The following was written by someone at EMD early in the development of their locomotives. It was found in an instruction booklet which was issued for an EMD locomotive school in the 1940's during the war.

A Diesel engine is an amazing assortment of bolts, nuts, valves, heaters, coolers, expanders, contractors, and other gadgets too numerous to mention here. All of these are screwed and welded together to form a single unit. This resulting unit is expected to start out with below the usual grade of fuel oil and change it into BTU - then the BTU into MEP - the MEP into RPM - the RPM into BHP - the BHP into KWH. Then the electrical gear takes over and makes a BHP out of KWH and RPM out of BHP, and then, if everything is in working order, you finally get MPH. All of this takes place in a fraction of a second in the confines of an all-too-small engine room. This gives you a rough idea of the confusion characteristic to all Diesel Freight Units.

The Diesel engine was invented by a man named Dr. Diesel. The Writer has checked back into his life and character, and is satisfied that this was not done with any malicious intent, as he was a very fine man and loved the human race. Had the idea been left as he left it, nothing would have happened to it. The responsibilities rest upon the shoulders of certain individuals and corporations and Diesel Engine manufacturers, so do not hold it against Dr. Diesel. The names of these men can be furnished during the discussion of this paper, if anyone feels that they might want them.

There are three main classes of Diesel engines. Namely, High-speed Diesels, Slow-speed Diesels, and No-speed Diesels. The principal difference is that the High-speed Diesel runs faster than the Slow-speed Diesel, and they both run faster than the No-speed Diesel. The High-speed Diesel makes noise faster than the Slow-speed Diesel. A Slow-speed Diesel can become a High-speed Diesel by the simple act of speeding it up. Either a High-speed Diesel or a Slow-speed Diesel can become a No-speed Diesel by merely shutting the fuel oil off. This is accomplished very easily. None of the Diesel engines invented up to now will run without fuel oil. This seems to be a characteristic of a Diesel engine. The engine can also be shut down by placing a monkey wrench in an appropriate place so as to jam the gear train, but as this method is not recommended by the manufacturer's association, we will omit it in this paper.

A Diesel engine has several important parts that should be mentioned, among them is the cylinder. This is a long round hole filled with air that is covered on one end with a cover full of holes containing valves that admit fuel, air and sometimes water and carelessly placed tools. These valves open and close according to a predetermined sequence of events. The other end is plugged with a movable plug called a piston. This is free to move up and down within certain limits and would come out altogether if it were not for the connecting rod. This connecting rod is important, too, as it is what changes MEP into RPM, and without it we would be stuck with the MEP, which no one knows how to use up to now. This whole assembly is held in place by crab studs and nuts to prevent it from joining the bird gang. Each cylinder has four crabs, so we might be more considerate of the noise that the engine makes, considering the noise that you would make if you had the same number of crabs.

To start a Diesel engine it takes a certain amount of knowledge, steady nerves, and a certain amount of bravery. First, you set all of the switches in the correct position, with the fuel pump shut off. Then open the relief valves and push the starter button all of the way in. If nothing happens, call a Road Foreman, and he will call a Diesel man to put the starter fuse in for you. Then try again. Let the engines turn several revolutions in this way. The primary purpose of this act is to clear the cylinders of any water that might have leaked in through the above-mentioned holes, or any other holes that were not mentioned. But it also serves another purpose, and that is helping the engineer gain a little confidence before giving it the works. It also adds prestige on the part of the onlookers that might be standing around - namely, the fireman, brakeman, and any laborers and EMD men (if it isn't too early in the morning). After closing the relief valves and turning on the fuel pump, you shut your eyes and push the starter button again. If everything is as it should be, everything about you will begin to tremble and then shake and the damnedest noise that you have ever heard will begin, and then you release the starter button, for this noise and commotion are a sure sign that the engine has started. When the smoke has cleared away and the onlookers have returned, look wisely at the engine oil pressure - then drop the isolation switch a few times to hear it spit. This never fails to impress the fireman and brakeman. Of course, this will not impress the EMD men, because by this time they will have already gone back to their hotel so that they will not be around when the floating pistons let go. Then, before you forget it, go up into the cab and open the throttle to see if the traction wheels will turn over. It is most embarrassing to be out on the main lines, running 60 miles per hour, and find out then that the traction wheels are not revolving.

There are many confusing things about a Diesel engine that you will learn as you gain experience. Among them is the indicator. It is considered a good practice to take indicator readings at regular intervals. An indicator is a gadget consisting of strings, levers and pulleys. The idea is to get a diagram drawing on a piece of paper. This diagram has to do with MEP mostly. To obtain this diagram, the instrument is screwed into a hole in the cylinder cover, mentioned before. It is connected by strings and other suitable gear to an oscillating part of the engine. Here, again, steady nerves and patience is necessary. The idea is to engage a loop on the end of the oscillating string to a hook attached to the indicator. The best way to describe this operation is to compare it with attempting to thread a sewing machine that is underway. If you are lucky and manage to engage a loop in the hook, the string is usually broken. The hook has never been known to break. After breaking a number of strings, one's patience is sure to wear out. Then the proper thing to do is to take a clean card and draw in a diagram like the one in the instruction book. This card is called an inphase card. With much less effort, you can make a hand-drawn card known as an out-phase card. But the out-phase cards are practically useless. So are the in-phase cards.

Another confusing thing about a Diesel freight unit is the interlocks. It is fairly infested with interlocks. There is one that keeps the unit from backing up while you are going forward. This, incidentally, is the only useful one up to now. But there should be another lock on the unit, and that is on the door between the engine room and cab, so that when the Road Foreman goes back into the engine room to see if there is any water in the toilet water tank, the fireman can lock this door and keep him back there where he belongs, but will never stay. After all, the engineer was put on the unit to run the train, so why not let him?

Another confusing so-called interlock keeps you from starting the engine with the overspeed trip kicked out. Here, a word of advice - when you fail to start an engine on account of someone having stopped it by tripping this device, phone the yard office at once and report water in the fuel oil. While you are draining the water out of the lines, filters, pumps, tanks, and so forth, someone is sure to discover this thing tripped and he will, of course, reset it. Then you are ready to try again. However, don't forget to notify the Road Foreman that you are now ready to go, otherwise he might get tired of waiting, get disgusted, and go up town and get drunk.

There is another interlock on the starting contactors that keeps the engine from loading up when the starting contactors are stuck. For some unknown reason this contactor seems to be unusually hard to locate, but there is a movement afoot to have a seeing eye dog assigned to each unit to lead the engineer to the contacts, so that he can tell the fireman to tell the brakeman to get him a flagstaff so that the fireman can break the stuck contacts loose.

Meanwhile, the conductor will be walking many miles up and down, up and down, the tracks and wearing out his shoes, so it is important to hurry. If he is afflicted with high blood pressure, it is very important that you hurry, and if he has already used up his shoe coupon, it is most very important that you hurry.

Diesel engines have innumerable troubles. They have combustion trouble, lubrication trouble, and smoke trouble. It has also been reported that they have female trouble -- this report, however, was checked by the writer, and it was traced to a typographical error where the word "engineer" was misspelled "engine." It would not come within the scope of this paper anyway, so it will be omitted. It might be taken up a little later in the course of conversation when we try to determine why are Road Foremen necessary and what do EMD men put on their expense accounts.

The power of a Diesel engine is measured in horsepower. Why, no one seems to know. Therefore, if you want to measure the power of an engine, the natural thing to do is to find a horse, hitch him to the engine and see which could pull the most. Here a word of caution is necessary. First, horses are scarce, and even if you could find one, it would be another problem to hitch him up to the locomotive - for with so many Road Foremen around who resemble the south end of a horse headed north, it would be very easy to hitch the Road Foreman up to the locomotive and put the horse in the cab with the engineer. Not that the engineer would mind, because he would be much better off with a whole horse in the cab with him than with just the worst part of one. But if there was no Road Foreman in the cab, who would ever think to look back in the log book and report everything that the man in front of him reported. And, after all, that is the only way that the Company can tell if the Road Foreman has ever been on the locomotive, so it is very important that he do this so that the Company will remember to pay him each month. Anyway, getting back to the horse, it would be very hard to find one that wouldn't be scared by the faces of the EMD men around, and he would probably end up by kicking the nose of the unit in and going home.

So it would be much better to rely upon the instruments that the electrical men have invented. They will indicate this power in terms of Amps, Volts or Kilowatts, depending on the individual whims of the electrical designer. With a little arithmetic these values can be converted to HP as nearly accurate as by using a horse. Of all the power generated, some goes to work, some goes to friction, some goes to heat, and the rest goes to hell, which is all that you could expect under the circumstances.

The writer recommends that the prospective Diesel engineer does not take these engines too seriously, or study about them too much in trying to learn all about them. By the time that he becomes familiar with one particular type of engine, it is obsolete, because the designer has the thought of some more interlocks to incorporate into the engine. It has also been noted that once an engineer gets to spending too much time thinking about this Diesel, it is almost impossible to get him off of that track. The best way discovered so far, to prevent this mental derangement, is to lay off as often as possible. A dimly lighted bar is the best treatment for this type of sickness. If the bar is frequented by blondes or brunettes, the treatment is double effective.