Civil Engineering heritage: Scotland - Lowlands and Borders
Date 2007
Event ID 578511
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/578511
The aqueduct between the reservoir measuring-house and Alnwickhill filters in Edinburgh is approximately 35
miles long, including nine miles of tunnel and 12 miles of cut-and-cover work, the remainder being bridges or castiron pipes in the open. There are altogether 21 lengths of tunnel, the shortest being 399 ft and the longest some 1.33 miles. The longitudinal section shows the positions of some of the tunnels and other works in the first five miles. The tunnels are either concrete, or of four-ring brickwork in heavy ground.
The aqueduct is laid on a gradient, mainly of 1 in 4000, and was made sufficiently large when constructed in
1901–05 to carry not only the water from Talla, but also from the adjoining watershed of Fruid–Menzion, developed in the 1950s and 1960s. The least dimension inside the aqueduct tunnels is 6 ft wide by 7 ft 6 in. high.
Some of the valleys on the route are crossed by inverted siphons for which cast-iron pipes, varying in diameter
from 27 in. to 36 in., were used. Only one line of pipes was required for the original supply from Talla, but
provision was made for duplication of the pipes in later years should this be required. The passage of time and
the development of the Fruid–Menzion scheme has shown the far-sightedness of this decision.
R Paxton and J Shipway 2007
Reproduced from 'Civil Engineering heritage: Scotland - Lowlands and Borders' with kind permission from Thomas Telford Publishers.
