War Plans Division

Zimmerit

You might have noticed that many German tanks during the Second World War had a textured coating on their hulls and turrets. This texture was from a compound known as Zimmerit.

Zimmerit was a countermeasure against magnetic anti-tank mines. Ironically, Germany was the most prolific user of magnetic anti-tank mines and, as such, developed ways to counter them.

Zimmerit was amazingly simple. All it did was provide a non-magnetic barrier between the mine and the steel hull of the tank. The textured pattern was little more than a method to increase the distance further. The goal was to put enough space between the mine and the hull that it could not properly adhere.

Zimmerit was made from a mixture of paste, sawdust, Barium sulfate, and other minor ingredients. It was applied to tank hulls, using towels and other tools to create the texture, and then hardened with a torch.

Zimmerit was introduced in 1943 and worked well in its intended role. However, its use was discontinued a year later due to reports that it caught fire when struck. This was later proven to be untrue, but the use of zimmerit was never restarted.

Photo from the German Archives
Bundesarchiv, Bild 101I-680-8282A-09 / Faupel / CC-BY-SA 3.0

A British Mk IV tank that had collided with and then become stuck on a tree during the Battle of Cambrai in 1917.

Several British tanks were bogged down during the battle, requiring them to be abandoned during subsequent German counter attacks. Some of these tanks were then recovered and put into service by Germany.

Photo courtesy of the Imperial War Museum
Photo:IWM Q 57499

A model of the self-propelled anti-aircraft gun submitted by General Electric for the 1970s DIVAD (Division Air Defense) competition.

General Electric proposed mounting their 30mm GAU-8 rotary cannon, the same gun utilized the A-10 warthog, onto the hull of the M48 tank.

The GE project was one of many submitted, but only two were selected for the prototype phase, the General Dynamics XM246 and the Ford Aerospace XM247. The XM247 would ultimately be selected though it was canceled after 50 had been produced.

Direct Hit!

Skip bombing trials at Lake Childress in Texas. A Beechcraft AT-11 Kansan successfully skips a dummy bomb into a canvas target screen floating on the water.

Childress Army Airfield specialized in the training of bombardiers. Using the AT-11 Kansan as the primary trainer, instruction was provided for bombardiers that would serve in everything from twin-engine bombers like the the B-25 up to the giant four-engine strategic bombers like the B-29.

Troops riding on the outer fuselage of an AH-64 Apache attack helicopter during an extraction exercise in Kosovo on 25 August 2007.

The AH-64 has provisions to allow troops to attach themselves to the helicopter, allowing them to hitch a ride. This is typically done for emergency purposes, including extraction, rescue, or infiltration missions. Up to four troops have been carried by a single Apache.

Soviet ISU-152 self-propelled guns disembarking from a tank landing ship during exercises in the 1960s

The Soviet Pacific fleet was one of the last operators of the ISU-152, using it until 1983. The vehicles served in the artillery role for Soviet marines.

Soldiers of the 4th Infantry Division examining some wine that they had liberated during the capture of Cherbourg, France in July of 1944.

The T14 Armata undergoing testing.

Not quite. This is the M1 TTB (Tank Test Bed), a variant of the M1 Abrams built to test an unmanned turret.

Development started in the mid 1980s and quickly led to the prototype seen here. The vehicle used a slightly modified M1 hull that placed the entire crew in the front of the hull. The normal crew consisted of a driver, tank commander, and gunner sitting side by side.

The M256 120mm gun was retained, but was placed inside of a smaller, unmanned turret atop the hull. There was no need for a loader in the crew as the gun was loaded from a carousel type autoloader. Up to forty-four 120mm rounds could be carried in the turret basket. The auto-loader worked extremely well in testing. It demonstrated a rate of fire of up to twelve rounds per minute and over the course of testing was operated 60,000 times without breaking down.

Naturally, if the concept worked so well, you might be wondering why it was not pursued further. This stems from the fact that the M1 TTB was a single part of a larger program. It was meant to be one of a series of prototypes, each experimenting with new tank technologies. While the TTB experimented with an unmanned turret, there were also prototypes experimenting with new guns, engines, and other components.

Once these prototypes were successfully tested, the final result was to take all of the accumulated data and combine it into one new next-generation tank. Unfortunately, the end of the Cold War killed the need for a next-generation tank and subsequently, all of the prototype testing was brought to an end.

Of course, the data still exists and it was no doubt used in the development of the latest abrams variants. The new M1E3 Abrams is to also utilize an unmanned turret and has no doubt used a lot of the data from the TTB prototype in its development.

One of the prototype 2S35 Koalitsiya-SV self-propelled guns.

During the development of a next-generation self-propelled gun to replace the 2S19 Msta-S, one of the Russian goals was a greater rate of fire. In a rather bizarre idea, the original proposal was simply doubling the number of gun barrels. The two barrels, featuring its automatic loading, would be installed on a new turret utilizing a modified Msta-S chassis.

After further consideration, and perhaps a dose of reality, the proposal was abandoned in favor of a far more conservative design.

The current 2S35 Koalitsiya-SV, still under development, is a simpler design with new gun and autoloader. While promoted as a part of the Armata family, the test units all use a chassis that seems to be based on the T-90/T-72 family.

A M45 anti-aircraft gun crew watch as Allied and German aircraft engage in a dogfight on Christmas Day 1944.

The M45 was a quadmount carrying four .50 caliber machine guns.