Steam & Excursion > What does this enlargement show about drive shaft?

Does this photo enlargement show three or maybe four expandable slip fitting on the drive shaft of Gilpin Tran Shay #4?  I guess that would surely be needed for some very sharp curves on the two foot gage mining tram of Colorado.

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I suspect that there is one, two-piece, slip fitting..
It would be reasonable that the round fittings are added reinforcements
to keep the outer 'square tube' from strong 'bursting influences'.

As the inner shaft extends ( out of the outer 'tube') to accomodate the curves,
it places a greater strain on the walls of the outer end of the tube.  
On left-bending curves, the reduced contact area  (depth)  of the the solid,  inner 
square shaft places increased 'bursting' forces on the reduced area of outer end
of the hollow square tube.  

The outer square tube is the driving member of two shafts.  
Improved designs ( sliding-fit, shaft designs) in the automotive/truck industry use multiple-groove, 
splined sleeves to distribute the twisting forces over a larger contact area. 

This application appears to be a field modification, and not a 'factory option'

IMHO.

​W.

( the owners might have added ' frame-weights'  to increase Tractive effort, possibly exceeding 
the original capacity of the drive train specs, possibly leading to earlier, failed square-tubes ) 



Edited 3 time(s). Last edit at 07/31/20 08:23 by wcamp1472.

These are collars that you see on the line shafts.  In the early Shays there were some tendencies to break line shafts because Lima had not built some of them for the smaller Shays strong enough.  The reinforcing collars were added from the factory as we see here to prevent the shafts from splitting.

In later years Lima made the line shaft on even the smaller Shays stronger and the use of collars was discontinued.

Martin

PlyWoody Wrote:
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> I guess that would
> surely be needed for some very sharp curves on the
> two foot gage mining tram of Colorado.

According to Mallory Hope Ferrell's book "the Gilpin Gold Tram;" "Maximum grade on the mainline was held to six percent and the minimum radius curve was sixty-six feet (or roughly a 87 degrees of curvature by my calculation). There is, however, some indication that the line was originally built with several curves of fifty-foot radius" (or about 114 degrees of curvature).  A bit sharp for Mr. Roland to get C&O 614 around the curve.



Edited 3 time(s). Last edit at 07/31/20 13:29 by SR-RL_Nr_10.