During World War II at the height of wheeled armored tank usage, the problem of negotiating wheeled tanks on the various terrains of Europe and the Pacific theater became obvious: tanks would become easily stuck in the quicksands of North Africa and Indonesia or in the swamps of France and southeast Germany, and of course a number of them were rendered immobile but salvageable by the enemy.
This in turn led to the abandonment of these vehicles or their outright destruction by fleeing drivers and occupants. In order to combat this, the United States Army commissioned the construction of a tractor-trailer capable of lifting and moving armored tanks from the battlefield.
Ultimately this saw the light of day as the M26 Dragon, a combination of an M25 Tractor and an M15 trailer, designed by the Knuckney Trucking Company of San Francisco, who had pioneered many of the tractor-trailer techniques used in mining operations and lumber yards across America. Nicknamed "the Dragon Wagon", it was capable of lifting and moving 40 ton payloads (effectively the weight of its most frequent hitchhiker, the Sherman tank) at speeds of up to 50 miles per hour. Eventually a modified version, the M26A1, emerged, this time without an armored cab (for increased speed.)
All in all, over 1,000 Dragon Wagons saw action during World War II. Featuring a state-of-the-art 6 cylinder 440 engine and a idiosyncractic self-lubricating chain drive (which threw oil all over the battlefields of Europe), the Dragon Wagon is perhaps most notorious for getting less than 0.5 miles per gallon. In addition to hauling tanks, each dragon was fitted with an A-Frame to handle downed airplanes, and were occasionally used to shuttle entire temporary buildings forward as the march to Germany began in earnest in 1945.
The Dragon Wagon itself was a monster, weighing in at close to 40 tons, and its winches and pulleys could pull combined weights of well over 50 tons as needed. Tanks were not only towed by crane, but could be driven or dragged up on to the M26's trailer and driven away in a matter of minutes - no small engineering feat in 1944.
After World War II, tracked tanks had won out the day of artillery design, and as wheeled tanks disappeared, so did the Dragon Wagons that serviced them. They saw limited action throughout the Korean War, and were eventually sold off to foreign countries and corporations who used them for special transportation of large vehicles and payloads.