log impellor didn't sink boat

C

ColinR

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www.victoriashadow.co.uk
but it felt like a distinct possibility. Yesterday I was taking the paddle wheel out and putting the blanking plug in (Raymarine ST 60). it has a nifty little pair of flaps which are supposed to spring up inside the tube and stop the fountain of water pouring in. Pushed the plug in but it jammed and wouldn't go in. so I pulled it out and shoved a sponge in to stop the cascade of water coming in. Then I had another go. No luck. So I poked around with my finger, meanwhile an absolute flood of water pouring in. This went on for some time, the automatic bilge pump activated and the water was getting up to the cabin sole. Eventually I managed to dislodge the obstruction which was one of those flaps which had come adrift, hoiked it out and shoved the plug in. I think I will remove the lot when next dried out, having a contraption like that inside the tube seems asking for trouble. All this happened on my mooring, I'm glad I wasn't at sea.

Colin
 
Hi Colin.
Don't know what your "Raymarine blanking plug" entails, but I use the wooden tapered blocks, available cheap from most chandlers, one of which is left conveniently to hand, close to the log thru-hull. When rammed into the thru-hull it seals the ope perfectly. Only problem then is to get that little wheel turning again!:)
 
ColinR said:
but it felt like a distinct possibility. Yesterday I was taking the paddle wheel out and putting the blanking plug in (Raymarine ST 60). it has a nifty little pair of flaps which are supposed to spring up inside the tube and stop the fountain of water pouring in. Pushed the plug in but it jammed and wouldn't go in. so I pulled it out and shoved a sponge in to stop the cascade of water coming in. Then I had another go. No luck. So I poked around with my finger, meanwhile an absolute flood of water pouring in. This went on for some time, the automatic bilge pump activated and the water was getting up to the cabin sole. Eventually I managed to dislodge the obstruction which was one of those flaps which had come adrift, hoiked it out and shoved the plug in. I think I will remove the lot when next dried out, having a contraption like that inside the tube seems asking for trouble. All this happened on my mooring, I'm glad I wasn't at sea.

Colin
Click to expand...

I assume you was getting lifted out, and thus why you removed the paddle wheel??? allthough still dont understand why you did not do that ashore??? I have an old paddle wheel system, no blanking bung, just a screw on blanking cap, easy peasey.
 
Hi Tel1,

It is normal to remove the impellor paddle wheel before lift out to avoid it being damaged by the slings of the hoist or crane. There's even a risk of the impellor housing being damaged too (which could be a big prob if it happens at lift in).
 
I'm assuming you have something along the lines of Raymarine B744V triducer made by Airmar.

xducerE66020B744V200153.jpg


For those who are unfamiliar this transducer has a removable plug which has the paddle wheel on the end. This can be swapped for a identical blank plug (presumably to prevent fouling etc) when the boat is not being used. (Very handy for those of us in the mud). There are two flappy valve things in the transducer tube one of which has obviously failed in this instance.

Chris
 
This is certainly a bit alarming. I also have an ST60 and have been known to retract the log for cleaning while on passage. I think I had better check my stock of wooden plugs and make sure there's one to fit.
 
tel1 said:
I assume you was getting lifted out, and thus why you removed the paddle wheel??? allthough still dont understand why you did not do that ashore??? I have an old paddle wheel system, no blanking bung, just a screw on blanking cap, easy peasey.
Click to expand...

I take the paddle wheel out and put in the plug when the boat is not in use. If its left in all season it gets fouled.

C
 
Leaving boat

I am going to leave my boat in an marina that I have not used before.

I have no reason to believe that anything will fail on the boat .However do you think it wise to plug all through fittings with wooden tapered plugs ,as a just in case procedure, I am thinking that they may expand with time being immersed
 
rtboss1 said:
I am going to leave my boat in an marina that I have not used before.

I have no reason to believe that anything will fail on the boat .However do you think it wise to plug all through fittings with wooden tapered plugs ,as a just in case procedure, I am thinking that they may expand with time being immersed
Click to expand...

Yes they would swell, and if you push one into a plastic transducer tube and leave it there, it is most likely to split the tube eventually.......:eek:

They're designed as a 'panic mode' leak stopper where a skin fitting or seacock has failed. Each of mine has one of the appropriate size tied to it on a lanyard .
 
rudolph_hart said:
Yes they would swell, and if you push one into a plastic transducer tube and leave it there, it is most likely to split the tube eventually.......:eek:

They're designed as a 'panic mode' leak stopper where a skin fitting or seacock has failed. Each of mine has one of the appropriate size tied to it on a lanyard .
Click to expand...

You can also damage the tube by over enthusiastic ramming of the cone into the aperture. The sight of a fountain of water coming into the boat is guaranteed to provoke at least a small frisson of fear in any sailor, which can lead to a panic manoeuvre to plug the hole. I have a wooden plug on a lanyard by the transducer, but use the screw cap cover if I need to take out the unit while afloat for a routine paddlewheel clearing operation.
 
ColinR said:
I take the paddle wheel out and put in the plug when the boat is not in use. If its left in all season it gets fouled.

C
Click to expand...

Oh, fair one, allthough i am on the crouch and i allways leave mine in. never fouled once in this manky river!
 
ColinR said:
but it felt like a distinct possibility. Yesterday I was taking the paddle wheel out and putting the blanking plug in (Raymarine ST 60). it has a nifty little pair of flaps which are supposed to spring up inside the tube and stop the fountain of water pouring in. Pushed the plug in but it jammed and wouldn't go in. so I pulled it out and shoved a sponge in to stop the cascade of water coming in. Then I had another go. No luck. So I poked around with my finger, meanwhile an absolute flood of water pouring in. This went on for some time, the automatic bilge pump activated and the water was getting up to the cabin sole. Eventually I managed to dislodge the obstruction which was one of those flaps which had come adrift, hoiked it out and shoved the plug in. I think I will remove the lot when next dried out, having a contraption like that inside the tube seems asking for trouble. All this happened on my mooring, I'm glad I wasn't at sea.

Colin
Click to expand...

I have a nasa log, none of this flap malarkey, though I have often read with envy from those that do have flaps and other contraptions to aid the removal of the log. What I don't understand in your story above, could you not use the palm of your hand to stop the water? This is what I do if I am just whipping it out for a second and clearing a bit of weed or scraping a barnacle off the blade, you can do this with one hand or better still let your crew get the barnacle smell under her finger nails!

For longer removal it really is not so difficult to fit the blanking cap, in reality little water is really allowed into the boat.. I guess it depends where your log is located. Your tale has made me realise that there is no perfect solution, so thank you for that! :confused:
 
We took our paddle wheel out and put the plug in about five years ago because we got fed up cleaning it. If you sail your boat a lot you instinctively know your speed over ground and the log isn't really necessary. Others may disagree.
 
We're on the River Orwell and if we leave our B&G paddle wheel in for more than about 3 weeks it fouls and stops turning - so I take it out every time we leave the boat and put it back in when we go sailing, using the B&G blanking plug. It's a bit of a pain but as relatively inexperienced sailors we value knowing our speed through the water (as opposed to the SOG from the chart plotter) so we can understand the effect (or not!) of our sail trimming
 
It's not just the Raymarine. I know of two boats that had NASA logs that sheered off at the hull interface, below the thread . In my case in mid-solent so I had to plug it with a bung (thankyou former owner) and make it to shore. In the other it fell off ashore. Both were embrittled and I read in an earlier thread that NASA advise to use a mastic sealant, not amn oil sealant like Sikaflex, which makes it brittle.

So how many others are out there with fittings awaiting collapse like this?

Needless to say neither boat replaced the log fitting, I'd rather do without than go through that again.
 
Good Riddance.

My log impellor is history - the VDO skin fitting has the replacement blank, a solid rod that effectively seals the tube, permanently in place. Instead, my Garmin plotter is more precise than any paddle wheel ever was.

Yes, I know that for some SOG is not enough and they like to know what their speed is through that moving carpet of water they are sitting on - but that's not me, I sail in the Med. where tidal stream is not so frequent.

I had years of having to remove the transducer every time I left the boat because I knew that those little white calcium worm houses would be jamming the impellor next time I returned and went sailing. Then it was on one side of the keel so that I got very different readings on different tacks that had nothing to do with different speeds.

I'm glad its gone and bless the day that GPS started giving me an accurate speed down to one decimal place, something that my primitive technology, moving parts knotmeter never accurately managed.
 
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we have an st60 and I always remove the paddlewheel and replace it with the blank plug at the end of the weekend - be interested to know if others don't and have no problems with it fouling up as if so might try leaving ours in - it is not antifouled at all .
 
PaulR said:
we have an st60 and I always remove the paddlewheel and replace it with the blank plug at the end of the weekend - be interested to know if others don't and have no problems with it fouling up as if so might try leaving ours in - it is not antifouled at all .
Click to expand...
We also remover our ST60 log when we leave the boat on her mooring - and I regret to say that when I forget and leave it in place, its always clagged up with weeds and growth and minor shellfish.
 
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