Thursday, April 22, 2010

And More Anchor Talk

The bronze anchor roller with extensions that I bought from Port Townsend is not going to work.  It was designed for a much larger boat and is way too heavy. It was also designed for a vessel fitted with a bowsprit that could be reefed forward to reduce the overall vessel length. I'll  salvage the roller extensions and enlarge the hole in the standard gammon iron to accept the larger 3/4 inch shaft. One roller and extension will be positioned and attached to the gammon iron to accomodate a Rocna anchor and the other to handle an aluminum Spade anchor. Two Rocnas living side by side on the two gammon iron extensions would have fouled each other under the sprit.

Rocna recommends the model 15 for a BCC size vessel ( 33 lbs is weight enough).  The anchor will shackle to 75 feet of 5/16 inch G4 chain spliced to 200 feet of 5/8 inch (16 mm) Gleistein polyester square plait (same as 8 plait) line.  The entire rode will stow just forward of the mast to keep weight as close to the center of the boat as possible. The windlass gypsy grips the 8 plait line better than 3 strand and the plaited line stows in a much smaller space than a comparable length of nylon. The polyester has half the stretch of nylon, is stronger when wet and has better abrasion resistance.

The secondary rode will consist of an aluminum model 20 Spade (weighs only 9 kg) on 30 feet of 5/16 inch G4 chain spliced to 200 ft of 9/16 inch Anchorbraid 8 plait nylon.  The entire rode is light enough to llive all the way forward in the anchor locker. The stretchy nylon rode is its own snubber at a 5 to 1 scope in 10 ft of water with 75 ft of rode out.

Manson makes an aluminum Danforth look alike that might work well as a stern achcor.  After I get the gammon iron and rollers put together and the new bowsprit dry-fitted I will post a few photos that should illustrate what I am talking about more clearly.

Saturday, April 10, 2010

Running Rigging

The mains’l will be loose footed and set with a peak and throat halyard, an outhaul and a downhaul. The stays’l will be hanked to the forestay and set with the halyard rove over a strop block. The head sails; Yankee, jib and Genoa, will all be free flying from a bowsprit traveler on a Coligo luff line furler. The jib halyard will be on a two part purchase. The topsail, jib and staysail halyards will fall to port while both the peak and throat mainsail halyards will fall to the starboard side so the sail can be hoisted and doused single handed.

The upper peak halyard block will be on the mast band with the jib halyard block. The lower peak halyard block is attached to the next mast band down with the port and starboard running backstays. Another mast band still lower down the mast will stay the stays’l halyard block on the forward side of the mast and the throat halyard crane on the aft side.

The port and starboard topping lifts and associated lazy jack lines will lead to a pair of cheek blocks mounted on the mast just below the lower peak halyard mast band.

The spar builder and rigger share some concern about the peak halyard arrangement as drawn on the sail plan. They contend that the fall should be on the lower block to reduce the potential for chafe and the fixed standing end of the halyard should be attached to a block becket instead of the gaff to allow the gaff span saddle(s) to be released when the main is down thereby eliminating the need for slits or openings in the mains’l cover.

I disagree. If you move the standing end of the peak halyard to a becket you keep the 3 to 1 advantage but on a two point lift from a single span…..ok, but not as comforting as the designed 3 point lift. Or you could reeve a two span lift with two saddles and a 4 to 1 advantage, but that introduces more friction and a longer tail. In his book “Gaff Rig”, John Leather specifically says that the peak halyard fall should be led to the upper block to achieve maximum peak height. And, employing a sail cover without openings should not be a problem as currently drawn. The one gaff span saddle and the standing end secured to the gaff can both be released and the halyard belayed to the mast to install the mains’l cover.

Wednesday, April 7, 2010

Standing Rigging

Bruce Tipton is an accomplished Port Townsend based spar maker.  Bruce will build the Sitka Spruce mast, gaff and boom. Bruce will also install as much of the rig as possible before shipping to Galveston. In an effort to document the details as shown on the sail and spar plan drawings I have tried to describe the various components that make up the standing rigging below: 
Each of the four shrouds will be 7 mm Dynex Dux line from Coligio Marine. The sprit stays will be 11mm dux and the headstays 9 mm.   The aft lower shrouds will terminate at the spreader and at the deck level at Coligio terminator fitting, Vectran lashings and deadeyes on the chain plate.

The cap shroud is attached to the mast band that also supports the jib halyard block and the upper peak halyard block. The lower end of the cap shroud is attached to a single chain plate in the same fashion as the lowers. Also on this upper mast band on the aft side next to the upper peak halyard block is the upper end of the topsail and trys’l leader. If this leader line is permanently set it should stand well off the mast. Perhaps it should be on a Pelican hook so it can be set up only when needed?

The sail plan calls for the forestay to bridle to the mast with support from a chock on the aft face of the mast. But since the stays’l halyard block on the forward side of the mast and the throat halyard crane on the aft face of the mast will both be at this same height maybe a mast band that accommodates all three is a good solution? The new bronze gammon iron cum anchor roller assembly is designed to accept the forestay at the deck on its Y shaped fitting just above the inboard end of the bowsprit. If a pelican hook could be a part of the forestay end fitting, it could be easily released and tied back to the mast so that a light air genoa or the asymmetrical spinnacker could be easily tacked through the foretriangle. Mr. Burnett disapproves de-tuning the rig in this fashion.

The head stay is positioned a few feet above the mast band that secures the cap shroud and upper peak halyard block. Since all sails set on the sprit end will be free flying the headstay is only assigned to mast support duties. And its only companion at this altitude is the spinnaker halyard block on a strop so no need for a mast band here. The head stay will attach on a soft eye against a thumb attached to the aft face of the mast; and at the bowsprit end on a bronze turnbuckle pinned to the cranseiron.

The running backstays attach on the port and starboard side of the mast at the lower peak halyard block location. A mast band with 3 or 4 eyes and toggles can stay these and the lower peak halyard block. How to attach the runners on deck is less clear to me. They have to be easily accessed on the inside of the bulwarks so deck mounted pad eyes would serve better than chain plates.  The leads should be fair to the self-tailing jib winches but not rely solely on them. They should be on a purchase and secure to a cleat or a cam cleat. I need to sit in the cockpit and take some measurements to see how these lines will fall.

OK I think I got everybody; two aft lowers at the spreader, 2 cap shrouds at the upper peak block in company with the jib halyard, the forestay between the lower peak halyard block and the spreader with the headstay, a pair of runners at the lower peak halyard block and lastly a topsail leader line running from the upper peak halyard block mast band to the main deck.

Materials list:
  • Dux for 4 shrouds, forestay, headstay, 2 runner pennants, tops’l leader, sprit stays and luff rope for genoa, jib and yankee head sails.
  • Black terminators and deadeyes for shrouds and stays.
  • New England V-100 line in black for lashings.
  • Bronze opening gaff span saddle.
  • Coligo luff line furler.
  • Bronze turnbuckles for forestay, headstay and sprit stays.
  • Bronze rod for bobstay.
  • Three black anodized aluminum (keep it light) mast bands, or just stick with bronze.
  • Tufnel blocks-singles, doubles and fiddles.
  • Gaff and main boom goosenecks.
  • Reef comb and bee blocks for reef pennants.
  • Bronze leathered gaff saddle.
  • Mast hoops black PVC.
  • Boom bale (send existing one).
  • Bronze deck pad eyes for running backstays.
  • Bronze mast bands.

Monday, April 5, 2010

More Anchor Talk

Steve Dashew makes an interesting case for mult-plait polyester instead of nylon. The 5/8 inch breaking strength is 12,200 and at 30% of breaking the working load limit is 3600 pounds. The polyester holds its full strength when wet, has more abrasion resistance and stretches less than nylon. The 8 plait in nylon is readily available but in polyester it cannot be found in diameters under one inch in the US. It looks like Yale used to make it but it is not on their website now.  Gleistein in Germany and Trem in Italy have it in 16mm.