Steam & Excursion > UP#4014 Departing Cheyenne-BoilerSwing

I finally happened to be in the right place at the right time to catch the "boiler swing" of
the UP 4014 as it merged on to main line eastbound leaving Cheyenne back on Monday,
7/8/19.  I was on the NW side of the Logan Ave overpass as it crosses the UP yard ... looking
northwest.  I tried to set up several times on the Cheyenne-Ogden-Cheyenne runs, but was not successful.
Didn't even try this time LOL ...

Odyssey
Evergreen, CO
 

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Good catch!

Nice, but doesn't appear to be THAT much "boiler swing".

Technically, the thing that swings is the chassis for the front (pivoted) engine.

The boiler and rear engine stays
“straight”, it’s the track arrangement that wanders.

Also, there are, transverse, lateral springs attached to the front engine, and flat, sliding surfaces that are supporting the front of the boiler.

These transverse (centering) springs
lead the boiler through curves and switches....

Which is why the later comment about lack of ‘pronounced displacement’ is appropriate...
The total overhang of the boiler is
greatly limited and controlled by that well engineered design.

Flange wear (as in fewer axles doing the guiding) is greatly reduced by distributing the ‘wearing surfaces’ over both the axles of the 4-wheel pilot truck, together with the drive wheels of the front engine.

So, it’s good to see the ‘controlled lateral’ of the front engine very effectively performing as it was designed..

W.

Posted from iPhone

Thank you Wes for the detailed info on the "boiler swing", ... appologize for my possibly poor choice of a subject header...
but it did trigger a real response!  ... I've got a much better perspective now ... glad I was able to share your
knowledge with other TO folk!

Odyssey
Evergreen, CO
 

Still, a very cool shot. Thanks for posting.

Randy in PHX.

Posted from iPhone