A Fast Offshore Cruiser - 16. Weight estimate.

The weight calculation of any boat has to be very detailed for it to be accurate. For the weight estimate to be detailed there needs to be data for every item and structure that will be installed upon the boat. At the stage that this design is at this is not possible, especially for the general arrangement.

The weight estimate is very much an estimate and is based upon actual data, of pre-built items e.g. cooker, and data from other vessels for items such as internal structure. The hull and deck structure is calculated.

The weights have been split in 14 separate groups, e.g. structure, saloon, installations etc, this makes it easier to see the distribution of weight round the vessel. A 10% margin has been included in each group this is a ‘fudge factor’ that is there because if the inaccuracies or lack of known data on the items and structures in the yacht.

The position of the vertical centre of gravity is low (-0.15m below DWL) which is produced by the high ballast ratio and all the ballast being in the bulb. There is a misalignment between the LCG and the LCB, about 0.35m, but this could be rectified easily with a reworking of some of the structures.

See Appendix D.3 for weights table.