A Treatise On The Principles And Practice Of Harbour Engineering

HARBOUR DESIGN 13 vessel missing the entrance of an embayed harbour. So it is scarcely safe to dogmatise upon the point. There may be advanced positions to which a lofty headland imparts all the advantages of a sheltered recess, and there are likewise cases in which deep coastal indentations afford very meagre protection from tempestuous seas. Where it can be assured without serions risk, the nearer the haven to the distressed ship, the better her chances of reaching it. Many seamen, however, prefer, where practicable, to ride at anchor in the open rather than make for the uncertainties of the shore. The requirements of a harbour of refuge may be summed up as three :— (a) Ready accessibility. (b) Safe and commodious anchorage. (c) Facilities for obtainitig supplies and for executing minor repairs. Upon the first point we have already dwelt a little. But accessibility depends not only upon the site of the harbour; it depends also upon its dis- position. The entrance must be conveniently placed and designed, so as to allow of its being easily taken by ships driving before a storm. A narrow entrance is difficult to negotiate, but, on the other hand, a wide entrance exposes the interior to the effects of rolling seas. Local circumstances will largely influence the determination of the dimension to be accorded thereto ; at the same time, it may be said that from 600 to 800 feet approximately represents the expression of modern British practice. It is not unusual to