Some technical challenges

This was arguably our most memorable trip to the Netherlands, in terms of fine weather and enjoyable visits.  But we were beset with quite a number of technical problems that needed resolving.

Fresh Water pump

The domestic fresh water pump failed just after we reached Middelburg, and details are given in the blog.  In fact, the pump was mechanically ok, but the microswitch driven by the pressure sensor had failed open-circuit.  For an hour or two we experimented with a simple push-button switch connected in oplace of the microswitch, and positioned near the galley, to give manual control over the pump, but reached the conclusion that this was not sustainable for the two or three weeks needed to see us home, so we looked for a better solution - whch turned out to be a replacement pump.

Joker Valve

The joker valve is no joke.  Some say its real name is ‘choker valve’ - but even that gives no hint of the ennuie (to put it mildly) that accompanies its replacement.  

It is a rubber non-return valve that lies in the path of the waste material being pumped out of the bowl.  If it is working correctly, it prevents water returning back through the base of the pump and into the bowl.  In normal use, these wear out after a year or two, and they can also be affected by lime deposits.  In either case they become unable to resist this reverse seepage.  There is no alternative but to dismantle the plumbing at this point to replace a faulty one, and it is a gloomy job, almost impossible to prevent some dark water spilling into places where it is not wanted - in our case, into the shower pan.  Rubber gloves are the order of the day, and copious buckets of water to sluice away the mess.  But there is a strange sense of satisfaction when the job is done and the plumbing works again!

Later in the trip, we had further problems when a crew member inadvertently pumped away with gusto while the seacocks were still closed.  This is apt to turn the joker valve inside-out, again preventing it from doing its job.  The remedy, once the pipework has been dismantled, is straight-forward - but no joke!

Engine fuel problems

During our visit to the Netherlands, we became aware that the engine was not performing as reliably as we expected.  It was more reluctant to start unless set to full throttle, and periodically, would stall if running at less than about 2000 rpm.  At 2000 rpm or higher, opening the throttle promptly would keep the engine going.  In every case, the engine would restart straight away after stopping, though needing a few seconds of spinning of the starter motor.  This is unusual for our engine - in normal conditions it has started immediately on first push of the button.

The primary filter had been changed in October 2017.  The secondary filter, a spin-on type, was changed at the same time.  We had been using an anti-bug preparation at every fill of the tank.  

I suspected an air leak into the fuel system.  Since diesels of this kind suck the fuel from the tank, there’s little or nothing to be seen if there is a minor air leak - no drips of diesel would necessarily be seen.

Interestingly, the engine did not seem to require bleeding from the fuel system to let it restart, but it is possible this was happening as the starter churned it.

At Vlissingen before the homeward passage, I tightened all the visible unions and hose clips.  I used an inflatable dinghy pump to slightly pressurise the tank via the ventilator to help try to identify leaks.  This showed there was a slight air leak at the take-off point on the tank for the diesel heater - but air needs to get into the tank from above to allow free flow into the filter, lift pump, etc.

Experience on the passage suggested this had improved things.  The engine ran reliably at 2000 rpm for some hours when our course took us into a head wind, which was by then moderating.  It still had a tendency to stall occasionally at lower revs, say 1200 or less, but it seemed that tightening the unions etc had significantly improved things.

Now we are back at base I plan to replace the flexible hose from the tank to the Delphi primary filter.  The worm drive clips are tight, but may be distorting the hose.  The two armoured flexible hoses at the engine end were both replaced in July 2017, so should still be OK - but their unions need checking for tightness.

Navigation light

The navigation light at the bow (red-green) failed during the passage - at night of course!  It ran satisfactorily for a few minutes, then extinguished.  Power cycling did not help.  Conditions were improving, but still too rough (and dark) to try and fix this on the foredeck, and far too much risk of losing a key component overboard.

We therefore ran under tricolour in place of navigation lights (we did have sails hoisted), and remained clear of designated big-ship channels except where crossing them.

On arrival at Shotley Marina, and in daylight, it was easily possibly to determine that the vertical filament of the 25W lamp had fractured close to the lower connection.  A tap on the bulb was all that was needed to set it into mechanical oscillation.  By tapping gently, it was sometimes possible to get the ends to touch well enough to light the filament, which then partially self-welded and stayed illuminated, though it was fragile.  And we could not really have done this at sea! Replacing the bulb was the only answer. 

One may wonder why we had not replaced it with an LED-based device before now, as we have done with the tricolour and the anchor light.  Those updates we made on the strength of the argument that they are in use while we are under sail, so economising on battery consumption is prudent.  Also they are at the mast head, so hard to access if a filament blows.  But LED replacements are costly, about £60.  Also, the R/G lamp is only in use when motoring, at which time the battery is being charged so the economy argument is not so strong.  And as the lamp is at deck-level it should in principle have been possible to change it under way.