Dec 192013
Weedcutter Nov 2011

The weedcutter on arrival at Ash Lock in November 2011

Members of the John Pinkerton maintenance team have been for a long time working on the refurbishment of the BCA’s weedcutting machine. For many years it languished on the Canal in a state of disrepair, when weed has been accumulating in the Canal and the BCA have had to hire in contractors to clear the worst of it. The Society decided it was a resource the Canal could ill-afford to be without, and John Wharf, the JP maintenance manager, was persuaded to lead a team to restore it.

Weedcutter arrival in 2000

The weedcutter soon after acquisition in 2000, with (from left) then canal manager Leigh Thornton, Tony Harmsworth, Brian Boner and ranger Jon Green

The machine, called (for some reason) Millie 2, was acquired in 2000 for the not inconsiderable sum of £60,000 (for more, read the BCN article announcing its arrival). It was purpose-built for the Canal by marine engineer Brian Boner (left). It gave service for a few years, but then there was a mechanical failure, and because of a combination of lack of funds and man-power, the BCA was unable to undertake the necessary repairs. And so it was left to the elements and it eventually filled with rainwater, which damaged the electrical circuitry and didn’t do the rest of it much good. It had to be rescued from the Canal to prevent it sinking altogether, and it thereafter spent a few years on blocks behind the Canal Centre. A hole had to be drilled through the hull to allow rainwater to drain away. So it was in a bit of a sorry state when the Society moved it to Ash Lock in late 2011 to undertake the repair work (above right). Unfortunately, there was also no documentation at all to go with it either.

The scaffold canopy

Restoration in progress under the scaffold canopy

So the regular Monday meetings started at Ash Lock, which were to occur weekly for the next 2 years. One of the first jobs was to construct a canopy around the weedcutter from scaffold poles and corrugated sheeting so that work could take place somewhat shielded from the elements (left). It wasn’t very elegant, but did the job.


The engine compartment

The rake attachment

The rake attachment

The weedcutter is a strange looking thing. It is paddle-driven, because weed would foul a prop, and powered by a hydraulic motor driven by a 1500cc Kubota engine (right). The arms at the front support either a rake or an oscillating cutter blade (looking much like a large curved hedge trimmer). Joy-sticks connected electrically to the hydraulics allow the driver to control from the cabin the paddles, the main arm articulation, and (depending on which is fitted) the cutter blade motor or the rake orientation. In operation, the cutter blade is lowered vertically into the water so its curved shape roughly fits the profile of the Canal bed, and when switched on, cuts weed growing on the bed of the Canal. Once weed has been cut, the cutter blade is replaced with the rake which then is used to collect and deposit weed on the bank. In practice, the rake (right) gets more use, since it is particularly useful to remove surface-growing weed, such as the pervasive hydrocotyl (in fact, the weedcutter’s first job will be to remove hydrocotyl weed in Woking).

Launch Day

Launch Day

The fact that the weedcutter is powered hydraulically was the first of the team’s challenges, since none of the team was a hydraulics expert, and getting to grips with its operation prevented much progress initially. Also as there was no wiring diagram, many hours had to be spent trying to untangle the electrical system. But, with help, and many phone calls to various suppliers, progress was eventually and steadily made, although there were many obstacles hit along the way. The cause of the original failure was identified and fixed (an unsuitable fuel valve control solenoid), and many improvements were made, not least the refabrication of the engine cover plates to prevent rainwater ingress, which took several weeks. A new cutter blade had to be sourced (as the original had rusted solid), and a new hydraulic pump had to be installed. To prevent the hull filling with rainwater, new bilge pumps were also fitted, powered by a separate battery circuit with charging provided by a small solar panel.

Maiden voyage

Maiden voyage with cutter blade fitted

After 2 years of work, the weedcutter was finally launched on 10th November (above left),

video icon 20x20 Watch a video of the weedcutter launch

and made its maiden voyage on 21st November (right). Even then, the story was not over. There had already been a hydraulic pipe blow-out which had taken a couple of weeks to fix (because getting a paddle wheel off was a real struggle). Unfortunately, another pipe blew during the maiden voyage, filling the engine compartment with hydraulic oil, and John and Pete Phillips had to spend a long day repairing this.

It powers along forwards at a walking pace, creating not a little wash as it goes (right). It also turns on a sixpence. However, it doesn’t do reverse – at all. Unfortunately, the bodywork design is such that water has nowhere to go when the paddles rotate backwards, and the net effect is no movement, or movement sideways. We will have to see if this proves to be a real problem in operation.

Weedcutter project leader John Wharf

Weedcutter project leader John Wharf

The machine has still to undergo a PUWER (Provision and Use of Work Equipment Regulations, 1998)  test, which basically establishes it is safe in operation, before it can be used in anger. It also still has to prove itself to be reliable and rugged in normal use, which will become evident pretty quickly.

The return of the weedcutter to service has taken considerably longer than expected (around 190 man-days were clocked up on this project) and cost rather more than was hoped (around £5K, of which about £4K was contributed by the Society, the remainder by the BCA). However we hope it will again make a significant contribution towards the maintenance of the Canal.

Many thanks go to all those who worked on the project: John Wharf, Pete Phillips, John Abbott, George Rhoades, Bob Harris, Ian Carmichael, Duncan Paine and Dave Catherall. Also to ranger Andy Foster who helped with welding, and Kevin Redway who organised the launch. I showed up occasionally with biscuits.

Martin Leech