Steam & Excursion > Washington Terminal 0-8-0 (1949)

Have year as 1949, no photographer .... #18 is an 0-8-0

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What a monster! I wonder if WTCo's power was all from the PRR mold?

*edit* found a photo on line of a WTCo 0-6-0 which was also a Pennsy design. Wasn't WTCo owned by Union Station users (RF&P, B&O, C&O, Southern, and PRR)?



Edited 1 time(s). Last edit at 06/26/19 12:10 by CPR_4000.

Deleted account virtual duplicate of below..



Edited 1 time(s). Last edit at 06/26/19 09:01 by wcamp1472.

The Walschaert valve gear is weird proportions....

The eccentric rod ( connected to the e-crank) is very short...
And the length of the ‘radius rod’ is remarkably long... the slot in the Walschaert link is a virtual straight line.... because the radius is sooo
long.

Walschaert eccentric rods generate weird valve events with the unusually short proportions.
The angles described by the short rod affect the even distribution of steam to the pistons....The acute angles described by the crank and the e-rod, make it virtually impossible that the distance traveled up the back portion of the crank-circle would be anywhere NEAR the short distance covering the front portion of the circle... called the ‘angularity’ of the eccentric rod.

The front end of the short rod connects to the eye at the bottom of the link.... thus, it’s a horizontal pendulum, and the two points of tangency ( to the crank-circle’s front half) have way less than 180 degrees of arc between them..

This arrangement looks like “a valve setter’s nightmare”—- geometric compromise is the order of the day..., it’s not gonna run ‘square’ no matter what you try adjust... being Terminal-work, square-ness is a “superfluous nicety”.... and not very useful..

With a large proportion of the crew’s time being spent sitting and waiting ‘efficiencies’ are a seldom seen luxury— idle time is very wasteful, but there’s no way eliminate the sitting and waiting..

A more typical Walschaert link is more logically positioned & pivoted about half-way between the valve rod and the eccentric crank, with a clearly evident curve to the link-block guide.

But, in switcher service.... such niceties as adjustable cut-offs are rarely used... mostly the action is constantly about reversing direction, acceleration, and gentle braking, along with slow-speed action...

Handling mostly passenger and baggage equipment is different than knocking freight cars around....
Passenger equipment, at a place like Washington Terminal, involves passenger cars that are often occupied by customers, sleepers and mail cars with mail-sorters busily at work...not to mention the crews in the dining cars!

So, passenger switch crews were adept at gentle handling of the various trains that they had to handle and assemble.

There were also WTCo
train-handling rules, as well as the Rules governing the handling of the individual tenant lines. That was a LOT to keep memorized..

So, simple valve gears, for basically only forward and reverse movements was adequate for the needs of the service.

That’s a very special photo of a vital performer, at one of the busiest terminals in the Country..

W.

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Edited 4 time(s). Last edit at 06/26/19 10:56 by wcamp1472.

Former PRR Class C

Okay, thanks Wes for the tutorial on odd valve gear on that chunky switcher. I note that the counterweights seem oversize relative to the rods they are to balance. Is this something about low speed operation, driver diameter or am I just seeing things?

I'm sure someone will find an example to set me right but that is the largest thing I can recall seeing with a slope back tender behind it. 

My suppositions...

Yes, the counter-weights do look way out of proportion, compared to the mass of the siderods...
but, the counterweights are actually hollow... The ‘compartments’ were divided ( by spokes) to make ‘pockets’ so that molten lead could be added as needed—- it’s possible that not all the (hollow) cavities were filled with lead.

I also suspect that the PRR 0-8-0 was not a ‘useful’ design... probably they became orphaned... and when WTCo. was looking for power.
Its possible that PRR got revenue/income for transferring the engines to Washington....

By this time, PRR had many members of the H-classes ( 2-8-0)
that became surplus, as road power... The old 2-8-0s were superior for the lighter-duty jobs, and could do main-line speeds, as well as being very versatile, and for the PRR, 0-8-0s were not worth the expense...

For WTCo. they got big engines for handling long strings of 90-ton coaches, and it was uphill getting out of Union Station..

Similarly, Potomac Yards inherited used ‘simple’ H-7 class, 2-8-8-2, locos from the C&O rr —- after the slow H7s were made obsolete by the arrival of the BIG Allegheny locos from Lima Loco.

At PY, the H7 locos made very capable ‘Hump’ engines—- they could shove ANY train, regardless of length over the humps, at slow speed. PY numbered them in the single-digits, probably had half a dozen of the beasts...

Soon the C&O 2-8-8-2s were replaced by NEW Alco S-type
( 1,000 hp) diesel switchers, typically married in pairs...for hump service..

Many variations of hand-me-downs populated the similar, ‘jointly-owned’ Passenger and freight facilities that were spread across the USA...from the east coast to the west coast...

Many were operated with 2nd-hand
Engines, etc,,

W.

Not proofed, yet..

Posted from iPhone



Edited 3 time(s). Last edit at 06/27/19 07:19 by wcamp1472.