What constitutes ballast on a yacht?

[BlueSkyNick]

In the olden days, boats had pig iron, stones etc in the bilges to keep the boat upright. On monohull yachts there is a keel.

Is the stated ballast simply the weight of the keel, or is there more to it?

Here am I sitting on the wing of our keel, the stub above the line is hollow. The stated ballast for a Starlight 39 is 3000kg (displacement is 7500kg).

Even though it is solid lead, looking at it I was wondering if it really weighs 3 tons!

 

[wrr]

Human Ballast on a Yacht.

Guests who sit in one position in the cockpit all day, do nothing to help and expect regular feeding and watering. Can't even get them to sit on the weather rail!

 

[Lucky Duck]

X Yachts include the steel strenthening grid attached to the keel at the bottom of the hull as part of the quoted ballast weight, which is IMHO is stretching things just a little bit.

 

[prv]

I have a vague rule-of-thumb recollection that lead is ten times as dense as water. If I'm right, then three tonnes of lead should take up 0.3 cubic metres. Does that seem about right by eye?

Pete

 

[VicS]

I have a vague rule-of-thumb recollection that lead is ten times as dense as water. If I'm right, then three tonnes of lead should take up 0.3 cubic metres. Does that seem about right by eye?

Pete

(From memory) density of lead is 11.4

 

[Wansworth]

In steel boats the steel work of the keel is counted as ballast.

 

[LittleSister]

X Yachts include the steel strenthening grid attached to the keel at the bottom of the hull as part of the quoted ballast weight, which is IMHO is stretching things just a little bit.

Well, surely if it's weight below the centre of buoyancy (?) it's performing the function of ballast, regardless of what it's made of and whether it also has any structural function?

 

[snowleopard]

Ballast is any weight used to provide righting moment.

On one OPB cruise I was given this to use. The others had mugs reading 'Captain', 'First mate' etc:

 

[Sybarite]

In the olden days, boats had pig iron, stones etc in the bilges to keep the boat upright. On monohull yachts there is a keel.

Is the stated ballast simply the weight of the keel, or is there more to it?

Here am I sitting on the wing of our keel, the stub above the line is hollow. The stated ballast for a Starlight 39 is 3000kg (displacement is 7500kg).

Even though it is solid lead, looking at it I was wondering if it really weighs 3 tons!

There is the stated ballast and then the effective ballast which may include the engine and tankage.

 

[Lakesailor]

This lead keel weighed 157 Kgs

 

[LittleSister]

There is the stated ballast and then the effective ballast which may include the engine and tankage.

The stated ballast being the 'added' ballast that has no other function, I guess.

 

[LittleSister]

This lead keel weighed 157 Kgs

​

What boat is that keel for?​

 

[BlueSkyNick]

Ballast is any weight used to provide righting moment.

Well, surely if it's weight below the centre of buoyancy (?) it's performing the function of ballast, regardless of what it's made of and whether it also has any structural function?

I think this is one and the same thing, and it makes sense.!

 

[Seven Spades]

Looks like you are using an electric toothbrush to remove the antifoul!

 

[Lakesailor]

What boat is that keel for?

It was a Micro Cup 18ft.

 

[jac]

It was a Micro Cup 18ft.

Wow that has been neglected.

Please tell me she now has a loving owner and doesn't look like that.

(Sorry for fred drift)

 

[Lakesailor]

Oh.

You haven't been following for a year or two?

Bought as a basket case. Decided too much work to end up with a boat you have to crawl around the "cockpit" in. Sold the good stuff. Dumped the rest.

 

[BlueSkyNick]

Looks like you are using an electric toothbrush to remove the antifoul!

it has felt like it at times !! All done now, with just one Sandvik scraper blade.

 

[jac]

Oh.

You haven't been following for a year or two?

Bought as a basket case. Decided too much work to end up with a boat you have to crawl around the "cockpit" in. Sold the good stuff. Dumped the rest.

Hm - Kit boat now then ??

 

[Lakesailor]

Just a couple of weekend's work.