The Air Force Civil Engineer Center in conjunction with the Air Force Research Laboratory recently introduced a first-of-its-kind runway rubber removal system for use at remote airfields.
The device, which uses a retrofitted Unimog designed for transport to airfields in austere areas of Southwest Asia, is the first rubber removal device designed to be transported by a C-130 Hercules.
Members of the 1st Expeditionary Civil Engineer Group took on this unique capability. Airmen from the group’s 577th Expeditionary Prime BEEF Squadron and 557th Expeditionary RED HORSE Squadron trained extensively over a two-week period on the operation and maintenance of the rubber removal equipment.
“This machine is one of a kind. In order to make it air-transportable, the manufacturers had to give it the ability to transform to a smaller version of itself,” said Capt. Kathryn Miles, U.S. Air Force Central Command’s A7. “The cab of the Unimog folds down and the windshield drops to make the overall height short enough to fit into a C-130.”
Taking rubber off the runway is important because every landing adds to the build-up of rubber, and that poses a risk to landing aircraft.
“Each time an aircraft lands, when the tires make contact with the runway, they are super-heated by the friction between the tires and the runway,” Miles said. “This causes thin deposits of rubber to adhere to the surface of the pavement. Eventually, over time, the rubber builds up enough to cause a hazard to aircraft especially in wet conditions.”
Besides being the first rubber removal device that can be transported on a C-130, it also allows the Air Force flexibility on the airfield. The expeditionary rubber removal kit comes with two systems: one uses a detergent to dissolve rubber from the runway before being rinsed off; the other is the ultra-high pressure water system — the retrofitted Unimog. The 1st ECEG will now be able to deploy with both systems to any airfield in the U.S. Central Command area of responsibility to provide this capability.
“The advantage to having the (retrofitted) Unimog is that it’s a much more flexible system for airfield managers with busy runways,” Miles said. “The detergent process requires a six-hour uninterrupted runway closure. The Unimog, on the other hand, can be used between take-offs and landings and still effectively remove rubber.”
The Unimog uses an ultra-high pressure water system to take the rubber off the airfield.
“The TracJet attachment puts out about 36,000 pounds per square inch from the cleaning head which resembles a large shower head,” Miles said. “The water coming out of the shower head puts out enough pressure to cut steel.”
After the rubber is taken off of the runway, the system also takes care of the resulting debris.
“The cleaning head essentially blasts the rubber off of the surface of the pavement and a vacuum system removes all debris and water left behind,” Miles said. “The water used to blast the rubber is stored in a bladder on the back of the Unimog and as that bladder empties, another bladder fills with the used water. The rubber solids are collected in two large filters.”
Although the ultra-high pressure water system does provide flexibility, it isn’t designed to be a complete replacement for using detergent to remove the rubber.
“While this machine is extremely effective at removing rubber, it is actually a supplement to the detergent system,” Miles said. “The detergent method is capable of removing 60,000 square feet of rubber in about six hours while the ultra-high pressure water system could probably only remove about 10,000 square feet of rubber in the same amount of time.”