LONDON, Ont. -- A made-in-Canada idea is saving American soldiers' lives.

Defence giant General Dynamics Land Systems, which builds military vehicles in London, Ont., is in the midst of replacing flat-bottomed hulls on its Stryker armoured vehicle fleet with a double-V hull, or DVH -- the brainchild of a local engineer.

The new design, with the vehicle's bottom shaped like two large Vs, deflects roadside mine blasts from the vehicle's vulnerable underbelly better than a traditional flat-bottomed underside.

Already, the U.S. Army has found "the number of injuries and fatalities dropped dramatically,” it said in a recently issued report on the new design for the Stryker -- used in combat for about 18 months now -- under fighting conditions.

"It is great to hear our customers are satisfied and the hull is a success in saving lives of those serving in the armed forces," said Fergo Berto, area director for the Canadian Auto Workers union, which represents some GDLS Canada employees.

Stamped in London, whose GDLS plant is among the world's largest wheeled military vehicle factories, the hulls are then shipped to a GDLS plant in Alliston, Ala., with the military replacing its flat-bottomed hulls under an "exchange" program. It costs $1.6 million per vehicle to make the switch.

"The DVH has been a very successful design -- it offers very good protection for the soldiers," said Kendall Pease, a GDLS spokesperson in Virginia.

A key to the design is that "it is not a weld, but a single piece" of steel, he added.

"You should be proud," Pease said.

The U.S. sent most of the vehicles with new design to help in its war in Afghanistan, which is calls Operation

Enduring Freedom.

"While deployed to Operation Enduring Freedom, the Stryker DVH has seen enemy fire and come through with outstanding survivability results," Lt. Col. Eric Frutchey, product manager for the Stryker fleet, wrote in the report.

"The majority of soldiers involved in those instances have walked away from the vehicles or returned to duty within a short period of time. Not only have the number of injuries and casualties dropped dramatically, but the severity of those instances has substantially decreased."

The army at first contracted 450 double-V hulls but in October ordered more, enough to equip two brigades by 2013.

The Stryker DVH also boasts enhanced armour, new suspension and blast-absorbing seats. It debuted in Afghanistan in early summer 2011.