What is breaking strain: ground tackle

[Tumshie]

3 hours ago, David Schweizer said:

Launching the Ground tackle suggests throwing it in, but when i did my Boatmaster Licence training, we were taught never to throw an anchor, but to lower it into thre water with the chain and rope neathly piled on the deck so that it will not foul on ther boat, or worse your feet/legs as it goes in, and being a 72 ft passenger boat we had a big anchor.

 

3 hours ago, LadyG said:

pffff .............. try anchoring a 76 footer under sail,  50 metres of chain laid out on deck, .............. preparation is the key.

There will only 10m of chain, which should be OK, and the rope can be lightly tied with rotten string, I can;t remember the nautical term,

 

1 hour ago, David Schweizer said:

What has that got to do with canals, or any non tidal rivers?

 

1 hour ago, David Schweizer said:

Of course they do , as you well know.  As indicated to LadyG, this is a Canal Forum and the maximuim length on most canals is 72ft. As it happens my licence entitled me to captain any passenger carrying boat much larger than the one we were operating.

Ooh a p!$$ing contest - such fun 

 

Ladies meet the Sailing Vessel Flying Dutchman - https://www.scotland-sailing.com/highlands-loch-ness-2019/

 

But at 130ft she is however a tiddler compared to the Lord of the Glens - http://lordoftheglens.co.uk/video.aspx

 

With the Lord of the Glens at 150ft she makes a 72ft passenger ferry look like a mini metro. 

 

Just as well the Caley isn't most canals innit. 

 

And anyone who says the Caley doesn't count is just a sore looser. 

 

 

 

Edited April 21, 2019 by Tumshie

[carlt]

1 hour ago, BruceinSanity said:

The highly experienced contributors to this thread don’t need telling, but for the less experienced who may be reading it, when choosing an anchor’s weight, it’s not whether you can manage to lift it to deploy it, it’s whether you can recover it. 

If I'm heading for a weir with no engine I want an anchor heavy enough to stop the boat not light enough to recover. 

 

When I had the ex-RNLI lifeboat my daily use anchors were 30kg and my "Oh oh! We're heading for the rocks" emergency anchor was over 200kg.

[LadyG]

2 hours ago, BruceinSanity said:

The highly experienced contributors to this thread don’t need telling, but for the less experienced who may be reading it, when choosing an anchor’s weight, it’s not whether you can manage to lift it to deploy it, it’s whether you can recover it. Since you don’t have a winch on a narrowboat, even when it’s straight up and down, if it’s covered in river weed it’s a quite incredible effort to get it back.

I'm not proud, I'd just find two fit young men to lift it for me. 

An FX55 is best part of £1000,  plus another £250 for 50 x 22 mm warp, you don't need to need to leave it to the fishes.

Plus, if it got caught on someone's prop, it would probably remove it. I had a look at the Fortress "user friendly" website,  there is very little in depth technical data, I'm not impressed. It's a marketing exercise. I prefer engineering.

Not sure if I am a highly experienced contributor, the jury is out., but recovery should not be a priority in emergency anchor selection.

 

Edited April 21, 2019 by LadyG
giving myself enough rope

[LadyG]

44 minutes ago, carlt said:

If I'm heading for a weir with no engine I want an anchor heavy enough to stop the boat not light enough to recover. 

 

When I had the ex-RNLI lifeboat my daily use anchors were 30kg and my "Oh oh! We're heading for the rocks" emergency anchor was over 200kg.

Those decks need swabbed!

[carlt]

15 minutes ago, LadyG said:

Those decks need swabbed!

The teak was pulled up and thrown out and the oak deck planks underneath caulked properly and varnished. 

[Alan de Enfield]

1 hour ago, carlt said:

If I'm heading for a weir with no engine I want an anchor heavy enough to stop the boat not light enough to recover. 

 

"Repetition adds emphasis"

 

Recovery is a bonus !!!

 

If I'm heading for a weir with no engine I want an anchor heavy enough to stop the boat not light enough to recover.

[howardang]

1 hour ago, Tumshie said:

 

 

 

Ooh a p!$$ing contest - such fun 

 

Ladies meet the Sailing Vessel Flying Dutchman - https://www.scotland-sailing.com/highlands-loch-ness-2019/

 

But at 130ft she is however a tiddler compared to the Lord of the Glens - http://lordoftheglens.co.uk/video.aspx

 

With the Lord of the Glens at 150ft she makes a 72ft passenger ferry look like a mini metro. 

 

Just as well the Caley isn't most canals innit. 

 

And anyone who says the Caley doesn't count is just a sore looser. 

 

 

 

Well, if you want a p'$$ing contest, how about these for size? 

https://www.bing.com/videos/search?q=anchor+handling+operations&view=detail&mid=FC0A6A591F3BD61EFC2DFC0A6A591F3BD61EFC2D&FORM=VIRE

 

Not really inland waterways though, but brings back happy memories - I think!

 

Howard

[Alan de Enfield]

1 hour ago, Tumshie said:

But at 130ft she is however a tiddler compared to the Lord of the Glens - http://lordoftheglens.co.uk/video.aspx

We were going into the lock as she came out - quite a 'big-girl'.

 

 

[Chewbacka]

Just a thought, but in a narrowboat, not many would venture onto a river if it was flowing much faster than about 2 to 3 mph.  In fact they tend to close the locks on the river Severn if there is much flow, so you can't go anywhere anyway.  So for inland waterways you may want to size you anchor based on a max speed of say 3mph.  Just something to think about.

[Naughty Cal]

3 hours ago, Tumshie said:

 

 

 

Ooh a p!$$ing contest - such fun 

 

Ladies meet the Sailing Vessel Flying Dutchman - https://www.scotland-sailing.com/highlands-loch-ness-2019/

 

But at 130ft she is however a tiddler compared to the Lord of the Glens - http://lordoftheglens.co.uk/video.aspx

 

With the Lord of the Glens at 150ft she makes a 72ft passenger ferry look like a mini metro. 

 

Just as well the Caley isn't most canals innit. 

 

And anyone who says the Caley doesn't count is just a sore looser. 

 

 

 

We woke up one morning to the sight of the Lord of the Glens gliding past the moorings and heading up Neptunes Staircase. It was a sight to behold indeed.

[Naughty Cal]

2 hours ago, LadyG said:

I'm not proud, I'd just find two fit young men to lift it for me. 

An FX55 is best part of £1000,  plus another £250 for 50 x 22 mm warp, you don't need to need to leave it to the fishes.

Plus, if it got caught on someone's prop, it would probably remove it. I had a look at the Fortress "user friendly" website,  there is very little in depth technical data, I'm not impressed. It's a marketing exercise. I prefer engineering.

Not sure if I am a highly experienced contributor, the jury is out., but recovery should not be a priority in emergency anchor selection.

 

I am intrigued as to what waters you are expecting to find yourself on with this 55ft narrowboat.

[cuthound]

17 minutes ago, Naughty Cal said:

I am intrigued as to what waters you are expecting to find yourself on with this 55ft narrowboat.

 

Well, if you get swept over a wier who knows where you might end up? ??

[LadyG]

27 minutes ago, cuthound said:

 

Well, if you get swept over a wier who knows where you might end up? ??

All roads lead to Rome.

[Alan de Enfield]

10 minutes ago, LadyG said:

All roads lead to Rome.

Surely not ?

 

You'll take the high road and I'll take the low road,
And I'll be in Scotland afore you.
Where me and my true love will never meet again,
On the bonnie, bonnie banks of Loch Lomond.

[howardang]

30 minutes ago, LadyG said:

All roads lead to Rome.

The road outside my door leads to Morrisons!

 

Howard

[Naughty Cal]

1 hour ago, cuthound said:

 

Well, if you get swept over a wier who knows where you might end up? ??

The bottom of the weir at a guess.

1 minute ago, howardang said:

The road outside my door leads to Morrisons!

 

Howard

The road outside my door leads to a building site.

[DaveR]

Just to go back a bit to the original question. In towing (and as such anchoring) professionally we used 50% of the breaking load as the guide to safe load for tow wires and anchor equipment. The 1/6 rule for lifting gear SWL is because the shock loading is greater with a "dead load" where as an object in the water (barge, ship, drilling rig) moves as the load comes on in a much easier way.

[Alan de Enfield]

34 minutes ago, DaveR said:

The 1/6 rule for lifting gear SWL is because the shock loading is greater with a "dead load" where as an object in the water (barge, ship, drilling rig) moves as the load comes on in a much easier way.

But a boat drifting down the river with no engine - drops the anchor - there will be a huge shock load much greater than the static load as the anchor sets.

 

15+ tonnes of boat at 3mph will transmit an enormous force as it is pulled to a dead stop.

[howardang]

49 minutes ago, DaveR said:

Just to go back a bit to the original question. In towing (and as such anchoring) professionally we used 50% of the breaking load as the guide to safe load for tow wires and anchor equipment. The 1/6 rule for lifting gear SWL is because the shock loading is greater with a "dead load" where as an object in the water (barge, ship, drilling rig) moves as the load comes on in a much easier way.

Horses for courses, and in situations you describe offshore, there is often/usually a significant catenary to cushion the shock load. That effect is not normally there with the scenarios under discussion. That is why the 1/6th factor is more appropriate in these scenarios. 

 

Howard

[DaveR]

10 hours ago, Alan de Enfield said:

But a boat drifting down the river with no engine - drops the anchor - there will be a huge shock load much greater than the static load as the anchor sets.

 

15+ tonnes of boat at 3mph will transmit an enormous force as it is pulled to a dead stop.

I would agree if the canal boat were a dead weight, but it is not. Even the use of rope as the anchor line produces enough stretch to, relatively quickly, slow the eate of drift down. 

 

10 hours ago, howardang said:

Horses for courses, and in situations you describe offshore, there is often/usually a significant catenary to cushion the shock load. That effect is not normally there with the scenarios under discussion. That is why the 1/6th factor is more appropriate in these scenarios. 

 

Howard

Again it is all relative. Having successfully used the anchor on a ship in an emergency. Scaling down the 48000 tonnes ship, 15 tonne anchor on 3" anchor chain (breaking strain 600,000 lbs) and weighing in at 110lbs per foot. For my 27 tonne narrow boat with a 15kg Danforth on 28mm polyprop after 10m of half inch chain. The narrow boat has more stopping power with the anchor. Anchors do not bite in a dead stop.

 

[Alan de Enfield]

3 minutes ago, DaveR said:

Anchors do not bite in a dead stop.

My experience of 'small boat' anchoring suggests differently.

 

There have been a few instances reported on this forum of NB's emergency anchoring and the shock load snapping off the T-Stud.

 

I have personal experience of anchoring my 38 foot Cat. in a 3 knot tide when the anchor set immediately and the shock loading ripped the 'winch' out of its mountings snapping the steel mounting plate.

 

I can well understand your suggestion that it would not happen with a Danforth, as a Danforth will rarely (if ever) set 1st time - it will drag along the bottom setting, breaking out, setting, breaking out until it eventually sets properly.

 

With 2nd generation anchors (Bruce, Danforth Etc) it is common to actually have to reverse to get the anchor set, this does not seem to be needed with the latest generation Mantus, Manson, Fortress etc.

Lloyds have actually now added a new category of "Super High Holding Power" to their anchor ratings to accommodate these 'new' anchors.

 

We are talking about a very different scenario to that of a 'big-ship' with a few miles of sea-room.

In the case of a boat 200 yards from going over a weir when the engine fails, you need a hook that'll set 1st time - every time.

[howardang]

5 minutes ago, Alan de Enfield said:

 

 

We are talking about a very different scenario to that of a 'big-ship' with a few miles of sea-room.

In the case of a boat 200 yards from going over a weir when the engine fails, you need a hook that'll set 1st time - every time.

I disagree that the scenarios are very different - the principles of good seamanship are the same no matter what vessel you are on.  It is obviously just a matter of scale. It is often not  the case that there are miles of sea room in a large ship scenario. It is just as likely that the anchor is needed to stop a ship which may have suffered a breakdown in a dock with very little room before a collision occurs, either with a berthed ship or a dock wall, a very similar case to the river/weir case you mention. That is one of the reasons why a prudent master makes sure that the anchors are cleared away, ideally walked out of the pipe and the windlass is manned with the brake when berthing. Courts don't look kindly on cases where an accident or collision occurs with one or both anchors  still in the pipe.

 

In the river/weir scenario, there is not so much debate about the nature of the bottom and as you know the most efficient anchor in the world will not save you if the river bed is unforgiving, even if the average boater is quick enough to let go in time! 

 

Howard

 

 

 

 

 

 

 

 

[LadyG]

19 hours ago, Alan de Enfield said:

"Repetition adds emphasis"

 

Recovery is a bonus !!!

 

If I'm heading for a weir with no engine I want an anchor heavy enough to stop the boat not light enough to recover.

I've got this clearer now, thanks all. The perfect scenario of  shipping in harbour having two anchors ready to deploy failed in a case which is on record, here somewhere. The Master did not take precautions, and there was a collision as the ship dragged.

With  NB, we have several unknowns, the skipper may not be in a position to launch the anchor at the optimum time, he has to leave the helm and to let go the anchor.

Edited April 22, 2019 by LadyG

[MtB]

12 hours ago, Alan de Enfield said:

But a boat drifting down the river with no engine - drops the anchor - there will be a huge shock load much greater than the static load as the anchor sets.

 

15+ tonnes of boat at 3mph will transmit an enormous force as it is pulled to a dead stop.

 

But it won't come to a dead stop. The anchor line roughly forms a catenary shape prior to the anchor setting, and the catenary being straightened out (along with the stretch in the rope warp) means a rapid deceleration happens, not a dead stop.

 

Assuming the anchor sets solid, which seems highly unlikely to me. 

 

 

[carlt]

And a decent nylon anchor line has a fair bit of shock absorbing stretch.