Taking a week fixing what broke in a weekend

We had an eventful weekend in the Stour and the broken list was extensive.

  • Initially the large domestic alternator had broken down and I had disconnected this to try and prevent any further damage.
  • The davits had stopped working and this seemed to be electrical in nature too.
  • We still had a problem with water flow to the engine
  • We had a sheered bolt in the impeller

To this list I added a couple of long outstanding jobs:

  • Replace the hydraulic rams for the swim platform and get this working again
  • Fix the mount for the navigation on the rib and make sure it now charges

Firstly the cooling problem.  We knew that this was related to the through hull and so the first technique we tried was to attach the filling end of the rib’s foot pump to the pipe from the through hull.  This would create air pressure that should shoot out whatever was in it like a torpedo.  Or not.  Lots of pressure and difficult (read almost impossible) to increase the pressure further with the foot pump.  So that didn’t work but we know there is something blocking it.  The next theory was to insert the dockside hose down the pipe and blast it out with water.  I do not like the idea of filling up the boat with a hose (water tanks excepted) but I wont be blasting for long.  With Maria holding the hose in place and a cloth over it to avoid any “blow-back”, we test slowly. I imagine Maria wouldn’t be too pleased if she and the engine room wee soaked by an icy blast of water.  One second burst, five second burst, five minute burst while I discuss with Peter, our neighbour, the problem I am trying to solve.  Oh sorry dear, forgot about the hose. Fortunately no drama or screams from the engine room.  Put everything back together and a quick check of the engine – we have full flow! 🙂  Subsequently, I heard of another technique that I also think would work which was to use a plunger from outside the boat, but Maria wasn’t keen for me to go swimming in the locked Marina water.

For the swim platform and impeller bolt, I will need to go to a chandlery to get spares (hydraulic fluid and bolts).  I go to Fox’s chandlery locally but they don’t have the right bolts and they are asking detailed questions about the rams and the pump before agreeing which hydraulic fluid I need.  I phone the UK distributor for the Bennetts rams who explains that any automatic transmission fluid will do so that saved me some money since it doesn’t have to have marine in the labelling.  On my return to the Ipswich marina, I see Lindsay from Seapower and explain my difficulty obtaining the right bolts for the impeller plate and he has a couple of spares “in the van”.  So I am sorted!

The sheered bolt is remarkably loose and I am able to spin this round with my nail to retrieve it.  Spin may be exaggerating a little, I can move it without drawing blood. I had tried to use a tool to help but the lack of visibility meant it was easier to feel your way with your nail. I replace all of the bolts with longer bolts having checked that they will fit correctly and that is another job ticked off.

Onto the hydraulics replacement, carefully lower the tank to a level where it wont try and fill the system when I take the old ones off.  Place a container under the rams to catch any fluid that leaks out.  The swapping over is easy and it is now time to try and bleed the system.  Back in the lazzarette, to find the reservoir lying nicely on its side and the hydraulic fluid coming out of a rip in the lid, thanks, and after I had tried to be so careful.  Refill the system with the new fluid. It is quite a small system and there appear to be no bleed valves so it’s a case of opening and closing the bypass while activating the pump.  It is all good and I am finishing the bleed when the platform starts to come up. And I am holding the down switch!  Our friend Mat, marine engineer on Song of the Whale, is coming for dinner, maybe I can pick his brains.  Mat and I take a look at this and the Davits.  It seems that whichever button you push it comes up, and if you swap the electrical connections over you can get it to open, no matter which button you push.  So a problem with the switching that needs to be solved when Ollie from Seapower comes back to the boat. To be fair this switch was wired when the platform didn’t work so easy not to get it right.

The davits are interesting and we spend time looking in the control box.  There is what appears to be a slow burn fuse that is located on the edge of the box and pokes through the box at the top.  This has the same pins as a car fuse and we swap this for one to test it.  The davits start to work.  Taking apart the black slow burn fuse reveals water is inside it (from all of the rain the previous weekend!).  We clean this all out and replace it.  The davits are now working perfectly. But who puts this outside of the box when there is likely to be water, we cover the top of this in tape to hopefully overcome this problem in the future.

As our final job for the moment, we take a look at the alternator.  alternatorWe had found that a bolt had sheered which held the casing of the alternator together.  This had come out and had significantly damaged the vanes of the fan, which also explained the noise Maria heard.  So we get the alternator off and I will take it to the local specialist to see what can be done.  On investigation the alternator is fried and badly damaged which makes it uneconomical to repair.  A replacement is available and should be with us within 24 hours.

It is interesting though that since removing the alternator, some electrical devices are no longer working, and the engine circuit will not power up.  I had taped off all of the wires for the alternator. We put the negative from the alternator onto an engine bolt and everything starts working again but we are both at a loss to explain why the engine earth is going through the domestic alternator.

The next day I have refitted the alternator and tightened everything up. Just as discretion is the better part of valour, cowardice is the better part of discretion so I want Mat to check my work before I restart the engine.  We are all fine and so decide to test the new setup.  The engine starts well, we have water flow and the charge is also looking good although the batteries are pretty full at this stage anyway. We are working our way through the list well.

The new mount for the rib navigation has arrived which is a straight swap with a little help from Maria to hold the screw driver on one side while I tighten the bolt.  Definitely not a one man job unless you are stretch Armstrong.  When perusing the instructions I discover the original problem.  Apparently the mount comes with an all weather cover for the electrical connections.  That will stop water pooling around them causing corrosion and the mount to fail! RTFM.

Another job ticked off and I’m feeling good – maybe just lift those davits….nothing!  Maybe they are on the engine circuit so I need to power that up.  Nothing! In fact no light on the engine circuit at all. So this appears to be the same problem that I had when I took off the old alternator….but the new alternator is fitted and the negative is connected again.  I speak to Mat quickly to get an opinion and we agree that I need to look into why the domestic and engine circuits are connected.  I have already checked the “parallel” switch, for anyone starting if the engine battery is dead, and this is set correctly.  So it is under the bed in the aft cabin to check out the wiring there.  negative meltdownThere is a problem, it appears the bolt holding the engine earth to the negative bar is loose (right hand side of picture).  This has caused arcing between the cabling and therefore heat build up with some scorching.  In fact one of the negatives has corroded and melted the insulation so much that it has melted through another wires insulation and these are welded together.  That will be what caused our problems and it could even have been what damaged our alternator.  In some respects we were probably lucky the alternator went rather than continuing to build the heat up and potentially start a fire under the bed.  This doesn’t explain why the old alternator used to provide the earth to the engine and the new alternator doesn’t, despite being identical.  The current view is that this was as a result of the damage to the alternator which provided that earthing thereby by-passing the corroded engine earth.  But I will update with more information as it is available.

In the interim we have put a bypass in place for the earth but the engine and alternators will not be used until the above is fixed.

All in all, not a bad week, since we fixed a lot of issues and uncovered a pretty major new one. At least we found them in Ipswich rather than in the middle of nowhere and know how to deal with them in the future – all part of the education!

 

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