Tank
With World War II the multi-turreted tanks proved impracticable, and as the single turret on a low hull design became standard, crews became standardized around a crew of four or five. In those tanks with a fifth crew member, usually three were located in the turret (as described above) while the fifth was most often seated in the hull next to the driver, and operated the hull machine gun in addition to acting as a co-driver or radio operator. Well-designed crew stations, giving proper considerations to comfort and ergonomics, are an important factor in the combat effectiveness of a tank, as it limits fatigue and speeds up individual actions.
Mine flail
However, tanks have the disadvantage of having the driver at the front, close to the flail and any explosions, and they can not go slow enough for effective mine clearance. Also, the weight of tanks makes them difficult to transport (by contrast, the 18-ton Hydrema 910 is light enough to be moved by air in a C-130 Hercules.) The tanks used have generally been obsolete models that have been highly modified - some work under remote control, others have had the driver's station moved to the rear. In modern times, there has been little military interest in an updated equivalent of the Sherman Crab or Matilda Scorpion - a substantially unmodified tank still capable of combat. In battle, the modern preference is to detonate mines with explosive devices (mine-clearing line charges), such as the Antipersonnel Obstacle Breaching System or the Giant Viper. During the Gulf War, the U.S. 2nd Marine Division made an attempt to breach an Iraqi mine field with a mine flail mounted on an armored bulldozer. But the flail was destroyed and the bulldozer crippled by an Iraqi anti-tank mine.