Ballast - access and adjusting

[Johny London]

I've been busy this week preparing my floor for a decorative surface (laminate I guess). This has involved cutting into some of the large ply sheets to make access hatches, a couple of which I will incorporate into the final floor covering. That way I can tweak the ballast later, if anything weighty is added ie radiators etc.

My boat is quite low at the stern and high at the bow - even now with only 20 litres of diesel and nearly full water. I've always thought it would handle better with the nose a bit lower (especially in reverse), so I took this opportunity not only to get the port/starboard thing spot on but I moved as much ballast from the stern as far forward as possible. A dozen breeze blocks are now up at the pointy end that were previously at the stern, but it has made little difference - maybe a couple of cm difference at each end.

I wonder if anyone can calculate if I'd be wasting my time to get more ballast out from the next section up from the stern and place it in the next section down from the bow. I expect it will make less of a difference each time as my take out and put in points gradually get nearer the centre? I can't quite figure it our.

The boat is 62ft, I don't know how much the breeze blocks weigh - I'd guess about 20k?

Having it dead level port to starboard seems to help with reversing.

[ditchcrawler]

You need something much heavier than breeze blocks and if you have a real problem with space use steel or iron

[WotEver]

32 minutes ago, ditchcrawler said:

You need something much heavier than breeze blocks and if you have a real problem with space use steel or iron

When I read the OP I assumed that what he called breeze blocks are in fact concrete blocks. But we all know what assuming does

[Johny London]

Yes I think they are medium density blocks - as I said, I estimate they are around 20kilos each. But I must admit I hadn't thought of using something heavier! Can anyone recommend exactly what? The size of the blocks means they just slip under the floor with a margin to spare, so depth is definitely an issue.

If I could get something that was about twice as heavy and replace maybe ten or twenty blocks at the bow end?

[linnit]

Tractor weights...cut up old railway lines..fairly easy to manage and heavy

[ditchcrawler]

10 minutes ago, Johny London said:

Yes I think they are medium density blocks - as I said, I estimate they are around 20kilos each. But I must admit I hadn't thought of using something heavier! Can anyone recommend exactly what? The size of the blocks means they just slip under the floor with a margin to spare, so depth is definitely an issue.

If I could get something that was about twice as heavy and replace maybe ten or twenty blocks at the bow end?

As I said iron or steel

[Johny London]

I was just trying to ascertain exactly what and where from - can I just rock up at the chandlers and ask for a long weight? Or do I need to find a scrap metal merchant and ask for lump iron or something? I imagine being metal it won't be too cheap.

 

[NB Lola]

I have some spare 28lb weights and a couple of 56lb ones, if you are interested Pm me

[Neil2]

2 hours ago, Johny London said:

I've been busy this week preparing my floor for a decorative surface (laminate I guess). This has involved cutting into some of the large ply sheets to make access hatches, a couple of which I will incorporate into the final floor covering. That way I can tweak the ballast later, if anything weighty is added ie radiators etc.

My boat is quite low at the stern and high at the bow - even now with only 20 litres of diesel and nearly full water. I've always thought it would handle better with the nose a bit lower (especially in reverse), so I took this opportunity not only to get the port/starboard thing spot on but I moved as much ballast from the stern as far forward as possible. A dozen breeze blocks are now up at the pointy end that were previously at the stern, but it has made little difference - maybe a couple of cm difference at each end.

I wonder if anyone can calculate if I'd be wasting my time to get more ballast out from the next section up from the stern and place it in the next section down from the bow. I expect it will make less of a difference each time as my take out and put in points gradually get nearer the centre? I can't quite figure it our.

The boat is 62ft, I don't know how much the breeze blocks weigh - I'd guess about 20k?

Having it dead level port to starboard seems to help with reversing.

There's a limit to what you can do with ballast on modern boats as with heavier baseplates and more equipment/furniture etc a lot of the "ballast" in the boat is actually fixed.  I know of boats that have no ballast at all in which case if you want to adjust the trim all you can do is add weight, not redistribute it.  

I recall looking at a boat some years ago that had such a problem with fore/aft trim, the drain channels on the integral handrails had been re-positioned further aft.  I thought at the time why not adjust the ballast but there wasn't much to play about with.  The boat had a very long swim for a 40 footer, too long, which didn't help. 

There's something to be said for boats with thinner plating and more movable ballast but I doubt it is an issue that troubles many folk unless it gets to the stage of plates sliding off the table.  

[Johny London]

Yes that's the thing too - aside from trying to get the nose down a bit, I'd like to get the stern up a tad, so moving ballast from one end to the other kills both birds with one stone so to speak - though I've almost reached the limitations with that approach now. I always find my stern getting grounded where others just get away with it. I noticed that the top of the rudder was quite well submerged, as an indicator. It's a couple cm below the water now (as opposed to maybe 4-5 cm under before I re ballasted). I don't know how relevant the rudder depth is though - I've seen some with the top bits out of the water.

I should add that I have put quite a lot of stuff in the stern cabin, but that's just how I want to live, so it's not really negotiable.

 

[BEngo]

An outfit called Mann Buck advertise in the meeja as being able to supply steel for ballast. Usual disclaimer on my part but I thimk Alan Fincher has either used them or spoken to them.

A big scrappy may also be able to help. I had some railway flat bottomed rail chairs from the scrappy at Sharpness dock for a previous boat.

 

N

[Johny London]

Just Googled and discovered that the blocks I have are likely 13.25kg each. So plenty of room for improvement!

Edited August 14, 2017 by Johny London

[system 4-50]

<pedant> You need ballast that is denser ie heavier for the same volume, rather than just heavier, ie bigger blocks </pedant>

You can have 100+ class A engineering bricks I no longer need (for free) but you will have to come and get them! (Cheshire!) But iron/steel would be much better. I got mine from advertising on this forum. Make sure that anything you buy will actually fit!

 

[Johny London]

Yes I obviously realise that it's about getting more weight into the same space! That's what I meant by room for improvement - the blocks I have are not that dense, so should be able to get something a lot heavier - it'll prolly have to be metal though I should think.

I have 27 blocks in the sections nearest the bow so that's only 360kg. If I could get something twice as weighty it should help get the nose down at least a little.

[ditchcrawler]

Probably buying bar cut to length from a steel stockist. I was lucky to get 2 ton of "pig Iron" ingots from an old trawler.

[Johny London]

I think for now, I will not lay any flooring until I have found something heavier to replace the blocks at the bow, which might be a little while. Glad I asked as I was pretty sure that was the one bit of floor that could be left without a hatch as it is and presumably always would be maxed out with ballast - until you guys gave me the idea for simply using something much heavier.

In the meantime I will move onto completing something else - there's plenty of choice.

[Glynn]

I bought 2 of these, they are 110KG each. Front tractor weights off a John Deere and I got them for £15 each, what a bargain.

Edited August 14, 2017 by Glynn

[Johny London]

Wow - a bit difficult to handle though?

I've tried to calculate the draft of the boat - by measuring up the side from the water, then back down again inside and through the floor to the base plate and working it out. As best I can tell the stern base plate (a couple meters from the aft end) is at 64cm (2ft draft) and a couple meters from the bow is 43cm (1'5" draft). So it looks to me as though the nose could come down a little, but the stern isn't too low? It always seems to get me grounded out though

[DaveR]

I got my railway line from NYMR, 1 yard at 90lbs (40kg) cost me £15. Make sure, which ever railway society you use, they know that you will buy the stuff and you are not looking for a freebie.

I got 6 yards (pre-cut) and cut them in half again with a large angle grinder (hard work for machine and me) but now have a number of pieces under the bench in the cratch.

This took off the big stern trim and allows me to move them side to side when I need to take the list off.

Simplsz

[Johny London]

That sounds just the ticket - though I will do my best to avoid getting anything I have to cut.

When you say, "...took off the big stern trim..." you mean it got the nose down more towards the sort of level the stern is at?

Am I even correct in thinking it's a good idea to get the nose down a bit? I read somewhere it's the only thing we have that acts as a keel so I've been thinking of that.

[DaveR]

2 hours ago, Johny London said:

That sounds just the ticket - though I will do my best to avoid getting anything I have to cut.

When you say, "...took off the big stern trim..." you mean it got the nose down more towards the sort of level the stern is at?

Am I even correct in thinking it's a good idea to get the nose down a bit? I read somewhere it's the only thing we have that acts as a keel so I've been thinking of that.

Legacy always had a good 3 inches stern trim. I have added the 8 short pieces up forward and now have her fairly close to even keel when the water tank is full. The other two lengths were needed to take the list off when I got rid of the washing machine in favour of a large fridge for the beer.

Maybe thats why the trim feels better.