OPERATIONS
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.
[Illustration: _Figure 49. Naples harbor cluttered with wreckage.
Wrecked and capsized merchant vessels line the quays. Note the damaged
warehouses. All cargo-handling equipment has been destroyed._]
=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:
(1) Extinguish fires and demolish unsafe structures.
(2) Sweep mines.
(3) Remove blockships.
(4) Remove booms and torpedo nets.
(5) Neutralize land mines and booby traps.
(6) Install AA and other protective works.
(7) Remove debris in water and on quays.
(8) Remove obstructions from exits to wharf areas.
[Illustration: _Figure 50. Masts of sunken freighter in harbor. The
enemy did a systematic job of sinking ships to block the harbor as much
as possible._]
[Illustration: _Figure 51. Sunken ships and bomb-wrecked quays give
some idea of the huge task of repair and construction in restoring the
port to usefulness._]
[Illustration: _Figure 52. Temporary bridge built on a keeled-over
freighter. Trucks are using it to unload a Liberty ship._]
(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—
1. Position blockship is in. That is, is it on its side, at an angle,
or resting on its keel.
2. Approximate size and type of vessel.
3. Nature and extent of its superstructure.
4. Would the removal or destruction of the superstructure leave
enough water between the hull and the surface for large vessels to
use the channel?
[Illustration: _Figure 53. Two half-sunken ships and the bomb crater
in harbor’s seawall and quay show the results of well-planned
destruction._]
5. Nature of bottom and effect of currents.
6. Is ship filled with rock or concrete?
7. Indications of mines and booby traps.
(_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—
1. What jobs the ship is to do and what priorities have been set on
them.
2. What materials, equipment, power, tools, and personnel the ship is
to furnish the port construction and repair group.
3. Whether temporary construction or repairs are to be made or
permanent repairs made.
4. Surveys to be made of underwater damage and obstructions in harbor
area.
(_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._
_1. Materials._ Materials required by the port group to start its
work can be furnished in limited quantities by the repair ship.
However until cargo ships can unload at the port, the group must
get locally the bulk of the materials it needs. The small amount of
cement, timbers, and structural steel that the ship carries can be
put ashore on the ship’s barge.
_2. Power._ Until local sources of power are restored or floating
power plants are available, power for lighting and for operating
equipment is supplied by the ship’s stationary and portable
generators and compressors.
_3. Equipment._ Such portable equipment as the clamshell bucket,
welding and cutting outfits, trailer-mounted fire pumper, and
pneumatic tools, is turned over to the group as it is needed.
If necessary, equipment operators are furnished from the ship’s
personnel.
(_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