PA

In article <Bw0rEz.30F@access.digex.com> terryfry@access.digex.com (Terry Fry) writes:
> In article <35752@cbmvax.commodore.com> grr@cbmvax.commodore.com (George Robbins) writes:
> >In article <BvsIDw.KGM@access.digex.com> terryfry@access.digex.com (Terry Fry) writes:
> 
> >They were straight AC "wired" as you put it.  Conversion to 60 Hz would
> >have required replacing the main transformer and related components with
> >60 Hz rated gear and inserting rectifiers in the traction motor circuits,
> >since the interpole "DC" motors that work effectively on 25Hz AC can't
> >be made to work well at 60 Hz.  Obviously, this amount of re-engineering
> >on "worn out" 40-50 year old equipment wasn't attractive, assuming that
> >space and other constraints would have allowed - any electric locomotive
> >more complicated that the 600 volt "trolley" motors are typically packed
> >full already.
> >
> 
> Those engines ran "before" my time, I was in high-school during the last 
> years of operation... and not anywhere near Potomac Yard to see any operations.
> 
> I once mentioned the GG1 in the same breath as rectifier, and did I recieve
> mail on that one.  Some of the more detailed messages I have since forgotten
> but the general difference still sits in my mind.  I often wondered
> that some of the GG1's logevity must reside in the simplicity of design
> they had.

Well, possibly, though I wouldn't overwork the notion of simplicity, they
were farily sophisticated for their time and took advantage of the best
technology available.

The other major factor is that they represent a refinement of the basic
design theme tested over several generations of Pennsy electric locomotives,
combining the AC motor technology* developed on the P5 and predecessors with
the articulated frame design successfully used on New Haven boxcabs.

* pairs of AC interpole traction motors suspended over the axles geared
to a "quill drive" consisting of a spool surrounding the axle with fingers
driving between "spokes" in the wheels.

Basically, there was nothing "better" available until the refinement of
high power mercury vapor rectifiers (later solid state) made possible the
GE E33 and E44 electric freight locomotives which which used diesel
derived carbodys and DC traction motors.  These (E44) were able to displace
the older P5 engines and some GG1's in freight service and the resulting
surplus of GG1's and declining passenger service left them in a situation
where they really didn't need a "better" passenger locomotive.

The Pennsy's solution to the Northeast Corridor was the Metroliners,
based on souped-up Budd MU cars.  These were supposed to be capable
of 120-160 MPH service (track conditions not permitting) and probably
bridged the gap between relying on GG1's entirely and needing a
replacement for both the Metroliners and the GG1's.

The Amtrak euro-engines are kind of a mixed blessing, it's interesting
to contemplate what the Pennsy would have come up with if they had
faced the GG1 replacement problem with their engineering powers intact.

-- 
George Robbins - now working for,     work:   to be avoided at all costs...
but no way officially representing:   uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
Commodore, Engineering Department     domain: grr@cbmvax.commodore.com
Newsgroups: rec.railroad