RE: L classes (Was Harris trains etc) maybe TAN
  Brian Blunt

I had a few drives of light 46s with one of my mates in years gone by.
Inadvertently started off in S/P on one occasion, certainly got a kick up
the bum from it.

Brian (enjoying some Bishop's Best Dark Ale)

From:TramsDownUnder@... [mailto:TramsDownUnder@yahoogroups.com]

Sent: Monday, 8 February 2016 19:39
To:TramsDownUnder@...
Subject: Re: [TramsDownUnder] L classes (Was Harris trains etc) maybe TAN

Gday Tony

I too like the 46 as well as the L

Thanks for the 46 stories

I like the full series and release the independent start

I heard a light 46, from a standing start,at one end of the Penrith
platform got to 60 MPH at the other. Is this poss ?

Cheers, Mick

On 6/02/2016 4:05 AM, Tony Gallowayarg@... mailto:arg@aapt.net.au
[TramsDownUnder] wrote:

Yeah, the 46s were powerful - the Ls weren't intended to drag trains up 3%
grades, and I reckon a 46 would beat a Hammersley C636 Alco on short term
overload horsepower, as they could briefly deliver around 6,000hp + starting
effort to the rail. But a 46 would begin to shimmy and gallop over 60mph,
they were not built for speed. 4620, the Granville derailment engine, had a
particularly bad rep for poor ride quality and probably should have been
banned from everything but pusher duty. It had been in several derailments
before Granville, and was regarded as a "hoo-doo".

After Granville it was scrapped.

When I was just out of my apprenticeship I was working at Chullora loco
works, doing a lot of bogie change work mostly on 44 and 45 class Alco
diesels, the occasional EMD (42, 421, 422 classes) and 46s. With the diesels
you had to crawl up between the traction motor and the bolster to disconnect
the motor leads, but on a 46 the connections were inside the carbody - much
easier and cleaner to get at.

To start a dead 46 you'd raise and hold up one of the pans with a long
wooden pole stowed on the engine, after closing the compressor switch -
you'd need about 40-50lbs of compressed air to keep the pan against the
wire. They were different to drive from a diesel, having series,
series-parallel and full parallel power notches plus the regenerative brake
notches which could be used as a kind of "cruise control" - when the line
voltage was higher than the back EMF they'd drive, when the motor voltage
was higher they'd brake - can't do that with a dynamic brake on a diesel
loco.

And if you wanted to do the equivalent of a full throttle, clutch-drop drag
racing start with a light engine - notch up full series, watch the ammeter
sweep round to the red zone, then release the air brake - it'd take off like
a raped ape with all wheels spinning and throwing sparks - no diesel would
do that anywhere near as well as a 46.

Tony G