Has your anchor ever dragged? Tell us.

[Sans Bateau]

Our 16kg Delta anchor usually digs in so well, when it returns to the bow roller it is caked in mud.

We had been at anchor in Newtown Creek for two days, lots of wind from the SW and spring tides giving fast tidal flows in the river. Not at any time did we have any concern for the job the anchor was doing, we had all chain scope down and there were few other boats around to worry about swinging circles.

However on the morning of the third day the wind really got up and whilst we were waiting for the tide to favour our passage we had 23knts of wind against a fast ebb. Needless to say the boat didnt know which way to settle, it was sheering around in all directions on its sufficient but short scope. After a little while of this she started dragging and after a couple of attempts to re-anchor it was time to leave so we gave up.

Did the sheering itself unsettle the anchor, was the 'ploughed field' that is Newtown enough stop it from digging in? We did not before or since have any anchoring problems.

 

[webcraft]

Our 16kg Delta anchor usually digs in so well, when it returns to the bow roller it is caked in mud.

We had been at anchor in Newtown Creek for two days, lots of wind from the SW and spring tides giving fast tidal flows in the river. Not at any time did we have any concern for the job the anchor was doing, we had all chain scope down and there were few other boats around to worry about swinging circles.

However on the morning of the third day the wind really got up and whilst we were waiting for the tide to favour our passage we had 23knts of wind against a fast ebb. Needless to say the boat didnt know which way to settle, it was sheering around in all directions on its sufficient but short scope. After a little while of this she started dragging and after a couple of attempts to re-anchor it was time to leave so we gave up.

Did the sheering itself unsettle the anchor, was the 'ploughed field' that is Newtown enough stop it from digging in? We did not before or since have any anchoring problems.

Can anchoring in a soft bottom with strong tidal flows result in tidal scouring round the anchor over a couple of days?

I am a great believer in scope. Chain in the locker is serving no purpose - if you have room to swing put it all out. Sheering at anchor is only likely to cause problems when the catenary in the chain is straightened, and more scope in gusty conditions will reduce the number of times this happens.

- W

 

[nathanlee]

I set off from Wells-next-the-sea only to run in to a whole host of problems with the boat, so made the decision to turn back. By the time I got back, I was far too late on the tide, so had to anchor in the bay to the west (can't remember the name off hand).

The sea was in a right 'orrible mood. Not particularly big, just choppy and random. I decided to try putting a bit of rag up and heave to, to ease the motion of the boat whilst on the anchor. This, to my surprise, did seem to work. I waited for ages to see if we were dragging, but appeared not to be.

The early start got the better of me and I ended up falling asleep (sat upright, I didn't intent to). I woke up an hour later VERY close to the sand bar at the entrance to Wells Harbour.

You have never seen a man weigh anchor and start the engine so quickly, I can tell you.

 

[shmoo]

60m in 35kt off IOW

'Twas about 6 years ago. our first trip in our first boat. We anchored off Bembridge as the weather was deteriorating and we we loosing light. We had overestimated our (personal) endurance and couldn't face the extra couple of hours to Portsmouth.

Put out a 17kg (or maybe its 19kg) Bruce on 20m chain spliced to about 40m 3/4'' anchorplait. We were just south of the fort in about 5 or 6m. Wind was about 25kts and rising. Went up in the night to about 35kt - 38kt steady with gusts only a little higher. Called the coasties and explained our position - they suggested Portsmouth, but at that stage there was no way I could have got the hook up. They said they could see me on their radar, and that we were in for a lively night!

We didn't yaw about much, in fact it was quite steady and we both slept for spells - with the timer set to 1 hour.

Anyway morning was nice weather and we had moved about 60m during the night. Anchor was nice and clean.

The admiral, who had never sailed before said "is it always like this?"

 

[Robin]

Our 16kg Delta anchor usually digs in so well, when it returns to the bow roller it is caked in mud.

We had been at anchor in Newtown Creek for two days, lots of wind from the SW and spring tides giving fast tidal flows in the river. Not at any time did we have any concern for the job the anchor was doing, we had all chain scope down and there were few other boats around to worry about swinging circles.

However on the morning of the third day the wind really got up and whilst we were waiting for the tide to favour our passage we had 23knts of wind against a fast ebb. Needless to say the boat didnt know which way to settle, it was sheering around in all directions on its sufficient but short scope. After a little while of this she started dragging and after a couple of attempts to re-anchor it was time to leave so we gave up.

Did the sheering itself unsettle the anchor, was the 'ploughed field' that is Newtown enough stop it from digging in? We did not before or since have any anchoring problems.

Strong wind against strong tide, yuk! I suspect the boat rode over the top of the anchor and pulled directly from the opposite side it was set? Another possibility is that the snatch at the end of each gyration did the deed, do you use a stretchy snubber? We use a nylon snubber line with a rubber mooring compensator wound in it as well which eliminates all snatch on the system. It is also difficult to anchor (or re-anchor) in strong wind over tide spots as even if you work out the best direction to set the anchor the combination of forces makes it difficult to set it.

Another thought is had the anchor really dragged or were you merely wandering around on a long scope? We had something similar in Newtown years back on our W33 when on day 3 and strong wind over tide we ended up inspecting the antifoul whilst dried out on the mudbank at LW, it also caught several others the same who were late for a Co32 rally in Lymington as a result!

 

[Romeo]

We didn't yaw about much, in fact it was quite steady and we both slept for spells - with the timer set to 1 hour.

Anyway morning was nice weather and we had moved about 60m during the night. Anchor was nice and clean.

The admiral, who had never sailed before said "is it always like this?"

Just for clarity, is that 60 metres or 60 miles that you had moved?

 

[peterb]

35lb CQR on a Najad 380. Anchored near Rosaire Steps at Herm, on clean sand, in a northerly 4 intending to stay the night. Wind backed and increased to a NW7 near HW. Became clear that the anchor was dragging (5:1 scope, all chain). No room to increase scope, so we upped and left for St Peter Port. Suspect that the wind shift was to blame, more than the strengthening.

 

[webcraft]

.
Forgot to say - yes, I have dragged once - in Puilladobhrain, generally considered a secure anchorage. Problem is it gets so crowded you often can't put a decent scope out. Putting out 15m when anchored in 3-5m may be all very well in theory but you definitely want more out if it blows up and if you are surrounded by other boats you just can't do it.

Boat was a Jeanneau Sunshine (36ft fin keel), anchor was ( If I remember) a CQR and we were on a little over 3-1 all-chain scope. No snubber - I hadn't learnt that very useful trick at that point in my sailing career. The anchor was dug in under engine. The wind got up to 25-30 knots straight in the entrance while we were in the pub and the boat had moved a fair way up the anchorage when we returned, luckily missing other anchored boats. Re-anchored in the dark (not easy in a F7 with lots of other boats around and not much room) and kept an anchor watch for the rest of the night. Luckily no harm was done, but I never leave a boat unattended on a short scope now.

Re. chain snubbers - we always use a 3m length of nylon which takes the snatch out of the chain in gusts and stops noise transmission, but I like the idea of a longer length of nylon with a proper rubber snubber for even greater shock absorption.

- W

 

[fireball]

Many moons ago - a 22'er at East Head - Ebb tide, not huge amounts of wind, CQR ~3m chain (!!) and ~20m of line. Nobody on board

Boat was holding fine until a passing dinghy caught the line with his rudder - this set the boat going backwards and I was swimming near the stern with one of my mates.
On noticing the anchored boat behind us getting close my mate swam ashore leaving me to hop on and start the engine - just in time to prevent us from hitting the boat astern! SWMBO then swam out and climbed aboard whilst I continued to motor holding the boat stationery to the ground. Then we reset the anchor and carried on our BBQ .... SWMBO a little black and blue from climbing aboard.

 

[AntarcticPilot]

Extreme example

Many moons ago, my father kept his Halcyon 27 in Dunbar harbour, on a permanent mooring. The ground tackle consisted of two anchors from Humber barges; each weighed about 2 cwt (that's about 100 kilograms each), with separate mooring chain from each to the bow of the boat, and the stern moored by long lines to the harbour wall. The anchors had been dug into the harbour floor by the harbour master. The anchors were probably Hall anchors - they were bought from a barge breaker's yard as scrap, so they didn't cost a lot! The scope was about 5:1, chain, well and truly over-specified.

Anyway, you would have thought this was perfectly secure, and for many years it was. However, one day there was a gale of colossal proportions - well over force 8. The harbour wall at Dunbar is high and protected by rocks, but waves were breaking over it continuously. The harbour is very sheltered, but even so a swell penetrated the harbour, and the wind was blowing directly from the anchor to the boat. We thought we were fine, and could ride it out in the outer harbour - but realized when the wind reached a new peak that the anchor was dragging! Not much - no more than a few feet - but in the confined space that was too much. We hastily got the engine going, cut all the mooring lines free as quickly as we could and motored into the inner harbour, where we were much more sheltered and rode out the storm. During this gale several other boats in the harbour were damaged and at least one completely destroyed.

Moral - even the most secure ground tackle can drag!

 

[Sans Bateau]

.

Re. chain snubbers - we always use a 3m length of nylon which takes the snatch out of the chain in gusts and stops noise transmission, but I like the idea of a longer length of nylon with a proper rubber snubber for even greater shock absorption.

- W

Yes I like this idea too, we use a nylon snubber, but adding a rubber snubber is a good idea. Out of interest, when we were anchored in Newtown, we had about 25mtres of 10mm chain down in 4meters of water. I think Robin got it right, I think we were blown over the anchor, together with the sheering, was our problem.

 

[LadyInBed]

Quite a few years back now I anchored in the wrong place in Lulworth cove, just inside and East of the entrance in all the kelp! 22ft boat on a Bruce, chain and rope.
The rational was to get out of the swell, but the wind picked up some more over night and another nearby boat who also started to drag woke me and warned me that I was dragging.
It was a pitch black night and finding a new spot single handed was no easy matter.

 

[Ubergeekian]

Only once, in Ardanamir. Strong tide NW - SE, variable wind from SW - NE. Every time the wind increased we, and every other boat there, swung round 90 degrees, pulled out, dragged back and dug in again. Avery time the wind dropped we swung back and did the same. Over the night the entire company zig-zagged to the east. I think we motored forward four times - every time we did so there was at least one other boat doing the same.

 

[shamrock]

Only the once, in the lagoon in St Maarten, one of my least favourite places. It was overcast and blowing 25kt when we set the anchor so we couldn't make out the patches of sand and weed. Dropped and set with strong reverse, all OK. About an hour later, wind up to 30 gusting 35 and we start going backwards. Lots of boats around. Thankfully we notice, engine on and can sort it out before there's any damage.

We think what happened is that the weed is very thick with strong roots so when we set, the anchor (33kg rocna) hooked in and held well. After that the roots began to snap, one at a time until there were few enough to let a whole clump come free and us with it. anchor was pretty much swamped in the stuff when it came up.

Next day a big 55 foot schooner went driftabout in a similar way and 'visited' five or six boats before someone got aboard and saved it from ending up on the shore.

We always set the hook hard whether we are stopping for lunch or for days, even if it means trying again and again (record is 7 times at Jost Van Dyke) It's worked for us.

 

[Robin]

Yes I like this idea too, we use a nylon snubber, but adding a rubber snubber is a good idea. Out of interest, when we were anchored in Newtown, we had about 25mtres of 10mm chain down in 4meters of water. I think Robin got it right, I think we were blown over the anchor, together with the sheering, was our problem.

We always used rubber mooring compensators in a nylon snubber line and actually had two, a standard one and a second line with a bigger heavy weather one. Before we had the proprietary mooring compensators (like 30 years ago) we made our own using multiple lengths of bungy whipped across a slack loop in the nylon snubber line. Now we are off to the USA our snubber lines are going with us too! I'm convinced that if you have the right anchor tackle for the boat and set the anchor properly and not in the weed so beloved by seahorses D) then the only real danger of anchor breakout is from momentary snatch loads.

 

[shmoo]

Just for clarity, is that 60 metres or 60 miles that you had moved?

Sorry, metres. Less exciting than 60 miles, which would have put us in Wiltshire somewhere.

I think I would have said 60M if I had meant miles, but I can't always be trusted on details like that.

 

[HoratioHB]

Yes I like this idea too, we use a nylon snubber, but adding a rubber snubber is a good idea. Out of interest, when we were anchored in Newtown, we had about 25mtres of 10mm chain down in 4meters of water. I think Robin got it right, I think we were blown over the anchor, together with the sheering, was our problem.

Little wheeze I got off this forum and spent all last year experimenting with is to put a bight of chain out behind the snubber, ie a great loop of chain from the bow roller down to the bottom and then back up to the snubber attachment on the chain. I used 5m of nylon as my snubber. The bight was normally just less than the depth of water (to stop it rumbling around on the bottom)and had two effects, one was to slow down the shearing/sailing I guess due to the extra drag, the other was to effectively give more scope without having to let out more chain. The weight of the chain bight helps keep the snubber and first part of the chain pulled down. It really seemed to work although in light airs I reduced it to stop it getting tangled around the chain.
We did drag once in a muddy bottom (Indian Creek Antigua) but never once after I used this method. Oh - 20 Kg Delta on a 42ft Jeaneau.

 

[KristiferColumbus]

I dragged about 300 meters in Priory Bay to the south last year but was alerted to the problem about three o'clock in the morning hearing the anchor grinding over the bottom.I wonder if I would have been able to do that if I had a snubber?
I suppose I have had my anchor drag several times but I have never forgotten the lesson I learned several years ago in Priory Bay again.That time I was only saved from total destruction by my anchor mysteriously hooking over a piece of rope tethered to the bottom at both ends.When I got home I found my CQR shank was bent like a banana.Lesson learnt,don't hang about to long when the wind turns onshore.
Anybody know how a piece of rope comes to be tethered in Priory Bay?

 

[npf1]

Horatio - any chance of explaining that technique in a bit more detail (cos I'm fick and didn't quite comprendez!)

 

[DaveS]

Dragging

Once with the current boat: Etap 30, 16kg Delta with 30m of 8mm chain in a depth varying with tide between 2.5 and 3m. Very kelpy bottom. Guess where?

Once with the previous boat (Etap 22) in more interesting circumstances. Bruce 10kg (I think) on 6mm chain, anchored behind island at north side of Carsaig Bay. A pal's E Boat tied alongside. Woke about 0400 with a feeling that something wasn't right, looked outside, and found that the scenery had changed! We'd dragged right across the bay, miraculously avoiding hooking the electricity cable, and hadn't quite gone aground yet.

We re-anchored independently...