Anchor Question Again

[GAJ52]

I raised a post some time ago about using an anchor while moored on the Thames overnight and received many very helpful comments - thank you.

One more quick question please on this subject, being a newbie I have never used an anchor in my life. Just say I moor with a water depth of 2 mtrs, what is a recommended amount of anchor chain to deploy and is it common practice to mark the chain is some way to a 'normal' amount of chain deployment.

This question is aimed mainly on inland waterways like the Thames rather than sea use.

Glen

 

[iCs]

Wow, this has potential to spark a huge discussion.

If using your bower anchor to hold the boat overnight, a lot of it is down to the location and the swinging room for the boat. I used to anchor overnight in the very big bend above Windsor marina, usually to about 12-15 m of chain, of which probably about 8-10 m were on the river bed. Remember, boats lie to chain, not anchors; the anchor simply holds the end of the chain in place. I always used to lay a kedge as well, and let the boat veer between them.

The nature of the bed counts for a lot too; my spot above Windsor was weedy, with poor holding. I wouldn't have anchored on that bed at sea, and it's why I laid more than the classic five-times scope of chain.

If you mean you're using a kedge off the stern on a bows-in mooring, then the lighter weight of the kedge is weighed against a longer scope; I would lay the kedge in midstream and pay out, before manoeuvring into position and sweating the kedge tight.

Either way, watch for sculls which will collide with you because they don't expect you to be there.

If you're on the non-tidal section, I'd recommend getting a lot of experience using the hook before anchoring overnight, because there are some very special considerations around going to anchor in those sorts of waters.

I mark my chain with coloured plastic markers every 10 metres on a big boat or 5 metres on a small one. A card kept in the wheelhouse or on the underside of the chain locker lid gives the colours for lengths.

 

[Jaysay]

I raised a post some time ago about using an anchor while moored on the Thames overnight and received many very helpful comments - thank you.

One more quick question please on this subject, being a newbie I have never used an anchor in my life. Just say I moor with a water depth of 2 mtrs, what is a recommended amount of anchor chain to deploy and is it common practice to mark the chain is some way to a 'normal' amount of chain deployment.

This question is aimed mainly on inland waterways like the Thames rather than sea use.

Glen

Some good advice here; perhaps I can add to it. I can recommend anchoring if moorings are scarce and/or you want peace and quiet at a place of your choosing. I used to anchor a lot on the Severn and Avon, where moorings are hard to come by, though I have never had the need on the Thames, where the bye laws state that you can anchor for 24 hours ( though who is to enforce it?)
The usual guidance is five times the depth so, in your case, 10 metres, which should be fine for the non-tidal Thames. I would recommend a stern anchor (kedge) as well to stop your boat swinging in the wind. Somewhere where wind and stream are in the same direction is ideal, especially if you do not have a kedge. Run astern under power briefly with the anchor out and secured to make sure it digs in to the river bed. At risk of being accused of stating the obvious, point upstream before dropping the anchor...
Pick a sensible spot (not at the bottom of someone's) garden, out of the fairway, on a straight stretch where you will be seen early and clearly. A stretch between two areas of overhanging trees is good, but you will need a surprisingly long gap. It has been my experience on the inland waterways that other boaters do not expect to come across an anchored boat, so expect the odd funny look or offers of help with a broken engine.
Use an all-round anchor night out all night (particularly important where disco/pleasure boats operate and quite a drain on the battery unless you have an LED or paraffin light). As stated earlier, the holding ground is critical, but as there is no information on this for the non-tidal Thames, the point is academic; you will just have to use trial and error. Also, as previously mentioned, it is not uncommon for rowers to run into you - they get confused, poor things.
As stated earlier, the weight of the cable ("chain" - yachtsmen call it the "rode") keeps the pull horizontal; the anchor does the holding.
The whole operation of anchoring and weighing (heaving the anchor in) can be a bit messy if you don't have a windlass, and can be a bit of a faff, but it is worth trying if circumstances dictate, and others will be suitably impressed (if, occasionally, baffled). Hope that helps.

 

[LittleSister]

Remember, boats lie to chain, not anchors; the anchor simply holds the end of the chain in place.

Nonsense! (And proved so time and again.)

1) If the anchor isn't doing anything, why do you bother with one?

2) And why do you 'sweat in the kedge' if it's doing nothing?

3) And why do you highlight the nature of the bottom and its 'holding' if the anchor doesn't need to hold?

The nature of the bed counts for a lot too; my spot above Windsor was weedy, with poor holding.

I would lay the kedge in midstream and pay out, before manoeuvring into position and sweating the kedge tight.

The reality is that, unless there's insufficient wind or current to straighten out the chain, it's the anchor holding you. The chain (or warp) merely serves to ensure that the pull on the anchor is as near horizontal as practicable (it's easy to pull the anchor out vertically, very difficult horizontally), and absorb some of the shock loads.

It's generally reckoned you need a minimum length of three times the depth (vertically bow roller to the bottom of the sea/river) for chain, and five times the depth with warp (rope). You need more than this in shallow water or in rough conditions.

 

[iCs]

Oh well, many days and nights on the hook and I know nothing.

I'll excuse myself here and let this real expert take over.

 

[Dave_Seager]

I think that the original question was about deploying the anchor when MOORED overnight so all the talk about locations and kedges may not help much. I often lower the anchor when moored overnight just in case some idiot decides to cast us adrift although it has never happened to us in about thirty years boating on the Thames.

The usual recommendation for scope is four times the depth if using chain or six times with rope. When on a mooring, the chain will tend to be piled on top of the anchor but the water will be quite shallow so there should not be too much of it. Do not forget to add on enough chain to reach the water, especially in shallow water where there will not be much chain out.

I mark my chain with coloured plastic inserts that clip into the links. Rather than mark in meters of chain, I prefer to mark according to depth as this saves mental arithemtic and requires less markers. I mark every four meters plus an extra meter for the distance from the bow roller to the surface, thus marks are at 1, 5, 9, 13 meters etc. The first mark is multicoloured and lets me know when the anchor is at the surface so that I can bring it up to the roller slowly.

 

[MinorSwing]

Oh well, many days and nights on the hook and I know nothing.

I'll excuse myself here and let this real expert take over.

Looks to me as though you've been lucky. I've anchored at sea and in rivers on many different occasions all over the world, and everything that LittleSister said is correct.
If you present yourself as an authority on a public forum you have to give the correct information. People's lives are at risk.

 

[iCs]

I'm not going to waste my time with a p&&&ing competition in a forum.

Anyone who lies to the anchor is a fool; that's a sign of too little scope.

All the advice here is worth precisely what those who take note of it have paid; mine and yours too. I didn't write a lengthy treatise on anchoring, but offered some brief tips in context.

Obviously, I shan't bother again.

And no, little sister misses the point and takes things out of that same context.

None of which, of course, is any help to the OP, who's now puzzled and probably mistrusting.

So, anyone looking for advice here would obviously better ask a consultant, with the relevant qualifications, for a written report. And foot the bill.

And all this primary school sniping just shows you and your like in your true colours.

I'll **** off now, and hope you will too.

 

[Cashbuyer]

A tight sweating kedge. I have some cream for that