Scottish Water is about to start a £12.5M refurbishment of the Katrine Aqueducts and has released a series of images showing the construction of the second structure in the late 19th century after they were found during an office move.
The recently-discovered photos provide a fascinating insight into construction of the second aqueduct which was completed in 1901 to supplement the original structure opened by Queen Victoria in October 1859.
The glass photograph slides, which have not been seen before by Scottish Water experts with decades of experience of working on the local water network, were recovered from a skip along with some books and drawings during an office relocation.
They include remarkable images of pioneers boring through rocky mountainsides with drills during the construction of the 38km-long second aqueduct which began in 1885 and was completed in 1901 to increase capacity and meet demand as the population of Glasgow burgeoned to more than 1M.
The aqueduct scheme, comprising the two aqueducts, takes water by gravity from Loch Katrine to the Milngavie and Balmore water treatment works before it is distributed to customers across a large swathe of Glasgow and west central Scotland.
The first aqueduct includes tunnels through mountainous terrain in the shadow of Ben Lomond and bridges over the valleys. The second aqueduct was constructed to accommodate the rapid expansion of Glasgow in the late 19th century. The two are as much as 10km apart on some stretches.
Scottish Water leakage field technician Steven Walker, who found the images with a colleague, said: “The pictures give a fascinating insight into the construction of the second aqueduct and some of the methods used which might appear archaic, and even dangerous, to us now but were the ‘new technology’ of the day at that time.
£It’s remarkable to think that the first aqueduct was so successful, and Glasgow grew so quickly, that within 30 years they had to repeat the process and build a second aqueduct to double the output. These pictures are an important part of that story and I’m delighted we were able to save them.”
In the construction of the second aqueduct, the engineers were able to take a more direct line because they had available improved boring and blasting equipment.
When the second aqueduct was constructed, the pneumatic drill and gelignite were available and progress was much more rapid than during the first aqueduct, increasing from 32m to 40m per month.
The possession of more efficient plant enabled the engineers, by tunnelling, to take a straighter line through the hills in the construction of the second aqueduct. This meant only eight bridges were required on the second aqueduct compared with 22 on the first.
The entire Katrine Aqueduct scheme cost £3.2m to build which would be about £320m in today’s prices.
The current refurbishment project on the Katrine Aqueduct is expected to be completed in 2020 and is being carried out for Scottish Water by contractors George Leslie.
It includes structural repairs of three stretches of tunnel and a bridge, improvements to the lining of tunnels and repairs and refurbishments of control valves. The entire length of the second aqueduct and the entire length of the first will be closed at different times during the project to enable the work to progress.