INDIAN HEAD, Md. ─ Naval Surface Warfare Center Indian Head EOD Technology Division’s Moser Facility recently received a facelift, bringing it from the analog age to the digital. The nitration facility, constructed in the 1970s, is the Navy’s sole source supplier for Otto Fuel II: a monopropellant used to power torpedo systems. Moser was designed to allow for continuous operation, while also keeping the operators away from the hazardous material and potential explosions during the nitration process.
For more than 40 years, it has done just that: producing energetics par excellence for the U.S. Navy and its allies while keeping its operators safe. The process for nitrating Otto Fuel is incredibly complex, especially when the system is operated using a punch-card operated pneumatics instead of any digital equipment.
“The Von Rohr Punch Card Programmer was a pneumatic sequencer that started up the nitration process at the beginning of the day and shut down the nitration process at the end of the day,” said Paul Desear, a chemical engineer with the Energetics Manufacturing Department. “The punch card programmer had a flexible programmable logic controller (PLC) card that was ‘punched’ and allowed air signals to pass through it to a series of pressure switches and pneumatic relays.”
Desear said the system was well beyond its service life and unreliable. Although work had already begun to replace it with a digital PLC, the punch card programmer completely failed to function in the middle of an Otto Fuel II production campaign while the contractor was in the process of building the replacement.
“I don’t know if you’ve seen the cartoons where they wind up self-playing pianos,” said Derek Reynolds, Chemicals Development and Manufacturing Branch manager. “That’s what it was doing, only it stopped functioning properly and the card wouldn’t move. We literally had to slide the card to get it to the right spot.”
Other facility challenges faced by Moser operators were removing the punch card programmer without damaging existing pneumatic relays and controls; replacing the pressure switches and pneumatic relays with digital solenoids valves inside the control console; and trouble-shooting unforeseen problems with the integration of the modern PLC and the existing 1960’s and 1970’s era security system and pneumatic controls.
“We took the punch-card reader to a clockwork guy and the best he would do is clean it up. He told us ‘I don’t have any parts. There are no more existing parts or any places you can get them’,” Reynolds said. “The Swiss company that made the machinery sent us a letter around 2000 that said we shouldn’t be using it; it’s beyond its service life.”
However, with the punch card system non-operational and any replacement parts needed no longer manufactured, the future became digital; but not necessarily easy.
“To physically replace it took about two weeks. It was a lot of planning upfront,” Desear said. “The new digital system was about 90% complete when we told the contractor we needed it now.”
Even with a relatively quick finish by the contractor, there was still the matter of testing the equipment and training for the operators that put the Moser staff several months behind their anticipated delivery of Otto Fuel to the fleet and foreign military sales (FMS) customers.
“We did a lot of dry runs. We did a lot of what are called water nitration runs which used water and nitrating acid instead of polyol,” Reynolds said. “From my perspective as a manager, I was a little nervous when we turned this thing on and nitrated that first time. Because if something happens, especially with what we’re making down here, it can turn bad very quickly.”
What they found however, was the upgrade from the punch card system to the digital version not only aided in the ease of remote operation of nitration, but also drastically decreased plant downtime and increased overall operational efficiency. According to Kris Propst, the facility’s engineering technician, “although there was initial difficulty in figuring out a way to make an operations panel meant to be analogue perform digitally, the upgrade makes operations that much smoother and reliable.”
“The [new PLC] is essentially a giant tablet,” Propst said. “It makes that a lot easier for the operator and from an operational standpoint, it does exactly the same thing at the same points. We can set the speed and everything like the old card. So it kind of does everything the same.”
Everything, but with a bit of a pickup in speed and reliability. Despite falling behind on Otto Fuel II production as the upgrade was being implemented, the crew rallied to set a milestone in delivering more than one million pounds of Otto Fuel to the fleet and FMS customer in early 2019.
“It’s been a pretty big challenge. [Kris] is a wizard and has kept the place running for us. He and his team really pulled it together,” Reynolds said. “It’s an old plant. We’ve done an incredible job keeping it running and these guys did a great job making this upgrade to it.”
NSWC IHEODTD – a field activity of the Naval Sea Systems Command and part of the Navy's Science and Engineering Establishment – is the leader in ordnance, energetics, and EOD solutions. The Division focuses on energetics research, development, testing, evaluation, in-service support, and disposal; and provides warfighters solutions to detect, locate, access, identify, render safe, recover, exploit, and dispose of explosive ordnance threats.
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