J Class Changes

[NW Mailing List]

Thanks to Bud Jeffries for the details on the J rod replacements.  I write 
most of my comments from my computer at work, and my reference books are at 
home.  I forgot about the 610 getting new rods.  I should keep my first 
edition of Bud's book at work.

Bud--Were these rods cast in Roanoke shops, and who designed the change?

Rick Morrison
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Subject: Re: J Class Changes



> Dave is correct, there were four J's that got the redesigned single rods: 

> 600, 605, 610 and 611. These were applied from 1952 to 1956-7 as needed 

> when a stress fracture appeared on a crankpin. This rod change involved 

> replacing the front, rear and intermediate side rods, the main and 

> eccentric rods, the intermediate driving wheels, and all of the crankpins. 

> This was very costly, therefore was only done when required. These rods 

> were designed in 1952 and were not interchangeable with tandem rods.

>

> Other changes noticeable on the J's. Previously someone wrote about the 

> change in design of the steps on the pilot and this was done beginning in 

> 1944. The bell was moved from the boiler top in the cowling to the pilot 

> deck in front of the left cylinder; this treatment was applied to the 

> streamlined K2's as well beginning in 1953. And the spoke pilot wheels 

> began being replaced in 1948 for the first 11 J's with solid rolled steel 

> wheels; the 611-13 get these as built. Beginning in 1953 these wheels were 

> replaced with cast steel wheels that were also solid.

>

> One J, no. 602, was built in 1942 with a trailer truck booster which 

> required some external piping. This was removed in December 1945 along 

> with the piping.

>

> Of course the six J-1's were built in 1943 with heavy non-roller bearing 

> rods and not being streamlined. From September to November 1944, the J-1's 

> were streamlined, received lightweight roller bearing rods and then 

> classed as J.

>

> These were the visible changes. There were quite a few changes that were 

> not visible.

>

> Bud Jeffries

>

>