Porsche Tiger (VK 45.01 P)

Porsche did not arrive at the Tiger competition as a newcomer to tanks; he arrived as a man with one unfinished tank behind him. From late 1939 his firm worked on the Typ 100, known as the Leopard and designated VK 30.01 (P) — a medium design of about thirty tonnes, and the vehicle on which the petrol-electric drive was worked out. Everything distinctive about the Tiger (P) was invented here first.

It never became a tank. Krupp was contracted in March 1941 to build three armoured hulls, with delivery promised seven months after the drawings arrived; by July 1941 the Typ 100 had been abandoned in favour of the heavier Typ 101, and the Krupp contract was simply transferred to the new vehicle. No armoured VK 30.01 (P) was ever completed. The Leopard exists in the record as a running chassis and a set of ideas — and the ideas went straight into the tank that would lose to Henschel.

In 1941 Germany ordered a heavy tank built around the weapon it already trusted most: a tank version of the 8.8 cm gun. Two firms were told to design it. Henschel, which built locomotives and had produced armoured vehicles before, went at it conventionally. Ferdinand Porsche, who had never built a tank in series and did not think like a tank engineer, went at it as an engineer of drivetrains.

Porsche had one advantage no drawing could supply: Hitler’s personal regard. He had designed the Volkswagen, he had the Führer’s ear, and he behaved throughout the competition like a man who did not expect to lose. That confidence is the whole story of the vehicle, and it is written into the production figures before a single trial had been run.

The VK 45.01 (P) did not have a gearbox. Two air-cooled Porsche Type 101/1 petrol engines sat at the rear and drove nothing but a pair of electric generators; the current went to two traction motors that turned the sprockets. There was no clutch to burn out and no gears to strip, and the driver had, in effect, a rheostat instead of a transmission.

On paper it solved the problem that plagued every heavy tank of the war — how to get 60-odd tonnes moving through a mechanical drive train that would survive the torque. Porsche had used petrol-electric layouts before and believed in them. What he had not solved was what such a system is made of, and that turned out to matter more than how it worked.

As a tank the VK 45.01 (P) was protected like its rival and not better, and it got no help from geometry: the front was stepped and close to vertical, a series of flat faces with truncated corners rather than a single sloped glacis, so the plate had to do the work that angling does on a better-shaped hull. The scheme rewards reading in detail: 100 mm on the upper hull front but only 80 mm on the lower front, 80 mm upper sides falling to 60 mm lower, 40–80 mm at the rear, 25 mm on the roof and 20 mm on the belly. The turret was thinner still where it mattered most — a 70 mm gun shield, 80 mm on sides and rear, a 50 mm cupola. The 200 mm frontal armour for which these hulls are remembered was not part of the tank at all. It was added in 1943, when the surplus chassis were rebuilt as the Ferdinand: a second 100 mm plate laid over the original and held to it by 32 conical-head bolts, some sources giving the pair as 90 and 110 mm rather than two equal plates.

The distinction matters because it explains why the doubling was possible at all. A turret has to traverse, and every kilogram added to its front has to be carried on a ring and turned by a motor; a fixed casemate has neither constraint. Porsche’s tank could not have carried that plate. The tank destroyer built from its hull could, and the difference between 100 mm and 200 mm of frontal armour is the difference between a vehicle that can be killed head-on and one that essentially cannot.

There was one exception, and it is the vehicle that matters most here. The single Tiger (P) issued for combat, chassis 150013, had a further 100 mm plate bolted to its front — the same expedient applied to the Ferdinands, on the same hull, for the same reason. The only Porsche Tiger that ever went to war therefore carried 200 mm of frontal armour, against the 100 mm of every hull that left the line.

The turret has the stranger history. Krupp designed one turret for the 8.8 cm gun, intended for the Porsche chassis, and built it on the same assumption as the hulls — before the competition was decided. When Henschel won, the turrets already in hand went onto the winner’s tank. The turret drawn for the losing design is the one the early Tiger I went to war in, with its curved front plate and its drum cupola, and it is the most visible thing Porsche contributed to the tank that beat him.

It is the one part of the programme that was not wasted. The hulls had to be rebuilt into something else and the engines were never used again, but the turret went into production essentially as drawn and served on the tank that is remembered as the German heavy tank of the war. Porsche lost the competition and supplied the winner’s most recognisable component.

In July 1941 — long before any comparative trial — Krupp received a contract to supply 100 armoured hulls for the VK 45.01 (P), for delivery to the Nibelungenwerk at St. Valentin in Austria, where the chassis would be completed into tanks. The turrets, also from Krupp, were ordered on the same assumption.

It was not a small gamble and it was not made in secret. Porsche was building the tank at scale on the expectation that his design would be selected, and the German war economy — short of everything — allocated steel and factory capacity to a vehicle that had not yet been chosen. When the decision went the other way, the hulls existed and the problem became what to do with them.

The two designs were shown to Hitler at the Wolfsschanze at Rastenburg on the morning of 20 April 1942 — his birthday — at eleven o’clock. Porsche’s engines had reached the Nibelungenwerk only on 10 April, ten days earlier, and had been installed in a vehicle that was in every sense a prototype.

The demonstration decided nothing. Both vehicles were driven, both had faults, and the competition went on for another seven months while the two firms and the Waffenamt argued about reliability, production capacity and materials. What the day did settle was the impression: Porsche’s tank had been assembled in haste around engines delivered ten days earlier, and it behaved like it.

The verdict was reached at the tank school at Berka. In July 1942 both designs went through extended testing there, and the Tiger (P) was rejected on two counts that no amount of political backing could argue away: the electric transmission was not reliable enough, and the vehicle’s mobility was poor — a 59-tonne machine that struggled on soft ground and could not be recovered easily when it stopped.

Behind the trials sat an argument about materials that Porsche could not answer at all. Electric generators and traction motors of that size need a great deal of copper, and copper was among the things Germany could least afford to spend: it was wanted for shell driving bands, for cartridge cases, for every kind of electrical equipment. A tank that consumed it by the hundredweight, in a country under blockade, was unaffordable regardless of how it drove. It is the same kind of decision that shaped the LaGG-3’s wooden airframe and the Liberty ship’s welded hull — a design settled not by what engineers wanted but by what the country had.

The end came by instalments. In September 1942 it was decided that the hundred part-built chassis would be completed as self-propelled anti-tank guns; in October the VK 45.01 (P) project was formally terminated; the vehicle was still running driving trials on 8–14 November; and on 22 November 1942 production was cancelled outright, with ninety hulls to be finished as assault guns carrying the long 8.8 cm. Porsche’s tank was tested for four months after the army had stopped wanting it.

A handful of the hulls — five to ten, depending on the account — were finished as tanks; the rest went to the Nibelungenwerk to be rebuilt as the Ferdinand tank destroyer, which is the form in which almost all of them saw the war. Three more became Bergepanzer recovery vehicles for the battalions operating those tank hunters.

One Tiger (P) fought as a tank. In the spring of 1944 the heavy tank-destroyer battalion s.Pz.Jg.Abt. 653 asked for a command vehicle, and chassis number 150013 was issued as a Panzerbefehlswagen VI (P), carrying turret number 003 and up-armoured with the extra 100 mm plate. It went to the Eastern Front in April 1944 as the mount of the battalion commander, Hauptmann Grillenberg, and worked alongside the Ferdinands built from the hulls of its brothers.

It did not last long. Tiger (P) 003 was gone by the middle of 1944, and how — destroyed, disabled or simply abandoned — is not recorded. The only Porsche Tiger to serve as a tank left no account of its own end.

The Porsche Tiger is usually filed as a failure, and by the only measure that counts — did it equip the army? — it was one. But the reasons are worth separating. It carried the same 8.8 cm gun as the winner and comparable armour; the turret Krupp drew for it went on to serve on the tank that beat it; and the drive train it was rejected for was solving a problem every heavy tank of the war would keep having. It lost on reliability, on mobility, and on a metal Germany did not have.

What it left behind is a strange inventory. A hundred hulls existed before anyone had decided they should, and the war spent the next three years finding uses for them: about ninety rebuilt as the heaviest tank destroyers Germany ever fielded, three as recovery vehicles, one — chassis 150013, armoured to 200 mm — as a battalion commander’s tank on the Eastern Front, and the rest never completed at all. Porsche’s confidence cost the German war economy a hundred armoured hulls and produced, by accident, the Ferdinand.

• Thomas L. Jentz & Hilary L. Doyle, Panzerkampfwagen VI P (Sd.Kfz.181): The History of the Porsche Typ 100 and 101 (Darlington Productions, 1997) — per lo schema di corazzatura.
• Walter J. Spielberger, Der Panzerkampfwagen Tiger und seine Abarten (Motorbuch Verlag).
• Karlheinz Münch, The Combat History of schwere Panzerjäger Abteilung 653 (J.J. Fedorowicz).