October 16, 2011: Many World War II era inventions continue in use by the military. One of the more prosaic of these innovations are the perforated metal matting that is used to rapidly create all-weather airstrips that can handle jet fighters and helicopters. The original Marsden Mats of World War II were made of a rust-resistant steel alloy. The sheets of steel had holes in them (to allow for drainage) and slots by which they could easily be linked together. In less than two days, engineers could build an airstrip over a kilometer long (usually 1.3 kilometers, or about 4,000 feet) that could handle aircraft up to 28 tons. That meant four engine bombers like B-17s and B-24s (but not the 30 ton, when empty, B-29). Many of those World War II Marsden Mat airstrips, laid down in remote areas, are still there. In more settled areas, the Marsden Mat panels were used for fencing and building materials, and if you know what to look for, you can find them, usually on remote Pacific Islands.

The current version of Marsden Mats is called PSP (Perforated Steel Planking) and comes in three meter (10 foot) long, 38cm (15 inches), 20 kg (66 pound) panels. PSP can handle heavier loads, but not heavy bombers like the B-1/2/52. PSP has recently run into another problem with modern warplanes; heat.

Over the last three years, testing of the STOVL (vertical takeoff and landing) version of the new F-35 fighter showed that its F135 engine, the most powerful to ever be used in a fighter, generated enough heat from to damage the PSP used for rapidly constructed airfields. The F-35B engine heat won't damage the decks of current aircraft carriers, but the PSP is toast, so to speak, and will have to be replaced with sturdier stuff.

The F-35B is larger, and puts out more engine blast, than the current STOVL aircraft, the AV-8 Harrier. The AV-8 first entered service in 1969. That early version was used mainly by the British Royal Navy and the U.S. Marine Corps. It was an 11 ton aircraft (7 tons when taking off vertically) that carried about two tons of weapons. In the 1980s, a more powerful 14 ton version was developed, which could carry three tons of weapons.

The F-35B, which will replace the Harrier, is a 27 ton aircraft that can carry six tons of weapons and is stealthy. In vertical takeoff mode, the F-35B will carry about twice the weapons as the Harrier, and have about twice the range (800 kilometers).