PPB artillery repairer engineers B.O.L.T.S. test bench

Photo By Laurie Pearson | Jacob Zeman, artillery repairer with Plant Barstow demonstrates the BOLTS test bench he designed and built to test components from the M777 Lightweight howitzer with support and guidance from Michael Brown, artillery repair leader, aboard Marine Corps Logistics Base Barstow's Yermo annex, April 25. The BOLTS test bench is the only one of its kind and helps ensure that M777 howitzers going out to the war-fighters in the field are fully operational.  

BARSTOW, CA, UNITED STATES

04.27.2016

Story by Laurie Pearson  

Marine Corps Logistics Base Barstow

The Breech Operating Loading Tray System test bench found at Production Plant Barstow, Marine Depot Maintenance Command aboard Marine Corps Logistics Base Barstow, Calif., is the only one of its kind and it was designed by PPB’s own Jacob Zeman, artillery repairman.
The M777 Lightweight 155mm howitzer replaced its predecessor because it was approximately 9,000 pounds lighter, making it more transportable in the field for warfighter use, explained Michael Brown, artillery repair leader with PPB. However, there was an issue with the M777's scavenge cylinder that needed to be addressed.
"By design the scavenge cylinder was engineered to weep a small amount of oil past the seals to provide lubrication for the dry side of the piston. In the (United States) this small amount is considered excessive and raises an environmental concern," said Zeman.
“It was enough of an issue that the manufacturer (BAE Systems Inc.), developed a work around, a band aid,” said Brown.
“We wanted to figure out why some of the cylinders were performing as designed and weeping very little, and others were leaking an unacceptable amount of hydraulic fluid,” said Zeman. "Once we found the cause, we developed a solution."
Upon analyzing the different cylinder variants, Zeman realized that some of the cylinders had a rough anodized finish and was the likely cause of the excessive leaking.
“The anodized finish is rough inside some of the cylinders,” Zeman explained.
“If you picture the peel of an orange,” said Brown, “that rough texture allowed weeping.”
Zeman then designed a platform on which they could test the scavenger manifold and cylinders, then repaired the rough anodized finish.
“Using a crocus cloth with medium then fine grit and WD-40,” he explained, “we make several passes along the 48-inch bore until it is polished and smooth.”
If there is a problem with a scavenge system, it can cause a two day setback in the repair and sale process for the equipment. By developing this solution to test and repair the issue, it ensures that fully functional and critical equipment is returned to the warfighter, said Brown.
When designing a new piece of equipment, both Zeman and Brown subscribe to the same general rule.
“We over engineer things,” they said.
“We obtained operating forces and pressures from the manufacturer's specifications and designed the test equipment to exceed those minimum requirements,” said Zeman.
“This allows us to recreate failures if we need to in order to really test the equipment properly,” added Brown.
Next for the B.O.L.T.S. test bench, Zeman will add the capacity to test and repair the Breech Activator, Breech Operating Mechanism Valve, Loading Tray Cylinder, Counterbalance Manifold and the Trunnion Pump, all of which he anticipates having fully operational by the end of summer.
“I go to Mike (Brown) with an idea and he lets me run with it,” said Zeman.
“I ask ‘what do you need’ then sign off on it,” added Brown.
“We bounce ideas off of one another, too,” added Zeman, “and that’s a valuable resource in itself.”

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• Date Taken: 04.27.2016
• Date Posted: 04.27.2016 19:36
• Story ID: 196703
• Location: BARSTOW, CA, US
• Hometown: BIG BEAR, CA, US
• Hometown: VICTORVILLE, CA, US