Normandy landings, Normandy Invasion, D-Day Invasion, Operation Overlord, or Operation Neptune. Whichever you call it, it still refers to the largest seaborne invasion in history when the Allied forces began the liberation of France on June 6, 1944. In preparation for the large Allied invasion operation, the engineers and designers had to work hard to come up with a variety of machines and vehicles that would bring the operation to succeed. So they created different vehicles with different specialties, weaponry, and other details. The result was unique and specifically modified vehicles made to help the Allies achieve their main objective: To liberate France.

Many of the tanks used that day could be categorized as Hobart Funnies: named after the British General Percy Hobart. He came up with the idea of producing many tanks based on the chassis of the British Churchill and the American Sherman.

Here are some of the results.

DD Tanks

Of course, you’d expect to see a DD tank on a D-Day Invasion, although the DD here actually stands for Duplex Drive or, if you’re feeling silly, Donald Duck. The Sherman Duplex Drive tank was made to be waterproof and had a secondary propulsion system to bring it onto the beaches of Normandy. It worked with the help of the “flotation screen” or inflatables that skirted around the tank to enable it to float, while the two propellers powered by the tank’s engineer allowed it to be driven in the water. While in the water, it could travel at about 4 knots and could do so in waves up to around 1 ft.

The Sherman DDs had mixed success when they were used on the Normandy landings. On most beaches, they worked without hassles, and many made it to the shore without a fuss. However, almost all of these tanks did not make it ashore on the Omaha beach. The greatest factor was the many increased casualty rate at the Omaha beach, where the DD tanks were supposed to give fire support.

Another factor was the weather conditions at the time of landing. On that day, the waves at Omaha could reach 6 feet, hitting the sides of the floating tanks as the crew struggled to make it to the land. This was a major struggle since the vehicle was only designed to manage waves up to around 1 foot.

Bobbins tank

Another problem that the engineers foresaw when they were thinking of the vehicles that would bring the operation to success was the sands at Normandy. Although they varied from beach to beach, the sand was generally too soft to support a huge number of vehicles that would be brought ashore that day. The Churchill Bobbins tanks were created to solve this.

Also called the “carpet layer,” as the name suggests, it was made to give the heavy allied armor and vehicles a passable road to the “exit areas” of the beaches. These exit areas were created by the troops tasked to make eight exit points on the beaches where the armor and other vehicles could exit. Once those areas were secured, the engineers would prepare them for an allied breakout, which was particularly important for the British troops at Sword beach as they were assigned to take Caen city, which was 9.3 miles away from their landing zone.

The tank was equipped with a coil (the Bobbins) that would lay a carpet made of cloth at the front of the machine where the infantry and the vehicles could step more easily and quickly, without the struggle of possibly sinking in the sand. Alternatively, the carpet could also mark a road that demining tanks had cleared and point the troops in the right direction.

Crocodile tank

The British military engineers developed the Crocodile tanks in 1943, which were basically the flamethrower model of the Churchill tank. Instead of a ball of turret machine gun that one would usually see on the hull of the tank, they instead fitted flamethrowers in the area.

These crocodile tanks could spring at about ten meters in line with the vehicle and be especially useful for attacking the enemy shelters, pillboxes, and bunkers without the need for demolition teams. Just like the Bobbins tank and the others, the Crocodile tanks were based on the chassis of the British Churchill tanks and the American Sherman. The 141st Royal Armored Corps was the first unit to be equipped with the Crocodile tank just shortly after the Normandy landing.

The Double Onion

This madness was pretty scary.  The modified Churchhill tank featured a metal frame implanted with explosives designed to breach a wall.  The tank would drive up to the wall so that the frame was laid flat against it and then the charges would be detonated from inside the tank by the crew.

Presumably, the tremendous blast would be felt inside the tank and it would be showered with the brick and concrete of the falling wall. It’s also hard to imagine that the crews liked driving a tank with a metal frame of exposed high explosives and presenting itself to enemy gunners as they moved into position.

The Canal Defence Light

Believe it or not, the most secret tank of Hobart’s funnies was the Canal Defence Light or CDL.  It was considered so sensitive that the allies intentionally misnamed it as the Canal Defence Light to conceal what it really was, a tank with a turret incorporating a powerful arc light that produced some 13 million candlepower.  The arc light was inside the turret of a Matilda light tank, the Churchhill tank, and then later the M3 Grant which was favored for its high turret height.

The operator would switch on the electric light which created an intensely bright arc of gas between two carbon electrodes.  The 13 million candlepower, which is an expression of the brightness of the light source is different from lumens which measure how much light is emitted was bounced between a couple of internal focusing mirrors inside the turret and then escaped through one or two vertical slits in the turret. The slits had shutters on them that could be opened and closed several times a second.  They could also be lit in different colors.

Because the slits could open and close they created a blinding strobe effect on those exposed to them.  While whole tank regiments of these tanks existed in the US and UK armies, they were only ever used twice, to cross the Rhine and the Elbe Rivers. They might have used them more, but the level of secrecy surrounding the existence of the CDL was so tight, that few allied commanders knew they even existed and didn’t know to ask for them to aid in night attacks.