Minutes of Proceedings of the Institution of Civil Engineers Volume 156 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1904 edition. Excerpt: ...piers would reduce waves to about one-ninth of their height when they reached the harbour-entrance. Referring to the concluding remarks in the Paper, he was of opinion that if piers on a sandy coast were constructed in an efficient manner, there should be no risks incidental to them. He agreed that there were many places on the coast without harbour-accommodation where openpiled structures would supply reasonable trade facilities, and could be constructed at comparatively small cost. Tho whole secret of the stability of such piers lay in keeping the decking and any superstructure above the level of the crests of the highest waves occurring during the highest known tides. He had often observed the effect of seas on open-piled structures during storms, and had never seen waves strike a blow against single piles; nor had he seen or heard of an instance in which piles in an open pier, well driven, had not been able to resist the heaviest seas. Mr. Sandeman. There were numerous positions, particularly on sandy coasts (Ceara being a very suitable example), where harbours could be economically made by means of piers, constructed of piling spaced a few inches apart and containing a filling of rubble, which, while affording efficient shelter, would not present a solid barrier to the sea. As regarded maintenance, he had constructed two such piers which had fulfilled their purpose efficiently; one being exposed to the action of the sea-worm was constructed of creosoted pine timber. It had resisted the worms for 12 years, and con Fig. 43.1 tinued to do so. Another open pier of greenheart timber which he had constructed in the Bay of Naples had resisted the action of the Teredo for 18 years. Besides economy, the advantage of such piers was the speed...