Bow Thruster Tunnel Leak - Repairs Macclesfield Canal Area

[Troyg]

Happy New Year to all.

 

Looking for recommendations. I am based at Lymeview on the Macclesfield canal and over the New Year period my bow thruster tunnel (Vetus 55kgf 150mm) developed a leak. I have done an emergency repairs with plumbers putty for now. It is a small hole allowing a small squirt of water coming in about the thickness of a tooth pick. 

 

Does anyone have experience with this issue? Will the tunnel tube need complete replacement or can you ‘re-sleeve’ the tube? 
 

Can people recommend anyone? I assume the boat will need to come out of the water for this type of welding work? My options are Kerridge slipway (closest but subject to availability!) and I would need to find a suitable welder. I was thinking of Hesford Marine on the Bridgewater at Lymm (been there before for blacking) but is some distance away. Another option is I have come across Stoke on Trent boat building on the Trent and Mersey. They would involve a lot less locks to get to them! Can anyone recommend them? Or anyone else in the Stoke area?

I spend long periods working away so I need to get this work done ASAP before I need to go away again.

 

Any ideas and recommendations would be very much welcomed!

 

Thanks in advance.

[Alan de Enfield]

19 minutes ago, Troyg said:

Does anyone have experience with this issue?

It is not uncommon and because it is 'hidden away' it never gets any maintenance - even from new, many boats with BTs do not have the 'tube' blacked, and they never seem to get looked at during the biennial hull blacking.

 

As the tube will have water in it, it is unlikely that yu will be able to weld it in the water, so, yes I think it will need to come out.

 

@matty40s is an expert on BT tubes, I'm sure he will be abale to advise.

 

 

[BEngo]

The tube has probably pitted and one of the pits has gone right through.  Where there is one there will be more. Once out and inspected you may be able to get it patched, but really it wants renewing.

 

Or you could just get the ends sealed up and do without a bow thruster.  It might sell for enough to partly pay for sealing the tube.

 

The cost of renewal completely will be much the same as the cost of putting a full sleeve inside, and you will have done  a proper job and eliminated any future corrosion between old tube and new sleeve. You will also maintain the gap at the tips of the thruster blades.

 

It needs to come out of the water to be fixed.

 

Have you tried the docks at Stone?

N

 

Edited January 3, 2021 by BEngo

[Jen-in-Wellies]

20 minutes ago, Alan de Enfield said:

It is not uncommon and because it is 'hidden away' it never gets any maintenance - even from new, many boats with BTs do not have the 'tube' blacked, and they never seem to get looked at during the biennial hull blacking.

In addition, it will be made from a stock steel tube, so the wall thickness will likely be thinner than the rest of the hull.

[David Mack]

If you need it sorted quickly, then use the nearest available dry dock or slipway and get a plate welded over each end of the tube. Any mobile welder will be able to do this - it does not need a boatbuilder. It's too cold for proper blacking at this time of year, but that won't matter. Then you can plan to get the boat out again at a more convenient time and location to get the tube replaced. Might as well combine that with hull reblacking too.

[eddieb]

Is the slipway at red bull not still operating,they winched us up the slipway to repair our rudder,out and back in within an hour.surely they would be able to spot weld the tube on the slipway

[ditchcrawler]

1 minute ago, eddieb said:

Is the slipway at red bull not still operating,they winched us up the slipway to repair our rudder,out and back in within an hour.surely they would be able to spot weld the tube on the slipway

At a guess its likely to need more than spot welding, if it already has pin holes then probably a lot is like paper. Middlewich Drydock is operating but I don't know if he would get a slot.

 

[Higgs]

8 minutes ago, eddieb said:

Is the slipway at red bull not still operating,they winched us up the slipway to repair our rudder,out and back in within an hour.surely they would be able to spot weld the tube on the slipway

 

I think you need the tube checking properly with ultrasound, by an engineer/surveyor that knows what they're doing. It will become an insurance issue, if your boat sinks. And it's now not that easy to hide the fact you have questions about the integrity of the tube. 

 

 

[Jen-in-Wellies]

Would it be sensible to knock a of suitably shaped wooden bung in each end? This could be done in water and hopefully prevent a sinking if further perforation occurs before it can be hauled out.

Jen

[Higgs]

8 minutes ago, Jen-in-Wellies said:

Would it be sensible to knock a of suitably shaped wooden bung in each end? This could be done in water and hopefully prevent a sinking if further perforation occurs before it can be hauled out.

Jen

 

It wouldn't be good to do that. There's no knowing what the pinhole is a sign of, it could be the tip of a weak area of tube. Whacking things in could create a serious problem, while the boat is in the water. 

 

 

Edited January 3, 2021 by Higgs

[eddieb]

I think a phone call to red bull who are boat engineers would be the way to go,apart from kerridge it’s the nearest place to get it out and checked at less than a days travel

[Higgs]

2 minutes ago, eddieb said:

I think a phone call to red bull who are boat engineers would be the way to go,apart from kerridge it’s the nearest place to get it out and checked at less than a days travel

 

Depending on what you find, consider sealing the tube up. 

 

 

[Jen-in-Wellies]

1 minute ago, Higgs said:

 

Depending on what you find, consider sealing the tube up. 

 

 

How often do you use the thruster? If rarely, then sealing it up is no great loss and has already been mentioned, selling it would help cover the cost of blanking off and removing the tube.

Jen

[frangar]

Is the tube in its own watertight compartment separate from the rest of the boat? 
 

If it is it means moving the boat and any other holes that might appear won’t sink the boat...I’d also be cautious moving the boat any distance...and wouldn’t use the thruster...is the hole roughly in line with where the bow prop would be? The aeration caused by the prop often makes the pitting worse in that area. 

[Higgs]

19 minutes ago, Jen-in-Wellies said:

How often do you use the thruster? If rarely, then sealing it up is no great loss and has already been mentioned, selling it would help cover the cost of blanking off and removing the tube.

Jen

 

I don't think sealing the tube would cause a great loss. I misunderstood that you were suggesting sealing the ends. My concerns would have related to trying to seal the pinhole with some sort of bunging device. But if it is at all practical to try to seal the ends of the tube, with the boat in the water, it would be worth considering. 

 

I'd also consider sealing the tube permanently, once out of the water. It would require a survey of sorts to determine the condition of the tube and whether it was worth keeping.

 

 

 

 

Edited January 3, 2021 by Higgs

[Tracy D'arth]

Kerridge is a proper dry dock and workshop. I have 2 bookings for March this year. They are your nearest dock.

I'm pretty sure that they could arrange a welder for you there. Phone in the evenings 01625574287  Mr Jackson.

 

If you want to drop down Cheshire Locks, Kings Lock in Middlewich have solved this problem before, Phone and ask Karren or Steve

Edited January 3, 2021 by Tracy D'arth

[Jen-in-Wellies]

6 minutes ago, Higgs said:

 

I don't think sealing the tube would cause a great loss. I misunderstood that you were suggesting sealing the ends. My concerns would have related to trying to seal the pinhole with some sort of bunging device. But if it is at all practical to try to seal the tube with the boat in the water, it would be worth considering. 

 

I'd also consider sealing the tube permanently, once out of the water. It would require a survey of sorts to determine the condition of the tube and whether it was worth keeping.

 

 

 

 

Yes, putting bungs in the ends, where hopefully the hull sides are good. I'd not want to touch the tube. Who knows what horrors are hidden there!

Another possibility would be to tie a tarpaulin around the hull at the bow, over the tube ends, so if a bad leak starts between now and a haul out it might at least be slowed down.

[IanD]

6 minutes ago, Jen-in-Wellies said:

Yes, putting bungs in the ends, where hopefully the hull sides are good. I'd not want to touch the tube. Who knows what horrors are hidden there!

Another possibility would be to tie a tarpaulin around the hull at the bow, over the tube ends, so if a bad leak starts between now and a haul out it might at least be slowed down.

A tarpaulin probably won't help, it's unlikely to be watertight enough to stop or even slow down the water leak through a small hole in the tunnel. Bungs might work but again they have to be a very good fit to stop water leaking slowly past them and then through the hole -- maybe running a fillet of silicone sealant around the edge of the bung where it meets the hull will help?

Edited January 3, 2021 by IanD

[Higgs]

 

I recently had a survey, as requested by the insurance company. There was no visible signs of rot or deterioration of the bowthruster tube. Without even an ultrasound test, the surveyor decided to make the bowthruster tube an issue. He gave me his anecdotal judgement on what could be lurking. This was enough for the insurance company to refuse to insure the boat on fully comprehensive. I agreed to exclude the bowthruster tube being covered in the insurance, to get the boat 'fully comprehensive'. If the boat sinks through bowthruster tube failure, I'm stuffed. 

 

At the next opportune moment, I will have the tube sealed. 

 

 

Edited January 3, 2021 by Higgs

[Jen-in-Wellies]

5 minutes ago, IanD said:

Bungs might work but again they have to be a very good fit to stop water leaking slowly past them and then through the hole

A taper on them and in softwood would solve that. Only needs to last till the boat can be pulled out.

[Tracy D'arth]

You could keep can of expanding foam handy just in case. Injected through a hole it will block the tube completely, like C&RT use to void fill lock walls.

[ditchcrawler]

10 minutes ago, IanD said:

A tarpaulin probably won't help, it's unlikely to be watertight enough to stop or even slow down the water leak through a small hole in the tunnel. Bungs might work but again they have to be a very good fit to stop water leaking slowly past them and then through the hole -- maybe running a fillet of silicone sealant around the edge of the bung where it meets the hull will help?

And chopping the weed grill off first to be able to get it in

[IanD]

1 minute ago, Jen-in-Wellies said:

A taper on them and in softwood would solve that. Only needs to last till the boat can be pulled out.

Absolutely, if you get them the right size and taper and circular, wood done properly works fine for bungs and barrels (and a nice barrel-built tankard my dad made many years ago).

 

But if people don't have the skill to make a well-fitting bung, some sealant will reduce the chance of it leaking...

[ditchcrawler]

2 minutes ago, Tracy D'arth said:

You could keep can of expanding foam handy just in case. Injected through a hole it will block the tube completely, like C&RT use to void fill lock walls.

This is the one I would go for

[IanD]

4 minutes ago, ditchcrawler said:

This is the one I would go for

That foam really needs something to confine it when it expands, the leak hole will be too small to inject it though and if you just squirt it into the open tunnel it'll probably expand out of the open end. Might work, or it might look like it has and still leak...

 

(I should know, I tried using it several times to fix a flat roof corner leak)

Edited January 3, 2021 by IanD