Run Flat Tire Inserts: Ground Combat Technology

Bulldog Direct: Run Flat Tire Inserts:  

Article in Ground Combat Technology


We are pleased to announce that we have been included in  the May / June 2011 Article in Ground Combat Technology. Military Tires Get New Mission. A large part of our business is dedicated to Run Flat Tire Inserts for both Government, Military and personal vehicle safety.

 Written by Henry Canaday

 GCT 2011 Volume: 2 Issue: 2 (May/June)

Military Tires Get New Mission



Ground vehicles still run predominantly on wheels, not tracks. That means tires must be tough, durable and maintain traction on a variety of surfaces. Increasingly, it means better tires should help cut fuel use too. Even the toughest tires are punctured sometimes, so run-flat equipment enabling continued movement away from an ambush, explosion or other tight spot is also highly desirable. Goodyear is the biggest supplier of tires to the U.S. military by a sizable margin. “We are the sole supplier on the Humvee, and there are tens of thousands of Humvees in operation,” noted Maylon Carroll, general manager, government and military sales. Goodyear has been the sole supplier since the inception of the HMMWV program, which is now in its third version.

“We are also on the medium tactical vehicle platform,” Carroll said. “BAE Systems is winding down on that and Oshkosh won the re-bid, and we are on that.” Goodyear also supplies tires for a few mine resistant ambush protected (MRAP) vehicles—for example, on the rear of Navistar’s MaxxPro wrecker MRAP. And Goodyear is one of two approved sources of tires for the family of medium tactical vehicles.

Vehicle manufacturers select tires for their products, but the government must approve the choice. Approvals come in two buckets: original equipment (first-fit) and sustainment. “In most cases there is more than one choice for sustainment. About 90 percent of tactical sustainment tires are Goodyear or Michelin,” Carroll said.

Goodyear has built its success over 100 years in supplying the U.S. military and still makes all its tires in the United States. As an American-owned company, Goodyear can work extensively with Sandia National Laboratories on modeling performance of tires and alternative tread designs.

“We are known for robust tread design,” said Technical Account Manager John Warchol. “We can take our commercial research and apply it to the unique needs of the military.” Treads designed for military uses must handle all kinds of surfaces, highway, cross-country, mud, sand and emergency situations. “If it is stuck, you must be able to lower the inflation and get out of the way,” Warchol explained.

One distinctive advantage is Goodyear’s Durawall composite on tire sidewalls. Used on HMMWVs, Durawall yields a 30 to 40 percent increase in puncture protection and resistance to cutting by curbs.

Military customers increasingly seek fuel economy. Goodyear has been selected to partner with Ricardo on development of a new vehicle under the fuel-efficient ground vehicle demonstrator program. This FED program will seek to alter engines, exploit composite construction and make other changes to cut fuel use dramatically. “They are looking to Goodyear to develop a tire that can reduce fuel consumption 4-6 percent,” Warchol said. The FED effort is aimed at a possible replacement for the massively deployed HMMWV.

One way to get fuel burn down is to adapt a rolling-tread compound used in Goodyear commercial tires. Some changes will be required because the military has special requirements for handling gravel chips. Goodyear can also go to a larger tire, 22 inches rim diameter and inflated to higher pressure, to improve fuel efficiency.

Mileage is the primary focus now. “The military wants to go faster with heavier weight, but with less fuel,” Carroll said. Still, Goodyear constantly works on other improvements, such as resistance to ballistics and ability to handle failures. The company’s DuraSeal technology helps on these fronts. Goodyear does not make run-flats, but Carroll notes that tires and run-flat technology must be jointly tested to ensure compatibility.

“We and Goodyear dominate the military wheeled market,” said Jonathan “Hoot” Wade, technical manager for Michelin military products. Goodyear may keep all those HMMWVs humming, but Michelin dominates the heavy-wheeled military market.

This market includes Oshkosh’s heavy equipment transport, the heavy extended mobility tactical truck, Oshkosh’s palletized loading system, General Dynamics Strykers and most MRAPs. “There are now many MRAP variants, and most have tires by Michelin,” Wade explained. Michelin tires are also on Oshkosh’s MRAP all-terrain vehicle. The reason for these choices? Wade argues that Michelin simply makes the best on- and off-road tires. “They are durable and tough and fit well with the mission profiles of the military.”

Wade said military customers over the last six years have sought to increase the load on each tire. “They want it go faster, increase load and reduce inflation pressure. Fortunately, our tires have been properly sized for vehicles. I always tell vehicle manufactures if they think the maximum load per tire will be 10,000 pounds, get a tire that can handle 14,000 pounds. Then you can reduce the inflation pressure.”

Fuel economy, improved by reducing a tire’s rolling resistance, has become more important for both commercial and military tire buyers. Wade said it is most important for commercial buyers because of the high annual mileage put on, for example, truck tires. “In the military, even though delivered fuel costs more, they don’t put as many miles on the vehicles, so it is not as quite as important.”



Finally, the military often wants the ability to operate with reduced inflation. “When you go off road, you can reduce inflation so you get a bigger footprint. There is less pressure per square inch, but with a bigger footprint you can still maintain control.”

Michelin also makes tires for other nations’ military vehicles. Wade said these forces tend to follow the U.S. lead in tire requirements.

Due to very demanding conditions and dangers posed by an immobilized vehicle, the military often uses run-flat devices with even the best tires. A run-flat is a specially made tire or auxiliary tire equipment that enables the vehicle to continue to be driven with punctured tires, if at reduced speed and for a limited distance.

Bulldog Direct Protective Systems makes two basic types of run-flats, President Dave Applegate said. Bulldog’s composite run-flat (CRF) tire insert provides flat-tire mobility for pneumatic tires. Special composite material reduces friction and heat buildup inside the flat.

The CRF is mounted inside a tubeless tire on traditional wheels using normal mounting tools. Each CRF is custom-built to meet load rating, distance requirements and rim specifications. The CRF can handle the weight of heavily armored vehicles. Made from a ballistic composite, the CRF can be reinstalled even when tires have been changed.

Bulldog also offers Rodgard run-flat inserts, which are made from two components: a roller and a runner. The runner is securely attached to the wheel in the drop center and provides a track for the roller to rotate around the wheel at the same speed as the tire, reducing friction and heat buildup. The Rodgard is highly resistant to ballistic attacks and can handle heavier loads than the CRF, but it is harder to install and more costly.

Rodgard gives vehicles with flat pneumatic tires much more maneuverability and control at high speeds. Special bearing interfaces and lubricant systems prolong its longevity. The Rodgard holds the tire tread and sidewall off the wheel rim, preventing it from being destroyed or coming off the wheel. Because the independent roller allows the tire to rotate at the same rate as the wheel, it minimizes heat buildup.

These Bulldog run-flats, offered for commercial uses, have been adapted for military uses. “For military vehicles, anything you see we are on it,” Applegate said. “That includes all Humvees and MRAPs and certain trucks.” ♦