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.