The cumbersome road wheel assembly of the Tiger I can be clearly seen in this photograph taken at the Henschel works. It is easy to understand why these wheels could become jammed solid with mud, ice or snow requiring huge efforts to repair.
The Tiger was essentially at the prototype stage when it was first hurried into service, and therefore changes both small and large were made throughout the production run. A redesigned turret with a lower, less bulky commander’s cupola was the most significant early change. To cut costs, the submersion capability was reduced and an external air-filtration system was dropped.
The rear of the tank held an engine compartment flanked by two floodable rear compartments each containing a fuel tank, radiator, and fans. German industry had not developed an adequate heavy diesel engine, so a fuel hungry petrol power plant had to be used. The initial engine was a 21 litre (1282 cu. in.) 12 cylinder Maybach HL 210 P45 with 650 PS (641hp, 478kW). Although a good and reliable engine, it was inadequate for the size and weight vehicle. From the 250th production Tiger Chassis 250251, this engine was replaced by the updated HL 230 P45 (23 litres/1410 cu. in.) with 700 PS (690hp, 515kW). The engine was in V-form, with two cylinder banks at 60 degrees. An inertial starter was mounted on its right side, driven via chain gears through a port in the rear wall. The engine could be lifted out through a hatch on the hull roof. The engine drove two front sprockets, which were mounted low to the ground.
The eleven-tonne turret had a hydraulic motor the drive for which was powered by mechanical drive from the engine. Rotation was slow and took about a minute to swing through 360º. The suspension used sixteen torsion bars, with eight suspension arms per side. To save space, the swing arms were leading on one side and trailing on the other. There were three road wheels on each arm, giving a good cross-country ride. However the smoothness of the ride was bought at a high price. The constant need to remove the front road wheels in order to gain access to the rear wheels was to become the bane of Tiger I crews from day one.
During action the laborious process of re-fuelling and re-arming the Tiger I was a never ending task for the hard pressed crew members.
The problem from the crew’s point of view was that the heavy wheels which had a diameter of 800mm (31 in) were overlapped and interleaved. Removing one inner wheel that had lost its tyre, which was a fairly common occurrence, could therefore require the removal of up to nine outer wheels. This was bad enough under calm conditions but it meant there was no way of making a fast change in the combat zone and many precious Tigers were blown up which could otherwise have been saved. The wheels could also become packed with mud or snow that could then freeze. Eventually, a new ‘steel’ wheel design, closely resembling those on the Tiger II, with an internal tire was substituted, and which like the Tiger II, were only overlapped, and not interleaved.
Another new feature which was to cause problems was the untested Maybach-Olvar hydraulically-controlled pre-selector gearbox and semi-automatic transmission. The extreme weight of the tank also required a new steering system. Instead of the clutch-and-brake designs of lighter vehicles, a variation on the tested and proven British Merritt-Brown single radius system was used. The Tiger I, like all German tanks, used regenerative steering which was hydraulically operated - the separate tracks could therefore be turned in opposite directions at the same time, so the Tiger I could pivot in place, and completely turn around in a distance of only 3.44 meters (11.28 ft.). Since the vehicle had an eight-speed gearbox, it thus had sixteen different radii of turn. If an even smaller radius was needed, the tank could be turned by using brakes. There was an actual steering wheel and the steering system at least was robust, reliable, easy to use and ahead of its time. The British T. I. Summary No. 104 was issued on 16th May 1943 gave the British troops in the field a pretty accurate summary of the type of tank they were facing.
An extract from the Tigerfibel, the commander’s manual: “If you travel 7km, your wide tracks will throw up the dust from 1 hectare of land. You will be recognised from far away and will lose your most efective weapon - surprise.”
Pz. Kw. VI
The following additional information on the Pz. Kw. VI has been collated from captured documents and reports from Russian and North Africa:-
(a) The tank can be submerged to a depth of up to 16ft for fording rivers and other water obstacles. Further information on this development is contained at Appendix C.
(b) An automatic fire extinguisher is provided. Heat-sensitive elements are arranged in suitable positions in the engine compartment. If fire breaks out, one of these elements will cause an electric circuit to operate the extinguisher which will there upon discharge a fire-extinguishing agent for a period of seven seconds. If the fire is severe, the circuit will remain closed and the process will be repeated one or more times until either the fire is put out or the reservoir of the fire extinguisher is exhausted. The reservoir holds 9lbs of extinguishing agent.
(c) The gearbox is preselective and is cooled by a fan which also cools the manifold.
(d) Standard German petrol with an octane number of 74 or 78 is used for the engine.
(e) Reference summary 102, appendix D, North Africa now reports that the total amount of 8.8cm ammunition carried is 92 rounds stowed in racks and bins, 46 rounds each side of the tank.
(f) It is confirmed that the 8.8cm tank gun is electrically fired.
(g) Oil capacities are as follows:-
