UP's steam engine drivers

[jockellis]

Does Union Pacific have to put one piece drivers under its steam engines or can they still have the removable tires?

[selector]

They have to repair/replace the tires.

[dldance]

3985 is getting its tires replaced this year as part of running gear maintenance.  (I almost said re-tired - that would cause a stir).  The biggest reason for separate tires is that the best steel for casting the drivers is not the best steel for wear and the steel the tires are made of is way too hard and expensive for casting.

dd

[jockellis]

Thanks. The reason I asked is that I thought I had read something which said the FRA no longer allowed separate tire/wheel combinations. I figured the tire needed to be a harder, longer wearing steel than the wheel but didn't know. But now bulldozers have idler wheels which are rebuilt with a wire arc welder which puts new high carbon steel on the old wheels. So I wasn't sure if steam running RRs could do the same thing.

[dknelson]

One of the heavy haulting Chicago railroads, I cannot recall if it was the Belt Railway of Chicago or the Indiana Harbor Belt, got diesels with wheels that had separate tires.  The reasoning was that the tires wore quickly in their service and that new tires were way cheaper than replacing an entire wheel w/traction motor on axle etc.  The process was more or less just like on a steam locomotive.  Similarly the central casting of a steam locomotive wheel is far too expensive and difficult to replace than a "mere" tire. 

I have never seen such badly pitted rails as I have seen on the IHB due to extremely heavy loads, wheel slip, and the difficulty of taking a line out of service for rail replacement.  I can only imagine what the wheels end up looking like.

Dave Nelson

 

 

[Virginian]

You could repair the tires on steam locomotives, or I suppose even the wheels, with the welding and machining method, but I would think it would take far longer and be more expensive than the press on tire method.

[TomDiehl]

You could repair the tires on steam locomotives, or I suppose even the wheels, with the welding and machining method, but I would think it would take far longer and be more expensive than the press on tire method.

Steam locomotive driver tires are not pressed on, they're shrunk on and off.

[Leon Silverman]

The FRA prohibition against separate tire/wheel combinations might be due the cause of an ICE trainwreck in Germany.  The steel tire literally unwrapped itself and punctured the car body due to fatigue effects of allowing the tire to flex on the wheel.  There was a rubber strip between the tire and the wheel itself,  something you do not see on a steam engine wheel since the tire is shrunk fit onto the wheel and cannot flex relative to the wheel, itself. 

[pmsteamman]

I wonder if they get a waiver from the FRA, or if the rule may be for diesels only.

[J. Daddy]

Is this why most tires were painted white? Does this track its tread wear?

[Lord Atmo]

pardon my stupidity, but what are "tires" in this context?

[Semper Vaporo]

Each drive "Wheel" of a steam locomotive is first affixed rigidly to an axle and then the two wheel/axle assembly is put on a wheel lathe and the outer edge of the wheels are shaped to a profile that has one of more ridges along its width.

A "Tire" is then formed from a ring of steel and placed on a tire lathe and the inner surface is given a complimentary profile that fits what is on the wheel and has in inner diameter of slightly LESS than the outer diameter of the wheel on the axle.

This tire is then hung near the wheel and a ring of pipes with lots of nozzles is position around it.  Gas (like heats your home) is pumped into the pipes and ignited at the dozens of nozzles to make a rather spectacular ring of fire to heat the tire. 

In being heated the tire expands in circumference until it can be slipped over the wheel (and the ridges in the profile of them both).  Well, actually a couple of guys with sledge hammers go to work on it to force the tire over the wheel!  Then the tire is allowed to cool which causes it to shrink to grip the wheel.  (During the cooling time, the guy with the gauge bars checks the distance between the wheels and makes sledgehammer adjustments to the guage.)

The ridges of the profile help to keep it from popping off when in use. 

Once the tire is firmly on the wheel the whole set is moved to the wheel lathe again and the tire is shaped to the correct profile and diameter for the engine it is for.  This includes forming the flange and taper of the wheel and ensures the whole thing, axle, wheel and tire, are concentric.

I have seen a couple of videos of this being done... wild!

 

[Anonymous]

The Tennessee Valley Railroad Museum in Chattanooga, TN, does "re-tiring" work for several steam operated museums.  According to one of the workers up there, they are one of the few places in the USA that still has the skills and facilities available for the job.

I may not be as observant as the more dedicated railfans here present, but I don't recall seeing "tires" on diesels.  The steam locomotives I have seen all have tires.

 

[Virginian]

You could repair the tires on steam locomotives, or I suppose even the wheels, with the welding and machining method, but I would think it would take far longer and be more expensive than the press on tire method.

Steam locomotive driver tires are not pressed on, they're shrunk on and off.

Pardon my terminology, but even though the tires are heated to facillitate installation and removal, they are still placed in a LARGE hydraulic press to install or remove them from the wheel/driver.  Thus those of us who deal with like situations frequently use the term pressed on or off.

[cprted]

CP 3716 (see avatar) is having its tires done after Christmas this winter. I think they're being sent to a shop in Vancouver. Southern Rail I think.

[Semper Vaporo]

You could repair the tires on steam locomotives, or I suppose even the wheels, with the welding and machining method, but I would think it would take far longer and be more expensive than the press on tire method.

Steam locomotive driver tires are not pressed on, they're shrunk on and off.

Pardon my terminology, but even though the tires are heated to facillitate installation and removal, they are still placed in a LARGE hydraulic press to install or remove them from the wheel/driver.  Thus those of us who deal with like situations frequently use the term pressed on or off.

The "Wheel" is pressed onto the "axle".  The inside diameter of the hole in the wheel is smaller that the the outside diameter of the axle and both are deformed as they are forced together. 

But the wheel "rim" has a profile that would preclude the "Tire" being pressed over it.  This profile is a variance in diameter across the width of the wheel.  The Tire has to be expanded in diameter to fit over this ripply profile.  The inner diameter of the Tire is the complement of the profile of the wheel.  This profile is so that the tire will not slowly (or even rapidly) slide off the wheel.  This could still happen and I have seen photos of a tire that has come off and has pretty much destroyed the side rods (and the side of the locomotive, too).

The heat of braking could cause the tire to heat enough to expand and come loose from the wheel, but if the profile was deep enough it might keep the tire from coming off the wheel.

 

[sabaj]

I have done welding since learning in high school about 1960. I would not trust  welding to  build a tire or wheel up and machining it on a steem engine because of the stress of the heating as you weld to the old wheel adding new materail. What normally happens when a weld breaks it is in the old steel next to the weld.

Due to Murffey's law of any thing that  can happen may happen you don't want to use build up on high speed applactions.  844 and 3985 are not used in slow speed switching operations. If it was a switch engine that never left the yard yes you could probally build up and machine it.

I  have repaired rusted out farm tractor rear rims  by welding and grinding them smooth since they never get over 15 miles per hour and the tire pressure in not over 15 psi but I would never use a wheel repaired like that on a highway vehicle.  We ( brothers sons and friends ) have welded and repaired rims too for demo derby cars but they get trailered to the arena.

I have done a lot of build up for the cement plant I worked for too. always slow speed such as dozers, shovels , ball mills, kilns, crushers and ect where public saftey is not and issue.

A broken wheel on a steam engine could cost a lot of dollars in time it took to remove the engine from the tracks even if no damage was done by just holding up the trains from running while it was being loaded to be hauled away for repairs.

[marknewton]

The "Wheel" is pressed onto the "axle".  The inside diameter of the hole in the wheel is smaller that the the outside diameter of the axle and both are deformed as they are forced together. 

But the wheel "rim" has a profile that would preclude the "Tire" being pressed over it.  This profile is a variance in diameter across the width of the wheel.  The Tire has to be expanded in diameter to fit over this ripply profile.  The inner diameter of the Tire is the complement of the profile of the wheel.  This profile is so that the tire will not slowly (or even rapidly) slide off the wheel.  This could still happen and I have seen photos of a tire that has come off and has pretty much destroyed the side rods (and the side of the locomotive, too).

The heat of braking could cause the tire to heat enough to expand and come loose from the wheel, but if the profile was deep enough it might keep the tire from coming off the wheel.

 

Interesting. I haven't come across this method. Where did you see it used? All the locos I have worked on either had Gibson rings or tyre studs.

Mark.

[selector]

Would you expand on those two, please, Mark?

[marknewton]

Crandell, Gday!

Tyre secured by Gibson rings have a lip on the front face, with rivet holes around the circumference. There is a shallow groove or slot in the rear face of the wheel centre with matching holes, and the rivets are driven through a ring that sits in the groove to secure the tyre after it is shrunk on.

Tyre studs are probably more common in British practice, there are holes bored in the rim of the wheel and these are use as a guide to bore holes into the tyre after it is on. The holes are then tapped, and a stud is threaded into the tyre from inside the wheel, between the spokes.

I'll see if I can find some photos or drawings to illustrate the two methods, and I'll post them.

Cheers,

Mark.

[selector]

Thanks, Mark.  I feel I understand your second description well.  I would guess that those studs are to inhibit the tire from creeping/slipping under load or hard braking?  Or is it for lateral retention....maybe all of the above?

The Gibson rings sound like I'll need an image or diagramme....I keep conjuring up images of a large gravel truck's split-rim type of design, but that wouldn't be right on a driver.

I'll wait.

-Crandell

[pimpz26]

This is a page from the book "Train Wrecks".

Clearly shows the tire and the wheel.

[bb4884]

In Pentrex's video "Steam across America" at the very end, they sow some work on one of the wheels of a Big Boy in the Cheyenne roundhouse.