In our last installment, we looked at the history of diesel-hydraulic road locomotive development in Germany. We noted the early development of twin-engined diesel-hydraulic road locomotives as early as 1953 by a consortium of German locomotive and engine builders and the DB itself; one of these early V200 locomotives is shown below from the Henschel Locomotive Engineer's Manual (pub. 1960.)
Design work progressed in high speed, light weight locomotive engines in Germany such that by 1959-1960 instead of 800 to 1100 HP V-12 engines, there were now V-16 engines capable of anywhere from 1600 to 2000 HP and transmissions which were capable of taking at least 1800 HP input by 1959. We will now move on to the ML4000C'C' as built for the US railroads - in this case, our data will be specific to the three units produced for the D&RGW railway.
Two further volumes will be consulted, whose covers are shown below.
These manuals are the Parts Manual for the ML4000C'C' locomotive, and the Diesel Engine Maintenance Manual for the ML4000C'C'.
Below is an overall external view of the locomotive as delivered from the factory. Remember to click any photos on this site to enlarge them.
Of course, one unit is shown, but it should be remembered that the original operation on the D&RGW for these units involved always using all three units in multiple, frequently with a dynamometer car. The intention was that three K-M units could replace the regular sets of EMD units D&RGW was using to haul trains, which normally amounted to six or seven units each rated 1500 or 1750 HP for traction.
Below we see an illustration from the parts manual showing the layout of equipment in the locomotive. Note that the engine compartments are leading, or are toward No. 1 end, from the radiator compartments but that the forward diesel engine's orientation is opposite that of the after engine because the Voith hydraulic transmissions are toward the ends of the locomotive.
Notable features in this illustration are the high mounted cab floor, raised over the high speed drive shaft for No. 1 powerplant; the compact diesel engines, each with two turbochargers mounted directly on top of the engine; the large Voith transmissions; and the cardan shafts (shafts with splines and universal joints) used to make the connections to drive the axles. Below, a diagram showing just the drive line components from the same manual.
The Dynastarter is both generator and starter motor; it starts the diesel engine through the high speed shaft (4) and thereafter functions as a generator for on board power and battery charging. The shafting is very obvious in this view, from engine to transmission, then to an intermediate gearbox, and finally to the axle drives.
The trucks and suspension on these locomotives are peculiar, largely because the mechanical equipment just described makes conventional center-pivot U.S. style trucks impossible. For this reason, K-M had developed a fairly complicated truck and suspension design for the V200, then for the six axle ML2200 / ML3000 and finally further for the ML4000 locomotive. Below, views of the truck construction and suspension arrangements.
Our final view is a cut showing the rear cab wall and the side cab view to give a complete idea of what the cab arrangement internally was like.
In our next and final installment on these locomotives, we will cover design details of the diesel engines, and discuss authoritatively the actual power ratings of these locomotives.