On Fri, 28 Jun 2013 19:34:43 -0500, Ignoramus10926
wrote:

http://igor.chudov.com/tmp/Union-Pac...Locomotive.jpg

Nothing - they recycled some of the doors from another locomotive that
had the lettering laid out differently - note the background yellow is
more faded on the forward doors. They save everything that's still
usable, and raid the boneyard for parts just like you do.

And the paint jobs are low priority, until there's a capital
investment program to re-paint them al in a new color scheme. A lot
of times it's "get it back in service and making us money" period.

The extra louvers on the rear doors might have been from adding
dynamic braking resistors to a loco that wasn't built with them - you
really don't know unless you have the shop records, or ask the
engineer operating it.

That would be far from the first monster that a railroad has built -
they took all the surviving EMD F series streamline locomotives and
re-bodied them into freight locomotives, because you couldn't see for
beans with the full bodies on them. You don't need to see close for
mainline cross-country work, but you do for switching and siding
deliveries.

They take locomotives with blown engines or wrecked bodies, whack off
the body, and turn them into "Slugs" - powered trucks for climbing
hills. At low speeds the generator in the locomotive is turning full
speed and putting out full power - but the motors in the trucks can't
use it all without burning up because they're creeping. (Even with
external fan cooling.) A Slug gets power from the lead power unit
locomotive.

Union Pacific even ran Gas Turbines for a while - Jet Engines running
on #6 Bunker Oil pre-heated. And they parked under bridges and melted
the asphalt off the road deck a few times... But when the supply of
cheap heavy bunker oil went away (as they figured out how to crack and
refine it into gasoline and diesel) so did they.

-- Bruce --