Germany tried its hand at heavy tank development prior to World War 2 in the early 1930s, producing five examples of the plodding, multi-turreted "Neubaufahrzeug" heavy tank series. These steel beasts, however, ran contrary to the expected successes of the "blitzkrieg" method of waging war which directly limited interest and their overall impact. However, as World War 2 became fully entrenched in the daily lives of Europeans, thought was once again passed to heavy tank development for the German Army - this also prompted by the arrival of evermore powerful Soviet breeds. Beyond its well-noted early light- and medium-class Panzers, there were the excellent Tiger I and Tiger II tanks of 1942 and 1943 respectively. Not one to sit on its laurels, German authorities sought even more powerful types during the latter stages of the war - "Super Heavy Tanks" - and this included the Panzerkampfwagen (PzKpfw) E-100 development - otherwise known as the "Tiger Maus" ("Tiger Mouse").
Design of the E-100 ran the conventional route of a track-and-wheel system fitted to a heavily armored hull with engine at the rear and a 360-degree traversing turret at the center of the hull roof. Henschel was charged with its development which, by mid-1943, was in direct competition with Porsche who had already secured a development contract for its super-sized 188-ton Panzer VIII "Maus" heavy tank. The Henschel design was to be "lighter" in form, initially covering some 155-tons of armor, weaponry and systems though its size and weight still limited it along European village roads and across its archaic bridges. The E-100 was allotted the same turret design of the Porsche Maus project, hence its informal name of "Tiger Maus". Additionally, the Tiger Maus would use many off-the-shelf components available from existing German stocks to speed up its initial development and subsequent production as well as expected in-the-field maintenance.
Work on the new tank proceeded through 1943 and into 1944. Maybach provided its HL230P30 V12 series water-cooled gasoline-fueled engine of 700 horsepower for the program (production-quality mounts would have been given the HL234 V12 instead). These engines were the same type as used on the preceding Panther medium tank and Tiger II (King Tiger) marks though - in the latter - it proved wholly underpowered for the behemoth. The track system was similar in design to those as seen on previous German tanks complete with large overlapping road wheels. The drive sprocket was fitted to the front of the hull with the track idler at the rear. The upper portions of the track were to be covered in armor "skirts" for base protection against anti-tank weaponry. The glacis plate was sloped up to the driver's position in the front-left hull just ahead of the turret emplacement. The turret itself sported thick angled sides and a heavy mantlet. The engine deck was expectedly flat with a pair of exhaust stacks fitted to the rear hull facing. The hull was suspended across a unique Belleville washer coil spring system. The complete crew complement was six including a driver, commander, loader, gunner and several loaders/machine gunners.
Authorities had yet to settle on the tank's primary armament and thought was naturally given to match or surpass existing Soviet designs which had now incorporated the powerful 122mm main gun. As such, the 128mm PaK 44 L/55 series gun system was a frontrunner to be the E-100's main gun armament of choice. However, it was also noted that the 150mm KwK 44 L/38 and 173mm KwK 44 series artillery guns were also being considered during development. Any of these fittings would have given the E-100 a definite edge on the battlefield - in both range and penetration values at any angle of attack. Amazingly, the vehicle was also expected to be outfitted with a 75mmm KwK 44 L/36.5 field gun in a coaxial installation, being able to deal with short-ranged armored targets with relative ease. Infantry threats were to be countered by a 7.92mm MG34 general purpose machine gun, presumably mounted on the turret roof.
Despite best efforts, the E-100's prototype development proceeded at a slow pace and this led to just the single incomplete example being captured by advancing British forces in 1945. At this point, the chassis, hull and wheel system were in place though little else was fabricated by the end of the war. The British loaded the hull onto an awaiting trailer and brought it to engineers for further study. Beyond that, the E-100 was scrapped for its metal and other useful material, formally signaling her end.
Like other German wartime programs, the E-100 was very optimistic in its scope. Such a large tank would have been a tactical liability in the fluid method of waging war during World War 2, particularly in its last months. The initiative once held by German forces was completely lost as it was forced to fight a defensive war since 1944. Its naval power was limited and its aerial prowess held in check, leaving only the fanatical remains of its ground army to provide the maximum thrust in any offensive (of which it did successfully on several occasions). Estimates have given the E-100 design a top speed of 25 miles per hour on ideal road surfaces as well as a 120 mile operational range - though this may have proved wholly optimistic as well. It is worth noting that both the British and the Americans were in the process of developing their own "super heavy tank" breeds by the end of the war, intended tackle the heavily fortified German defense en route to Berlin (neither entered serial production). The Imperial Japanese Army was also in development of a super heavy tank of their own by war's end but to no avail. The Soviets enjoyed success with their IS series tanks and only proposed the KV-4 which was never moved on. The Germans, however, took on active development of both the E-100 "Tiger Maus", the Panzer VIII "Maus" super heavy tanks and entertained the ideas of the massive Landkreuzer P.1000 "Ratte" and the Landkreuzer P.1500 "Monster" - the latter two existing in paper form only.