For use on a saturated, slide-valve locomotive, originally equipped with a hydrostatic lubricator, would there be any significant advantage to replacing it with a mechanical lubricator?

The three-feed hydrostatic lubricator is on hand, a mechanical would have to be obtained. The mechanical can also feed valve oil to guides, etc. The locomotive in question is a simple machine, with one air compressor being the only additional point of steam lubrication.

Displacement lubricators have a reputation for being messy and unreliable, but there seem to be plenty of locomotives out there operating with them.

Howard P.

Bernie Watts can also repair hydrostatics. You need to know how to use and maintain them and also how chokes work at the downstream end....... mechanicals are still available off the shelf with parts and support for industrial customers and pose no obsolete operating challenges so if there's a lost skills differential they may be the more rational approach. On a saturated slide valve engine you will need a terminal check valve with a low to moderate cracking pressure at the downstream terminals, perhaps some small volume of steam injection as well to carry the oil further than the top surface of the slide valve between balancing plates. Farmer Stan used a Trabon Mul T Shot pump to lubricate entire locomotives points which operated off the pulses in the air pump's air cylinder when the compressor operated, which didn't seem sensible to me as when the engine was running and consuming no air it was starved for oil until you shut off steam and applied brakes, when it was flooded. I like them for just oiling the steam end of the air pump operated from the air end's pulsations, with another mechanical or hydrostatic unit lubricating the cylinders, valves, Xheads and whatever else. So, if you have old heads used to hydrostatics use them if you have them, if not conversion to mechanicals may be a good idea.

I worked for a very talented CMO and I asked him about one over the other. This RR had mechanical lubricators on their three running locomotives. His response was one was not really better than the other. Similar to what Dave said it all came down to the operating crews knowing how to use them and paying attention if something is abnormal in your use of oil. That should tell you something is wrong, not what is wrong. But then you know to go looking. Same for keeping an eye on something getting too much oil or running hot between runs.

On a SY mike I had to find a wide open line on the engineers side and the mechanical lubricator was on firemans side. The lube lines turned into a tangled rope when going behind the cylinders. Making it near impossible to trace what line went where. I tried a number of things and ended up cracking the oil lines and lightly back pressuring to the lubricator so we knew what line did that. Then we marked what line went where by process of elimination. This line was not plugged but was pouring way to much oil on the crosshead slide. The CMO or one of the other mechanics would fix the adjustments once we found which valve adjustment {?} was the culprit. I do not know the proper names for the mechanical lubricator parts. So a crew member saw a problem or noticed one lubricator "sump {?}" was using to much oil. This time it was very easy to see the excess oil dripping all over. I think the CMO was right on the money, If you have a well trained crew either will work well and one is not an advantage over the other. It is your crew doing their jobs being observant that makes both work well. If either is broken both will need repairs but one being better than the other? Your operating crew doesn't need to be mechanics but they need to know how to use them, what to look for and then report it even if they do not know what or how to fix it. I used to think the mechanical lubricator would solve problems. But if a lube line breaks, becomes plugged or comes out of adjustment with too much or too little it is still not working. Same as a hydrostatic. Don't think we can make a steam locomotive idiot proof. Our crews need to learn to look, listen and feel when things are not right. My not so humble opinion free of charge. Regards, John.

Hi Howard,
One thing to consider is if you change to a mechanical then your air compressor will not be getting oil when the engine is not moving unless you also add an air impulse oiler as described in a previous post.....mld

WABCO and NYAB made - in the modern steam era - their own proprietary air powered steam oil pumps which bolted onto the air pumps themselves, but good luck finding any. The Mul T Shot was under $300 last time i checked. Combined with a small low pressure terminal check (also off the shelf) makes a good air pump mechanical unit. Only use one feed out of 12 (volume controlled by combining multiple feeds). I have no financial interest in any of this hardware. The old school mechanicals controlled feeds by controlling the length of stroke of the plungers in each lubricator pump (which all draw from the same sump of oil.) I found a problem once with some pumps having worn to the extent that they wouldn't force oil against the pressure in the valves and cylinders - locomotive got no oil while running until shut off then vacuum sucked all that built-up oil into the valves where it burned showing a nice cloud of black smoke coming out of the snifters and ring collapsed....... the worn pumps work a treat on Xheads and other non back pressure locations so don't throw them away.

From experience -

The hydrostatic requires more intelligent supervision. The mechanical functions without any skill other than filling the tank with oil.

The hydro can be adjusted easily for more/less oil flow, from the comfort of the cab. A mechanical requires trial and error adjustment, and you can't do it while the train is moving.

On the other hand, with the hydro, because you are staring at it in the cab all the time, you know for sure whether oil is flowing or not. If the mechanical locks up or plugs, you don't know maybe until a week later when some damage is done. Most American engines have the lubricator out on the running board, but many of our Scandinavian engines have the lubricator in the cab a) to keep the oil warm and b) to make supervision clear. Our Swedish engine has the lubricator right in front of the Engineer's post, and there is a separate sight glass on each feed.

The hydro requires daily adjustment, because its function changes with steam, oil, and external temperature. Often the hydro has a master valve that closes all except the air pump for long dwells in the station, and of course you need to remember to open/close this every trip.

The hydro has no moving parts, so effectively it has an unlimited life. The mechanical can wear out.

I think it should be part of the (written) operating procedure, that the hydro be timed every day to a certain number of oil drops per minute in every sight glass. This would be especially important with occasional volunteer operations where there is not enough regular accumulated hours of experience to just rely on "judgement".

There was a time before WWI when lubricating oil was expensive, and watched carefully for consumption. White's "American Locomotives" discusses this. The hydro makes it easier to ration oil. With the mechanical, considering how hard it is to adjust, I would err on the side of more oil consumption. So I would expect the mechanical to consume more oil, which would be acceptable as the cost of lubricants declined in the 20th century.

Also, the feed from a mechanical can vary with the cutoff if the lubricators mechanism is driven by the valve linkage whose range of motion also varies with the cutoff. So, please install driving linkages carefully.......

I have been running mechanicals on Flagg 75 Jeddo 85 and Lehigh Valley Coal 126 for nearly 20 years now. I've found them to be extremely reliable and worry free once set up and adjusted accordingly. I probably run a little more oil than necessary but figure that's cheaper than repairs. I home built my air compressor oiler out of off the shelf components ,(as well as the governor's,but that's another story) and since then the pump will run on as little as 5 pounds of steam.
They are all either Manzel or Madison-Kipp lubricators I bought off eBay or at steam shows at very reasonable prices. I've worked with hydrostatics in the past and for the previous stated reasons avoid them. I got to many other things to watch over while the engine is running. One less thing to worry over makes life easier.

.

Agreed - but if any of you out there are like us, the pump you are installing has been sitting out in a boxcar for 60 years. It came off an unknown locomotive in a scrap line. It is covered in rust and dried oil. You have no idea how it will perform. It will require adjustment and observation.

We recently (3 years ago) did this with our current tank engine restoration. We made up a test stand to test the pump. This European pump has external adjustments and sits in the cab, so at least we can make adjustments as we go during the day.

Testing the pump with hydraulic fluid and a test gauge after cleaning but before filling with steam oil will let you know of any issues. I'd look for at least 450 PSI output pressures for feeding any pressurized component.

The mechanical pumps should be serviced often. They will gain water that will freeze. Also, on many makes, the pumping units will have fine screens on the take up that will need cleaning. Most mechanical pumps are easy to work on and will work with considerable wear.

Here are the lubricators in our current active and nearly active fleet:

The locomotive I work on is superheated with piston valves, 175 PSI boiler pressure, and has a Nathan 5-Feed hydrostatic lubricator.

I have heard this reputation for hydrostatic lubricators being difficult to use. In my experience, the reputation is undeserved. Of course, there are other steam railroaders on this forum with much more experience than me, so they may disagree. The hydrostatic lubricator on my locomotive works happily just about all of the time. The process of filling and starting the lubricator, and timing the feeds, takes perhaps 10-15 minutes each morning. Somebody who does it everyday can probably do it in less time.

One benefit to the hydrostatic lubricator is this:
Suppose you're out oiling around, and you notice that, say, the right piston rod is looking drier than normal. You're worried that it's not getting enough oil. So, you poor a little steam oil directly onto the piston rod, then go up to the cab, and increase the feed rate a little to correct the problem. If you encountered this situation with a mechanical lubricator, you wouldn't be able to make an adjustment so easily. Now, I suppose there is a counterargument that a well-set mechanical lubricator will usually feed the right number of drops regardless. Both kinds can fall victim to clogged lubricator chokes.

I do agree that the level of knowledge that the crew needs is greater with a hydrostatic lubricator. But it's not like they need a PhD about it. Learning the information about hydrostatic lubricators contained within the ICS book on lubricators is most of what they need to know. Not to be snide, but if an engine crew is not smart enough to be able to understand the construction and operation of a hydrostatic lubricator, they should not be in charge of a locomotive. I mean that seriously.

DO NOTE, THOUGH, that it is important to be careful when opening the oil fill plug on a hydrostatic lubricator if the lubricator has been under steam pressure recently. If you don't do it right, steam escaping from the reservoir will carry a blurp of hot steam oil out of the lubricator and into the cab. One time, another engineer was refilling the lubricator while I was in the engineer's seat. Both the cab ceiling and I got hit by a nice slug of steam oil. If it had gotten in my eye, the consequences might have been severe, so wear safety glasses when you do it. Not trying to scare you though. You can read more about refilling one in this thread:

viewtopic.php?f=1&t=44830

I would suggest staying with hydrostatic lubrication to preserve the historic integrity of the design of your locomotive. Thanks for helping keep steam alive!