Steam & Excursion > Shorpy railroad photo today

Shorpy (one of my favorite sites) photo today of Santa Fe 3910 on the slip track at San Bernadino after an overhaul.  That would have been fun to watch.
Photo Delano on Shorpy.com

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Not a steam guy, but do I see that they blocked the loco in place, then ran the heck out of it to check the work!?

Does the rail under the drivers look a little worn down?

The full-size view

https://www.shorpy.com/node/27652?size=_original#caption

Trailing truck says something-something-San Bernardino --
what does something-E stand for?

The drivers are spinning backward -- did RRs like
to "break engines in" both ways?

Engines run in both directions and everything is checked both directions.  I don't know how much running was done on the slipping track. It would be easy to get carried away with a high speed slip.  I'm sure she is coupled to a big dead load before slipping. Valve settings, anything binding and looked over afterward before releasing her for duty. Most likely will also make a run on a local or something to finish breaking in. 
Date on the trailing truck stencil is 3-30-43, so railroads needed anything that could turn a wheel back in the WWII days.  I'm sure the Santa Fe was crazy busy then.

I'm familiar with one shop town with a number of lines radiating out of it in which steam engines were broken in after shopping on one of the least traveled lines out of town. They ran out about five miles to a junction and then in reverse back. (There was no turning facility at the junction.)

There are some videos out there of a "grease track" in action if you can find them.

I am also familiar with an incident where the throttle got disconnected on a steam engine out on its run and the drivers kept spinning in place. Witnesses remember big gouges in the rails from the heat. There was no lubricating grease on that one!

Victor Baird

Disconnected throttles ( old style, one-piece type) are generally constructed with 2
different diameter pistons and a lower balancing chamber...the smaller one is a
balancing-piston.

The differential piston diameters allows a balancing force of 90% of 
boiler pressure to assist engineer in operating the throttle.

The design ensures that faults with the throlle operating linkage 
results in a closed throttle.  But, there may be cases where 
a broken piston ring of the throttle gets jammed... and it 
won't close.... or other very rare instance.

On modern, multiple poppet, front end throttles all have a bottom
pressure-chamber and each poppet  has a lower 'balancing' piston, in
the balancing chamber, of about 90% of the diameter of the.flow-control piston.

There is a lateral shaft across and under the individual poppets.  
The cam's lobes open and hold open the individual poppets, as the 
engineer opens the throttle.   They close in sequence, as the throttle
gets closed.

The individual balancing pistons make throttle operations easier, even at 300 psi 
boiler pressure.  I don't know of any reports of a multiple-poppet, front-end 
throttle ever failing in a stuck-open manner.

​W.
 

1522 has the old style throttle that must be lapped as it has an upper valve seat and a lower one in the casting. It could be a tedious job to lap both in just right.  Lapping compound and prussian blue intil they were perfect.
We were ready to leave on the next morning and the engine was fired up and the throttle was leaking to beat the band. After exhausting all ideas and as a final act I set the brakes, put her on center and chained the drivers and yanked the throttle open and slammed it shut about ten times. and on the last one it shut perfectly.
All I could conclude is that a small piece of scale or something had gotten pinched between the valve and the seat. I guess slamming and opening finally blew it away and restored order.
Valve can be open just a few thousands of an inch and will leak.  Made the trip the next day without a problem.

Wes, this story about the disconnected throttle was told by an Wabash engineer to his railroader son. His dad, A.C. Montgomery, was firing that locomotive on a local at Crocker, Indiana and would have started on the railroad before the Depression (but was laid off during the Depression and had to start over his seniority date). Therefore, it was an older locomotive, perhaps a 2-6-2,. I recall him saying that a section of that rail was cut out and saved by someone in management. We had no idea what happened to it. Per his interview, Clarence's dad said that the throttle got disconnected in the boiler--whatever that means.

Victor Baird



Edited 1 time(s). Last edit at 02/11/25 16:51 by wabash2800.

> ... yanked the throttle open and slammed it
> shut about ten times. and on
> the last one it shut perfectly.

When it finally shuts, you can tell
immediately it's no longer leaking?

wcamp1472 Wrote:
-------------------------------------------------------
> Disconnected throttles ( old style, one-piece
> type) are generally constructed with 2
> different diameter pistons and a lower balancing
> chamber...the smaller one is a
> balancing-piston.
>
> The differential piston diameters allows a
> balancing force of 90% of 
> boiler pressure to assist engineer in operating
> the throttle.
>
> The design ensures that faults with the throlle
> operating linkage 
> results in a closed throttle.  But, there may be
> cases where 
> a broken piston ring of the throttle gets
> jammed... and it 
> won't close.... or other very rare instance.
>
> On modern, multiple poppet, front end throttles
> all have a bottom
> pressure-chamber and each poppet  has a lower
> 'balancing' piston, in
> the balancing chamber, of about 90% of the
> diameter of the.flow-control piston.
>
> There is a lateral shaft across and under the
> individual poppets.  
> The cam's lobes open and hold open the individual
> poppets, as the 
> engineer opens the throttle.   They close in
> sequence, as the throttle
> gets closed.
>
> The individual balancing pistons make throttle
> operations easier, even at 300 psi 
> boiler pressure.  I don't know of any reports of
> a multiple-poppet, front-end 
> throttle ever failing in a stuck-open manner.
>
> ​W.
>  

Wes, as I recall Doyle once told me about the pilot valve on the 4449 coming loose from it's yoke and ended up getting cocked. It wasn't really right for a long time after that until a few years ago we made a new one. It seats a lot better now.

Scott Gordon