Section IV. Anchoring site selection considerations
16-8 Barge requirements
16-8.1 Barge is designed to operate in sea conditions not exceeding Sea State 3. This is a condition not exceeding a
combination of winds up to 16 knots, waves to a height of 6 feet, and currents up to 3 knots. Therefore, barge must be
operated in protected waters or be within range of reaching protected waters prior to arrival of major storm activity.
16-8.2 Depending on sea conditions, barge may be operated in areas with a minimum low tide depth of 8 feet. Operating
at depths of less than 15 feet requires use of the starboardside water suction pipe rather than bottom mounted seachest.
Most tugs used to position and recover the barge, due to their draft and propeller
clearance requirements, will not enter water with an operating depth of less than
16-8.3 Optimum depth for normal barge operation is between 25 and 35 feet.
16-8.4 The barge must be anchored within 2000 feet of the high water shoreline so the 2500 feet of shore discharge
water hose can reach the shore connection.
16-8.5 In depths greater than 50 feet, anchors may not hold. At these depths, the angle between the seabottom and the
anchor/anchor cable becomes so great the anchor flukes may not be able to rotate enough to dig into the bottom and hold
the anchor in position.
16-8.6 The barge must be anchored with its stem facing the beach and in direct line with the shore facility hookup point.
16-9 Beach and shore requirements
16-9.1 Area must provide sufficient level space for establishing a water distribution facility with road access to the shore
16-9.2 Area must provide sufficient smooth, hard ground for location and anchoring of beach winch for pulling in barge
water shore discharge hose. This winch weighs about 6 tons, and area must provide access for rough terrain forklift to
enter a beached LCM, pick up the winch, move to the designated site for the winch and position it. Area must also
provide suitable method for anchoring beach winch. This is normally done by driving six to ten 5-foot stakes into the
ground and securing the winch to the stakes.
16-9.3 Area must provide sufficient smooth hard ground for establishing connection point between shore facility and
barge water discharge hose. Area must have sufficient slope to encourage drainage of excess water.
16-9.4 Area must provide smooth, gradually decreasing grade from connection point to shore high water line and then
underwater to barge location.
16-10 Oceanographic requirements
16-10.1 Optimum site has minimum current, sea action, and natural harbor to provide protection from adverse weather.
Sea direction is generally set by prevailing winds. Even when current is fairly strong (up to 3 knots), wind direction
normally establishes sea direction. Therefore, prevailing winds must be determined before selecting a site.
16-10.2 Sea bottom conditions must provide a very high probability that anchor will set and hold. Mud and sand bottoms
normally provide this. Rock and/or coral may be more difficult.