Author Topic: Anchor Roller Modification  (Read 3068 times)

blue-max

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Anchor Roller Modification
« on: May 04 2016, 07:11 »
[Topic split by Nigel]

Can anyone explain to me why it is nessary to have a wider drop nose fairlead than the fixed channel as is so clearly shown on nigel's photos.

It means that the chain runs against the side of the fixed channel and also makes fitting a chain stopper difficult if not impossible. On this arrangement the rollers should perhaps have their centres offset. My idea because I want to fit a bigger anchor with a longer shank (45 cm) is to extend the roller forward. I plan to have a plate roughly 15 cm x15 cm welded at the base of the existing fitting so a pre-made fixed roller can be welded in an extended position. The roller in the new fitting will be removed and the holes for the pin used for hinging the adapted drop nose fitting. The existing drop nose component will be taken apart and slimmed down to fit inside the new roller channel (85mm) with new rollers. On the starboard side I may fill the gap caused between the new fitting and the cranked side of the original bow roller fitting.
Any thoughts about this before I commit?

Salty

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Re: Anchor Roller Modification
« Reply #1 on: May 05 2016, 04:54 »
[Topic split by Nigel]

My idea ..........is to extend the roller forward. I plan to have a plate roughly 15 cm x15 cm welded at the base of the existing fitting so a pre-made fixed roller can be welded in an extended position.

Any thoughts about this before I commit?

Think about the forces involved and the extra loading on where your bow roller is secured to the deck that will result from this extension. Wanting a bigger anchor is not necessarily the same thing as actually needing a bigger anchor. A more efficient anchor does not necessarily need to be bigger than the standard size anchor that Bavaria provide. Indeed at last years Southampton boat show, there was a stand there where several different types of anchor were compared with a new type, and all were of the same size for a fair comparison. The new type of anchor, and I'm sorry I can't remember what it was called or who made it, was very considerably more efficient than the Bruce pattern anchor my boat was provided with and which I still use. When I was at sea and when at anchor, we always kept an anchor watch, and if there was any chance of the anchor dragging, we either paid out more chain which sorted the problem, or we up anchored and steamed around until the weather conditions improved or a more sheltered anchorage was found. Part of the secret of anchoring is to put out enough chain to ensure that the shank lays parallel to the sea bed where the anchor then serves to secure the end of the chain. In those days it was the length of chain on the sea bed that held the ship, not the anchor.

blue-max

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Re: Anchor Roller Modification
« Reply #2 on: May 06 2016, 06:00 »
Strength can be designed in to any modification and extension - i can see from modern yacts with straight stems an extended bow roller is the norm - it avoids damage to the grp from a swinging anchor.I'm still looking for a reason for the wider drop roller which also lacks strength and is prone to bending/distortion. Also the current arrangement does not afford any space for a chain stopper which is useful and takes the strain off the windlass when at anchor. I fancy an Ultra anchor - made locally and goes well with the stainless chain - 27 kg is the recommended weight and the shank to the pin hole is 45 cm. It is self launching so maybe I don't need to bother with the articulated front rollers.