EarlyDieselEngines

Early Diesel Locomotive Engines

It is common knowledge that both ALCO's subsidiary McIntosh & Seymour and Baldwin's De La Vergne produced, when tasked to do so, diesel engines for locomotive service which fell into the category of large bore, long stroke and medium speed. That they did so is no surprise; in fact, Baldwin chose this path after the trend in the industry had been somewhat established by earlier manufacturers. The emergence of the Winton two-stroke diesel as a major force in the market had yet to occur. Let's take a brief look at this kind of engine in general, which makes a great comparison with later high speed engines (such as the ALCO 244 pictured and explained in detail on a separate page.)

This is the 1000 HP ALCO 539 engine, with six 12 inch by 13 inch bore and stroke cylinders, and turbocharger. This was used in the familiar ALCO-GE 1000 HP switchers, and the 1000 HP road switcher, which later became known as the RS-1. It follows early marine engine practice in many design features, and is actually an evolved form of the slightly older 538, which was developed from the 531. (The codes for these indicate first year of test; the 531 first ran in 1931.)

At right is the engine base. Many early engines with a large cylinder size used the base to contain the main bearings and thus the crankshaft; we can clearly see this here. Other later engines of other types commonly used the cylinder block to contain the bearings, thus having all of the removable cylinders, heads and bearings attached to one unit.

1931 was the year that saw the appearance of not only the ALCO 531, but also saw Baldwin purchase the De La Vergne Company, which then developed the famous VO engine for locomotives. The engine is seen here, as well as one of the familiar Baldwin switching locomotives powered by it. This engine in its main production form had 12.75 by 15.5 inch cylinders, and ran at 625 RPM maximum. Note that the combustion chamber is contained inside of the cylinder head; the burning gases vent through a throat into the cylinder to work the piston.

The VO engine as originally produced had a number of problems, which Baldwin had to address and fix. Finally, in 1946, a totally redesigned engine appeared, but one which was largely based upon the VO.

Both the Alco 531/538/539 series and the Baldwin VO series powered thousands of locomotives. Both were essentially developed in the early to mid 1930's, and were based not only upon practice with marine diesel engines but also were based upon trends that had been set in the locomotive industry up until this time. The most significant indication prior to the 1930's as to which direction the design of locomotive diesel engines would take was the contribution of Ingersoll-Rand, who had, back in 1925, produced the first successful diesel engine for diesel-electric locomotives to actually be placed in series production. This engine is very often mentioned as the first successful locomotive diesel, but is never actually seen. That is, until now.

This is the Ingersoll-Rand 300 HP Oil-Electric Locomotive Engine. It utilized six 10" X 12" cylinders, was normally aspirated, and was rated at 300 brake horsepower. The engine had a primitive governor design, which allowed changing speeds with loads for a given throttle position. The idle speed was between 250 and 275 RPM, depending upon auxiliary load. At wide open throttle with light or no load, speed was 570 to 575 RPM; at full rated load developing 300 BHP the top speed was 550 RPM. Two slightly different models, the 360C and 420C were built, differing only in slight design details such as location of fuel transfer pump and in some injection and valve timing events. The rated power and speeds remained the same.

The incredible manual for these diesel engines, suspected to have been printed in 1935, shows different types of locomotives powered by this engine. The early ALCO/GE/Ingersoll-Rand box cab units are not shown; only units built after ALCO split from the consortium are depicted. Here are two shown; an Illinois Central box cab containing two 300 HP engines, and Bush Terminal No. 2, in a new switcher style body with one engine. It is interesting to note the appearance of this latter engine as simulating later road switcher units but in miniature. However, these units were clearly for yard work, not over the road work.

The design of this engine is a whole order of magnitude older in concept than the ALCO and Baldwin engines shown earlier. This engine used exposed pushrods and rocker arms, and had cylinders not contained fully inside the cylinder block. These were hallmarks of very early diesel engines, which in many cases were designed through modification of large gasoline or multi-fuel engines. At left, an extreme oblique view of the Ingersoll-Rand engine from the accessory end.

At right, oil flow diagram which also shows generator mounting flange and flexible coupling from crankshaft to generator shaft.

The section of the Ingersoll-Rand engine shown at left is simply referred to as the "housing." It is the main strength member of the bottom of the engine. It houses the main bearings and crankshaft, and is mounted on top of a base (not shown) which supports the weight of the engine and contains the oil sump. In this view, the housing is upside down. The section at bottom left of the photo is actually the top covering for the camshaft housing, with holes to allow the pushrods to pass.

At right, one of the six cylinder units. The studs at top are to attach the cylinder head. The flange, bottom center, is for cooling water; the large holes are hand holes for access to clean the water jacket. These are bolted onto the housing; note the flanged base of the cylinder unit.

The cylinder heads of this engine are extemely interesting and unusual when compared with the vast majority of modern locomotive engines. They contain separate combustion chambers; note that the piston is at top dead center here, and has a conical top crown with a small center section even more fully raised to partly enter the combustion chamber throat. Two fuel injection nozzles are used per cylinder, in a cross-fire arrangement. This configuration is one of several possible variations of the Price injection system which can be found in early medium and low speed diesel engines for many applications.

Of further interest is the fact that the cylinder heads make, as the manual states, "metal to metal contact with each other" and thus form another strength member of the engine, longitudinally, when mounted and bolted to the cylinders and to each other. The Ingersoll-Rand engine, then, has two main strength members (the heads and the housing) unlike the vast majority of others in which either the base or the cylinder block is considered the main strength member. Also unusual is the fact that the cylinder heads contain passages which actually form the intake and exhaust manifolds, running lengthwise down the engine.

Many of the design particulars of this engine would see no further production in locomotive engines, but in many basic characteristics the concepts would live on. In basic size, and roughly in layout, the early ALCO and Baldwin engines took the Ingersoll-Rand design and not only expanded upon it but improved it as well. Only with the coming of Winton, Electro-Motive and General Motors would major changes in the basic concept of US diesel locomotive engines be developed, helping to trigger a period of intense development, which would last for decades, finally wiping out any resemblance to this early generation of locomotive diesels.

Ingersoll-Rand manual courtesy Dave Davis. All others Will Davis.