PARAVANES
On the other hand, the Allies had a way of sailing right through fields of enemy mines with little danger. Our ships were equipped with "paravanes" which are something like the "water kites" used by mine-sweepers, and they are still used in the waters of the war zone. Paravanes are steel floats with torpedo-shaped bodies and a horizontal plane near the forward end. At the tail of the paravane, there are horizontal and vertical rudders which can be set to make the device run out from the side of the vessel that is towing it, and at the desired depth below the surface. Two paravanes are used, one at each side of the ship, and the towing-cables lead from the bow of the vessel. Thus there are two taut cables that run out from the ship in the form of a V and at such a depth that they will foul the mooring-cable of any mine that might be encountered. The mine cable slides along the paravane cable and in this way is carried clear of the ship's hull. When it reaches the paravane it is caught in a sharp-toothed jaw which cuts the mine cable and lets the mine bob up to the surface. The mine is then exploded by rifle or machine-gun fire.
Courtesy of "Scientific American"
Hooking Up Enemy Anchored Mines
In some forms of paravane there is a hinged jaw which is operated from the ship to shear the cable. The jaw is repeatedly opened and closed by a line that runs to a winch on the ship. This winch winds up the line until it is taut and then the line is permitted to slip, letting the jaw open, only to close again as the winch keeps on turning and winding up the line.
Guarded by steel sharks on each side, their jaws constantly working, a ship can plow right through a field of anchored mines with little danger. To be sure, the bow might chance to hit a mine, when, of course, there would be an explosion; but the ship could stand damage here better than anywhere else and unless the bow actually hit the mine, one or other of the paravanes would take care of it and keep it from being dragged in against the hull of the vessel.