Mine Sweeping Operations 

The Implicit and other aggressive class minesweepers swept mines by entering the mine field
 first and towing sweeping gear astern. To reduce the chance of detonating a magnetic mine
the Implicit was constructed of wood, non ferrous metals and was routinely degaussed to
reduce the ship's magnetic signature. Hence the phrase “wooden ships, iron men.”

Mine sweeping consisted of mechanical sweeps and influence sweeps.

Mechanical sweeps were used to cut the cables of moored mines. Mechanical sweeps used
explosive cutters attached to a sweep wire towed behind the Implicit. Towed bodies or kites
 were attached to the wire and were used to maintain the sweep at the desired depth and
 to divert the sweep wire out and away from the side of the ship. A float or paravane was
 attached to the end of the sweep wire to keep the equipment from sinking and striking the
 sea bottom.

Influence sweeps used towed equipment that emulated a particular ship’s magnetic
 and acoustic signature causing the mine to actuate and explode. Influence sweeps
used magnetic generators and acoustic simulators.  Copper mag tails were used to pulse
several thousand watts of electrical current through the sea. Kites and paravanes were used
with the magnetic generators and acoustic simulators. Tubular canvas flotation devices
were attached to the mag tails.

Once the equipment was in the water and streamed several hundred yards out and away from
 the stern, the minesweeper entered the mine field. The ship steamed back and forth through
the mine field until the entire field was swept. Maneuvering the ship at the end of each pass
 was severely restricted.  If the ship was turned too sharply the gear on the inside of the
turn would sink and the wire may separate if the gear bottomed.  The gear on the outside
 of the turn would shear wildly because of the increase in speed and the tow wire could 
separate under the additional strain.

Starboard crane preparing to lift a paravane

Attaching electrical cable used to power an acoustic device

Acoustic device on the left with a paravane on the right

The wire cables used to stream the mine sweeping gear are shown on the winch drums. The electrical
cable used to power the acoustic device is shown above the drums resting on the rollers.

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