All vessel [sic] hereafter built shall have the centreboard through the centre of the keel, and constructed as per plate.

The head ledges of centreboard cases in vessels of 200 tons shall not be less than 6 x 10 inches, 300 tons 7 x 11 inches, 500 tons 2 x 12 inches, 800 tons and over 9 x 14 inches. The plank for centreboard case, for one-third the height from keelson to deck, shall be one inch thicker than the head ledges, the second third shall be same thickness as head ledges, and the remainder or top strakes, can be one inch less than head ledges. The cap of centreboard case must not be less than three inches thick in vessels of 300 tons and less, but if over 300 tons must be in proportion, and shall extend the whole length of the same including head ledges, with a chock at each end for chain and shipping line, said chock to rest on the cap with ends let on to the beams, flush with the top of deck and well bolted down through the whole, with stopwaters near each end, and well caulked. The plank for the case shall be secured with edge bolts not more than two feet apart, each bolt to pass to the centre of third strake of each bolting The ends of plank to be secured with four bolts in each plank of twelve inches width, driven through and clenched on each side. The first and second edge-bolting of case to be driven through the keel and clenched. The head ledges to be secured with four clench bolts at the lower end, passing through the keel and head ledges; the same through keelsons and riders. The plank of centreboard case shall no in any case exceed twelve inches in width, and must be clear of heart and sap. The centreboard case shall not in any instance exceed thirty feet in extreme length. Vessels of twelve feet hold and upward, shall have a strake in centreboard case at least fifty per cent. Thicker than the head ledges, for the purpose of securing the brace beams bearing thereto.

Size of bolts required for centreboard cases in ends of plank

Edge-bolts for centreboard cases:

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