Page 174 - NAVAL SCIENCE 3 TEXTBOOK

180 NAVAl. SKILLS

a large pelican hook that is shackled to the towing pad and made Rigging. The term riggillg is used for all wires. ropes, and
fast to a towing hawser. The hawser is attached to one of the towed chains supporting masts or kingposts (vertical poles), and oper-
ship's anchor chains. which is let out through the bull-Ilose and ating booms and cargo hooks. Stmufillg riggillg includes all lines
veered to about 20 t:lthoms. that support masts or kingposts but do not move, sllch as stays
The length of the towline-hawser and chain-is adjusted and shrouds. RWlllillg rigging includes all movable lines that run
to hang in a deep catenary. This catenary helps to relieve surges through blocks, such as lifts, whips, and vangs, described below.
on the line caused by movements of the two ships. Proper towing Booms. A bool/l is a long pole built of steel. The lower end is fit-
technique requires that the towline be of such scope that the two ted with a gooseneck, which supports the boom in a boom step
craft are "in step." Both must reach the crest of a wave at the same bracket. The frec end is raised or lowered and held in position b)' a
time. or the towline will be whipped out of the water under ter- cable called a toppillg lift. Booms range in capacity from 5 to 75 tons.
rific strain. Once properly rigged, the towing vesse( must barely get Booms are moved into position, and cargo is moved into and
under wa)' as the towed vessel begins to move. A sharp start or jerk out of holds by running rigging. 'lopping lifts mo"e the ITee end of
ma)' part the towing hawser. Speed is gradually increased to about the boom "erticall), and hold it at the proper height. Inboard and
5 or 6 knots for the duration of the tow. outboard guys. or mllgs, move the boom horizontally or hold it ill
working position owr a hatch or dock. The cargo hook is raised or
lowered byemgo whips running from winches.
Cargo Handling

Cargo is loaded or oftloaded b)' ship's gear, or dockside winches
Underway Replenishment
and floating cmnes when in port. At sea the ship's gear is llsed for
undem'a)' replenishment (Un Rep) either b)' another ship (ConRep), In addition to anchoring and mooring, one of the more fre-
or b)' helicopters (VertRep), in which case ,'er), little ship's gear will quent deck seamanship evolutions done by the deck personnel
be used. Amphibious and mobile logistic ships have hea'T-lift cargo of naval ships is underway replenishment (UnRep) while along-
systems. In sllch ships, deck seamanship is mainly concerned with side another ship (ConRep). Such operations may involve the
heavy-cargo handling. Sailors in these ships need to know about all transfer of fuel, cargo, ordnance, and sometimes personnel by
the parts of cargo gear and the variolls "rigs" for handling cargo. high/hie tmns/er. Normally the ship receiving the transfer maneu-
vers alongside the suppl)'ing ship, Once alongside. light heaving

When a ship is secured to a pier, the mooring Several booms and their rigging are shown in use by this oiler during an under\'Jay replenish-
lines are usually doubled up, as shown here. ment of another ship alongside,
Then light line is used to bind the parts to-
gether, and conical rat guards are put in place
so that rats and mice cannot crawl up the lines
onto the ship.