World War II was a conflict of epic scale. The war efforts across the globe involved a lot of moving parts. That meant there were many chances for mistakes. They ranged from experimental weapons that failed to strategic oversights that had devastating consequences. Here’s a list of 10 blunders from WWII that are strange, interesting, or utterly unbelievable.

1 The US Navy’s Mark 14 torpedo was woefully unreliable in the early years of WWII. One reason for its problems was the Navy didn’t perform tests that would destroy a torpedo because they were considered too expensive.

The Mark 14 was developed in the 1930s. During testing, the torpedoes were not equipped with actual warheads to avoid wasting them. The problem was the practice torpedoes were more buoyant than the real thing. So, when real torpedoes were used in battle, they tended to run too deep and pass far underneath enemy ships. Once this problem was corrected, it revealed there were also issues with the detonation mechanism. Many torpedoes hit enemy ships with an audible clang but never exploded. Other problems with the Mark 14 included a tendency to explode prematurely and cause little damage to the target or to run in circles and endanger the ship that launched it.(source)

2 In 1942, the British Special Operations Executive (SOE) ignored signs that their radio operators in the Netherlands had been captured.  They continued sending information and agents directly into enemy hands until 1944.

SOE had a secret code system that was meant to ensure radio messages from operators in the field were legitimate. It included a security check where errors were purposefully included in parts of the message. If a message lacked this security check, it was a sign that the radio operator had been captured and was being forced by the Germans to send messages.

The SOE’s head of codes realized that the operation had been compromised, but was told by a superior to not discuss the matter with anyone. The reason may have been political as the SOE did not want to admit their failures. As a result, the Germans had access to important information and were able to pass misinformation to SOE. Dozens of agents who were later dropped into the Netherlands were immediately arrested. Two captured agents were able to escape and tried to return to Britain, but the British believed a false message that said the pair were actually German agents so they were arrested.(source)

3 To save steel and aluminum resources, the British had plans to build aircraft carriers out of ice. In 1944, a prototype was built on a lake in Alberta, Canada. The plan was scrapped when they realized building a full-size version would use up more money and machinery than a fleet of standard carriers.

It was known as Project Habakkuk. The idea was conceived by Geoffrey Pyke who worked at Combined Operations Headquarters. The plan was to build the carriers out of a mixture of wood pulp and ice called “pykrete.” When compared to ice, the material was stronger, more buoyant, and slower-melting. However, in testing, they realized a pykrete ship would require extensive steel reinforcement and an onboard refrigeration system with complex ductwork. Also, during the development of the project, the range of aircraft had been extended. This closed the Mid-Atlantic gap that had been one of the main reasons for the project’s development.(1,2)

4 In 1945, a German U-boat began flooding due to the captain’s improper use of a newly designed toilet. It was forced to surface and was bombed by British patrol planes.  The crew had to abandon ship.

In contrast to Allied submarines which used onboard septic tanks, German U-boats saved space and weight by discharging their toilets directly into the ocean. However, they could only discharge their toilets when near the surface where water pressure was lower. Later, they developed a new toilet system for use deep under water. It used a series of chambers and a pressurized airlock.

The new toilet was complicated to operate as a series of valves had to be opened and closed in the correct order. In fact, each U-boat had a specialist on board who was trained in the proper procedure. The captain of U-1206 tried to figure out the toilet himself, but he made a mistake and the U-boat quickly started flooding. Making matters worse, the water reached the submarine’s batteries causing a reaction that produced chlorine gas. At the time, the U-boat was only eight nautical miles off the coast of Scotland. It surfaced, and one man was killed in the bombing attack that followed. Three men drowned and 46 were captured after abandoning ship.(1,2)

5 In the final years of WWII, the British military designed a rocket-propelled cart called the “Panjandrum.” It was designed to speed across a beach and blow a tank-sized hole in concrete walls. Testing revealed it was dangerously unpredictable.

The weapon was meant to help break through the large concrete defenses that were part of the German’s Atlantic Wall. The Panjandrum had two, 10-foot diameter wheels connected with a drum that contained explosives. Each wheel had rockets arranged around its perimeter for propulsion. The weapon was predicted to be able to carry a 4,000-pound load of explosives at speeds of about 60 mph. A number of tests were performed between 1943-1944. The Panjandrum careened wildly around the beach, and the rockets had a tendency to come loose and fly away.(source)

6 In 1945, the Brazilian cruiser Brahia sunk itself during anti-aircraft target practice. One of the crewmen firing at the practice target accidentally hit depth charges on a rack at the stern of the ship. The boat sank in three minutes.

The boat was towing a kite behind it for practice target. The anti-aircraft gun was not equipped with guardrails that would normally prevent the gun from being aimed at the ship. Survivors of the accident were stranded on makeshift rafts until they were rescued four or five days later. Reportedly, some of the survivors were driven mad by the lack of food, high temperatures, and sun exposure. They jumped into the water and were eaten by sharks. The accident resulted in over 300 deaths, and only 36 survivors were rescued.(source)

7 In 1941, FBI director J. Edgar Hoover declined an offer of help from Dusko Popov. Popov who was a double agent working for the British. He is considered one of the main inspirations for James Bond. He had offered the FBI help setting up a spy ring, as well as intelligence, that warned of the attack on Pearl Harbor.

The Germans believed Popov was working for them as a spy, so he had access to valuable information about Axis plans. The British Secret Intelligence Service gave Hoover notice that Popov was coming for a meeting. But Hoover distrusted Popov and apparently disliked his playboy lifestyle. While waiting for weeks for an appointment to see Hoover, Popov had been living in a penthouse apartment and wooing a number of rich and famous women. Hoover criticized Popov about that behavior and threatened to have Popov arrested and deported under the Mann Act.  That law stated it was a felony to take a woman across state lines for “immoral purposes.”

At the meeting, Popov had provided Hoover with a three-page list of targets that the Axis was seeking information about. One full page of the list was devoted to Pearl Harbor. Hoover did not forward the information to the military.(1,2)

8 In 1942, a German pilot mistook South Wales for France. He landed at a Royal Air Force training station, allowing the British to capture his Focke-Wulf 190 plane and gain valuable information about its capabilities.

The pilot had become disoriented during a dogfight over the English Channel. As he came in to land, British identified the plane as German. As soon as it stopped, a British Duty Pilot jumped on the plane’s wing and took the German pilot prisoner at gunpoint. Since it was a training station, the only weapon the duty pilot had was a flare gun.

It was the only time during the war that the Allies captured an intact FW-190. Afterwards, the British flew the plane 29 times in test flights and mock combat trials to learn the best ways to fight it. Later the plane was partially dismantled so they could conduct tests on its engine performance.(source)

9 On May 24, 1940, the German military delayed its advance on Dunkirk where a large force of Allied troops was facing certain defeat. Thanks to the delay, more than 330,000 Allied troops were evacuated. Hitler later tried explaining away this blunder as intentional, saying he was giving the British a sporting chance.

Hitler made the decision to delay his army’s advance based on recommendations from his field marshals. They said the tanks should stop and wait to allow infantry to catch up. Before that decision was made, the Allies had considered their troops at Dunkirk to be doomed. After the evacuation, Winston Churchill called the rescue a “miracle of deliverance.” In 1945, Hitler said Churchill never appreciated the “sporting spirit” behind the decision to not annihilate the Allied force at Dunkirk.(1,2)

10 When the Allies stormed the beaches of Normandy on June 6, 1944, the Germans were caught completely off guard.

The Allies had successfully misled the Germans about the date and location of the invasion. The Allies used tactics including “leaking” false information and dropping dummy paratroopers. They also used planes to release strips of metal foil that German radar operators misinterpreted as a naval convoy.

In addition to these deceptions, the Germans were confident that the Allies would not invade at the time due to poor weather conditions. As a result, the senior commanders in charge of Normandy’s defense were away taking part in a war game. Also, Field Marshal Rommel was in Germany for his wife’s birthday.

As the invasion unfolded, many Germans still believed the Normandy landing was just a diversion. There were two panzer divisions available to launch a counter attack, but Hitler was the only one with the authority to order it. A field marshal requested Panzer support at 7:30 am while there was cloud cover that would protect them from attack by Allied aircraft. But Hitler slept in until noon that day and no one woke him. Once awake, he delayed sending the Panzers until 4:00 p.m. By that time, the clouds had cleared and the Panzers were pinned down by aircraft.(1,2,3,4)