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Sir John Rennie
Published by Good Press, 2019
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As the shore, particularly on the Scotch side of the channel, was very precipitous, rugged, and mountainous, it was impossible to measure with anything like accuracy a base line from which a series of triangular observations could be made so as to connect the two coasts together; Mr. Griles was therefore obliged to resort to the Bay of Luce, situated about 10 miles to the east of Port Patrick; it had this disadvantage, however, that in consequence of the intervening mountains neither the Scotch nor Irish coast could be seen. But there was no alternative, for no other convenient place could be found to measure a base line. The head of the Bay of Luce, however, at low water consists of an extensive district of flat sand 6 miles long, admirably adapted for the purpose of measuring a correct base line. This plan was accordingly adopted, and a base was measured 6 miles in length, first by the common chain, then by another chain consisting of steel links each 5 feet long, and lastly by well-seasoned deal rods each 10 feet long; these measurements were repeated with great accuracy several times, and a mean was then struck by which the variation was reduced to a fraction of an inch. It should also be observed that the measurements were taken when the atmosphere was about the same temperature, so that the final measurement was reduced to as near accuracy as practicable. Having established the base, strong vertical staffs with flags at their summits were then accurately fixed upon the summits of the neighbouring mountains which overlooked the Irish Channel, and from which on a clear day the opposite coast of Ireland could be distinctly seen. From each end of the base the above-mentioned angles were taken with one of Troughton’s best 7-inch theodolites, between the different mountain stations, and the distance between the extreme points of these stations was accurately calculated, so that it gave a base line of about 30 miles along the Scotch coast, from whence correct sights were taken on flagstaffs fixed on the high land above Bangor, Donaghadee, and Ballantrae, including the Copeland Islands on the opposite coast of Ireland. These observations being taken on different levels, were subsequently reduced to the same plane, so that the exact distance was obtained between the different stations on each side of the channel, and a correct chart was made. In addition to the general survey, detailed hydraulic charts were made of the places on each coast which were best adapted for making harbours of the size required, viz. Port Nessock, Ardwell, and Port Patrick, on the Scotch side, and Bangor, Ballyhone, Donaghadee, and Ballantrae, on the Irish side of the channel; and as there was a great variety of interests concerned, each proprietor being desirous of having the permanent ports established on his own property, it was finally decided by the Government, at the recommendation of my father, that the whole of the surveys should be submitted to the arbitration of the Trinity Board, to select one port on each side of the channel which was best adapted for establishing a communication by packets between the two countries for letters and passengers in the most expeditious, convenient, and effective manner. The Trinity Board, after having given the subject their most mature consideration, ultimately decided on Port Patrick on the Scotch, and Donaghadee on the Irish side. This decision was approved of by the Government, and Mr. Rennie was desired by them to prepare designs for harbours in both of the above places; he did so, and the Government ordered them to be carried into effect under his direction: for a more particular description the reader is referred to my work on British and Foreign Harbours. During the progress of these surveys I learned a great deal in this important department of civil engineering, and personally surveyed the bay of Port Nessock and the Copeland Islands, which gave me an excellent lesson, as, on account of the rugged nature of the coasts, they were attended with considerable difficulties.
As already observed, in the following year, 1815, I was placed under Mr. Giles’ direction during the whole period of the survey of the river Tyne, which had been entrusted to him by my father also. In the same year I was under Mr. Giles during the surveys for the Barnard Castle, and Stockton and Darlington railways and canal; and I subsequently made a hydraulic survey of the port of Blythe for my father, and for which he afterwards made a design for its improvement. I had been previously employed under Mr. Giles in the surveys for the eastern extension of the Kennet and Avon Canal. During a part of this time our head quarters were at Windsor; and one Sunday afternoon I recollect very well attending the promenade on the terrace at Windsor Castle when His Majesty King George the Third, accompanied by the Queen and Royal Family, made their appearance with their attendants and joined the promenade, and were received in the most loyal and affectionate yet respectful manner. I also about the same time assisted Mr. Giles in the survey of the Thames in the vicinity of Woolwich Dockyard, the accumulation of the mud in front of which was so great at that time that it threatened to render that dockyard useless. The evil to a certain extent has since been remedied by removing a number of the projections which interfered with the currents of the ebb and flood tide, according to the plan laid down by the late Mr. Rennie, although, as he clearly pointed out, it would be impossible to improve the river to such an extent in front of Woolwich and Deptford dockyards as to render them fit for the construction and accommodation of large vessels of war; and therefore he recommended that they should be abandoned and sold, and that a proper establishment should be made at Northfleet capable of accommodating at all times of tide any number of the largest vessels of war at that time in the navy, or that might be built hereafter. This dockyard was intended to be so arranged that all classes of vessels of war could be built there; and it would contain establishments for manufacturing cordage, sails, anchors, guns, smith work of every kind, together with depôts of provisions, and stores of all sorts, all of which were to be arranged in such a manner that each operation of building, repairing, storing, and fitting out for sea should be completed in the order required; so that a vessel, after having been built, might be transferred at once into a dry dock to be coppered, then take in her masts, ballast, rigging, sails, stores, provisions, guns, boats, and seamen, and sail at once complete to her station from the centre dock-gates; in the same manner, when returning from her station, she might be repaired and fitted out again ready for sea. The saving effected by such an establishment would have been immense, and the service would have been performed in a far more expeditious and effective manner. Mr. Pitt was then Prime Minister, and his master mind at once acknowledged the advantages of such an establishment; it was accordingly approved of by the Government, the land was bought, and it was ordered to be carried into effect, but the unfortunate death of that great minister and the change of Government effectually put a stop to all further proceedings in this direction. Since that time the old dockyards of Woolwich and Deptford, Sheerness and Chatham, have been improved and enlarged, at an expenditure as great as would have completed Mr. Rennie’s establishment at Northfleet, without half the efficiency or accommodation. The old useless dockyards of Woolwich and Deptford, which the late Lord Melville, when First Lord of the Admiralty, condemned and ordered to be sold, have been retained, and the increase of unnecessary expense has been enormous, whilst the evils complained of have not been remedied till quite lately.
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