This is an incomplete list of gasoline engines designed by Maybach AG, manufactured by Maybach and other firms under licence, and fitted in various German tanks (German: , French: ) and half-tracks before and during World War II. Until the mid-1930s, German military vehicle manufacturers could source their power plants from a variety of engine makers; by October 1935 the design and manufacture of almost all tank and half-track engines was concentrated in one company, Maybach AG, located in Friedrichshafen on Lake Constance, S. Germany.
Friedrichshafen was also home to the Zahnradfabrik (ZF) factory which made gearboxes for Panzer III, IV, and Panther tanks. Both Maybach and ZF (and Dornier) were originally subsidiaries of Luftschiffbau Zeppelin GmbH, which also had a factory in the town.
The firm designed and made a wide range of 4, 6, and 12-cylinder engines from 2.5 to 23 litres; these powered the basic chassis designs for approximately ten tank types (including tank hunters and assault guns), six half-track artillery tractor designs, plus two series of derived armoured personnel carriers. Maybach also designed a number of gearboxes fitted to these vehicles, made under licence by other manufacturers.
Maybach used various combinations of factory letter codes (discussed below) which specified the particular ancillaries to be supplied with each engine variant: the same basic model could be fitted in a number of vehicles, according to the original manufacturer's design requirements. For example, the basic 3.8 and 4.2 litre straight-6 engines (the NL38 and HL42) fitted in various half-tracks could be supplied in at least 9 different configurations, although every component was to be found in a single unified parts list.
However, as the war progressed, a number of problems hampered the German armaments production effort. The factory's inability to manufacture enough complete engines as well as a huge range of spare parts, meant that there was often a lack of both. Conflicts between the civilian Reich Ministry of Armaments and Munitions and the German Army led to a failure to set up an adequate distribution system, and consequent severe shortages of serviceable combat vehicles. In April 1944 an Allied bombing raid put the Maybach factory out of action for several months, and destroyed the ZF gearbox factory.
By the end of the war Maybach had produced over 140,000 engines and 30,000 semi-automatic transmissions for the German Wehrmacht.
Maybach history, 1935–1945 In order to rationalise Germany's military vehicle production, sweeping changes were made to its entire automotive industry. The re-organisation was overseen by , head of Wa.Prüf. 6 (Weapons Inspectorate 6, responsible for tanks, armoured vehicles and motorized equipment) of the Heereswaffenamt (HWA). By late October 1935, Maybach had been designated the sole designer and manufacturer of tank and half-track engines for the entire Wehrmacht, with production later outsourced to other firms including its subsidiary Nordbau (Norddeutsche Motorenbau GmbH) in the south-eastern Berlin suburb of Niederschöneweide beside the River Spree.
Maybach AG made very few complete parts of its engines at all. Almost everything was bought in from other suppliers. Its main activity was precision machining of the castings and forgings of its own design, made by outside manufacturers, and producing complete assembled engines on a separate assembly line. Completely finished crankshafts were supplied by , in Remscheid- :de:Hasten. In addition, machined pistons (Mahle KG), piston rings, roller and ball bearings, fuel pumps, carburettors (Solex), and complete electrical equipment (Bosch) were acquired as finished parts from outside sources.
Although a steady supply of spare parts is essential to an army in the field, the production of complete engines always took priority over providing spares. According to Albert Speer, Hitler himself never realised this importance: "One of his worst failings was that he simply did not understand the necessity for supplying the armies with sufficient spare parts."
Germany never achieved the industrial capacity needed to keep its military vehicles running efficiently: when the Russian campaign got underway, the deficiencies of the armaments industry and the organisation of maintenance depots became obvious. The German armed forces suffered from continual shortages of spare parts for tanks and half-tracks until the end of the war. When the first Tiger I tanks arrived in Russia in autumn 1942, there was only one spare engine and one transmission for every 10 tanks. A critical lack of spare parts meant that most of them were out of commission within a short period, sometimes for weeks on end. Despite various attempts at re-organisation, friction between the distribution systems of the German Army (das Heer) and the civilian Ministry of Armaments (and from 1944 the 'Rüstungsstab') often led to confrontation and inefficiency. Some of this can be blamed on Karl-Otto Saur of the Ministry of Armaments, whose ruthless drive for greater overall production figures tended to override the need for testing and durability concerns, and the manufacture of enough spare parts.
According to Stieler von Heydekampf, president of the Panzer Kommission from 1943, German tank production was at a major disadvantage throughout the war because the main firms involved were heavy equipment manufacturers. It would have been more effective if the programme had been given to Ford Germany and Opel (owned by General Motors) because of their real mass production experience, but this was not done because of their American associations.
Maybach's monopoly on engine production proved to be the bottleneck in German tank production. From 1942, after the German invasion of the Soviet Union, Maybach started dispersing its manufacturing activities, licensing eight other firms to manufacture its engines. Adler Werke in Frankfurt/Main built the HL42 from January 1942; Saurer Werke in Vienna, Krauss-Maffei (Munich), and Borgward in Bremen were licensed to build the HL62 & HL64; Maschinenfabrik Bahn Bedarf (MBB) in Nordhausen made the HL109, and also the HL120—along with Maybach's subsidiary Nordbau in Berlin and MAN in Nurnberg; and Auto Union in Chemnitz (Siegmar Werke) made HL230s, having tooled up from October 1943–March 1944. Henschel & Sohn in Kassel made large quantities of major components for Maybach in 1943–1944: 2,434 crankshafts, 1,850 crank cases, 32,121 connecting rods and 8,196 'closing covers' (undefined - maybe valve covers or possibly cylinder heads).
Maybach from August 1943 also organised 11 of its own dispersal machining sites located from a few miles away to some 60 miles distant; the finished parts were then sent to a designated factory for assembly. These precautions allowed manufacture of complete engines to take place away from Friedrichshafen. On Hitler's orders in March 1944, the extensive cellars below the town of Leitmeritz (now Litoměřice, Czech Republic) on the river Elbe were to be used for the anticipated assembly for HL120 and HL230 tank engines, in case a manufacturing plant were to be bombed.
Despite these precautions, by late 1943 there was still a severe shortage of spare tank engines. Rather than concentrate on proven designs, Maybach continued to bring out new, relatively untested models; the wide variety of engine types seriously hampered efforts to fix the multiple defects which Maybach engines developed under combat conditions. The extreme difficulty of stocking so many spares at the front, several thousand kilometres away from the factory, swiftly led to vehicles being unserviceable for combat. Because the armaments industry was already working at full capacity, it was not possible to completely replace obsolete models with new versions. Instead, the number of tank models and types within each series issued to the field forces increased steadily, which only made the maintenance and repair situation worse.
Severely damaged tanks from the Russian front were initially shipped back to Germany, or to the Nibelungenwerk or the Vienna Arsenal for repair; but the prospect of inevitable delays often meant that vehicles were instead cannibalised at the front for parts. Often when a new engine was delivered, there was little left except the hull of the tank it was intended for. Nevertheless, the maintenance crews did their best, often retrieving knocked-out tanks under considerable difficulties.
As the war progressed, new Maybach engines tended to be rushed into production, without adequate testing and improvement. As a result, they were viewed as unreliable (although this would be expected of any un-developed engine). All the 325 new Panther tanks delivered to Russia in early 1943 had to be returned because of serious defects in the steering; they were underpowered by the HL210 P30 engine, and its replacement, the HL230 P30 (which didn't arrive until late 1943) suffered from over-heating, fires in the engine compartment and blown gaskets.
By way of comparison, the Soviet Army used a single basic engine (the V-12 diesel Kharkiv V-2) to power the majority of its tanks – with a few modifications – starting with the BT-7M and its successor the T-34, producing @ 1800 rpm in 1939; the SU-85 and SU-100; the KV-1 and KV-2 (600 hp with supercharging in 1939); and the IS-2, ISU-122 and ISU-152 and the T-10. Maybach didn't produce a more powerful acceptable engine until late 1943 with the HL230 P30.
Starting in March 1944, a series of Allied precision and area bombing raids put the Maybach factory out of action for several months. Those of 27/28 April and 20 July especially inflicted heavy damage on the plant. However, engine production continued at the various dispersed machining sites and manufacturers. If the various firms making Maybach motors under license had not been in a position to continue producing engines, the German Army's entire tank program would have been seriously jeopardised.
Although the German Army used various combat vehicles appropriated from other countries, they continued to be powered by their original engines. Maybach engines were fitted to the German fighting vehicles for which they had been designed.
General design All Maybach engines for AFVs which reached series production were gasoline four-stroke water-cooled designs. The firm's managing director, Dr. Karl Maybach (son of the founder Wilhelm Maybach), had stated that "he was born water cooled and wanted to die water cooled."
Before the war the fuel industry had indicated that petroleum was going to be easier to produce than synthetic diesel, and development of gasoline engines was therefore favoured. By around 1943 the situation had turned around, but by then it was too late to change. Dr. Ferdinand Porsche had consistently pushed for air-cooled diesels, but his organisation's designs never functioned satisfactorily. The twin large Porsche gasoline V-10 engines slated for the Tiger (P) never worked satisfactorily, and two over-worked Maybach HL120s were fitted instead to drive the electric generators and final drive motors in the subsequent Ferdinand.
A number of Maybach motors shared the same basic design but had different engine sizes, the larger engines having bigger cylinders to increase the capacity. Similar engine designs had shared parts lists, e.g. the NL38 and HL42; the HL57 and HL62; and the HL108 and HL120.Photos of various front covers at
The 6-cylinder Maybach engines used a single Solex 40 JFF II down-draught () carburetor, and earlier V-12s used two.Photos of Solex 40 carbs (end of page) at Later V-12s used Solex 52 JFFs.
A hand-cranked inertia starter (Schwungkraftanlasser) was fitted to the V-12 engines to supplement the Bosch 24V electric starter motor (powered by two 12V batteries) in cold weather.Illustration in .
Nomenclature Introduction