Canal Manager Fiona Shipp explains the works going on along the Canal this Winter
Our winter work programme is now underway with towpath side vegetation cutting already having taken place on Ash Embankment. The softbank works (work to repair sections of towpath bank that have eroded usually due to wear from dogs clambering in and out of the water) that didn’t get completed last winter are already underway, whilst this years’ programme is currently being procured and are due to start as soon as that process is complete. The lock gates are measured and on order for late January and the principal inspections have started at Woodham, with Locks 3 to 6 being inspected first.
There is a lot of work each autumn to prepare for each winter. Areas of work need to be surveyed and prioritised, and specifications and plans drawn up, budgets considered and then work put out to tender or quote depending on the value of the work. This process can take a while and hence sometimes we don’t know exactly when work is going to take place until contractors have been awarded the work. Some of the winter works require sections of canal to be drained, a complicated process that needs to be planned carefully. This year for example we need to install many sets of stop planks (wooden dams) to keep the houseboats between lock 1 -3 in water, and the contractors dry, while we carry out the works. This is going to require daily careful water management.
Lock Principal Inspections and Repair
It takes about a day to fully inspect each lock which has to be emptied of as much water as possible in advance and larger fish rescued and moved. It’s a 2-person job on the day to inspect, with our Canal Engineer supported by one of the Canal Rangers. Every bit of the lock is poked and prodded and if needs be measured as well. Each area is photographed for our records in a systematic way.
After the inspection all the work is then written up for each lock and an itemised list of work is issued to the contractor. We have an overall budget for each group of locks based on the average spend per lock in previous years – although of course not every lock requires the same amount of work, so each group of locks need to be assessed together and then work prioritised to make the best use of the budget available. The most common types of work are pointing to brickworks in the chambers and wing walls, rebuilding of sections of wing walls (the walls on either side of the canal just before you enter the lock) and clay packing behind the wing or chamber walls to block water leaks running through or around the back of these which is usually what leads to holes and depressions around the lock top. We also carry out any work to remove missing bricks on the quadrants (the bits your feet use for bracing when pushing open the balance beams).
Principal inspections are carried out on a rolling programme approximately every 10 years, so any works need to be made to last. Lock gate replacements are carried out on a different cycle as an average lock gate lasts about 25 years. All of the gates are inspected every year in the summer, with locks then prioritised for replacement based on the current age and inspection results the following winter.
In January, sections will be more fully drained (than they will be for the inspections) while a professional fish rescue company will come in at the same time and move all remaining fish over a period of about 4 days. Contractors will then install temporary fencing around the locks before getting started. We always try and maintain access to the towpath during the course of these works.
The canal is over 200 years old with many structures originating from this time and even those rebuilt during the renovation in the 70’s and 80’s are nearing 50 years old. The works to inspect and maintain the canal assets are vital to keep it safe and working as well as to preserve this important heritage feature, that we are lucky enough to have running through Surrey and Hampshire.
Fiona Shipp, Canal Manager, Basingstoke Canal Authority