Zimmerit was not used on all German armored vehicles.
This early-production Tiger II with a Porsche turret lacks the stuff.
All real men are smitten with tanks. The latest M1A2 Abrams SEPv3 main battle tank weighs 149,000 lbs. and can beat 42 miles per hour on a decent road. Its Honeywell gas turbine engine puts out a cool 1,500 horsepower, while the tank’s 120mm M256 smoothbore cannon will reach out and kill stuff at 2½ miles. The Abrams is the very embodiment of serious military power.
Like many of today’s modern wonder weapons, it was the Nazis who really got the ball rolling. For all their well-documented moral depravity, the Germans during World War II were some undeniably snappy dressers. They also pioneered many of the weapon systems so critical to modern combined arms warfare.
Assault rifles, cruise missiles, and the attack submarine all had their genesis in Nazi weapons research labs. Additionally, it was Heinz Guderian’s Blitzkrieg that introduced the world to the modern main battle tank. Originally designed simply to get troops out of the trenches during World War I, by the late 1930s the Germans had developed the tank into something else entirely.
The Germans transformed the lumbering behemoths of the First World War into the dynamic armored arm of decision. While the Germans fielded dozens of different armored vehicle designs during the course of WWII, it was the vaunted Panther and Tiger getting all of the press.
Realistically, however, it was the humble assault guns, the StuGs and the Jagdpanzers that did most of the serious killing. These turretless, low-slung armored vehicles were relatively cheap. They also lent themselves to the defensive actions that defined the German war effort for the last two years of the conflict.
The common denominator of all those German armored vehicles was a curiously rough external finish. At a glance the stuff looks like drywall mud crudely contoured with a serrated trowel. The Germans applied this material to the steel armor of their tanks before their final coat of paint. They called this weird goop zimmerit.
The Hafthohlladung was a magnetic shaped-charge weapon the Germans developed for use against Allied tanks. Photo: baku13, CC BY-SA 3.0 via Wikimedia
The Königstiger Tiger II was the biggest, baddest German
production tank of the war. This example was captured in
Normandy and is covered in zimmerit anti-mine paste.
The Zimmerit Story
Zimmerit was a paste-like substance the Germans used to coat their armored fighting vehicles starting about mid-war and extending to the very end. Once set, zimmerit formed a hard, concrete-like covering atop the vehicle’s steel armor. The theory was the rough raised surface would preclude the attachment of magnetic antitank mines.
There were some concerns later in the war zimmerit might actually be flammable and contribute to the destruction of these vehicles in combat, but this turned out to be unfounded. For its intended purpose, zimmerit worked just fine.
The magnetostatic strength of a magnet decreases with the cube of distance. That’s the reason a magnet seems to snap in place once you get it close to a steel surface.
Magnets can be very powerful, but their effect is greatly diminised by range. By applying this rough stippled surface to their tanks, German engineers ensured magnetic mines could not get a firm grip with which to adhere.
Zimmerit began as a thick putty. It was applied at the factory and then flash hardened using blow torches. It was quite durable. Despite the innately rough environment in which these vehicles operated, the zimmerit remained relatively intact.
The vast majority of zimmerit exhibits the characteristic ridged pattern. Some StuG III assault guns had this material applied in a waffle configuration but it was unusual.
The ridged concrete-looking stuff on the side of this German Tiger Tank is zimmerit.
The Weapon
The reason the Germans went to all the trouble of slathering their armored vehicles in this sticky hard goo was the Hafthohlladung. Developed in 1942, the Hafthohlladung was also known colloquially in the German ranks as the Panzerknacker or “Tank Breaker.” This term was a derivation of the same word used to describe a safe cracker. The word literally translates to “Adhesive Hollow Charge.”
The Hafthohlladung consisted of a cone-shaped explosive charge mounted atop strong horseshoe magnets. The standard version weighed about 7 lbs. and was fired via a pull cord with a time delay. In practice, some very brave antitank troops would run up to an enemy tank, slap this thing in place, snatch the little ball out of the top to light the internal fuse, and scamper away.
The Hafthohlladung would punch through 5½” of rolled homogenous armor and was shockingly effective.
The zimmerit on some StuG III assault gun exhibited this curious waffle pattern.
The Problem
The truly curious bit, however, was the Germans were the only combatants during the war to field magnetic antitank mines. The Hafthohlladung was simply a cracking weapon, but nobody else used it. The Nazis went to all the trouble to create a countermeasure to a weapon only they utilized.
With the crystalline clarity of hindsight, every square inch of the zimmerit was utterly worthless — it was never used for its intended purpose, not one single time. War can be a funny thing indeed.