How long should your anchor chain be?

[rowland al]

1 hour ago, Clodi said:

The only problem with this is when travelling downstream  where there is not enough room for a narrowboat to swing around, you definitely don't want to end up wedged across the stream.

Sometimes common sense must contradict  the 'rule'. Hopefully we'll never need to have to use ones anchor, however I grew up on the Great Ouse and conditions can change rapidly catching even experienced locals out.

I live in West-Wales and just a couple of weeks ago we suffered tremendous rainfall causing our local river systems to rise by 20' practically overnight, unfortunately claiming a young mans life and breaching flood defences causing millions of pounds worth of damage. Always prepare for the unexpected.

If you are going downstream and anchor from the stern, wouldn’t the flood current swamp into the rear cabin (on a trad narrow boat)?

 

Ok being wedged can’t be nice either and could lead to a sinking if the boat can’t float upwards. 

 

 

[Alan de Enfield]

14 minutes ago, rowland al said:

If you are going downstream and anchor from the stern, wouldn’t the flood current swamp into the rear cabin (on a trad narrow boat)?

That is indeed the problem.

 

Being anchored actually pulls the anchor point (front or back) lower in the water, and the faster the flow the lower it gets pulled.

Most boats are much lower at the stern than they are at the bow and would be swamped - which is why the recommendation is always to anchor off the bow.

 

If the river is that much narrower than your boat then maybe just steer to wards the side and use your anchor as a grapnel and hook a tree (or whatever). Grabbing a tree, or getting the stern swamped are probably both better than going over a weir.

 

Yes - we all know the argument about the upstream part of the Thames ……………………………. 

 

But - You also need to be prepared for when you are on a 'proper river' at 200 yards wide, with a 20 foot drop on the weir and a 5mph flow that will roll a NB under the protective Dolphins.

[rowland al]

8 minutes ago, Alan de Enfield said:

That is indeed the problem.

 

Being anchored actually pulls the anchor point (front or back) lower in the water, and the faster the flow the lower it gets pulled.

Most boats are much lower at the stern than they are at the bow and would be swamped - which is why the recommendation is always to anchor off the bow.

 

If the river is that much narrower than your boat then maybe just steer to wards the side and use your anchor as a grapnel and hook a tree (or whatever). Grabbing a tree, or getting the stern swamped are probably both better than going over a weir.

 

Yes - we all know the argument about the upstream part of the Thames ……………………………. 

 

But - You also need to be prepared for when you are on a 'proper river' at 200 yards wide, with a 20 foot drop on the weir and a 5mph flow that will roll a NB under the protective Dolphins.

I nearly rolled my boat turning against the flood on the tidal Trent once. It scared the shit out of me.

 

Narrow boats aren’t built for that kind of thing really, but I guess we all like a challenge. 

[Keeping Up]

I have an anchor with 60ft of chain and 20ft of rope, ready to deploy from the bow. Travelling downstream on a river that would be too narrow to let the boat swing around I use a mud weight of 56lb from the stern on 50 ft of rope. If the river is flowing slowly it will stop the boat; if it is flowing quickly I know that it will drag, but it will slow the boat considerably and give me time to consider and implement the best solution (fix the problem, get into the trees, bring the anchor to the stern, wait for a wide bit and drop the anchor from the bow, etc).

[Clodi]

As already mentioned narrowboats are not built for fast-flowing rivers. Mud-weights are great also deployed to hopefully keep you in the stream and not over the bank when (hopefully) the flood subsides.

Given the limited amount of safe working area on my particular boat carry & deploy my anchor from the stern. The anchor wharp is secured to a bow fitting which is secure enough to withstand the shock & it gives me the option to secure it to the stern should conditions dictate. Remember travelling downstream when the flow is faster than you means any steerage is hit and miss to say the least

[yabasayo]

Five times the water depth is the general rule of thumb for offshore sailing (which I have done a lot of) but it doesn't all need to be chain.

5  metres or so of chain with the remainder being nylon anchorplait is easier to handle and recover and provides elasticity to reduce snatching.

Modern burying anchors (Sarca, Rocna etc) have amazing holding power in mud/sand. Obviously the size of the anchor must be proportional for the boat. Have sat out several gales in exposed anchorages with such an arrangement.

[Momac]

I had quite  a bit of anchoring practice recently including some training.

We were advised to try to get 50metres of chain out, in not more than 10metres depth. 40ft boat .

That was in big pond with no tides - Ionian Sea

[MtB]

 

With 50m of chain out, I don't think you'll actually need an anchor of the end of it.

 

 

[Alan de Enfield]

54 minutes ago, Mike the Boilerman said:

 

With 50m of chain out, I don't think you'll actually need an anchor of the end of it.

 

 

The voice of ignorance.

[rusty69]

1 minute ago, Alan de Enfield said:

The voice of ignorance.

Yeah! Wot you want?

[MtB]

3 minutes ago, Alan de Enfield said:

The voice of ignorance.

 

Charming.

 

But true all the same - in 40 years of boating I've never needed to use an anchor. Nor can I recall any of my circle of acquaintances ever using one in anger either. 

 

I still reckon that in the millpond circumstances mentioned in the post I was commenting on, 50m of chain would hold the boat. 

 

 

[bizzard]

The lavatory chain in the council house where i was brought up, no, the second house, the first was a pre-fab, had a big hard rubber ball handle to pull it. we used to remove it to play ball with but had to keep putting it back when someone wanted to use it.  The cistern wouldn't flush properly which the council were unable to fix so I fixed it with suspended Meccano counter weights. Councils need Meccano sets badly.

My sister and I played Saturday morning school in the Lav. She'd sit on the throne surrounded with all her dolls, instructing them, whilst I the Headmaster sat on the landing awaiting pupils being sent out to be punished.

Edited November 3, 2018 by bizzard

[howardang]

11 minutes ago, Mike the Boilerman said:

 

Charming.

 

But true all the same - in 40 years of boating I've never needed to use an anchor. Nor can I recall any of my circle of acquaintances ever using one in anger either. 

 

I still reckon that in the millpond circumstances mentioned in the post I was commenting on, 50m of chain would hold the boat. 

 

 

For what it's worth, I remember a story some years ago about a very large American Aircraft carrier that went to anchor in very bad weather. One anchor out with lots of chain. The ship maintained station without dragging for a couple of days with no problem. When the weather moderated they decided to send a diver down for an exercise and to check that the anchor was bedded in satisfactorily. When the diver returned, he reported that the anchor was sitting on the bottom, upright,  on the crown,and the anchor had never been on its side so the flukes had never dug in. The ship had ridden out the gale by the weight of the cable alone!

 

Howard

[rusty69]

Quote

The lavatory chain in the council house where i was brought up, no, the second house, the first was a pre-fab, had a big hard rubber ball handle to pull it. we used to remove it to play ball with but had to keep putting it back when someone wanted to use it.  The cistern wouldn't flush properly which the council were unable to fix so I fixed it with suspended Meccano counter weights. Councils need Meccano sets badly.

 

 

....sounds like a b̶a̶l̶l̶ ̶a̶n̶d̶ ̶c̶o̶c̶k̶  cock and ball story to me Bizz!

Edited November 3, 2018 by rusty69

[Dr Bob]

The problem I see on anchors for NB's is that few will have had any experience deploying an anchor so that even with the best kit it is going to be very hit and miss. On a lumpy water boat, the skipper is likely to be proficient deploying anchors (and we were having lived full time on one for 3 years)....as you do it very often. You practise and learn the skill. Unfortunately most NBs are not set up to deploy (ie no anchor windlass) and recover an anchor - so no one ever does it. On a lumpy water boat, you dont just dump it all overboard and expect the boat to hold. It's the same on an NB.

I agree with Mike the Breadman that on the cut you dont need it...but obvioulsly on a river you do.

[bizzard]

There used to be an escape artist performance at the Tower of London, on The Green, where a chap asked the audience to wrap him all up with chains, and truss him him up like a chicken with the chains and pad locks then put a big sack over him. He would escape in 2 minutes. Someone offered to bring they're own chains and pad locks to tie him up with but he wouldn't have any of it.

[LadyG]

3 hours ago, Mike the Boilerman said:

 

Charming.

 

But true all the same - in 40 years of boating I've never needed to use an anchor. Nor can I recall any of my circle of acquaintances ever using one in anger either. 

 

I still reckon that in the millpond circumstances mentioned in the post I was commenting on, 50m of chain would hold the boat. 

 

 

Well lets have a wee debate, I mean to say, would any serious boater really boat for 40 years and not bother carrying an anchor? Answers on a postcard.

50 m of bog chain would not hold a 10ft pram dingy, 50m of 10mm chain might do so, but I think I'd prefer even a tiny folding grapnel on the end to nothing at all.

In a full on Force 10 it would be advisable to tie on to something,  you can use the anchor rode to back up your 12mm mooring washing lines.

On salty waters I've seen our anchor chain stretched taught, even though we were in a relatively sheltered anchorage, the wind can gust from almost any direction. 

We sat up with the engine on, one night at Isle Oronsay it was gusting over 50knots, it was pretty hairy, we were on a fishing vessel's mooring as he was safely tied up in harbour, it held .

Edited November 3, 2018 by LadyG

[rusty69]

I put a large hook on the end of ours.You never know, I might catch a big fish one of these days.

[Alan de Enfield]

27 minutes ago, rusty69 said:

I put a large hook on the end of ours.You never know, I might catch a big fish one of these days.

[rusty69]

1 minute ago, Alan de Enfield said:

 

Arrrghhhh, It save on diesel if ya can harpoon a passing sperm whale.

[Momac]

5 hours ago, Mike the Boilerman said:

 

With 50m of chain out, I don't think you'll actually need an anchor of the end of it.

 

 

Not so. 

In one anchorage we could not get the anchor to hold against the engine in reverse.

 

Edited November 3, 2018 by MartynG

[Naughty Cal]

15 hours ago, MartynG said:

Not so. 

In one anchorage we could not get the anchor to hold against the engine in reverse.

 

Luck of the draw sometimes as we have managed to get ours to hold with just two times the water depth of chain out (didn't have anymore to put out) in pretty lumpy conditions.

 

Yet could not get it to hold with over six times out on another occasion in similar conditions in the same anchorage.

[rusty69]

We lost our anchor in lumpy conditions. Thankfully we had a spare.

 

I expect all inland boats carry a spare just in case

[LadyG]

On 02/11/2018 at 22:36, MartynG said:

I had quite  a bit of anchoring practice recently including some training.

We were advised to try to get 50metres of chain out, in not more than 10metres depth. 40ft boat .

That was in big pond with no tides - Ionian Sea

And  did your your yacht just happen to have 50m chain and a windlass. ?

 

[Momac]

1 minute ago, LadyG said:

And  did your your yacht just happen to have 50m chain and a windlass. ?

 

It had quite  a bit more than 50m. I don't recall exactly the full length. 

The electric windlass was  essential .