Swim depth and anode's

[TGweeder]

Hi everyone.

 

Thanks everyone for your input on my last post very very helpful and appreciated.

 

I have a few more .. and no doubt will have more after these.

 

So fist question what depth should the swim be in the water ? 

I think I read somewhere an inch but want to check. See image for fun as the boat has been sat with a empty water tank for some time.

 

Second question. would the anode's not be better where I have marked in green instead of where it's currently located ?

Seems silly as I am aware that they have a working area and having them so far back is kinda halfing there ability to protect.

 

I have more things to ask with photos but just getting my head around stuff abit at a time.

 

 

 

Options please ? thank you all again kind regards Tim 

[pete.i]

From a bit of rushed research that I did a couple of years ago anodes have an effective distance either side of roughly a meter (or just over a yard when we come out of the EU.) Their effectiveness is also reduced or eliminated if they have to work round the bend of the hull. Ideally they should be along the straight side of the hull as well but that leaves them vulnerable to being caught up in locks and things.

 

I don't know about your swim depth. Mine is an inch or so below the red band and that seems okay to me.

[BEngo]

Technical point: The swim is the bits which form the pointed part running back to the prop.  The bit you are talking about is the counter plate.

The swim should be fully immersed and the counter plate should be on the water, or slightly immersed.  The test is does it lift too much when reversing so that the propellor draws in air ( Ventilation, often inaccurately called cavitation), leading to the 'gurgle,gurgle, thump' method of stopping. If it too deep you will hit the bottom more often, and use more fuel, and maybe make more wash than you want.

 

Many boats can get away with the counter plate clear of the water when stationary, as it pulls down when going ahead, but mooring stern to the wind on a draughty night is likely to produce a noisy night as the waves slap up against the counter.

 

Suck it and see is the best approach, adjusting ballast to give the minimum immersion that works. Remember the levels in your diesel water and poo tanks will also have some effect.

 

 The anode is right at the back to protect the bronze propellor.  It will probably still do that if you move it forward as suggested.

N

[TGweeder]

31 minutes ago, BEngo said:

Technical point: The swim is the bits which form the pointed part running back to the prop.  The bit you are talking about is the counter plate.

The swim should be fully immersed and the counter plate should be on the water, or slightly immersed.  The test is does it lift too much when reversing so that the propellor draws in air ( Ventilation, often inaccurately called cavitation), leading to the 'gurgle,gurgle, thump' method of stopping. If it too deep you will hit the bottom more often, and use more fuel, and maybe make more wash than you want.

 

Many boats can get away with the counter plate clear of the water when stationary, as it pulls down when going ahead, but mooring stern to the wind on a draughty night is likely to produce a noisy night as the waves slap up against the counter.

 

Suck it and see is the best approach, adjusting ballast to give the minimum immersion that works. Remember the levels in your diesel water and poo tanks will also have some effect.

 

 The anode is right at the back to protect the bronze propellor.  It will probably still do that if you move it forward as suggested.

N

Thank you for the correction with reference to the counter plate. 

I am new to it all.

We moved the boat from Cain hill to Hilperton on Sunday with a experienced hand he didn't like me calling the windless a winder or handle.

I soon got told ????.

 

thank you for your feedback ?

48 minutes ago, pete.i said:

From a bit of rushed research that I did a couple of years ago anodes have an effective distance either side of roughly a meter (or just over a yard when we come out of the EU.) Their effectiveness is also reduced or eliminated if they have to work round the bend of the hull. Ideally they should be along the straight side of the hull as well but that leaves them vulnerable to being caught up in locks and things.

 

I don't know about your swim depth. Mine is an inch or so below the red band and that seems okay to me.

Thanks Pete ?

[ditchcrawler]

1 hour ago, pete.i said:

 

 

I don't know about your swim depth. Mine is an inch or so below the red band and that seems okay to me.

I can't see a red band, maybe the anode is to protect the stern gear where the dissimilar metals are and stop the zinc leaching out of the prop

[GUMPY]

With all tanks full my counter sits on the water, when I got the boat it was a couple or three  inches below the water untill I pumped a few hundred litres of water out of the bilges

I only discovered the water as the boat had been  transported by road and the floor was wet where there was no plumbing, I had to cut an inspection hatch to get into the bilges.

Something to check,  both the surveyor and I missed it during the survey.

Edited April 3, 2019 by Loddon