A team of scientists and engineers at Naval Air Warfare Center Weapons Division China Lake, Calif., recently set a world record for producing the most thrust for a rocket sled test on the Supersonic Naval Ordnance Research Track at China Lake.
The team spent about nine months preparing for the test event held on April 26 that produced 1.14 million pounds of thrust in about .9 seconds. That roughly equals the amount of thrust generated by all three space shuttle main engines at lift-off, or six Boeing 777s at take off,
“By far, that’s the largest amount of thrust that’s ever been attempted anywhere as far as we know,” said Ty Denney, lead engineer at SNORT. “This was a final event for a test series that started back in 2007. It was an epic means to close out the test program.”
It took 131 individual motors to achieve this milestone – 114 MK-16 Mod 2/3 Zuni rocket motors and 17 Multiple Launch Rocket System motors. The gross weight for the sled was 74,000 pounds. On average, a sled used at SNORT usually weighs about 4,000 pounds with the test item generally weighing in at about 2,000 pounds.
Completing this test event was a joint effort that required teamwork from across multiple functions at NAWCWD. Denney led the team on the one-of-a-kind sled design. The design itself took about a year-and-a-half to complete from scratch. The machine shop in the NAWCWD Weapons and Energetics Department fabricated the sled over a period of five months.
“There was a lot of cross-command effort to pull this off,” said Eric Laskey, a branch head at SNORT. “Everything about this test was large in scope and scale – from loading the propulsion and the instrumentation, to transporting the sled to the track. It truly takes a team effort to accomplish a test like this.”
The sled traveled more than 13,600 feet in about 30 seconds and met the test objective of 16.8 Gs acceleration.
“The G force was not a record, but because the test item was so heavy, the amount of thrust it took to achieve that acceleration was the record,” Denney said. “The goal wasn’t to be fast. The goal was to induce a certain amount of acceleration on the test item, and we achieved that.”
Stopping the sled on the track was no small feat. Water-braking was used to bring the behemoth sled to a stop over the distance of about 1.5 miles. Water flows into the middle of the track from SNORT’s 500,000 gallon pond, and is recirculated during the test using a pump.
“The water brake scoops the water out of the track trough and shoots it out the sides of the sled,” Denney explained. “It was the largest water brake we have ever built. We entered the water at 400 mph, so it was going to take quite a bit to bring the big sled to a stop.”
Several records have been set and broken recently at SNORT, which celebrates its 60th anniversary in 2013. This test broke the in-house record that was set at SNORT last June. The peak average thrust achieved during that sled test was 800,000 pounds.
“This test was one for the books,” said Denney. “Years from now people will look back on this event and ask ‘Did we really do that?’”
SNORT is the Navy’s only rocket sled test facility and at 4.1 miles is the second longest high-speed track in the world. The facility provides high-speed testing that allows systems to be evaluated under controlled, dynamic conditions.