Section 4 Special loads

4.1.1 The procedure calls for evaluation in conditions out of normal design, as may occur during manufacture and installation and in survival condition. This Section aims to give guidance for these loads.

4.2.1 Composite materials can be sensitive to pressure lateral on the laminate. Insufficient support of the mast when laying down can lead to de-lamination in way of the supports. Lifting by a single sling can have a similar effect. Contrary to metal construction, composite construction can delaminate with no external markings. Verification as to whether damage has occurred as a result of handling is therefore difficult and the best way to avoid such internal damage is to include the ability to withstand the envisaged handling in the design process. When the exact procedure is not yet known, an outline of typical actions (support, lifting) can be used instead, and procedures may be developed later as a combination of these typical actions.

4.2.2 The loads to be applied of course depend entirely on the action carried out and the procedure used. In the absence of exact data, accelerations from transport damage statistics can be used.

For lifting operations using cranes, an acceleration of 0,5*g can be assumed. (note : LAME code, noting that a mast may weigh less than the SWL of a crane and subsequently may see higher accelerations than used for crane design at full load.)

In either case, the initial assumptions should be checked against the actual procedure.

4.3.1 Motions of the yacht in survival conditions can be estimated from model tests or computations. In the absence thereof, accelerations and amplitudes as given in the Rules and Regulations for the Classification of Ships, July 2022, Pt 3, Ch 9, 11 Wind propulsion systems can be applied, in combination with wind loads corresponding to a wind speed of 63 m/s.

4.4.1 Dynamic loads in sailing conditions can be determined from simulations or other established computation techniques. In the absence of detailed information, an allowance for dynamic loads can be assumed by a factor of 1.33 on the combination of load by wind and own weight.