Anchor Size/Type

[blackrose]

That's the total scope length, most boats don't have that amount of chain. If you are in more than 10m of water your scope should be no more than 5 times the depth of water.

 

(The scope is the combined chain/rope length)

 

Edited to say: This is a reasonable guide to scope length:

 

" The scope (length of anchor line) should be determined according to the water depth below your keel and the wind conditions -

less 10m : 3 times the water depth, up to Force 3;

5 times the water depth, up to Force 6;

7 times the water depth, up to Force 9.

 

More than 10 m : no more than 5 times the water depth.

 

• Beyond Force 9, you should set 2 anchors, either each on its own line (allowing a 60° to 90° angle or both anchors on the same line with a 2 to 5 m chain interval.

 

Sounds like I need to procure some more chain and perhaps another anchor... although as a fair weather sailor I never go out in those sort of conditions. I can't believe people were moving their boats yesterday & today - they must be keen (or stupid!)

[Alan Saunders]

. . . the next morning it took me the best part of half an hour to get the anchor up as it had gone so deeply into the mud. In the end I just drove over it to pull it out, the bow went down about two feet before it released. . .

 

Julian

If there is a chance of the anchor fouling you'd best use a "tripping line". This is a lighter rope attached to the 'wrong' end of the anchor shaft. Driving over the anchor will not break it out if it is hooked onto a solid object like a cable or a sunken wreck. Even if the anchor is buried in the best mud a very small force on the tripping line may pull it out. Get the anchor warp straight up and down then pull on the tripping line. If it doesn't budge, secure the tripping line and 'overrun' the anchor. Thetripping line may be a little shorter than the anchor warp.

 

If I may bore you with an anecdote:

When I had a small boat, an ancient 18', 1 ton, clinker, mahogany on teak, plus 1/4" of fibreglass mat with a 30HP Perkins outboard motor, in Portsmouth Harbour over thirty years ago I always used a tripping line except once. I was fishing off The Blocks when I noticed some paper in the water. Then I realised it was a fiver and then that it was my fiver which I had stuffed into my hip pocket after buying fuel. So, up with the anchor and let the boat drift after the money. No amount of power from my oversized outboard would break the anchor free though it forced the bow down and resulted in undignified girations. In the end I had to cut the anchor warp. I had lost £15 worth of anchor (a folding grapnel) and warp as well as the fiver. I should have buoyed the warp - it was a floating rope and I am certain someone must since have come to grief with it wrapped around their propellor. By the way, I caught not one single fish.

 

Those were the days! VAT on 'leisure products' was 25% and £3,500 pa was a good wage! How much, relatively, is a Danforth and a decent length of chain and rope now?

 

Alan Saunders

[Midnight Rider]

Greetings

 

I have to say that I've never carried an anchor in many years of boating, but then again, I've not done much river work.

 

I'm moving to a mooring on the Soar & considering an anchor. Might venture on the non tidal Trent, but no other rivers in the near future. I've got a 63ft Trad, by the way.

 

I've done my homework on the previous threads & read the comments here, but I'm still none the wiser.

 

Surely we can forget the published tables, as they seem to refer to sea going craft in tidal waters?

 

We then have to rely on the advice & experience of others. The problem is that some want an anchor that will hold in Grimsby harbour and in my case, on the Soar.

 

I have to say that if I can't away with something folding & 15 / 20 kg max -- dicky back to consider -- I think I'll take my chances.

 

The Foblight hs been mentioned before -- expensive, but it would be ideal for me --- has anyone used one?

 

I'm new to the forum --- finding it really helpful.

 

Tony

[Big Steve]

Try one of these, http://www.fortressanchors.com/ very light, very expensive, very good. In their tables they recomend only a few feet of chain, makes everything a lot easier. Available from www.jimmygreen.co.uk in the UK.

[GUMPY]

If there is a chance of the anchor fouling you'd best use a "tripping line". This is a lighter rope attached to the 'wrong' end of the anchor shaft. Driving over the anchor will not break it out if it is hooked onto a solid object like a cable or a sunken wreck. Even if the anchor is buried in the best mud a very small force on the tripping line may pull it out. Get the anchor warp straight up and down then pull on the tripping line. If it doesn't budge, secure the tripping line and 'overrun' the anchor. Thetripping line may be a little shorter than the anchor warp.

 

I was also being lazy and hadnt bothered with the line, which I do have and a buoy to mark the anchor.

Where we were anchored ( near the mouth of the Roach) there is no solid stuff just tons of east coast mud.

 

J

[Midnight Rider]

Try one of these, http://www.fortressanchors.com/ very light, very expensive, very good. In their tables they recomend only a few feet of chain, makes everything a lot easier. Available from www.jimmygreen.co.uk in the UK.

Thanks Steve --- will have a look

 

Tony

[saltysplash]

Isn't the chain guage also relevant? (as well as the displacement of the boat you're trying to stop.)

 

I've got 10m of 10mm link chain attached to about 30m of 22mm rope on a 30kg anchor, but by the sound of things this isn't enough chain (or rope). My boat's about 28-30 tonnes, but when I go out on the tidal Thames I've no idea how deep it is? 50ft in the middle perhaps? That would mean I'd need 150ft (or 45m) of chain! Or can I reduce the chain length with a better chain/rope combo?

 

 

You will be able to work out the depths on the thames with the aid of a chart and tide tables.

 

Reeds Nautical Almanac has lots of very useful tables and info and shows you how to use them

[blackrose]

You will be able to work out the depths on the thames with the aid of a chart and tide tables.

 

Reeds Nautical Almanac has lots of very useful tables and info and shows you how to use them

 

Thanks, I've got an Imray chart so I'll have a look together with the PLA tide tables.

[saltysplash]

Thanks, I've got an Imray chart so I'll have a look together with the PLA tide tables.

 

 

Just take the lowest chart datum marked on the chart and add the guestimated height on the tables and that will let you know (5 times the depth for warp)how much chain and warp you need to throw over the side

 

calculating your current depth is a bit more complicated and tide tables are a big help there

[Alastair]

If I was wanting something for occasional use on a slow-flowing river, I'd carry an anchor and a mudweight. A large bucket filled with concrete and a loop of chain would do for the mudweight.

 

Then I'd fasten the mudweight with a continuous loop of rope, so I could just cut/untie the rope and pull it through the mudweight's chain.

 

Rig the mudweight so it can be levered/tipped overboard in an emergency. Cheaper than an anchor, and no strained backs.

 

If I was anchoring in a regular basis, I'd have an anchor winch. We have one for the 110kg anchor on Elbrich, as I don't fancy hoisting that by hand.

[RLWP]

You will be able to work out the depths on the thames with the aid of a chart and tide tables.

 

Reeds Nautical Almanac has lots of very useful tables and info and shows you how to use them

 

This is the problem we faced when buying an anchor. We were going to move the boat down the Manchester Ship Canal, and the regulations siad we needed an anchor. We had been told about the "five times the depth" bit, but how deep is the MSC? Or the Weaver? Where do you find out?

 

Richard

 

In the end we had to resort to going to the chandlers and doing the "Close your eyes, open your wallet and repeat after me - Help Yourself" routine...

[tomsk]

That is indeed the problem of dropping (not throwing!) an anchor from the bows of your boat when going downstream. The boat will swing around until the bows face upstream. If the river is not wide enough or there are bridges or other traffic nearby this could be dangerous, so some people keep the anchor at the stern if going downstream. However if you deploy an anchor from the stern there is the possibility that in certain conditions your stern could get flooded by a strong current or ebb tide. I would feel far more comfortable anchored in a strong current with my bows facing upstream.

 

Unfortunately here is no easy answer to this dilemma, but basically it's a good idea to have anchors at both ends and then you're ready to do what you think is best at the time, according to the particular situation.

 

Fence sitter!

[blackrose]

Fence sitter!

 

Shirt lifter!

[Dalesman]

This is the problem we faced when buying an anchor. We were going to move the boat down the Manchester Ship Canal, and the regulations siad we needed an anchor. We had been told about the "five times the depth" bit, but how deep is the MSC? Or the Weaver? Where do you find out? Richard In the end we had to resort to going to the chandlers and doing the "Close your eyes, open your wallet and repeat after me - Help Yourself" routine...

You will find that The Manchester Ship Canal is about 30 feet deep, while the River Weaver is only about 10 feet if that..!

[tosher]

Try one of these, http://www.fortressanchors.com/ very light, very expensive, very good. In their tables they recomend only a few feet of chain, makes everything a lot easier. Available from www.jimmygreen.co.uk in the UK.

 

I've used these on yachts at sea and they would definitely be my first choice if not so expensive. Very light and easy to handle, suberb holding in fact they take so well that sometimes it can be a bit difficult to them out. tosher