J Class Changes

NW Mailing List nw-mailing-list at nwhs.org
Tue Sep 2 13:13:01 EDT 2008

610 also had its tandem rods replaced with single rods and larger hubs.

I believe part of the reason was the long crankpin on #4 axle drivers. The new rods were closer to the surface of the drivers resulting in shorter crankpins and less bending stress.

Dave Stephenson

--- On Tue, 9/2/08, NW Mailing List <nw-mailing-list at nwhs.org> wrote:

> From: NW Mailing List <nw-mailing-list at nwhs.org>

> Subject: Re: J Class Changes

> To: "NW Mailing List" <nw-mailing-list at nwhs.org>

> Date: Tuesday, September 2, 2008, 7:37 AM

> The "extra" side rods were removed on three

> J's in their first life: 600,

> 605, and 611. Actually, the rods on these engines were

> completely replaced.

> As I understand it, the reason had to do with a stress

> failure of some kind.

> Check out photos of the various J's and you will see

> that the replacement

> rods had much larger rod bearings on drivers 2 and 3. I

> would call this an

> ungrade applied as necessary, and only three engines got

> it. 611 was the

> last of the three to get the new rods.


> Also 611 in its second life had two generators installed

> instead of the

> original one.


> --Rick Morrison


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