Civil Engineering heritage: Scotland - Highlands and Islands
Date 2007
Event ID 929415
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/929415
North Pier
Before the construction of the North Pier, the entrance to the harbour was seriously affected by the southward drift of coastal sand and the deposition of material washed down the Dee. To alleviate this problem, the North Pier, designed by Smeaton, was built from 1774–80 under the
superintendence of resident engineer John Gwyn by direct labour. It was about 1200 ft long, 16–30 ft high, with a breadth of 20–36 ft at the base and 12–24 ft at the top, the dimensions increasing seawards. The work, which
cost £16 000, was successful. The construction is vintage Smeaton with a trapezoidal cross-section, external walls of horizontally coursed small squared blocks and internal stone hearting.
Besides shielding the harbour mouth the pier, by constricting the channel of the Dee, created a scour which prevented the formation of a sandbar. In 1789, in order to further narrow the entrance channel and to mitigate the effects of any easterly swell penetrating the harbour, a catch pier, Abercrombie’s Jetty, was built at the landward end of Smeaton’s pier.
Unfortunately the increased flow in the river from these measures undermined the foundations of the pier. In 1797 Rennie proposed remedial work to secure the foundations but no action was taken.
In 1802 Telford was consulted about improvements to the harbour, and from 1811 work began under his direction. This included, under the able superintendence of the Board’s resident engineer John Gibb, an extension by 1816 of the North Pier seawards by a further 900 ft in substantial construction at a cost of £66 000. The granite blocks were laid diagonally to give them greater resistance to the force of waves.
From 1869–79 the harbour entrance was greatly extended under the supervision of the Harbour Board’s resident engineer, W. D. Cay. First, a new South Breakwater was built and then, from 1874–77, the North Pier was lengthened by a further 500 ft with an ingenious application of mass concrete taking the total length to nearly a half mile, the preliminary design for which using concrete bags is shown in the section. These measures extended the harbour mouth into deeper water and increased its width.
R Paxton and J Shipway, 2007.
Reproduced from 'Civil Engineering heritage: Scotland - Highlands and Islands' with kind permission from Thomas Telford Publishers.
