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Changing steam locomotive to roller bearings
https://www.rypn.org/forums/viewtopic.php?f=1&t=25725		 Page 1 of 2
Author:  Afboone [ Thu Aug 07, 2008 9:48 am ]
Post subject:  Changing steam locomotive to roller bearings
I read alot on here about friction bearings and some of the railroads now don't like the friction bearings on railroad equipment. I understand in a way why, I'm an military aircraft mechanic and our landing gear on the aircraft have friction bearings, we call them bushings, and they can be a real pain from general wear to complete failure when not maintained correctly, grease is your friend.
So my questions are:
1. Can a steam locomotive be converted to roller bearings without major mods?
2. What would make a current carrier happy? What I mean is do they want to see just the axles? or every moving joint needs to have roller bearings.

Thanks again.
Author:  Dave [ Thu Aug 07, 2008 10:09 am ]
Post subject:  Re: Changing steam locomotive to roller bearings
The only retrofit of a steam locomotive from friction to roller bearings that has been done in recent times proved ineffective in the long term.

The challenge is fitting a cannon axle assembly into the smaller pedestals in the locomotive frames built for seperate traditional boxes with friction bearings. New frames would need to be part of the retrofit, not just replacing the bearings in the boxes with other sorts. this would also require some serious reconfiguration of spring rigging, brake rigging, etc.

There's adequate unemployed modern steam out there to make this work unnecessary.

dave
Author:  whodom [ Thu Aug 07, 2008 11:08 am ]
Post subject:  Re: Changing steam locomotive to roller bearings
Another alternative would be to use the "floating driving axle" arrangement used on at least the early N&W A's. These engines had a large diameter roller bearing mounted in the back face of each driver. The inner race rode on the outside of a relatively small diameter cannon box. The axle didn't really support the weight of the engine.

Although I've never seen it stated, I suspect the idea behind this arrangement was to allow roller bearings to be retrofitted to existing engines without replacing or modifying the frames. Of course this would require new castings for the drivers to accommodate the roller bearings, and might end up costing just as much as a frame replacement.
Author:  Aarne H. Frobom [ Thu Aug 07, 2008 1:23 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
"What would make a current carrier happy (about operating a steam engine)?"

Generally, going away and not coming back. If a carrier does agree to operate a preserved steam locomotive, it's because it has satisfied itself as to liability exposure, crowd control, insurance coverage for passenger operations, conflict with freight schedules, demands on operating staff and crews, and a multitude of other serious issues. Style of bearings will be the least of their concerns.

Aarne H. Frobom
Author:  Dave [ Thu Aug 07, 2008 2:33 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
Out of the box idea: axles don't turn, wheels do. Provides a very large diameter of available bearing area between the stationary hub of the wheel and the crankpin location on the "rotor". Axles become structural members that float up and down without rotating in bearingless boxes supported by the spring rigging.

No idea if it can be done practically or not......

dave
Author:  SouPac [ Thu Aug 07, 2008 3:40 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
Forum members,

This discussion has three different issues bundled into it.

1) Why steam is not running on the main

2) How to make steam locomotives more economical to maintain

3) How to integrate more modern technologies into a primitive machine

There are many reasons people cite why steam runs less frequently on mainline railroads. It really has everything due to money. Host railroads have reduced their physical plant to minimum capacity in order to decrease maintenance costs. Insert extra train and that stresses the whole system costing railroads money. Add into this the cost of insurance, amtrak certified cars, etc and most mainline steam is parked with the ability to run just fine without any major work. Roller bearings are not the problem here.

As for the issue of making steam more economical to maintain, roller bearings are enticing due to their appearance of almost zero maintenance. This is only an appearance as rollers require their own set of maintenance procedures however. Also, rollers have a really interesting propensity to get damaged when you clip the ground on a wheel center and weld on the frame. Think about all that amperage jumping between the races and the rollers in a grease filled environment. Not a pretty picture... I think a problem with many steam programs is the feeling that once something is "fixed" it should stay that way. This is frankly an unsophisticated understanding of the technologies found in steam locomotives. Locomotives are more of a PROCESS of maintenance and rebuilding than they are a PRODUCT which will last. If a steam program lacks the commitment or funding to keep up with the needs of their charge, they will fail.

As I see it:

Roller bearings are no panacea and in some ways are more problematic than a plain bearing. Plain bearings if properly maintained, cleaned, lubricated, and NOT ABUSED (this is the big one) have an incredible service life. At higher speeds they actually have less resistance than roller bearings. They can accomodate angular misalignment which roller bearings cannot. Plain bearing materials have the ability to absorb contaminant so as not to immediately destroy bearing surfaces. Have you ever looked at a roller bearing that went bad? Usually failure is fast and catastrophic. There is no ability to "timesaver", run up on a wedge, and limp home. Granted this happens less often with rollers but where do you find appropriate steam locomotive roller bearings at any cost without having potentially ruined a locomotive if the idea does not work out?

End of story: The technology works...

Plain bearings are a maintenance issue, but there is just no way to make a steam locomotive bullet proof. By nature they are out of balance, brute force, non-finesse machines which break themselves in service. New technologies will not fix the problem unless the entire system of power transmission was redesigned along principles common to internal combustion (balancing, harmonic dampening, smaller reciprocating parts, greater rigidity, etc.). To be sure some notable examples were created such as the N&W Js. However, for locomotives not designed to make use of these engineering principles, fixing one aspect of the mechanical whole will only give you problems. To make a locomotive trouble free, spend the time improving tolerances, alignment, etc. If a locomotive is slayed, roller bearings are not going to help.

Best,

Stathi Pappas
Author:  Ryan Scott [ Thu Aug 07, 2008 4:06 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
No offense, but I believe you would have a bit of a problem holding quarter when the axles do not turn with the wheels.

Having been around a friction to roller modified locomotive, only to modify it back to friction bearings, my opinion is to stay with frictions. See this link if your interested:

http://www.trainweb.org/tusp/news/news_arc.html#GSMR

If you were going to build new mainline locomotives, I would certainly look at using rollers. In any case, you must ask yourself the questions:

1. Does the machine really need rollers? Is there a mechanical need or advantage for roller bearings to be specified?
2. How much is the cost difference in equip, vs the cost to maintain & operate?
3. What is the life span of the machine, and the lifespan of parts availiblity.

For an example for question #3, which will be easier to repair: an 80 year old steam locomotive, or an 80 year old diesel locomotive? Try to buy a new crankshaft or liners/pistons for a (Lima-)Hamilton engine. Diesel parts are similar to roller bearings in that they require a great deal of very specialized machinery and knowlege to build. Your not going to chuck up a peice of metal in the lathe and make new rollers or races for 'ol 97. I think in the future you will see those first generation diesels parked, because it was easier and cheaper to make parts for the steam locomotive.

(incidently, if someone knows where to get some injectors and injector pumps for a Lima Hamilton diesel, please let me know, I need at least six of each .. . )

Ryan
Author:  Dave [ Thu Aug 07, 2008 5:10 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
Quarter is a problem - but only on the occasion when both sides are on dead centers simultaneously. My worry was how to run more than one set of coupled wheels.........

Shays, no worries.

dave
Author:  whodom [ Thu Aug 07, 2008 5:39 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
On the "floating driving axle" roller bearing setup I described, the axles DO turn, and they DO connect the drivers to one another, and they DO maintain the drivers in quarter. The axles are NOT supported by and do not turn on bearings. The roller bearings are mounted within a recess in the hub of the drivers, and transfer the load to the outside of the cannon box which is supported in the normal way by the locomotive's suspension.

This is a clear case of one picture is worth 500 forum postings. Check the 1941 Locomotive Cyclopedia if you'd like to see a drawing, or I'll try and scan and post an image from mine when I get a chance.

That said- I think I agree with the sentiment regarding sticking with conventional bearings for tourist steam. Whatever else can be said about rollers, it is a PITA to change them and requires some major machinery to accomplish.
Author:  Trevor Heath [ Thu Aug 07, 2008 7:21 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
Gent's

In the 1980's 80+ Beyer Garratts (160+ engine units) in Zimbabwe were converted to roller bearings as part of a program to extend the life of steam traction in that country due to the availability of local coal and the complete lack of oil resources......

Some are still operational today.

TH
Author:  robertmacdowell [ Thu Aug 07, 2008 8:07 pm ]
Post subject:  Re: Changing steam locomotive to roller bearings
Aarne H. Frobom wrote:
"What would make a current carrier happy (about operating a steam engine)?"

Generally, going away and not coming back.


Aarne H Frobom. There's a name from my Michigan days - one I hold in high esteem in high steam.

I would attribute that attitude to the big eight Class I's: UP, BNSF, CN, CP, CSXT, NS, KCS and Amtrak. I would consider them no-mans-land for steam. Now if you delete those from your state's system map... in a lot of states, that doesn't leave much.

But in Michigan, oh my. It leaves some very healthy regionals with good rail suitable for mainline steam. And to boot, one of the only (if not the only?) preservation group focused on mainline-capable passenger coaches. Yup, if i were a mainline steam engine, that's where I'd want to be! :)
Author:  Afboone [ Fri Aug 08, 2008 7:58 am ]
Post subject:  Re: Changing steam locomotive to roller bearings
Thanks, I think! Man I didn't know I needed a flame suit for this! Just kidding.
It sounds like the friction bearings are the same as our aircraft landing gear bushings. As long as you keep them greased your ok. Does anyone know if there is an automatic greasing set up for the friction bearings?
Author:  JimBoylan [ Fri Aug 08, 2008 9:23 am ]
Post subject:  Re: Changing steam locomotive to roller bearings
robertmacdowell wrote:
Does anyone know if there is an automatic greasing set up for the friction bearings?
That's how the father of Mr. Hennesey Slidewell of box car door opener fame made his fortune.
Steam locomotive lubrication dispensers powered by the lost motion of the driving wheel sets moving in their frames!
Author:  Aarne H. Frobom [ Fri Aug 08, 2008 10:01 am ]
Post subject:  Re: Changing steam locomotive to roller bearings
Don't be afraid to ask questions. It beats learning the hard way.

One of the things we've learned the hard way is that the major problems associated with operating a steam locomotive in the 21st Century are organizational and economic. The machinery is the easy part. Another lesson we've picked up along the way is that people starting out in this field frequently assume that modifying the machinery can ameliorate institutional problems, especially if they come from a high-tech field. In the worst cases, modifications like roller bearings are a substitute for doing the work that's really needed, or because no one knows how or can find the money for a $250,000 firebox job. This is why I'm suspicious of any proposal to "modernize" historic equipment. (This doesn't apply to modifications undertaken to solve a real operational problem, such as oil firing to solve an emissions or ash-disposal issue, or a bigger tank for added range.)

Regarding automatic lubrication of solid bearings, journal pads are about as automatic as you can get. Locomotive driving boxes have cakes of hard grease that are held against the bottom of the journal by springs. Again, automatic. Provided, of course, that someone pours in oil at intervals, and knows the rate of consumption of the hard grease and renews the grease cakes before they're consumed. That is not automatic, but is part of the managerial challenge. The non-rotating surfaces of a modern locomotive are oiled by mechanical pumps (that must be filled daily), serving up to 60 points with machine and valve oil. All of which must be inspected to assure that the oil is really flowing.

And Michigan is indeed not a bad place to operate a steam locomotive. This summer, Pere Marquette 1225 has operated on or across 4 carriers in all its solid-bearing, coal-burning, 6-ET-equipped glory. The carriers all had plenty of relevant questions, but no one asked about the bearings.
Author:  co614 [ Fri Aug 08, 2008 10:21 am ]
Post subject:  Re: Changing steam locomotive to roller bearings
I'll gladly leave the question of converting a friction bearing equipped loco. to rollers to those mechanically qualified to answer.

I can relate from extensive (and yes, expensive) first hand experience with first RDG. 2101 (AFT 1) and later RDG.2100 and a little time with GTW 6325 that friction bearing equipped steam locomotives demand a LOT of care and feeding to live successfully at 79 mph. After spending an enourmous amount of time and money trying to get the Hennessey oil lubricators on the 2101 to function reliably we converted her to grease cakes with improved results, but still were constantly making sure she was getting sufficient grease etc.

Then came the 614-- and what a delightful change. You run all day at track speed, spend about 15 minutes at the end of the run to shoot a little replacement oil in the mains and your good to go for another 300/400 miles! And never a lick of trouble.

I can only speak for myself to say that I would NEVER by choice go back to a friction bearinged locomotive after having had the absolute pleasure of working with an all roller bearinged one!

Ross Rowland
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