14. CONDITIONS OF CAPTURED PORTS. a. General. Enemy destruction of a port’s facilities generally may be divided into two classifications.

(1) Channels and harbors. Offshore obstructions in the waters of the harbor include booms and torpedo nets, debris, prepared sunken obstacles, destruction of navigation aids and moorings, and damage to underwater pilings and foundations. It is the engineer port repair ship’s job to remove or destroy these obstacles and to make the underwater repairs.

(2) Damage to shore installations. The destruction of shore installations includes damage to utilities, shops, warehouses, railway spurs and yards, roads, bridges, locked basins, cargo-handling equipment, piers, wharves, and quays. It is the mission of the port construction and repair groups to repair and put these facilities back in operation.

b. Enemy damage to captured ports. Although the conditions outlined below will not hold true in all cases, they were found in captured ports.

(1) Warehouses and shops. All warehouses and shops were destroyed by demolition and fire.

(2) Utilities. Electric, water, gas, and communications systems were put out of commission by demolition and removal of parts.

(3) Locked basins and docks. All locked basins and closures were destroyed; walls of basins were collapsed by explosives.

(4) Wharves and quays. Demolitions destroyed the inshore 100 feet of quay full width to a depth of 30 feet. Mines destroyed all cranes and blew out the face of the quay in sections about 40 feet long, 30 feet back, and 20 feet deep. Cranes usually are spaced about 75 feet apart.

(5) Miscellaneous. Delayed-action mines and booby traps were placed at strategic places, even in sunken boats and ships.

(6) Channels and harbors.

(a) Ships were sunk to block entrances to harbors.

(b) All mooring buoys and channel markers were removed.

(c) All boats and lighters available to the enemy were sunk adjacent to quays, wharves, and piers.

(d) Wharf cranes and debris were blown into channels alongside wharves and quays. (See figs. 49 through 53.)

15. OPERATIONS OF PORT REPAIR SHIP IN A CAPTURED PORT. a. General. The port commander is responsible for the restoration of the port’s facilities. He orders surveys made of the extent and nature of the damage and from them determines what work is to be done and who is to do it, sets priorities, and estimates time, personnel, materials, and equipment required. Before actual repairs can be started, the following preparatory work usually has to be done by Army and Navy units:

(9) Install navigation aids and moorings.

b. Following are some of the jobs the port repair ship might be required to do:

(1) Install navigation aids in entrance channel. After the harbor area has been swept of mines by the Navy, the port repair ship marks the entrance channel with buoys. This is done by soundings and by using hydrographic charts of the harbor. Soundings are made by the ship’s fathometer, by lead lines, and by a portable depth finder. The portable depth finder works on the same principle as the ship’s fathometer (par. 8) and is installed on one of the two powerboats. The powerboat operates ahead of the port repair ship, takes continual soundings, and marks the boundaries of the channel. The crew of the powerboat is constantly on the alert for underwater obstructions and signals the ship if any are found and whether the ship must change her course or stop.

(2) Blockships.

(a) A blockship is a prepared underwater obstacle sunk to prevent ships from following navigable channels. One or more blockships may be found in an entrance channel. These ships are often filled with rock or concrete to make them more difficult to remove.

(b) When soundings, intelligence reports, or information received from the minesweepers indicate the location of a blockship, a diver is sent down for reconnaissance. The information required to determine the course of action is—

(c) This information determines whether the superstructure can be cut through or flattened with explosives or if the hull has to be broken up before the channel is cleared. Destroying the hull is a long, difficult task and should not be attempted if the removal of the superstructure affords enough clearance.

(3) Harbor.

(a) General. When the port repair ship enters the harbor, her master reports to the port commander for instructions. These instructions include—

(b) Removal of small sunken craft and debris. Small boats usually are sunk alongside wharves and quays to prevent ships from approaching close enough to unload. Also, cranes and sections of the wharves blown into the water have to be removed. Divers examine the debris and determine whether it can be pulled out of the way into deeper water or if it first must be broken up. Since the use of large quantities of explosives may further damage adjacent quays and piers, debris too heavy and bulky to hoist and drag is cut into smaller sections by underwater cutting. Then these sections are raised by the cathead and pulled out of the way by the ship. Small, sunken craft often can be salvaged by sealing up the hulls and pumping out the water with salvage pumps. This type of salvage work can be done from the 50-ton barge which leaves the repair ship free for other jobs.

(c) Furnishing materials, power, and equipment.

(d) Use of the ship’s shops. The ship’s shops are used to make parts for and to repair port machinery and equipment. Typical jobs are to repair engines and motors and to construct or repair cargo-handling equipment.

(e) Underwater construction and repairs. The ship’s divers may be required to repair the underwater structures of damaged piers and quays. Broken or weakened pilings or timbers may have to be cut and removed so new ones can be placed. Also, the foundations of harbor breakwaters or sea walls may require strengthening or repairs.

c. Safety of ship. While operating in the close waters of the harbor, especially while threatened with the additional hazards of debris, mines, underwater obstacles, and enemy air attack, the safety of the ship is of paramount importance. The master of the ship is responsible for her safety. He sees that the gun crews are at their stations and that enough deckhands are available for the extra work required in mooring and maneuvering.

d. Summary. Speed is essential in port repair work to eliminate the necessity of landing troops, stores, and equipment over beaches for any length of time. The engineer port repair ship has an important part in getting this work started by opening the harbor to navigation and by furnishing power, equipment, and supplies to the port construction and repair groups. The shops on the ship help prevent stoppages caused by breakdown of machinery and equipment because they can repair or manufacture essential parts that may be needed. In short, the port repair ship is the spearhead in getting port reconstruction work under way and, by its ability to do many different tasks, helps to speed up this work and keep it going.

? U. S. GOVERNMENT PRINTING OFFICE: 1945—628131—TM 1045