Lewes bomb facts for kids

The Lewes bomb was a special kind of explosive device used during World War II. It was made by mixing diesel oil with a powerful material called Nobel 808 plastic explosive. This unique bomb was invented by Lieutenant Jock Lewes in 1941. He was one of the first members of a famous British commando group called the SAS.

How the Lewes Bomb Was Invented

Why Was This Bomb Needed?

The SAS commandos often had to sneak behind enemy lines. They needed a special bomb that could both explode and start fires. This bomb had to be light enough for a small group of soldiers to carry. It also needed to be strong enough to destroy enemy aircraft on airfields. The Lewes bomb weighed about 1 pound (0.45 kg), so one soldier could carry many of them.

Designing the Bomb

At the time, the bombs available were too big and heavy for paratroopers to carry. Lieutenant Lewes started experimenting with different materials. He tried various mixes of things that could explode or start fires. He learned what worked best through trial and error.

The final design of the Lewes bomb used about 1 pound (450 g) of plastic explosive. To this, he added 1⁄4 pound (110 g) of thermite, a small amount of diesel oil, and some steel filings. Inside this mix, a two-ounce (60 g) piece of dry guncotton was placed. This guncotton acted as a booster, helping the main explosive go off.

A detonator was also added, connected to a fuse that would burn for thirty seconds. Sometimes, the bombs were set off using pencil detonators or special booby-trap devices. These could include switches that would trigger the bomb when pressure was released.

It's not fully clear what the bomb was kept in, but it was probably a small canvas bag. When used, the bomb was placed inside the cockpit or on the wing of an enemy aircraft. The goal was to ignite the plane's fuel, causing it to burn and be destroyed.

Challenges with the Bomb

The Lewes bomb had some problems. The detonators could be unreliable. Sometimes, they didn't work, especially if it rained heavily during a raid. The desert heat also affected the timing of the detonators. For example, in December 1941, some soldiers reported that their 30-minute fuses went off in just 18 minutes because of the warm night.

Despite these issues, the Lewes bomb was very effective for the SAS against parked aircraft. After an attack in December 1941, Italian engineers found some unexploded bombs. They repaired the fuses and placed the bombs on old aircraft, just as they had been found. They reported that "in every case the firing of the charge... set the fuel alight... causing complete destruction of the vehicle." They also noted that the fires were mainly due to placing the bombs accurately near the fuel tanks, rather than any special quality of the explosive itself.