After seven years of research, a scientist at the UK’s Defence, Science and Technology Laboratory (Dstl) has found ‘bomb-proof’ pants worn by troops on the frontline survive even the most vigorous laundering–using a cement mixer.

The Tier 1 Pelvic Protection System, or ‘blast pants’, mitigates injuries caused by roadside bombs. It was the result of an Urgent Operational Requirement (UOR) issued by the UK Ministry of Defence (MoD) back in 2010 during the Afghanistan conflict, in which more than 340 soldiers reportedly died from blasts. This meant the developers had little time to fully test the pants during the procurement process.

Dstl scientist Mark, whose full name cannot be disclosed, has been testing the effect on the durability of protective clothing, including the pants, of repeated laundering. He used a number of wash types including a cement mixer–the washing machine of last resort used in front-line operating bases with limited resources. The research revealed no deterioration in protective qualities.

Mark said: “The introduction of fragment protective fabrics into combat clothing meant we needed to understand the effect of laundering on the performance of these fabrics. The research revealed evidence that the fabrics used retained their ballistic protective performance, while other potential fabrics showed improvement after washing.
“A number of wash types were investigated in the research, which included washing in a cement mixer.”

Working with the Armed Forces in Iraq and Afghanistan as part of the scientific advisory branch led Mark to this discovery, which earned him a PhD from Cranfield University in the UK. His research is now being used to help developers manufacture the next generation of fragment protective clothing.

He added: “I started work in the field of body armour 20 years ago, and served with the UK Armed Forces in both Iraq and Afghanistan as part of the scientific advisory branch. With friends in the Armed Forces, it became a personal battle to help protect those who were putting themselves in harm’s way.”

A time-honoured tradition?

It turns out that soldiers have been using this technique for a long time. A newspaper article from the Marine Corps Chevron, published on 28 February 1946, revealed that US soldiers in Okinawa, Japan were using cement mixers to do their laundry during World War II.

Staff Sergeant Phil H. Storch, a Marine Correspondent, reported: “Marines and Seabees of the 2nd MAW are enjoying this luxury. And the laundry is operated by Okinawan women, who have learned that their new-fangled washing machine is far superior to the old-fashioned method of beating out clothes on a rock.

“The mixer, useless for its intended purpose after prolonged service, required alterations when converted. These were taken care of by Seabee machinists and Marine transportation men.”

Turning a cement mixer into a washing machine: the Okinawan method

First, the cement mixers blades were removed and replaced by six 2×4 bumpers, similar to a standard washing machine. One side of the mixer was sealed by welding an oil drum top in place. On the other side, the chamber was kept watertight by fitting it with a steel door, the gasket of which was made from a rubber lining of a Japanese plane’s fuel tank.

The door is locked using a screw of an anti-aircraft gun. Two 90mm shell casings were welded together and fitted inside an oil drum. Heat from a fire under the drum rose through the shell casings and the water could be kept at any desired temperature. Finally, a piece of hose attached to the outlet valve is used to fill the washing machine and separate rinsing tubs made from oil drums halved lengthways.