Does anyone have experience with using spacers to correct excess wear on steam locomotive driver hub liners and driving boxes? I have in mind something like the SABECO Bronze split washers that are shown on the bottom of page 693 in the 1941 Cyclopedia.

brian2564@msn.com

Installing a floating hub liner to correct a lateral issue can get you out of a tight situation in a case where the hub liner falls right out of the box in the middle of the season and there is no time to do the proper repair involving dropping the wheel set and installing a new hubliner. They can pose their own risk for damage if the right conditions exist.

I know of an engine where the above scenario took place, which ended in a burned out crown brass, and scored and heat checked journal. Normally, a driving box will have the crown brass end protrude past the end of the box proper by, say 1/4". The hubliner is, say 1/2" thick in the same area, leaving it 1/4" proud of the end of the crown brass. On the engine in question, the hubliner came loose from the box and fell out completely. The mechanics made and installed a floating bronze washer to take up the lateral. The O.D. of this washer was the same as the old hubliner, and the I.D. was just larger than the journal.

The problem arose in that the crown brass is what the new washer bore against, rather than the box itself. At the first good lateral loading, the bronze taper pins holding the crown brass in place sheared off, and the crown brass slid in until it was flush with the face of the box and the floating washer could then bear against the box proper. This was an oil lubricated driving box, with the journal lubricated through the hollow bronze taper pins. When they sheared off, all lubrication was cut off to the journal, and the problem wasnÂ’t caught in time. When I saw the box, the crown brass was squeezed out between the box and the journal like toothpaste out of a tube.

As a result, they ended up dropping the axle anyway, and added to the expense and trouble by needing the journal turned, and a new crown brass. If you have the time, you are well advised to make a proper repair the first time around in every case.


Strasburg Rail Road
kelly@strasburgrailroad.com

Kelly:

Would you say that floating liners are a good practice for trailer and lead wheels? Seems to be plenty of reference to that use in 30s-40s Cycs. Your opinion, please.

And, has there been any trial of "modern" materials such as an engineering plastic or Nylatron for this application?

HP

hpincus@mindspring.com

> And, has there been any trial of
> "modern" materials such as an
> engineering plastic or Nylatron for this
> application?

Hi Howard - Stone Mountain Scenic RR cut out "horseshoes" of nylatron with a bandsaw and jammed them down between the boxes and hubs on the steamers back when they shoved them with diesels using hostlers control stands on long extension cords from scrapped B units. I reckon they worked for a while and were easy to replace. Makes me a bit uncomfortable as a permanent repair.

dave


irondave@bellsouth.net

My two cents? Floating hub liners, or any sort of floating bearing is a fine idea as long as it is properly designed, installed, and thought through. My illustration above was merely to show what has happened when a floating bushing was thrown in as a “quick fix” for a missing fixed hub liner. I had no intention of condemning floaters across the board.

I have no experience with any of the “plastic” bearing materials in locomotives. I believe that years ago, the D&S was using Nylatron for side rod with mixed results. I don’t know if they still do.

Strasburg Rail Road
kelly@strasburgrailroad.com

> My two cents? Floating hub liners, or any
> sort of floating bearing is a fine idea as
> long as it is properly designed, installed,
> and thought through. My illustration above
> was merely to show what has happened when a
> floating bushing was thrown in as a “quick
> fix” for a missing fixed hub liner. I had no
> intention of condemning floaters across the
> board.

> I have no experience with any of the
> “plastic” bearing materials in locomotives.
> I believe that years ago, the D&S was
> using Nylatron for side rod with mixed
> results. I donÂ’t know if they still do.
We at Mid-Continent have used Nylatron with good results in a quick fit repair situation. Skip has used it on the front truck of the Saganaw #2 and had no trouble. It seems to be the right material for small locomotives but,if used a proper retaining design system should be worked out ahead of time to insure that it won't be spit out. Nylatron can work for crosshead lateral bearings but is not good to use to line eccentrics on Stephenson cams as it tends to extrude and work out.

On another note:
I have been using Garlock Steel backed plastic bearings with good results on most of the pins with the Stevenson motion. The 1385 and D&R 9 has applications with zero problems.

fwantz@pressenter.com