By Staff Sgt. Benjamin Rojek, 30th Space Wing Public Affairs
/ Published June 17, 2008
VANDENBERG AIR FORCE BASE, Calif. -- As part of their continuing commitment to safety, the 581st Missile Maintenance Squadron teamed with the Training Device Design and Engineering Center here to create a training model of one of their more dangerous components.
Known as a ballistic actuator, the 12-foot-long metal cylinder is built to pull open a 110-ton launch enclosure - the large door that covers a missile launch facility - in seconds.
"Usually, it takes a hydraulic pumping unit to get it off and it takes 30 minutes to push it," said Ray Brown, an ordnance mechanic with the 581st MMXS here. "It's a pretty massive door."
In order to move the door that quickly, the ballistic actuator uses a series of springs, bearings and cables, as well as gas pressure, to create a "slingshot" effect. Unfortunately, it's all those parts that can make the work of refurbishing the parts a difficult task.
The men who work in the 581st MMXS, a detachment at Vandenberg out of Hill AFB, Utah, know all about these dangers. Two of their own were injured a few years ago during a routine refurbishing job. In the old way of dismantling the ballistic actuator, two men would lock the cylinder on a pedestal, connect two metal poles and "unscrew" it open. Unfortunately, the gas pressure inside the actuator was still high and the more than 100 pound piston flew into the air. The metal bar hit one of the mechanics. He survived, but was seriously injured.
"After that, we've built all these safety devices," said Ernest Greenwood, the 581st MMXS flight chief. "Having a 3-D type mock-up and explaining to these guys, 'This is how it is when it's extended; when the pressure comes in, it's going through this port' - and physically being able to see it on the structure you're working on - it's invaluable."
While the life-sized, working model of a ballistic actuator was the idea of the 581st MMXS, it was the Training Device and Design Engineering Center that made it a reality.
Joaquin Tinker, a mechanical engineering technician with the TDDEC, took parts from old, unsalvageable ballistic actuators and, using technical orders and other documents, created the training version. It is open in two parts to show how the piston moves in the cylinder, as well as where all the parts are located.
"With this you can see the springs, you can see the ball bearings, you can see how things move inside," Mr. Tinker said. "They can walk right up to a real one and say, 'Oh, there it is.' There's a lot of things that they do, and this helps explain how (the actuator) operates. And on the real one, there're all kinds of tiny little ports and stuff so you can get a good view."
The challenge, he said, wasn't in creating the mock ballistic actuator; it was in designing special fixtures and processes to make the final product. Because of the size of the actuator, their regular equipment just wouldn't do.
"There were a lot of modifications, a lot of fixtures that had to be built ahead of time," Mr. Tinker said.
In the end it was all worth it, since the 581st MMXS will have a tool to more safely train their incoming employees, as well as a way to help veteran mechanics refresh their memories on ballistic actuator construction.
"We all had ideas of what it was going to look like, but this way better than we imagined," Mr. Brown said. "I wasn't expecting this much detail. I can show every aspect of this thing and how every little piece works. It's just perfect, beautiful work."
Mr. Greenwood agreed, saying the training tool is invaluable when it comes to a safe work environment.
"What you're trying to do here is minimize mistakes, and that's what this does by being able to show you how this is seated, this how you do this, this is how you assemble it, and this is what it's going to look like," he said. "The bottom line is safety."