Joseph LaGrave, operator and driver of the crane, explains, “We use crane trucks for hover testing rockets under tether. We have the control issues of hovering rockets well in hand and are presently testing some new engine designs. Out of convenience we decided to use the back of the truck as a test stand as it permitted rapid testing.
“Our typical load is four 230l Dewar flasks of liquid oxygen, four 55 gallon tanks of ethanol and 18 to 24 helium bottles for pressurisation. Prior to a test we place a stripped down rocket on the bed then plumb and wire it to the test motor mounted on the back of the truck. We then fill the tanks from the previously mentioned Dewar flasks and tanks and pressurise.
“Normally everyone retreats a safe distance, the test is conducted and we refill to test several times in one day. As we are somewhat unorthodox in our approach to rocketry it was inevitable that we would push the crane truck around with the rocket motor. On this past Saturday the total weight of the truck as loaded was 54,000lb when we decided to make a short run with the brakes off. The test was only 10 seconds in duration.”
It might have only been a short trip, and the rocket provided only limited power, but perhaps it points the way to a new solution to the problem of getting lifting equipment to customers as quickly as possible?
Check out the video on Cranes Today’s new video news page to see the rocket crane in action.
