DUNNAGE 391
The working of derricks is, however, the middle operation when
(oading or discharging There is the labour o! making up the sets OT
slings to feed them, also the distribution of the goods when landed,
either in the ship's hold when loading, or into a lighter, or on the quay,
when discharging. The three operations of slinging, transporting,
delivering, should be organised to time in with each other as closely
as circumstances and the human element will admit.
Winches —The engine-room staff attend to the overhaul of winches,
windlass, steering gear and other deck machinery. The deck staff,
however, are called upon to work them and they should, at least, be
able to pack the glands at the ends of the cylinders steamtight, as
they may give out when working cargo and a mechanic not available.
The job is a simple one.
Care should he taken before starting a winch to open the cocks in
the cylinders to drain off any water that may be lodging in them.
The steam should be turned on gently at first, especially if the winch
has been standing idle for some time and this is particularly necessary
in cold or frosty weather. When frost is severe the winches not in
use are sometimes kept turning slowly out of gear to prevent the steam
pipes from cooling off and freezing up.
DUNNAGE.
Most vessels have permanent dunnage or ceiling covering the tank
tops consisting of 3-inch planking resting on bearers about 2 inches
deep, which form an air space between the tank top and the ceiling to
dry up moisture.
Portable Side Battens consisting of boards about 6 inches broad and
2 inches thick, spaced about 9 inches apart, are fitted into cleats on the
side framing of the ship; the battens may be arranged horizontally 01
vertically and sometimes diagonally. Stokehold Bulkheads are usually
fitted with battens and other bulkheads also. This permanent dunnage
is usually sufficient for rough cargoes and for goods jbhat are not liable
to absorb moisture.
Additional Dunnage should, nevertheless, be laid at the bilges where
watSer is likely to accumulate, also on stringers and stringer plates
where moisture from condensation or otherwise may trickle down
the shell plating and framework of the ship and lodge on the stringer,
Matting should always be laid on the ceiling for bale goods and bag
cargoes, and if the nature of the cargo is likely to draw moisture a»