help me for anchor locker spacing

Hello, this is Ray, who's studying marine interior in New Zealand.

While I was studying, I was wondering how long I should design for the anchor locker of my 8m yacht.

Just in case of being struck, impact should be considered for that anchor locker, so I have done a research for the anchor on 8m vessel.

Anchor size is going to be 42", 106.68cm, and how long should it be anchor locker for the design?


Thank you for reading newbies thread.

 

Skenes has the table for building a proper chain box that will accept and discharge the chain with no hassles.

 

Here's what I have on file:

from an old project, don't remember the source, but all sources I found stress the need for a tall narrow locker to prevent the chain from jamming.

 

Are you talking about anchor storage ? or anchor chain storage ?

The best anchor chain storage lockers are tall pyramids. Wide base, narrow top and mounted as low as possible in the forepeak to generate maximum gravity fall on the chain as it exits the windlass and stacks in the box.. . Chain naturally stacks in a pyramid shape, the narrowing shoulders of the pyramid prevent the chain from shifting and tangling when sailing and as you know all heavy equipment on a sailing yacht must be secured to withstand a 360 degree roll. Its a simple task to securely close off the small neck on top of a pyramid shaped anchor chain locker by driving several ss bars thru the anchor chain box walls..

A proper ocean going yacht carries 100 meters of chain.

Good anchor and chain sizing knowledge is contained here.
http://www.rocna.com/kb/Chain

 

An 8m boat in my neck of the woods normally doesn't carry chain other than 3 or 4 M on the bitter end section attached to the anchor. As such the storage should be suited to accomidate rope, normally samson braid but often three strand twisted nylon. The big requirements being volume and shape to allow the rhode to naturally coil and uncoil, a drain into the bilge at the bottom and an access hatch to allow freeing up any fouling of the coils in addition to airing out. Anchors are generally lashed to the deck, or in a bow roller set up.

A yacht is not defined by the vessel but by the care and love of her owner.

 

Rope chain anchoring works, but since this Kiwi is doing a design exercise it would be wise to include proper ground tackle handling in his design.

The design challenge for ground tackle is for the anchor to be self launching off the stem roller and since all sailing yachts are sensitive to weight in the ends....get the anchor chain weight aft as close to the mast step as possible.

Im presently anchored in 17 meters of water with 60 meters of chain out. A very typical scenario that would be impractical with a rope chain rode

 

Agree on the chain locker design aspect of it if the vessel in question is of heavy displacement where by the weight of 100M of chain has a negliable effect on fore and aft trim. However if of light displacement not sure it's a good idea to have that weight forward . Might be acceptiable if as you say if it can be routed aft somewhat away from the ends. Again it's one of those questions that possibly has two answers My past vessels (motorsailers) 26/28 ft, 10,000 displ. I only used rope/chain combinations with a one oversize rated plow on the bow. Often anchored in 8 to 10 fathom (20M) without problems. However depending on the conditions and time I also send down a little weighted helper on a messenger. In heavy anchoring weather I still prefer my 25% oversize fisherman on rocky bottoms.(taking care on tide and wind changes) The one anchor I mistrust in our rocky bottom area is a bruce. No doubt chain is the best but not all small craft are equipped with a windlass or two wrestlers on crew -- Geo.

A yacht is not defined by the vessel but by the care and love of her owner