Free Chatham Dockyard by Philip MacDougall

impressed with Parkin’s scheme, choosing to employ John Rennie, the leading engineer of the age, to undertake a feasibility study. Despite a clear statement that Rennie was only to give his opinion on Parkin’s projected improvements to the dockyard river frontage, the engineer devoted most of his attention to a number of alternative ideas for the general improvement of the entire yard. These were presented to the Admiralty during the summer of 1814, with Rennie both outlining the general defects of the yard and how these might be overcome.
    In his report, and given that the problem of silting was at that time unresolved, Rennie not unnaturally devoted a fair amount of attention to this particular issue. In addition, however, he also drew attention to other weaknesses in the usefulness of the yard, these relating to the limited value of some of the existing building and repair facilities together with a general lack of storage space. With regard to the former, he specifically drew attention to the dry docks, these having seen no substantial improvements since the beginning of the previous century. Built for warships of an earlier age, they did not havesufficient depth for the accommodation of the much larger warships that were now regularly being brought to Chatham. According to Rennie’s calculations it was the Old Single Dock that had the greatest depth of water, this being 18ft 3in on a spring tide and 14ft 9in with a neap tide. Yet, with that additional depth acquired at the height of a spring tide, this dock still required a further 3ft of water for a first rate to make an unobstructed entry. As it happens, such vessels were brought into dry dock at Chatham, but to do so these ships had to be heaved on to blocks that were often 3ft above the base of the keel.

Still used in the manufacture of rope is this forming machine that dates to 1811 and was the product of Henry Maudslay, a leading engineer of the age.
    A further factor that counted against the efficiency of Chatham’s existing dry docks was that they were constructed of timber rather than stone. Originally this had made a great deal of sense, it being cheaper and easier to build in timber. However, docks constructed of timber lacked durability, with those at Chatham, as already demonstrated, sometimes needing to be repaired at times that proved less than advantageous.
    Although it would not have been impossible to completely modernise the dry docks at Chatham, any proposals were normally pushed aside on grounds of expense. The Chatham dry docks, as they stood, were of a very simple design, their shallowness partly resulting from the method used for their drainage. Unlike a series of dry docks that had been recently built at Portsmouth and Plymouth, those at Chatham had no attached pumping system. Instead, all four of Chatham’s dry docks relied upon gravity drainage, with water receding from these docks during the normal fall of tide. To provide the necessary additional depth, these docks would not only have to be rebuilt (preferably in stone) but the increased depth would have taken them to a point that was beneath the river Medway’s low tide level. As a result, a sophisticated pumping system would have to be introduced in order to remove large amounts of accumulated water. Rennie, aware of all this as he was, made a proposition that looked for a series of gradual improvements, rather than a dramatic and immediate wholesale rebuilding of the dry docks in the yard:
[As to] the shallowness of the dry docks, the plan I propose will not alter them; but as the docks are generally in a bad state, they must ere undergo a thorough repair, and when this is done, it will be the proper time to lay the floor of them sufficiently deep to take the largest ships to which their respective lengths are adapted; and such additional docks may be made as the demands of the public service may require, which perhaps may be to double the number of the existing docks. 1
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