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Alan de Enfield

Member Since 20 Oct 2010
Offline Last Active Yesterday, 10:15 PM
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Posts I've Made

In Topic: refitting out narrow boat

Yesterday, 09:11 PM

i have the boat out of the water she had 2 holes in bottom some one had post create repaired (now fixed) drove her up from nuneaton np , the main reason for replate was 4mm in places on bottom sides were ok , could have just repaired but as i intend to live on her decided to fully repair with 10mm botttom , am also making a few changes , moved the front bulkhead back so got a bit more sitting out area in the summer , making her a large one bed  , also going to fit new windows

 

As you have added several tonnes in weight with the ADDITIONAL 10mm base plate you will need to check the height above the waterline of any hull-openings (engine air-intakes, sink drains, exhaust etc etc) to make sure they are a safe height (recommendation is 10")

 

If they are now too low you will need to remove ballast from under the floor - ideal time - as whilst you are moving bulkheads etc, you can lift the floor and remove the ballast.


In Topic: Choosing The Right Anchor

Yesterday, 08:18 PM

That table is missing quite a lot of anchor types and seems to be focused on plough anchors. Mine is a Stockless anchor.

 

These days it seems no one is using anything other than 'plough' type anchors - another series of tests from "Yachting Monthly"

 

Attached File  Yachting Monthly -Anchor Test Nov09.pdf   1.06MB   6 downloads


In Topic: Choosing The Right Anchor

Yesterday, 08:08 PM

That table is missing quite a lot of anchor types and seems to be focused on plough anchors. Mine is a Stockless anchor.

 

Each to their own - but as quoted above :

 

In the same locations stockless anchors four times the weight were recording pulls a quarter of the Rocna’s results.

 

Stockless anchors are consistently out performed by modern variants. (by a factor of 16 times in the case of the Rocna)

 

As Ian says in post #11 - for a canal / river boat the anchor is the last chance and needs to work 1st time - everytime. For a sea going / estuary boat, if it doesn't set immediately it doesn't matter and you can just re-set it. 

 

Recently our 20Kg Brittany anchor ( a fairly good one but which we are currently replacing with a 30kg Mantus) dragged about 6 or 7 times during the night, the anchor alarm sounded and we just re-deployed eventually getting 10x water depth (in 6 foot of water) with 100% chain.

 

Maybe it is time to review your anchor and the requirements you have for it.


In Topic: Choosing The Right Anchor

Yesterday, 05:14 PM

Has a narrowboat ever been swept over a weir?

 

Yes - quite a lot.

 

There was one I know of on the Trent last year.

Caught on the 'dolphins', wife fell overboard, husband grabbed her, couldn't turn off the engine, prop still going round, had to let her go to avoid her getting cut-up by the prop.

Wife went over the weir, he stopped the engine, NB 'rolled under' the Dolphins, he was swept overboard.

 

Boat righted, went into the trees, stern rails, top-box etc all smashed, husband and wife survived, boat recovered.

 

C&RT provided a skipper' to get the boat into our marina as they were a bit 'frit' of going alone.

 

Year before - we pulled a boat 'off the wei'r on the Trent - fortunately his anchor had set about 50 yards before the weir, but it was a brown-trousers job.

 

Don't forget that in times of high water, boats in a hurry would 'shoot the weirs' to get back to reload quicker - waiting for the lock was time, time was money. (and they were a lot bigger and deeper draughted than a NB)


In Topic: Choosing The Right Anchor

Yesterday, 04:32 PM

Can you advise who did this testing?

 

I found more tests here http://www.petersmit...nce-testing.php

 

I always seem to find good things in Oz and NZ!

 

I believe it was part of a series of tests undertaken by Motor Boat Monthly -

Here is another review in which they did not bother to test the Danforth.

 

Attached File  MBM_Rightpick Anchor Selection.pdf   5.86MB   6 downloads

 

They didn't test the Mantus, but did test the Rocna and the Manson (2 of the 'other' latest generation anchors).

I understand that Lloyds Shipping had to add an extra category of 'certification' called SHHP (Super High Holding Power) to accommodate these latest designs which are so much better than the HHP (High Holding Power) of previous designs, such as the Bruce.

 

Anchors can also be tested against others with the desired standard; should they hold at least the same load in comparison, this then is accepted as equivalent. Its designer confident that superior performance would be displayed, the Rocna anchor was tested by RINA against a New Zealand built copy which already had SHHP classification from Lloyd’s Register. In clay, the Rocna 25 recorded pulls at an average of 6,250 kgf, while the larger Manson Supreme 27 kg managed an average of 4,665 kgf; in soft mud, the Rocna averaged 635 kgf versus the copy’s 560 kgf. In the same locations stockless anchors four times the weight were recording pulls a quarter of the Rocna’s results. Unfortunately such test results are rarely published so inspecting the basis of classification can be difficult.

 

The anchor weight is not always the most critical guide to performance.

 

As can be seen on the MBM tests a much lighter (22lb) 'Fortress' anchor outperformed many of the heavy weights (38-39lb) under test