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“There is no truth in the observation of some people, that all discoveries of importance are already
PRINTED AND PUBLISHED BY JAMES BQUNSALL,
Mechanics' MAGAZINE office, 166, FLEET-street.
ACCOUNT OF THE REMOVAL OF THE LIGHTEIOUSE AT SUNDERLAND. BY JOHN MURRAY, ESQ., C.E.
[From Minutes of Proceedings of the Institution of Civil Engineers, Session, 1844.]
SUNDERLAND ranks as the fourth port in the United Kingdom in respect of tonnage. The shipment of coal, which is the principal business of the place, amounts annually to about 1,300,000 tons. Lime is also extensively shipped for Yorkshire and Scotland. There are various manufactories in the town and neighbourhood, and the building of ships is carried on to a great extent. The population of the united towns of Sunderland, Bishopwearmouth, and Monkwearmouth, amounted, according to the census of 1841, to 57,057, including about 4,000 Seamen. The harbour has been, since the reign of George I., under the control and jurisdiction of Commissioners, appointed by parliament. For some years past, the average revenue, arising principally from the shipment of coal, has amounted to about 16,000l. per annum. The funds so collected, have been expended in deepening the shoals, removing rocks and other obstructions and building piers at the mouth of the river. These piers, having been originally executed in a superficial manner, soon showed symptoms of decay, and it was found necessary to rebuild the eastern or seaward portion of them. The late Mr. John Rennie was consulted, and his advice was, that the piers should be prolonged with solid masonry into deeper water. The south pier has, in consequence, been rebuilt in a substantial manner with ashlar masonry, in blocks of stone, varying from 5 to 7 tons in weight, properly backed with a glacis of rubble stone. The eastern part of the north pier, during the last ten years, has been taken down, under the author's superintendence; a new pier has also been built, in the direction suggested by Mr. Rennie, and approved, by his son Sir John Rennie. This pier has been executed in the strongest manner and with excellent materials, forming altogether a handsome and substantial piece of masonry. The most beneficial effects have been produced by the adoption of these plans; the channel to sea has been straightened and deepened by dredging, and the bar has been lowered and kept in a stationary position, so as to give 4 feet of water upon it during low water, or 18% feet at high water of ordinary spring tides. Near the termination of the north pier, there was built, in 1802, by Mr. Pickernell, then engineer to the Commissioners, an octagonal lighthouse of polished stone. Its height was 60 feet 2 inches from the base to the cornice, terminating with a lantern, the
cupola of which was 16 feet above the cornice, making a total elevation of 76 feet 2 inches above the pier. Its breadth was 15 feet at the base and 8 feet 6 inches at the cornice, having a spiral staircase up the centre of the building. It was subsequently lighted with coal gas from nine patent burners with parabolic reflectors. In the beginning of the year 1841, before the works at the north pier-head were terminated, an alarming breach was made by the sea in the projecting part of the old pier, on which this lighthouse stood, and it became imperative, either to take down the building immediately, or to repair the pier in an expensive manner. On the 7th of April 1841, the advantages of having a new lighthouse on the high ground near the fort on the south side of the river, and the difficulties of removing the present one from its then critical situation, were discussed at the Board of Commissioners. The result was, that the author (Mr. Murray) received directions to prepare the materials necessary for carrying into effect the project he had suggested of removing the building in an entire state, on a cradle of timber, to the eastern extremity of the new pier. In consequence of the breach before alluded to it was necessary to remove the lighthouse in a northerly direction, on to the new pier, before it could be taken to the eastward, and its axis required to be turned in order to make it correspond, or be parallel with the altered direction east and west of the new pier. The raised platform of the new pierhead, where the building was proposed to be placed, being 1 foot 7 in. higher than the original site of the lighthouse, it became necessary, in providing a proper height for the entrance doorway, either to descend a few steps from the platform or to lift the base, and consequently the whole building, to the proper level. It was deemed advisable to adopt the latter course. The first of these operations was to take the building northward. On the 15th June the masons began to cut apertures on the north and south sides of the building for the reception of the cradle or platform of timber, See plan, fig. 2, and elevation, fig. 3, the two middle balks were threaded through consecutively, and the apertures were made no larger than absolutely necessary for that purpose. The upper course of stones below the torus moulding was not disturbed, and the bottom of this course was made to rest immediately upon the cradle timbers. The upper surfaces of the beams, where they