Some interesting questions came up at a recent meeting regarding EMD 567 engines, about lube oil practices relating to EMD engines in museum and shortline service. I am posting some of that information here in an effort to share it with those who might find it useful.

The oil change and sample monitoring intervals, as well as the general maintenance practices, stated in EMD Scheduled Maintenance instructions are based on “typical” railroad practice. Many of the early MI’s on scheduled maintenance carried the disclaimer “to be modified to suit the type of service and operation”.

Up until the late 1940’s, Scheduled Maintenance requirements for 567 engine locomotives were covered by Maintenance Instruction 1605. This was replaced in the early 1950’s by MI 1704. Both of these MI’s cover recommended lubrication intervals and applicable lubricants for many items of equipment on the locomotive in addition to the diesel engine. These are good guidelines for use in museum and shortline service with the exception that many lubricant change intervals were written based on mileage intervals that will never be achieved in museum or shortline service.

In recent years MI 1724 originally written for the SW1000 and SW1500, and MI 1738 and MI 1740, written for the roots blower and turbocharged locomotives respectively, have been much more readily available and tend to be seen and used more often. The MI 1738 and MI 1740 in particular are based on the needs of a major freight railroad that are hardly applicable to museum or shortline service.

In occasional service, the accumulated effects of light engine loading and water condensation in the engine crankcase tend to have a much greater effect than if the engine were being operated on a major railroad. Lack of load results in varnish and sludge accumulation in cylinder liners, can contribute to poor combustion, and eventually can generate oil out the stack which degrades the appearance of the equipment as well as making a mess for operating personnel and visitors. Planned heavy load use or occasional operation on a load box can reduce the accumulative effects of light load operation.

Every time the engine is operated and shut down, condensation forms on the engine moving parts and interior of the crankcase as the engine cools. The condensed moisture collects in the bottom of the oil pan as well as in the clearance in bearings. The more frequent the shutdowns and cooling off, the more water condensation is accumulated. This is a distinct difference from major railroad service where engines may operate 92 days between inspections without being shut down. Consequently engines in museum and shortline service should be checked frequently for water accumulation in the oil pan, a small amount of oil should be drained and allowed to settle in a glass bottle so it can be checked for water. This also allows you to see if lower liner seals are leaking water in older 567 engines.

Pre-lubrication of the engine before starting after an extended shutdown is a good practice not only to lubricate the engine bearings but also to displace any condensed water that accumulated between the bearing and the crankshaft before you attempt to start the engine. In the long term, accumulated condensation in the bearings of engines in occasional service will tend to pit the crankshaft journals and erode the bearings.

If the articles section of RYPN were still serviceable, I would have preferred to post this as an article instead of an interchange item, but that area has been out of service and inaccessible since about 2007, thus this is being posted here.

PC

Is there not still a procedure where you send the article text to dcollison@rypn.org with notes that you want it put up as an article?

If that is not currently supported, I'd like to see it be.

I might also add that as we come up with the various kinds of 'best practices' and potential manual chapters in Becky's thread, we provide some version of them as articles. This would put new life into that section, which I think would be a very good thing...

It appears that the last story posted in the Articles section of RYPN was May 26, 2008. If use of the articles section is still available you would expect to see some more recent articles than seven years ago. The photo links on some of the articles have become dislocated over the years and the photos no longer load along with the articles.

When the articles section was brought up some time ago in one of the very lengthy discussions about making RYPN the "Internet Journal of Preservation", I believe it was indicated that the section is not available for posting, that there was nobody maintaining it. If that has changed perhaps someone will let us know.

In any regard, restoring the photo links usually takes just a few minutes work on most websites, just linking the frame to the image file in the correct folder, so the articles section having not been repaired in the last seven years is probably a pretty good indication that it is not accessible or there is no one to maintain it.

PC

There is work taking place behind the scenes to perhaps rectify the problem with the articles. In the meantime, why not submit it to the ATRRM for inclusion in their online magazine.

It has been sent.

PC

[quote="PCook"Every time the engine is operated and shut down, condensation forms on the engine moving parts and interior of the crankcase as the engine cools. The condensed moisture collects in the bottom of the oil pan as well as in the clearance in bearings. The more frequent the shutdowns and cooling off, the more water condensation is accumulated. This is a distinct difference from major railroad service where engines may operate 92 days between inspections without being shut down. Consequently engines in museum and shortline service should be checked frequently for water accumulation in the oil pan, a small amount of oil should be drained and allowed to settle in a glass bottle so it can be checked for water. This also allows you to see if lower liner seals are leaking water in older 567 engines.


PC[/quote]

I think you have it backwards. Think of your coffee cup. You never see condensation on the outside of the cup because it is too hot, above the dew point of the air surrounding it. You DO see condensation INSIDE the cup as the water vapor from the hot coffee meets the cooler upper surface of the cup. The amount of water vapor above the surface of the coffee is much higher than the surrounding air and the dew point inside the cup is correspondingly closer to the temperature of the coffee. Thus the condensation.

It is no different than short distance driving in your car. The most condensation will happen on startup when water vapor inside the engine meets the metal parts that are below the dew point of the air inside the engine. Water can condense on hot parts only if those parts are cooler than the dew point of the air inside the engine. If an engine is not allowed to come to full operating temperature, the water that has condensed on the walls of the block or on other cooler parts will not be evaporated, nor will the water vapor inside the engine be driven off and out of the engine. The important consideration is to operate long enough at normal operating temperatures to ensure that the water vapor inside the engine is driven off.

How much water vapor can enter an enclosed crankcase? I would think that when an engine runs and gets hot, the water vapor trapped inside will be driven off. As long as the crankcase is kept closed up, no water vapor, or very little, will be able to reenter the crankcase as the engine cools.

Last week I pulled the crankcase cover off of the Alco 539 on USS 70. There was no surface corrosion at all on any of the machined surfaces of the crankshaft or rods. This tells me that in thirty years of sitting out in the weather, no water vapor had been able to enter the crankcase. and this crankcase cycled from over 100 degrees to below zero many times just from ambient temperature changes.

BTW, if you want to do an oil analysis on your locomotive, here is a place to start: http://www.blackstone-labs.com/free-test-kits.php

He is talking about condensation on a cold block from saturated ambient air against cold metal -- as in dew. I'm sure he will tell you why ambient humid air enters and circulates in an EMD crankcase.

More specifically, he is talking about water in the oil. What happens is that the 'dew' slides down, following gravity, and the droplets coalesce and fall below the oil level. Water will not evaporate from below oil in the crankcase, just as it will not evaporate when it condenses in the diesel fuel. You may note that the operating temperature of the oil is kept below the boiling point of water, so the water in the sump doesn't 'boil off' within a few minutes of starting.

The principal 'normal' reason to run an engine for a relatively long interval when it is started is not to remove water from the lube oil. It's to ensure that the initial condensation of H2O from fuel combustion does not stay condensed in the exhaust system and cause problems there. To a lesser extent, you want to be sure that any air in the coolant passages has had a chance to be expelled and the internal passages themselves well-wetted; starting just long enough to splash them with water and then expose them to air is an invitation to corrosion.

If I had a 567- or 645-engined locomotive, I would consider regularly running the lube oil through a centrifugal water separator and filter. The modern version of those things is relatively inexpensive (and can double as a simple treatment plant for waste oil used for steam firing) and it might even be possible to hook one in as part of a bypass filtration system (which constantly circulates a small percentage of the oil through a high-efficiency filter and separator; it would be extremely difficult to achieve good filtration with required main oil flow, but is simple with the small 'auxiliary' pump used on the bypass line). Of course, I would also consider plumbing the bypass pump in for use as a 'preluber' -- but that's just my opinion that the bearings in historic engines should be treated like jewelry. And it is in the bearings and other lubricated surfaces in contact, not the visible surfaces inside the engine, that are at risk from water in the lube oil!

Both these techniques are better than the 'classical' gravity water separator as found on the fuel system of old diesel automobiles and trucks, and probably at the base of the oil pan on these EMD engines. But that doesn't mean that tapping off any condensate (or coolant leakage) isn't a good and prudent maintenance step whenever starting the engine -- nearly as important as making sure there's no hydraulic lock on a 4-cycle diesel engine before trying to start it...

Thank you Mr. Ellsworth, excellent posting.

EMD engine crankcases are constantly ventilated when operating, using suction from the blowers in the Roots Blower engines, and from a draft tube or eductor in the turbocharged engines. This creates a suction in the crankcase and outside air is drawn in around shaft end seals and by top deck cover gasket leakage. Some moisture comes in with the air, lots more enters when you open the top deck covers.

Smaller engine manufacturers agree with the description Hamster provided for condensation formation.

Large diesel engines act like a house in the wintertime after you shut them down. The outside exposed walls of the oil pan and the handhole covers go cold very quickly and condensation forms on the engine interior side of those colder metal surfaces and runs down into the oil in the pan. The situation is made worse in early 567 engines if there are lower liner seal water leaks as seals age and harden.

PC

Oh yeah, sorry. I forgot the 2 cycle vs. 4 cycle differences in engine design.

Overmod, the subject of water in oil is something that I have been looking into quite a bit recently, with respect to lube oil on our 4,000 HP stationary steam engine. On a warm damp day following a cold snap the oil drains can collect upwards of 10 gallons of water. I am designing the lube oil system with the ability to not only separate out the water but also find a way to remove the dissolved and emulsified water to the extent possible. Whether it be a vacuum oil dehydrator or a centrifuge, not sure yet. Whatever I install will most likely be something that I stumble across on ebay or HGR Industrial Surplus. Such a system can be made portable for regular use in treating locomotive lube oil.

I agree that locomotive bearings and journals should be treated like jewelry, and plan to do so to the extent practicable.

The best thing to do is have your oil tested regularly and see whats going on in the oil. When numbers start climbing over a period of time then adjust accordingly. Many larger problems can be found out in the very early stages by keeping track of whats going on in your oil.

I've decided on our Alco to change the oil and set up a regular testing program working from a know baseline. Also gives me a chance to clean out the sump and plumb in a prelube system.

I'm sure Howard will chime in, but I believe we (RMNE) installed an accumulator and a valve for draining the water from the oil in our FL-9, NH 2019. We have loaded it up against the dynamics on our U-23B in the past, but only for testing purposes.