Diesel 40" wheel specification

Owen S. Paulsen · **Posted:** Wed Feb 19, 2014 1:24 am

When the Index Groove (Witness Groove) is what an show maximum what distant to tread of the wheel.
I say it Witness Groove =36" a the tread of the new wheel.

If you take Witness Groove =36" away about will a 1. 1.5 or 1.75 go, So flange in O.K.
Correct?
I you take Witness Groove =36" away about will at .25, So flange in O.K.
Correct?
Am I right the this?

Stan Paulsen

David Johnston · **Posted:** Wed Feb 19, 2014 1:46 am

The witness groove on a 40 inch diesel wheel is there because there are times that the inboard corner is so full of dirt and grease that is can not be used with the steel wheel gauge to determine rim thickness. In this case the gauge can be turned around and the rim thickness can be read using the outboard groove. Your own situtation will determine what the condemning limit is.

Flange height is still read with the steel wheel gauge with the long leg on the inboard side of the flange and the finger touching the gauging line. Again, your own situation will determine the condemning limit.

Lincoln Penn · **Joined:** Wed Feb 02, 2011 9:40 pm **Posts:** 841

Isn't the witness groove on a 40" wheel at 38"?

superheater · **Joined:** Sun Aug 22, 2004 11:54 pm **Posts:** 2605

What is a "witness groove"?

Howard P. · **Posted:** Thu Feb 20, 2014 5:42 pm

Attachment:

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The slight groove around the edge of the rim, just inboard of the point the wheel "breaks" to curve toward the wheel center, is the witness groove. In the photo, it passes though the lower part of the chalked numbers/letters.

Howard P.

PCook · **Joined:** Sat Jul 02, 2005 7:16 am **Posts:** 2127

I wonder if the model railroaders have caught on yet to painting traction motors that way.

PC

etalcos · **Posted:** Thu Feb 20, 2014 10:54 pm

Rim thickness for condemning and wheel shop purposes is taken at the back rim face, and using a scraper if needed to get rid of the crud. The witness groove is there for wheel size matching and shimming purposes (think minimizing wheel slip and leveling of trucks). Experience has taught that this does make a difference -- we had two wheels "condemned" for thin rim that suddenly became legal when properly gaged. I have used the measurement off the front rim face when close is good enough, but when it really matters, measure off the back face.

Now on a more important topic, I wonder what Howard has that uses an 83-20, GE, Hyatt wheelset??? Hyatt + GE was an unusual (non standard) combination on most roads.

ETA
Wheel Pit, Tennessee

HudsonL · **Joined:** Mon May 24, 2010 10:22 am **Posts:** 548

Quote:

Now on a more important topic, I wonder what Howard has that uses an 83-20, GE, Hyatt wheelset??? Hyatt + GE was an unusual (non standard) combination on most roads.

A EMD with Alco trucks?

-Hudson

MEC_557 · **Posted:** Fri Feb 21, 2014 6:51 pm

HudsonL wrote:

Quote:

Now on a more important topic, I wonder what Howard has that uses an 83-20, GE, Hyatt wheelset??? Hyatt + GE was an unusual (non standard) combination on most roads.

A EMD with Alco trucks?

-Hudson

They are planned to go under New Haven RS-3 #529

Owen S. Paulsen · **Posted:** Mon Feb 24, 2014 6:02 pm

I think this do same front Witness Groove an and FRA Thin rim a back side.
The only that in left do in flange: high to 7/8 correct? An a Flange Height Measurement show amount the for height will read.

A Height a back side for W601A (say height on 1 1/16 at STD 0 on 17 what STD mean a what do find place a W601A.

Stan