CABGO GEAB 389
distribute the thrust of the derrick to the neighbouring members of
the ship's structure
The derricks are fitted with spans, either of single chain or a wire
purchase, the latter being more popular as the derrick can be easily
upended to any desired angle; also with two guys consisting of wire
pennants with rope purchases on their ends. The big derrick
is rigged in the same way but with heavier gear and triple or quadruple
lifting purchase and span. When lifting a heavy weight the mast
must be stiffened with preventer backstays
The illustrations, pages 45 and 46, show a Mannesmann tube derrick
being tested with a load of 42 tons on the ss. Clan Macarthur. A few
ships employed in special trades where heavy machinery may occasion-
ally be carried are fitted with gear to lift loads exceeding 100 ions.
The Factory and Workshops Act insists upon all chains, hooks,
swivels, shackles and derricks being tested and examined periodically.
When they are passed by H.M. Inspector of Factories, a Registered
Certificate of Test and Examination is issued and kept on board the
ship. All gangways, hatch and deck openings should be guarded,
when possible, against the possibility of persons inadvertently stumbling,
particularly during a temporary stoppage of cargo work. Apart from
the hurt to individuals arising from an accident, it is well to remember
that the Employers' Liability and Workmen's Compensation Acts
are comprehensive and far reaching, and it is the duty of officers as
the responsible representatives of their employers to see that all pre-
cautions are taken to ensure that everything in connection with the
handling of cargo is satisfactory and reasonably safe.
The cargo gear should be overhauled at sea, when Gins, Runners,
Shackles, Guy Falls, etc., should be examined and refitted if required.
Goosenecks of derricks should be lifted and greased occasionally. When
the loading of a hold is completed the hatches are put on, covered with
tarpaulins and battened down securely. Derricks are lowered into
their crutches and lashed down. If the ship is proceeding on a long
passage the gear is unrove and stowed away in its appointed place.
Provision is made in some ships to stow the gear in a compartment
within the coamings of the hatch; in others, where the heels of the
derricks are mounted on a table, or tabernacle, built round the mast,
the enclosed space is utilised as storage accommodation.
Derricks are rigged and made ready for cargo work when entering
the port and, if possible, before the ship reaches her berth in readiness