J Class Changes

NW Mailing List nw-mailing-list at nwhs.org
Tue Sep 2 17:14:12 EDT 2008

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
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



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