Ballast

[galeus]

I have a Nimbus 29C and have owned it about 7 years.
It has always had a list to s/board, something I have just accepted and I suppose thought one day I'll add some ballast.
I have the boat up for sale and a friend of mine took the boat out to show a prospective buyer and both remarked on the list.
I need to do something about it and am wondering exactly what to do.
The water and diesel tanks are central and it is a single engine/duoprop.
The 4 batteries are on the portside and the calorifier and cooker on the s/board side, it all seems about proportionate.
We both were sat on the boat the other day on the portside bench seat on the back deck and it is about level; he's a big bloke and I would guess our combined weight is about 30 stone.
Any thoughts?

 

[silverdee]

quick google will find places that sell lead ingots- nothing wrong with using a few. Obvs if you can find any heavy stuff already on boat to shift to port thats helpful / better.

 

[BruceK]

Before adding ballast see if you can find original manufacturer layout drawings and see if something has been added or moved.
Look and see if you are carrying any additional weight in storage.
Try moving heavy items about, batteries etc. if possible
Negate any influences such as black water holding tanks.

Then if you still have to add weight think about buoyancy neutral weight. Mine developed a slight list when I increased the number of house batteries and gets amplified by the fuel tanks either side which are not uniform in size to compensate for genny use etc (no balance pipe). I also have a larger calorifier and holding tank that negates moving batteries about. I used wakeboarding Sumo Sac for ballast. As it has a pump in and pump out system I can ballast the boat on the fly.

 

[jrudge]

I have a slight list ro Stbd on my S58. It is only really noticeable when you swim round the boat as the water is above the trim line on one side and close on the other

The snag is it takes a lot of weight to move it which you have just found out.

You could drain the Callorifier!

 

[BruceK]

In the OP's case he only has to move 15 stone from one side to the other.

 

[stelican]

My 135 amp batteries weigh 30kg each.
Moving two of these to the the adjacent position on other beam in effect equals adding 120 kg to that side
You probably already knew this!

 

[BruceK]

My 135 amp batteries weigh 30kg each.
Moving two of these to the the adjacent position on other beam in effect equals adding 120 kg to that side
You probably already knew this!

no. it adds sixty to counterbalance. What the OP wants is 30 aside so instead of counterbalancing with sixty move 30 of it. or in his case ~100 kg. What he cant then move has to be ballasted. So if he moved 2 batteries making up 60 kilo he'd still need ~40 kilo of ballast. (all things being equal from the keel line)

 

[jimmy_the_builder]

no. it adds sixty to counterbalance. What the OP wants is 30 aside so instead of counterbalancing with sixty move 30 of it. or in his case ~100 kg. What he cant then move has to be ballasted. So if he moved 2 batteries making up 60 kilo he'd still need ~40 kilo of ballast. (all things being equal from the keel line)

Surely if he moves 2x30kg from one side to the other, he is -60kg on one side and +60kg on the other, or in other words 0kg on one side and +120kg on the other...?

 

[BruceK]

I might have to ask for a refund on my expensive education but round a fulcrum a load of X at Y distance is balanced by another X at -Y distance on the opposite end.
So the OP has 30 stone at +Ydist from the keel line he has to compensate for. He can either add 30 stone at -Ydist or move half of X across. i.e. 15 stone............<>.................15stone to balance

THIS should not be confused with the fact that should he in your example balance the full load the fulcrum point will be carrying 60 aside increasing the total weight of the boat by 120kg, which is not a good thing.

 

[jimmy_the_builder]

I might have to ask for a refund on my expensive education but round a fulcrum a load of X at Y distance is balanced by another X at -Y distance on the opposite end.
So the OP has 30 stone at +Ydist from the keel line he has to compensate for. He can either add 30 stone at -Ydist or move half of X across. i.e. 15 stone............<>.................15stone to balance

THIS should not be confused with the fact that should he in your example balance the full load the fulcrum point will be carrying 60 aside increasing the total weight of the boat by 120kg, which is not a good thing.

My education was more Aldi than Eton, so I've got no idea what a fulcrum is - but regardless I can't see how moving 60kg (from Stelican's example, and my subsequent post) from one side of the boat to the other would increase the total weight of the boat by 120kg.

 

[BruceK]

I'm not so brazen as to comment on your education but I'd love to see how adding 2x30kg to one side adds 120 kilo to it. It could only equal 120 kilo total weight if you added another 2 x 30kg to the opposite side to balance it.

As for fulcrum think of a balance scale

in one side you have 2 x 30kg weights on one side. How do you balance it?

a) move one of the 30kg weights across to the empty pan. Total weight at fulcrum is still 60kg
b) add 2x 30 kg weights to the opposite pan. Total weight at fulcrum now 120kg

 

[jimmy_the_builder]

I'm not so brazen as to comment on your education but I'd love to see how adding 2x30kg to one side adds 120 kilo to it. It could only equal 120 kilo total weight if you added another 2 x 30kg to the opposite side to balance it.

As for fulcrum think of a balance scale

in one side you have 2 x 30kg weights on one side. How do you balance it?

a) move one of the 30kg weights across to the empty pan. Total weight at fulcrum is still 60kg
b) add 2x 30 kg weights to the opposite pan. Total weight at fulcrum now 120kg

Ah ok. The bit you've missed (I think) is that Stelican's point was that he was *moving* 2x30kg from one side of the boat to the other - not simply *adding* 2x30kg to one side (ie option A in your example here). But still - in terms of the list of the boat (and nothing else), isn't that just the same as adding (not moving) 120kg to one side?

 

[BruceK]

the OP says it took two blokes totalling 30 stone to balance the boat. I'm saying he should not look for 30 stone ballast. He should move as much as he can of any equipment / storage items he can from the offending side totalling no more than 15 stone to compensate.

If he can only move 5 stone across he will have a 20 stone imbalance and will need to compensate with that amount of ballast.
If he can only move 10 stone across he will still need 10 stone of ballast.
etc
Every bit of ballast he adds obviously adds to the total weight carried so the optimum at no extra weight will be move just 15 stone across.
Failure to do this will add a further 30 stone to counterbalance his boat and on a single engined 29 foot boat that is an awful lot of dead weight.


However I see Stelican's point and then would concurr. I didnt read it that way. Mea culpa

 

[jimmy_the_builder]

the OP says it took two blokes totalling 30 stone to balance the boat. I'm saying he should not look for 30 stone ballast. He should move as much as he can of any equipment / storage items he can from the offending side totalling no more than 15 stone to compensate.

If he can only move 5 stone across he will have a 20 stone imbalance and will need to compensate with that amount of ballast.
If he can only move 10 stone across he will still need 10 stone of ballast.
etc
Every bit of ballast he adds obviously adds to the total weight carried so the optimum at no extra weight will be move just 15 stone across.
Failure to do this will add a further 30 stone to counterbalance his boat and on a single engined 29 foot boat that is an awful lot of dead weight.


However I see Stelican's point and then would concurr. I didnt read it that way. Mea culpa

Gotcha. We are in violent agreement. You're saying 'don't add 30 stone, just move 15 stone'. I'm saying 'moving 60kg is the same as adding 120kg'. All good. Beer earned

 

[stelican]

Can I simply add that "Been there got the T shirt"

 

[BruceK]

join the crowd. Take a walk along any marina with a critical eye. Most boats at rest have a slight bias.

 

[stelican]

Largest addition I have made was 300kg aft!

 

[Portofino]

Check there’s no water from whatever source in a bilge compartment .
Check any plumbing fittings on the stb side are not leaking .
Thirdly a bit left of field but a good buyers survey will pick this up ........any foam or balsa core on the listing side is wet , absorbed water = more weight = list more noticeable on a small boat .

But although you say it’s always been like that in your ownership thing is new std boats same spec may not list .


I had a similar issue slight list to stb on a 17 ton boat .Turned out 600L of 3 y old diesel in custom long range tank .My fault I forgot about it being full this tank has no gauge you suppose to drain it into the 2x mains to top em up on a planned long trip .Generic manual for the boat was silent as it’s a bespoke feature .This LR tank was as outboard as it could be .The mains are near the CL .
Fortunately I had dosed the LR tank with “ Starbrite “ fuel snake oil and it seemed to work so I just diverted it off into the mains and emptied it .
Once the 5/600 Kgs sat outboard went the boat sat more / less well balanced .

 

[BruceK]

Largest addition I have made was 300kg aft!

hopefully rectified with bigger meatier engines :encouragement: :encouragement:

 

[Bouba]

Would the forum agree that single engine boats are more susceptible to listing?