More steam locomotive operators are converting to oil lubrication of driver journals due to the unavailability of suitable cellar grease. Much of the specific information I have been able to find is 8 plus years old. Based on the information I have, including searching this forum, talking to people in the industry, and personal experience, the "standard practices" for conversion of driver journals from grease cake to oil lubrication are, generally, as follows:

1. Crown brasses may be Babbitt lined (SP practice) but most often are not. Clearance in the range of .010 -.015. Smooth finish with no oil distribution grooves. A 1/16" x 1/16" oil return grove along the inner and outer edge of the brass.

2. I have seen some discussion of using a specific type of bronze for the crown brass when using oil lubrication but it does not appear to be essential.

3. Cellar boxes fit with a fairly close clearance to the axle, usually with no or minimal oil/dust seals. Where space permits a box with an additional oil reservoir may be used, otherwise no changes in the cellar box dimensions.

4. Standard journal pads in the boxes. Oil supplied by a line or hose running into the top or plumbed into the side of the box, oil cups or button head fittings attached to the side or bottom of the box. When I last checked in August of last year the Armstrong Oilers manufactured and sold by the North Yorkshire Moors Railway in the UK and, I believe, used by TVRM for their conversions are not available in the US.

I would be interested to hear from those who have experience with this. What works, what has not worked, and what you would recommend as the current best practice for conversion.

Russ Fischer
Cumbres & Toltec Scenic Railroad

call me goofy but theres an automobile grease used on threads to prevent them from seizing. Aside from that N&W had done some automated lubrication which included such application, probably oil.

IMHO, oil is the only way to go for axle boxes. 936 bronze works well with .015 to .020 clearance, with the greater clearance on the mains. I made a test on one locomotive using Babbitt lining on one axle and it does run 10 degrees cooler than the unlined. However, nothing ever runs hotter than 120 degrees so the point is moot. Babbitt lining does provide warning of a heating issue on the road prior to scoring an axle. However, if you are at phantom curve when an axle starts running hot, I doubt an olfactory warning is of much use.

I always set up boxes for both top and bottom lubrication, although in your situation applying a button head to the cellar and not adding the oil holes from the top oil reservoir would be advisable to exclude contaminants. I would never rely on a hose supplying oil to the cellar as they invariably abraid, tear, and compromise the oil cellar.

Standard journal pads work well if pre saturated with oil and kept that way. Spring pads are certainly effective but are harder to source these days. Use a grade of oil designed for the purpose and better than just plain journaltex if possible. I have always had good luck with pbj 100 for this purpose.

These observations are proven in service on locomotives I rebuilt which are very similar to yours running approx 5,000 miles per year.

Best,

Stathi

Use babbit on your bearings, and use leaded bronze /brass, also called Red Leaded BRASS and Red Leaded Bronze, to cast your bearings from. The lead in the metal adds lubricity and preserves your axles when you get wear through the babbit, and you surely will at some point in time.

Babbit is softer than brass and bronze.

When two metals com together the harder metal cuts the softer metal. Babbit will extend the life of your axles many times over using only unlined brass/bronze bearings, that do cut axles, just not as fast as the axles cuts the unlined bearing.

You want the best lube, the softest babbit (for your psi), the slipperiest and softest ( within reason) bearings on your axle journals. That all prevents wear on every part except the babbit, but your babbit should be thought of as sacrificial and expendable with the aim of preventing axle damage and costly mntc. By sacraficing itself to prevent expensive axle damage and wear. You should always have an extra set of fresh bearings in stock and changing them out is much preferable to axle replacement.

That is what I was taught by a very successful steam locomotive designer and builder.

Also, . Sand is harder than many metals, so sand cuts them. Sand in your bearings is worse than no lubrication at all. Keep the sand away from your bearing surfaces. Sanding the rails over a year of use, on a typical steam locomotive that has few seals and easy access for sand to enter cellars, will cause more wear to the drive train than a decade or two of use with no sand use. When you think of sand in your bearings, just think of: Sand paper.

Modern diesel locomotives have been designed to seal out the sand used for adhesion, so it has a much smaller effect on wear than it does on the open surfaces of a steam locomotive.

On steamers, try to seal the sand out of your surfaces, or don't use the sanders, and find a locomotive heavy enough to not need the use of sand to get the tractive effort required to pull your train, or pull a liter train and disconnect the sanders.

Let the rocks fly, I'm ready!

Their website states that they have sold oilers to the US.
http://www.armstrongoilers.co.uk/

.

If you have a good pattern with plenty of machine stock and work with a decent foundry you will not get sand into the casting. When making molds I use a no bake system instead of greensand, and the molds are hard as a rock. Coated with a zircon mold wash there will be no sand infiltration into the mold cavity.

The curved bearing inserts that are used for the driver boxes are well suited for centrifugal casting, but I don't want anyone to think that all bearing blocks can be cast that way or that sand casting is taboo for all bearings.

We used centrifugally cast bronze from a foundry in Omaha. I had them rough them with the center hole 1" off center and we machined them from there. Still a good deal of waste bronze, but the brasses were beautiful, no voids or anything. Machined easily and made great crown brass.
I wish the oil lubing was more prevalent back then because we would have went that way instead of grease cellars. In spite of what some of the guys tell you, if you don't have a cache of Hi Tex 8 squirreled away, you won't find anything that works as well on a mainline engine. We finally used up the last of ours about the time the 1522 was retired.

This is very interesting as we have a lot of heavy running gear work to do including new axles and brasses. So - is anybody using oil forced fed under pressure through the top center of the brass down grooves? Is this overkill and inelegant if maintaining oily waste in the cellar works fine? Ideas about practical and unobtrusive traction sand and road dust excluders?

I believe that is what one of the S160's I saw at Tysley had featured with it! Multiple Nathan lubricators (3 I think) and hoses running from two units to the axle boxes. I would bet my $.02 cents that this was a force feed system.

Can't help you about conversion but can tell you that you can get Armstrong lubricators delivered to the US.
I have helped install 28 of them on the two QJs in Iowa. Worked quite well and brought down the temp on the trailing truck quite a bite.


Dan

I was unaware there was not a suitable grease available. The grease I developed, sold by Steam Services of America, has led to reduced operating temperatures on the rods of the NKP 765 versus Texaco hytex 8, reduced axle temps on the R&N 425, as well as reduced rod temps on another mainline 4-8-4. Grease is for more suitable in many applications and since a grease exists which is absolutely effective..... why convert to oil especially under more demanding service conditions?

Kelly is hands down correct. Sand casting is substandard due to inevitable sand intrusion, the inability to get a truly homogeneous blend of elements in high lead bronze, and it is generally a wash (cost wise) compared to the cost of continuous cast even before you factor in the shorter life span of a sand cast product.

I will soon be testing the composition of the RDG 2100 crown brasses (for several reasons) which are original to the RDG service life of the locomotive. I'll be happy to post the results. It should be pointed out that on locomotives with higher bearing loadings crown composition becomes much more of a science. A bronze which is suitable for grease may well not be for oil and the other way around.

The bronze specified for brasses which are to be babbitted is generally C945. As a side note regarding lined crown brasses, the brasses are babbitted with what is a tin based material versus the lead based material of car brasses.

The baldwin standard practice books call for a clearance of .015". This is also the clearance utilized on the Southern 630 and 4501, I'd say it works pretty good at real speed and under real load.

There are multiple railroad and manufacturers standard practices which agree with the other, there is really no need to "figure it out" when established and proven practices are available.

Cheers, Jason

Russ,

You're only a short Day's drive away. I'd be happy to show you how we set up 4960 if you wanted to make the trip.

Eric Hadder
CMO
Grand Canyon Railway
928-635-5770

Jason: there are eager tribology nerds hanging on everything you do, me not least among them.

Part of the situation here that I think people need to consider is that a solid driver bearing is not quite the same thing as a watch or clock bearing, and not quite the same as a pressure-lubricated hydrodynamic bearing, either.

"Common wisdom" in horology is that the softer metal will cut the harder one, over time: much of the dirt and contaminants that inevitably work their way in are hard oxides, similar to fine sanding abrasive or compound, and they embed in the soft metal and their edges wear the hard journals -- I believe they will even do that for things like chilled iron with extensive carbide content. One reason for 'total-loss' lubrication is that it keeps the bearing 'flushed out' from a clean supply to prevent the damage.

"Pressure oiling" as in an internal-combustion engine has been tried, and it seems to crop up every so often when one of us armchair engineers thinks how obvious a Good Thing it would be. And it is ... if you can maintain the seals, and equivalent of a closed-crankcase, that characterize a system which has positive required supply pressure. It's possible that the EPA will come to regulate rod-lubricant losses as pollution, in which case we're likely to see an efflorescence (I use that word advisedly! ;-)) of interest in supply-and-return pressure feed combined with the sort of good seal in the M-942 grease-lube bearing standards -- extended to take the internal pressure and flow.

SOME of this can be handled via cross-drilling, and the feed need not be continuous (meaning that Isothermos-like passages in the bearing may not be needed to assure continuous crossflow on a large proportion of the actual bearing surface 'all the time'; a point of introduction of pressure feed and a 'tap' around the working circumference in the typical direction of rotation may be enough. Personally I prefer the idea of the drilled passages being the low-pressure 'return', and dedicated hoses and supply through hardlines on the rods the 'supply', but I'm not going to argue that as dogma if wiser heads disagree.

I am presuming that a 'common' lube tribology and set of bearing/journal compositions (including intermediate drilled sleeves as on the FEF main pins) can be developed. Otherwise, my understanding is that existing types of mechanical lubricator can be adapted to feed from different reservoirs 'in parallel', so if a separate system is desired for the rods vs. drivers that could be done.

There are two concerns I haven't seen mentioned yet that I think should be. One is that a new bearing, no matter how carefully it is (cost-effectively) machined and 'free of sand' or transfer of silica into the bearing surface at the plane of initial finishing, is going to have to 'bed in' against its newly-machined journal, and this is not something that a hard bearing on a hard journal does well without some sort of initial lapping action.. I believe this was borne out in some of the 'white metal' controversy (in Fryer and other sources, iirc) in British 19th-Century practice -- and again here with the idea of a harder material vs. babbitt.

A soft bearing composition with heavy loading (as in a locomotive with high superposed axle load) is going to be heavily dependent on hydrodynamic film to keep journal asperities from causing fairly amazing cumulative wear; in the absence of either a copious continuous feed or active pressurization this will result in enlarging clearance fairly quickly up to the point where the lube film either starves or vecomes so thin it does not prevent asperity contact. Much of this and some aspect of your organization will start to resemble that for Bulleid in the latter 1940s...

Meanwhile, I've seen it repeatedly noted that small, almost unavoidable tram and differential-expansion issues require relatively high working clearances on practical non-roller rod bearings. This has immediate consequence for the volume of oil that must be present in the 'whole' of the void between the bearing eye and the journal. and for whatever prevents this volume from 'exiting' under the closing pressures forcing the oil into the lube film. My own opinion (based on some observation of poorly-maintained IC engines) is that an amazing amount of clearance in rod bearings might be tolerable with (1) high-volume oil feed at sufficient pressure to keep the 'wedge' of the void ahead of the developing film full, and (2) good elastomer or hybrid edge seals (perhaps working against lips machined in the outer edges of the rod eyes to take internal pressure without wear leakage) that have the few tens of thou compliance to accommodate the necessary play in the rods. (I do not see any problems with quarter if all the rods have the same nominal play allowance...)

There is a sort of intermediate approach that is technically possible, which would be to use harder grease in spring cellars (a la Mr. Alemite Man) and then supply a much larger amount of the material backed by servo air (from the independent brake main reservoir, for example) or periodically cycled for additional feed volume by some mechanism. For driver boxes this might be thought of as a hard-grease version of a Hennessy lubricator with power feed instead of the Rube Goldberg lateral pumping setup.

Even pressure feeding the grease cellars isn't going to save the day if the grease is inferior. We're considering prolonged track speed running on mainlines, sometimes under pretty good load. We tried several "miracle" hard grease products, a couple of which ran out the bottom of the grease cellar. Hi-Tex 8 worked fine for us.
I'm liking what I'm reading about the oil lube on 630 and 4501 and how cool it runs. Were we still active, we would close the book on snake oil grease and start over with oil.
I'm thinking the SP was a big user of oil in the cellars. Don't know if they were pressure fed or not. I would like pressure fed from the top of the brass to keep flushing.
That's just my opinion, your mileage may vary.