Prevention – All Clogged Up (Boue)

Bird’s Nest Soup

Rivers and canals are delightful, leafy places, often with languid shallow waters. Even if the water is not that languid, it will contain mud, silt, twigs, leaves – all sorts of particles that can clog up your engine cooling water intake, supply pipe or filter. This is a hazard when travelling along; it becomes worse when passing through locks because there the languid soup boils up and whatever was lying peacefully at the bottom or at the surface gets properly mixed in, at a time when you will be using the engine – in forward and reverse gears – critically.

Not surprisingly, engine cooling problems – blockages – occur most often during and immediately after, locking. [Except of course, for the obvious actually running into some shallow patch of mud]. The engine cooling alarm shrills away and immediate turning-off (to prevent serious damage through overheating) is called-for, with consequent loss of power and control. The first time this happened we were mid-Seine – we turned off, looked around for a ‘refuge’ to moor to, saw two peniches bankside, drifted in their general direction as much as we could, then switched on for as short a time as possible whilst we got into position and tied-up.

Backwash, Check and Clean

Through necessity we discovered the remedy. Use a hand or foot pump, via the filter bowl inlet hole, to backwash the boue out of the pipe and the inlet. The dinghy footpump works extremely well for this purpose – we keep it conveniently to hand, with the appropriate adaptor already plugged into its hose. We also learned that checking and cleaning the filter basket at setting-off, at midday lunchbreaks, and after having arrived was a necessity. The stuff that gets pulled in and trapped there is amazing. Whilst we were moored next to a big Finnish motor cruiser, they cleaned their twin filters and inspected their (to us) giant-sized pump impeller. The pile of twigs that came out of the filters looked like a bird’s nest. There were only two vanes left on the impeller.

Lock in, Tie up, Turn off

On the Midi the situation is far worse than anywhere else we’ve been – the overheating alarm problem occurred three days running. We have adopted a preventative strategy that consists of checking, cleaning and backwashing whenever we stop, and stopping to do that when appropriate. We also turn the engine off in locks – after having set our lines, etc. This is what the VNF say you should do, but we’ve never yet seen anyone do it. Except now, us.