Y Class rebuilding possibility

[NW Mailing List]

I finally pulled your(?) book; I'd forgotten about all the  
incremental changes going from the original Y5 to the Y6b.  Even with  
all those changes, the real shift in overall layout was from the Y4  
to the Y5, it seems.  Some roads might have even classified the Y6s  
as additional sub-classes of the Y5.

Could it be said that the Y6b was the last "big steam" loco built?   
Interesting that USRA or developed-USRA designs were 3 of the "last"  
steam locos built - Y6b; S1a, last Class 1 steam built and the C&O  
2-6-6-2s the last ALCO steam built.

pete groom
On Mar 12, 2007, at 8:12 PM, NW Mailing List wrote:

When the Y5s were built in 1930-32, they all had bar frames with  
cylinders bolted to the frames and the axles had friction bearings.  
When the Y6s were built, they got bed castings with integral  
cylinders as one unit, and the axles had roller bearings. Because of  
the success of the Y6s having more reliability and lower maintenance  
costs due the bed casting and roller bearings, it was decided to  
upgrade the Y5s by replacing the bar frames and cylinders with  
bedcastings and roller bearings similar to the the Y6. Thus the Y5  
were "modrnized" and made equal to the Y6.

Bud Jeffries
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