Re: European freight yard operations vs US Operations

On Thu, 03 Sep 2009 10:18:23 -0700, David Nebenzahl
<nobody@xxxxxxxxxxxxxxx> wrote:

On 9/3/2009 12:48 AM Twibil spake thus:

In an interesting and little-known sidelight; the Southern Pacific's
cab-forwards had a built-in advantage in the weight-transfer
department: where a normally oriented articulated would *lose* weight
on the pivoting driver set as the locomotive climbed a grade -possibly
causing a loss of traction- the pivoting set on cab-forwards actually
*gained* more traction on grades, which explains why these locos had
such an outstanding reputation for not slipping.

Warning: tangent.

Speaking of cab-forwards: in retrospect, with 20-20 hindsight, that
design makes *so* much more sense than the traditional cab-behind one
(including the weight advantage you mentioned). Makes me wonder,
naively, why it wasn't adopted much earlier and universally. Why was a
clearly inferior arrangement taken as "the way it must be done"? Why
force the engine driver to control a huge locomotive with its train from
a vantage point with limited sight, as if peering through a small peephole?

Not with coal firing. Many "standard" locomotives could be supplied
for oil or coal.

There were problems with this layout though - there was at least one
fatality when oil pipes under the engine leaked causing wheel slip in
a tunnel.

From Wikipedia:

One problematic aspect of the design, however, was the routing of
the oil lines; because the firebox was located ahead of the driving
wheels (instead of behind them, the usual practice), oil leaks could
cause the wheels to slip. A nuisance under most conditions, it
resulted in at least one fatal accident. This occurred in 1941 when
a cab-forward with leaking steam and oil lines entered the tunnel at
Santa Susana Pass near Los Angeles. The tunnel was on a grade, and
as the slow-moving train ascended the tunnel, oil on the rails
caused the wheels to slip and spin. The train slipped backwards and
a coupler knuckle broke, separating the air line, causing an
emergency brake application and stalling the train in a tunnel that
was rapidly filling with exhaust fumes and steam. The oil dripping
on the rails and ties then ignited beneath the engine cab, killing
the crew.

And I think there were crew concerns about safety in a collision. I
know there was a fatality when a cab forward hit a flat car.

Also they weren't used to a truck under the firebox that "steered" the
engine into curves instead of just carrying the weight so there were
some early problems with this.

(As a further tangent, it always cracks me up to think of all those
letter "F"s painted on early diesel locomotives, so the hidebound steam
engineers would know which way was supposed to point forwards. When was
this practice dropped?)

Heck, Union Pacific steam locomotives had "UP" painted on the back of
the tender to show which way to re-rail it.
.

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