A Treatise On The Principles And Practice Of Harbour Engineering

HARBOUR DESIGN. 33 work even fell outwards under the pressure of the water pent up within the harbour. In consequence of this disaster, the walls, after repair, were raised an additional 9 or 10 feet in height, and this has so far proved satisfactory, for no case of overflooding has since occurred. The incident afforded an opportunity for a review of the design with the object of ascertaining whether any modifications were desirable. In 1883, a local Committee convened at Madras to consider the official report of Sir John Hawkshaw, Sir John Coode and Professor Stokes, recommending a basis of reconstruction, advocated the adoption of an improvement scheme of their own, with a new entrance facing north-east. In assigning their reasons for wishing to abandon the original entrance, the members stated that : No matter what the direction of the wind, the unceasing swell on this portion of the coast rolls in with the crests of the waves parallel, or very nearly so, to the coast-line. In no case is it believed that the angle exceeds 30 to the general line of the coast. The result is that seas enter the present mouth freely, and, owing to the small length of the harbour, are not dispersed before reaching the shore at its base. The action is, of course, greatly intensified during storms, and particularly with the wind from the east. At such times, the sea inside the harbour, though not so high as outside, is certainly of a dangerous character, being exceedingly broken. Taking these and other facts into considération, the committee have to record their opinion that unless means be found for closing entirely the present entrance, no radical eure will have been applied to the chief defect of the work as at present designed.”1 In 1887 they issued a further statement. “ It is agreed on all hands that, owing to the frequently disturbed state of the water, the facilities for landing and embarking passengers, cargo, etc., offered by the harbour, are very much restricted, nor would it be feasible for the same reason, to use, without serious interruption, wharves or jetties along the shore-line, or to keep in safety within it such improved lighters, tugs, and other harbour craft as would greatly inerease its value as a trading port. Much cargo is said to be lost overboard in the process of transhipment, and, for want of tugs, no sailing vessels use the harbour at all.2 “ The present or east entrance we believe to be the easiest and safest for ingress or egress, but not only does it admit the sea in the manner described, but we are of opinion that the time is not very far distant when the depth at the entrance will be so far reduced as to become too shallow for the larger class of vessels frequenting the port. “ The alternative is an opening in the north-east corner with a covering arm. This is the plan favoured by the Madras Board, and to this we have given our most careful considération. “The opinions of the captains of steamers frequenting the port differ materially. Some see considerable difficulty and danger in taking an 1 Official Papers, Madras Harbour, 1902, p. 39. 2 Ibid, p. 53. 3