Blimey, my anchor's BIG!

[David W]

Soooo, after muchos research and reading I worked out that for our boat 70 x 12 widebeam and approx 40 tonnes we would need a huge anchor and a lot of chain to be super safe on the Thames.

 

It's just been delivered to my office - and it's MASSIVE! I didn't really pay attention to the dimensions on the website (stupidly). Am now hit with the quandary of where to store the bloody thing... I'm thinking the roof somewhere. Just not sure where or how...

 

It's a 30kg Danforth "style" from here. Bit of a bargain, actually. I also got 15m of chain for it, additional rope on order elsewhere.

 

So, to my question - does anyone have one as big and, if you do, where and how do you keep it??

 

 

[Paul C]

Well, you have a 70x12 widebeam, there must be space somewhere......I guess you'll be wanting an anchor winch too. And the electrics for it.

 

We keep ours under the front seat.

[Alan de Enfield]

A danforth is not a particularly efficient / effective anchor design and the weight /size of these anchors is much higher than (say) a Bruce anchor for a partiular boat weight.

 

As an example for a 60 foot - 25 tonne boat the recommended Bruce is 20kgs whilst the recommended Danforth is 40kgs.

 

You should probably have a Danforth around 40-50kgs for your boat (70 foot & 40 tonnes)- alternatively 2 anchors each of 30kgs would 'do the job'

 

I would suggest that in order to maximise the effectiveness of what you have got - that you go for 100% chain

Suggested chain would be AT LEAST 12mm

Breaking strain of 12mm calibrated chain is only 7 tonnes, and 30 metre weighs 114 kgs

 

You may have to look at the possibility of having bracket(s) made for the bow of your boat and have the anchors 'hanging' there - ala 'big ships'.

 

Have you considered how you are going to deploy and retrieve an anchor of this weight ?

 

Edit to add link

 

http://www.jimmygreen.co.uk/p/technical/chandlery-technical-articles/chain-strength-weight-guide

 

Note - an anchors holding ability (and hence recommended size) is detrmined by a number of factors in addition to boat size and weight - bottom type, amount of chain used etc etc

Edited April 2, 2014 by Alan de Enfield

[Phil Ambrose]

Wherever you keep it make sure you can deploy it easily.

Phil

[Paul's Nulife4-2]

Hi ya,

Good size,if 100% Chain !.

I've only got a 41ft X 11ft Widebeam, But Anchor A LOT.

I'm sure you know that it's not necessarily the size of your Anchor,,it's how you use it.

So don't be shy,Practice,Practice, & Practice.

I would rig it for immediate use,& store as low down as possible.

I've got 1 X 25kg Main, & 2 X 20kg Second and Kedge,Danforth type Anchors.

And a 25kg Delta Anchor.

All on Chain, Totaling some 60mts, So i can set 'For an Aft' or 'Bow Tandom' Or 'Bow Y' Depending on Ground,Length of Stay and Weather conditions.

 

All my anchors are Stored ready to Deploy, both on the Bow and at the Stern. With the Delta on the fordeck patiently waiting in reserve.

Edited April 2, 2014 by Paul's Nulife4-2

[Alan de Enfield]

 

Factors such as vessel windage, displacement, beam, length, existing chain size and overall what the vessel will be used for all marry together to determine the best size for you. This isn't an exact A=B so it pays to err on the side of caution if in doubt.

 

From a NZ boating website

[Paul's Nulife4-2]

Good guide Alan,

 

It's also worth noting, weight of Anchor used on the graph is in pounds,not Kg.

[Alan de Enfield]

Good guide Alan,

 

It's also worth noting, weight of Anchor used on the graph is in pounds,not Kg.

 

Agreed - but it does confirm that a 70 foot boat 'should' have at least a 100lb / 125lb anchor (50- 60kg approx) and 'heavy' boats, and blunt bows boats need bigger anchors.

[Keeping Up]

But does it take into account the shape of the boat, especially if it's a narrowboat (although I know the OP has a widebeam)

[Paul's Nulife4-2]

Oh yes, Your Probably Spot on Alan. ( How many meters to 70ft anyway,,21ish ?)

I just thought it would be an easy thing for people to 'not notice'. Especially as they use Meters for boat length. But Pounds for Anchor Weight.

To be honest,don't mess about when it's your home,its worth spending a bit on an Anchor or as my preference is Anchors and loads of Chain. I rest well at night !.

And as we both suggested, There are SO many variables. But one rule I stick to is More Chain is good in most cases!.

Edited April 2, 2014 by Paul's Nulife4-2

[nb Innisfree]

50kg! Gordon Bennet, where am I going to fit a derrick to lift and deploy it? Might find room on our rear cruiser deck but no room at the front. With my not inconsiderable upper body strength I wouldn't have hesitated in lifting and deploying it when I was younger but I wouldn't risk my back now.

[Paul's Nulife4-2]

Yes,it's heavy isn't it,awkward, and a bugger if dropped on your foot, Electronic or Mechanical help is a big advantage, There is a cpl of pictures in I think the 'General interest' section of the Gallery of my Tiny, but capable Electric Winch,and Howser tube on my fore deck. That I find invaluable,,but then again I am a Single Hander,as the dog can't help with Chain !.

 

It's also worth noting and proving the Anchor size Fitted if and when you have any Survey or RNLI Boat Safety Cheacks done. For insurance purposes !.

Edited April 2, 2014 by Paul's Nulife4-2

[Alan de Enfield]

Its often a problem that buyers (of anything) do not appreciate the implications of their choice - it could be buying a Grade 2 listed building, and when you put up a 'security light' to light up your path - you get fined £1000's, buying a dog and realising that when you go on holiday you either take it with you, or pay to put it in kennels, or buying a turkey and not realising that you have to kill it before eating it, or

buying a humungous boat and not considering the safety equipment and its deployment or retrieval.

 

It is pointless having a tiddly anchor, as all it will do is give you a false sense of security.

 

One of the most effective ways of improving ( or worsening ) the likelyhood of dragging the anchor is to change the scope of the rode / chain

 

 

Scope / Holding Power

 

10:1 100%

7:1 91%

6:1 85%

5:1 77%

4:1 67%

3:1 53%

2:1 35%

 

 

scope of 2:1 (length = 2x water depth) makes the anchor only 35% effective

scope of 3:1 (length = 3x water depth) makes the anchor only 53% effective

scope of 5:1 (length = 5x water depth) makes the anchor only 77% effective

scope of 10:1 (length = 10 times water depth) makes the anchor 100% effective.

 

If you are using a 'low efficiency' anchor like a Danforth then you cannot afford to have it working at 23% efficiency - or even 50% efficiency.

 

Edit as the table didnt work

Edited April 2, 2014 by Alan de Enfield

[Grace and Favour]

I well recall the problems I had in researching the required anchor & chain requirements for our boat (60' x 12' and 35 tonnes)

 

Despite numerous conversations with chandlers, and even anchor manufacturers, the advice we received was either vague, or contradictory.

 

(And also had a problem in that the exit for the hawse pipe was low, and the anchor shank would have to be short!

 

Eventually decided to go for a 35Kg Halls, with 40m of 10mm grade 80 Stainless chain.

 

And, as my name is not Geoff Capes, installed a winch to lift it all.

 

All in all, 'twas an expensive job, though, as some members will recall, we did need to deploy it in an emergency half a mile above Cromwell Lock on the River Trent - -

 

It was money very well spent.

 

So my advice to the OP is take your time to determine accurately what you need, err on the side of caution (over spec not under spec), do the installation well.

 

Remember, you can have a short cut with your hair, and take a short cut across the park, but never take a short cut with your safety.

Edited April 2, 2014 by Grace & Favour

[John V]

20 metre Humber barge I have 160 lb CQR 100 metres 12mm chain and a Lowfrens Falkon winch. it cost a lot but in a tideway it gives excellent peace of mind

[DustyDave]

That's a big anchor! That's a huge boat! Got any piccies for me to drool over? I'm not sure I could deploy a 30kg anchor of that size without damaging the boat or myself.

 

Dave

[Paul C]

That's a big anchor! That's a huge boat! Got any piccies for me to drool over? I'm not sure I could deploy a 30kg anchor of that size without damaging the boat or myself.

 

Dave

 

I think in the heat of the moment with the adrenalin flowing, deploying a 30kg anchor would be possible. Retrieving would be the challenge...

[patty-ann]

Especially if it sinks in the mud.

[Paul C]

Especially if it sinks in the mud.

 

I believe (never had to do it for real though...) the unsticking is easy - you drive the boat over the anchor and use the momentum of the boat to turn/unhook it from the bottom). Its the pulling it up out the water, especially once its weight of 30kg is felt in air, rather than the slightly lower force while it displaces water.

[Alan de Enfield]

John V, on 02 Apr 2014 - 7:56 PM, said:

20 metre Humber barge I have 160 lb CQR 100 metres 12mm chain and a Lowfrens Falkon winch. it cost a lot but in a tideway it gives excellent peace of mind

 

CQR - one of the best overall performing anchors. Not a lot between those and the Bruce

[ditchcrawler]

Oh yes, Your Probably Spot on Alan. ( How many meters to 70ft anyway,,21ish ?)

I just thought it would be an easy thing for people to 'not notice'. Especially as they use Meters for boat length. But Pounds for Anchor Weight.

To be honest,don't mess about when it's your home,its worth spending a bit on an Anchor or as my preference is Anchors and loads of Chain. I rest well at night !.

And as we both suggested, There are SO many variables. But one rule I stick to is More Chain is good in most cases!.

But you are out on the lumpy stuff, not on the Thames

[Alan de Enfield]

 

I believe (never had to do it for real though...) the unsticking is easy - you drive the boat over the anchor and use the momentum of the boat to turn/unhook it from the bottom). Its the pulling it up out the water, especially once its weight of 30kg is felt in air, rather than the slightly lower force while it displaces water.

 

It is easy - when you do it on a daily (or multiple times a day - ie sea fishing) you use a technique called 'Alderney Ring' where a ring and a buoy + the engine do all the work for you.

 

https://www.youtube.com/watch?v=-7v8uiDWFnE

[Bod]

 

It is easy - when you do it on a daily (or multiple times a day - ie sea fishing) you use a technique called 'Alderney Ring' where a ring and a buoy + the engine do all the work for you.

 

https://www.youtube.com/watch?v=-7v8uiDWFnE

 

Be an interesting exercise, on a canal, with a narrowboat!

 

bod

[Alan de Enfield]

 

Be an interesting exercise, on a canal, with a narrowboat!

 

bod

 

I cannot imagine the need on a canal just get off and walk.

 

I think as far as narowboats/fat boats are concerned if we need to deploy the anchor its likely to be an emergency on a river and the last thing I'd worry about is losing £100 anchor - I just want a guarantee that it will keep me off the weir until the problem is resolved, or I'm towed out of danger - just cut it away onece the problem is resolved.

 

Having said that I'm sure there would be plenty of room to use the Alderney Ring on the Trent, Severn, Thames and probably a few more.

[Paul's Nulife4-2]

But you are out on the lumpy stuff, not on the Thames

Yep, But if someone is thinking of getting an Anchor for there Boat, Then get the Proper Set up for That Boat Size,in a Worst Case scenario situation.

in my view,It's pointless having a completely useless, undersized Anchor in an Emergency

Situation,on relatively Deep,Fast Flowing Commercial Tidal Rivers, or even some Canals like the Caledonian Canal for instance !.

After all,One would hope you would have a life jacket for example,Would you prefer a 3rd hand Child's one off of EBay, for an Adult !.

Or one that is Fit for purpose,in a worst case scenario !.

Would you want a Car with 'Sort of Breaks' !, OR one 'With Breaks' !.

Just my view, it's ofcourse a personal choice.

Brings to mind an advert currently on YV ref Parachutes,Shark Cages and Climbing Rope. Makes me smile.

Edited April 2, 2014 by Paul's Nulife4-2