Home ] Design ] Label Explanation ] Movies ] [ Beaching Equipment ] LCVP ] 03 Deck ] 02 Deck ] 01 Deck ] Main Deck ] Crew Compliment ] 2nd Deck ] 3rd Deck ] 4th Deck ] Schematic ]


Beaching Equipment & Procedures

General Beaching Procedures:

The LST's purpose is to land combat ready men and materials directly to the enemy shore.  To do this the ship must be beached.  Generally, running a ship aground or intentionally beaching is something all captains avoid.  When it does happen, it is generally done because it is the only way a captain can prevent a damaged ship from sinking.  The LST Captain, on the other hand, is not only expected to intentionally beach his vessel, but also to back it off on his own, without assistance.  Beaching trim is obtained by flooding or pumping out the salt-water in the forward ballast tanks, as well as changes in the fuel and fresh water ballast tanks located farther aft.  The desire is to place the bow as close to the water’s edge as possible.  For most beaches, it was not possible to drop the leading edge of the ramp onto dry land, so pontoon or bulldozed earthen causeways were often used effectively.

The underwater beach sand contains a considerable water content which acts as a lubricant to slide the LST’s bottom up onto the beach closer to the shoreline.  The disadvantage is that under the pressure of the ship it causes the sand to produce a suction which will resist the forthcoming retraction.

When an LST beaches on a normal sand bottom, there is no sudden jolt, it is more like a toboggan coming to the end of its run.  Damage can occur when rocks, coral heads, or metallic objects are struck.

 Beaching and retracting is a complex exercise, and will be further explained in its two-parts, but the general requirements are: 

  1. the ship must be heading into the beach directly perpendicular to the wave action as she grounds  --  preventing the surf from attempting to broach her, as it would if being pounded on either  quarter;

  2. the stern anchor is placed to windward with as close to 600-feet of cable laid out from the stern winch after grounding, as is practical;  (relative bearings taken on landmarks nearly abeam should be used to determine the “let go” point for the stern anchor)

  3. the possible requirement for the use of the engines and/or rudders to maintain the beaching without broaching or backing off while unloading;

  4. the movement forward, while beached and unloading, may not be advisable if personnel or equipment safety factors are involved;

  5. the stern anchor cable must be under strain as the ship backs off the beach to insure it does not become fouled in the screws or rudders;

  6. the use of ballast water is to be circulated through the ship to supply fire main pressure, flushing water, cooling machinery, etc., should the ship be left high and dry by a receding tide.

 Beaching to discharge cargo:

 For a normal beaching to discharge cargo, in the change from ocean-going to beaching trim, we pump out ballast forward and may take on ballast aft to obtain the desired trim.

 The bow doors would be undogged except for the top dog  (specially-designed turn-buckles).

Consider the stern anchor placement position.  The stern anchor will be placed about 900 feet from the shoreline.  The calculation of about 600-feet of cable, plus 300-feet of ship from bow forefoot to stern winch,  plus 150 feet from the bow to shoreline, less 50 feet of slack, less 100 feet of offset to windward.  The anchor will be in about 4 to 5- fathoms of water, and permits a safety margin of about 300-feet of cable on the winch drum.  The cable is marked with yellow bands at each 100-feet -- 1 yellow band at 100-feet; 2 yellow bands at 200-feet; etc.  As a warning, the stern cable is painted yellow the entire distance between 700 and 800-feet, and painted red between 800 and 900-feet (the bitter end). 

The engine speed used in beaching is generally TWO-THIRDS or even STANDARD, with the objective to place at least 30% of the area of the hull bottom aground.  The bow must be forced a considerable distance beyond the point of contact, even with as little as a 4-foot draft on the forefoot of the bow.  It was common to drive the ship up onto the beach sand for about another full-foot of water depth or more, or about another 50 to 100-feet after first contact of the bow forefoot.  Basically, with 30% of the hull bottom in contact with the beach, it means the contact would extend to a point slightly aft of the main deck ramp. 

 Once the ship has grounded and has been driven as far up the beach slope as she will go by use of the ship’s engines, it is desirable to take steps to insure that the ship will remain in place.  The salt water ballast tanks are re-flooded to hold the ship on the beach more firmly, and to partially compensate for the weight being off-loaded.

 Then a strain on the stern anchor cable would be taken to assist in preventing broaching.

 The remaining bow doors dog would be removed, the doors opened, and the ramp lowered.

 The ramp may very well be lowered into a depth of 3-feet of water at a distance of some 150-feet from shoreline, to as much as a 5-feet depth at a distance of 250-feet, without consideration being given for sandbars.  This would exist on the designed beach gradient of 1-foot drop in every 50-foot distance to seaward from the shoreline.  This would be the case when assuming a forefoot draft of as little as 4-foot to as much as a 6-foot draft.  Marrying to a pontoon causeway may be required if the cargo needs to be “dry”.

Retracting from the beach after discharging cargo:     

After discharge of cargo, the ramp would be washed and raised, the bow doors would be closed and dogged.  All equipment used in tie-downs, etc. would be stowed, and the ship made ready for sea. 

When ready to retract from the beach, the forward ballast is pumped out, lightening the bow and letting it come free from the sand more easily.  The stern anchor would have been winched to take a strain once the ship was beached.  The stern anchor now has the job of helping to keep the ship from broaching in the surf while retracting from the beach, until the ship can be effectively maneuvered by engines and rudder control in the deeper waters.   

 Beach suction can be a significant factor in retracting operations.  Due to the weight on the sand, the lubricating water has been squeezed out and friction replaces it.  The objective is to move sand away and reintroduce the water film necessary to lubricate our hull’s movement.  Many times the engines must be ordered “all back full” to create a propeller wash strong enough to move the sand away from the hull.  In addition, it may be necessary to swing the stern from side to side with engine power, but not so radically as to induce a severe swing that risks a broaching.  Even the use of fire hoses being directed on the sand at the edges of the hull have been tried.

 In a crowded beaching area, some skippers have dragged the bow anchor underfoot to prevent the bow from swinging into another vessel as it backs from the beach.

 The stern anchor cable must have a continual strain taken to prevent overriding it and fouling the screws.

 Having laid the stern anchor (kedge) out about 600-feet has the advantage of a sufficient scope of cable to provide maximum holding power, and once the anchor is aweigh while retracting from the beach, a good decision can be made of the water depth sufficiency to begin the maneuver of turning the bow to seaward.  Other factors in deciding to make the turn would be the strength and direction of the surf, and the wind. 

 Finally, the ship would be re-ballasted to provide the desired ocean-going trim.