Jamey Smith adjusts the angle of a M777 medium, towed howitzer at Anniston Army Depot. A laser tracker, seen on a stand in the far left of the photo, makes a series of measurements, which will be used to manufacture new slipper pads for the weapon. T...

ANNISTON ARMY DEPOT, Ala. -- Until recently, damage to the cradle of a M777 medium, towed howitzer meant the entire gun had to be demilitarized.

A pilot program, which ended here in March, proved a theory by government and BAE Systems engineers and changed the prospects for these weapons.

They can now be rebuilt with a new cradle.

A new slipper pad procedure, developed by the team of engineers in Hattiesburg, Miss., uses a laser tracker to accurately measure the movement of the howitzer's barrel through its full arc of motion - from 0 to 1,275 angular mils.

"The pads help anchor the weapon, if properly calibrated, and improve its accuracy," said Bob Rosch, a depot mechanical engineer.

The laser tracker takes a measurement every 100 mils as the gun traverses its full arc of movement.

The measurements are then translated into specifications for replacement slipper pads, metal spacers which slide along a runner as the weapon is raised and lowered.

Just like the glass slippers in Cinderella, the four slipper pads on each M777 must be tailored exactly to the weapon they will be placed on. Even the smallest deviation from specifications can mean a large difference in accuracy.

"The slipper pads are not a one-size-fits-all part," said Jamey Smith, an artillery mechanic working on the M777. "The pads have to be calibrated to the cradle."

The depot's Directorate of Public Works machines each new slipper pad to the specifications provided by the laser tracker for the weapon's new cradle. The cradle replacement ensures the gun can be rebuilt for the war fighters at a savings of approximately $2.5 million.