1874
THE NEW ZEALAND GAZETTE.
[No. 49

Method of Testing.

88. Every derrick shall be so tested by subjecting it to a test load 25 per centum in excess of the required safe-working load: Provided that the excess load need not exceed 5 tons. During the test one derrick shall plumb the hatch and the other shall plumb overside the ship, both being in the normal working positions. The weight shall be lifted by one derrick and swung over until it is wholly supported by the other derrick, or each derrick may be tested separately by a dynamometer or other loading device.

Limit of Test Load.

89. Nevertheless the test load applied to a derrick shall not exceed that which, in the opinion of the Chief Surveyor of Ships, may safely be applied thereto.

Examination.

90. After testing, all gear shall be examined to see that no deformation or other defect has occurred or developed.

PART XIV.—SAFE-WORKING LOADS.

Short-link Chains.

91. The safe-working loads for short-link chains shall be those set out in Table No. 6 in the Third Schedule hereto.

Single and Collar Slings.

92. The safe-working loads for single slings and collar slings of short-link chain carrying the load on a single part of the sling shall be those set out in Table No. 6 in the Third Schedule hereto.

Two-legged Slings.

93. The safe-working loads for slings of short-link chain carrying the load on two parts or legs of the sling shall be those set out in Table No. 7 and Table No. 8 in the Third Schedule hereto.

Long-link Chain.

94. (a) The safe-working loads for long-link chains when used over sheaves, pulleys, or drums, or when used as slings, shall be two-thirds of the safe-working loads for short-link chains set out in Table No. 6 aforesaid.
    (b) The safe-working load for long-link chain when used otherwise than over sheaves, pulleys, or drums, or when not used as slings, shall be those as set out for short-link chains in Table No. 6 of the Third Schedule.

95. (a) The safe-working loads for enlarged-link chains when used otherwise than over sheaves, pulleys, or drums, or otherwise than as slings, shall be those set out in Table No. 10 in the Third Schedule hereto.
    (b) The safe-working load for enlarged link chains when used over sheaves, pulleys, or drums, or when used as slings shall not exceed two-thirds of the safe-working load of a short-link chain of the same diameter as the enlarged-link chain as set out in Table No. 9 of the Third Schedule hereto nor the safe-working load set out in Table No. 10 of the Third Schedule hereto.
    (c) When the inside width of an enlarged link exceeds the greatest width specified in Table No. 10 for the diameter of the link, the safe-working load for such link however used shall not exceed that computed from the formulæ set out in Table No. 16 for a ring with a diameter of iron and inside diameter corresponding to the diameter and inside width respectively of the enlarged link.

Rings.

96. The safe-working loads for rings made of iron of the respective diameter set out in the Second Column of Tables No. 12 and No. 13 in the Second Schedule hereto, and having the respective ring-diameter set out in the Third Column of the said tables, shall be those of the short-linked chains set out in the First Column of the said tables.

97. The safe-working loads for rings having proportions differing from those set out in Tables No. 12 and No. 13 in the Second Schedule hereto shall be proportionate to those prescribed by the last preceding regulation so as to vary therefrom directly as the cube of the diameter of the iron of the ring and inversely as the mean of the inside and outside diameters of the ring.

98. Alternatively the safe-working loads for rings may be computed as set out and described in Table No. 16 in the Third Schedule hereto, and a load so computed, although it may differ from that prescribed by Regulations 96 and 97 hereof, shall be deemed to be the safe-working load for the purposes of these regulations.