How much Ballast

[johnnie1uk]

Hi Guys

We have had our NB for around 8 months now and have gradually been putting more and more on her, there is brick ballast in the bows and also in the stern engine compartment, when she is full of fuel and water the boat seems quite low in the water, I am wondering should I remove some of the ballast, this would make the bow and stern compartments a bit less cramped.

[Alan de Enfield]

Is the 'more and more' that you have been putting on her above the water line ?

 

You need to keep your weight low down to keep the C of G low and minimise rolling.

 

How low in the water are you ?

Is there any chance of water going up your thru' hull fittings (exhaust etc) ? (particularly if you go on a River)

 

Try removing a little ballast and see if the boat 'rolls' too much

[Chewbacka]

Things to think about as well as Alan's important comments above -

 

How deep are you currently in the water? Are you dragging on the bottom of the canal?

The boat is better if the bow is slightly higher than the stern

The back of the boat wants to be low enough to avoid drawing air into the propeller

The ballast should be arranged to keep the boat level from side to side.

[Dinz]

[Going by your location] if it is on the K&A then you will soon be removing it all if you actually want to move in the summer months & get close to the towpath!

[MtB]

Hi Guys

We have had our NB for around 8 months now and have gradually been putting more and more on her, there is brick ballast in the bows and also in the stern engine compartment, when she is full of fuel and water the boat seems quite low in the water, I am wondering should I remove some of the ballast, this would make the bow and stern compartments a bit less cramped.

 

 

In broad terms a mordern narrow boat would be ballasted at the stern so the uxter plate is about an inch under water with the boat at rest. Any more than that and I'd be taking ballast out.

 

And then ballast the bow so there is roughly a 6" rise along the side deck from stern to bow.

 

Post us a recent photo of your boat taken side-on for a shedload more opinions.

[ditchcrawler]

When you say more room I am wondering how high these bricks are stacked

[Alan de Enfield]

When you say more room I am wondering how high these bricks are stacked

 

It does beg the question as to who fitted it out, was it a DIY fit out on a bought shell / sailaway ?

Who signed off the stability RCD declaration (if built 1998 onwards) ?

 

Normally a 'manufacturer' would have enough experience to ballast a boat 'almost' correctly without resorting to a large number of 'bricks'.

[johnnie1uk]

Thanks for your feedback so far.

[MtB]

Thanks for your feedback so far.

 

It wasn't 'feedback' so much as answers mixed with requests for more information.

 

Some feedback from you would be welcome!

[johnnie1uk]

Sorry i've been offline a couple of days.The boat was built 1976 (debatable) by Liverpool boats and has been refitted so the ballast has probably been moved/changed, the bricks are stacked in the bow compartment to the shape of the bow, and in the stern, some in the bilge, some on the opposite side to the batteries on top of the Uxter plate.( the flat shelf each side of the engine), when I rock the boat to rinse after a pumpout, she stableises very quickly so I think the ballast is in the right place.

We are CCer's not on the K&A yet. Wiltshire is my P.O.address, .I think I will leave well alone as recently we came up the Stratford and there wasn't a lot of top clearance under those little wrought iron bridges.

[John V]

If you are happy with the actual ballast weight (in other words your draft is more or less correct) but it is simply the amount of room it takes then simply replace the bricks with steel or iron ballast (steel is approximately 4 times as heavy per cu ft as concrete (concrete about 148lb per cu ft steel 450lb per cu ft)

 

ok make that 3

Edited June 1, 2016 by John V

[Guest]

If you are happy with the actual ballast weight (in other words your draft is more or less correct) but it is simply the amount of room it takes then simply replace the bricks with steel or iron ballast (steel is approximately 4 times as heavy per cu ft as concrete (concrete about 148lb per cu ft steel 450lb per cu ft)

 

ok make that 3

I think you will find that it is actually 3.040540541

Didn't realise that steel was so much heavier than concrete. We live and learn

I have been thinking of using conrete in our engine hole for ballast as i could cast it to the shape I want, but steel would seem far more efficient. On the look out for 56lb weights now.

[ditchcrawler]

I think you will find that it is actually 3.040540541

Didn't realise that steel was so much heavier than concrete. We live and learn

I have been thinking of using conrete in our engine hole for ballast as i could cast it to the shape I want, but steel would seem far more efficient. On the look out for 56lb weights now.

When we launched our boat the ballasting was a mile out so I had to move a ton of slabs out and put a ton of iron just one side

[Chewbacka]

When we launched our boat the ballasting was a mile out so I had to move a ton of slabs out and put a ton of iron just one side

When we had finished fitting out we had a 5 degree roll on the boat, didn't want to take the floor up so used tractor weights on the side of the boat at the back of a couple of cupboards.

Some bargins do come up on ebay, whereas 56lb weights are trendy collectors items and always expensive.

Something like these - http://www.ebay.co.uk/itm/Ford-Tractor-Weights-/381646224943?hash=item58dbe33e2f:g:ynUAAOSw6btXQup-

[ditchcrawler]

I used pig iron which had been used as ballast on a trawler, each bit weighed 14 lbs I think

[Guest]

When we launched our boat the ballasting was a mile out so I had to move a ton of slabs out and put a ton of iron just one side

That was a lot! I think about 5 cwt is needed for mine.

[John V]

img054 by mudlarker2, on Flickr

 

The heap at the back is some of the ballast in Sabina H 6" x 6" x 4" blocks of steel ........8 tons of it plus another 2 tons of pig iron

[ditchcrawler]

That was a lot! I think about 5 cwt is needed for mine.

I had to remove almost all of the slabs and then replace them with iron in the front left quarter all under the floor