For more complete description and information, also got to: www.EmeraldOE.com
THE BOAT
The hull is based on a scaled-up version of the traditional multi-chined Seabright Skiff, considered one of the most seaworthy small craft. It is made from multiple layers of marine plywood fully sheathed in epoxy-impregnated Xynole polyester cloth. A box keel provides a sump for the engine, tankage, and internal ballast, making for a low center of gravity. Foam-core sandwich decks and cabin tops reduce weight above. The hollow box spruce masts were originally junk-rigged, so they are free standing. When it was converted to a twin-headsail ketch, shrouds were added to the main mast to provide counter-tension to the headsail stays. The standing rigging is redundant for its support. The mizzen remains unstayed.
The boat is in excellent condition. There are no leaks to the below decks; there is never any mildew even after being laid up for months at a time. Every single item in the inventory above functions like new. In addition, there are original manuals for nearly every item listed.
Unique feature 1 – The Keel
A 3’ draft is unusual for 50’ monohull. This is typically achieved with a tilting centerboard. The impact is tenderness and reduced stability because of a higher center of gravity. That can be addressed with a lifting, ballasted keel. Tien Hou’s NACA foil shaped keel adds 3500 lb. of ballast that extends to a draft of 6’ 5”. This provides the stiffness of a deep-keel hull and full righting ability in the event of a knock down. At its base is a delta-shaped foil wing that improves hydrodynamic effectiveness in reducing leeway. The wing tucks snugly under the box-keel when the keel is raised, allowing the vessel to lay upright if dried out on a level seabed; it can be careened for inspection or cleaning without tilting.
Lifting ballasted keel designs are rarer than light weight centerboards because they are more challenging to engineer. The system I designed for Tien Hou met that challenge and has functioned flawlessly for 17 years. The keel retracts vertically into a 14” wide trunk separating the two berths in the main cabin that extends just 19” above the cushions. Drop leaf dining tables hang on the sides. Thus, some privacy when sleeping but face-to-face conversation at mealtimes.
The trunk’s 2” laminated walls support the two 4” x 8” laminated beams that the keel hangs on. A 2” schedule 80 ss pipe riding on greased Delrin plain bearings does the heavy lifting. As the pipe rotates, 3/8” Amsteel Dyneema lift lines (combined minimum tensile strength of the over 48,000 lb) on custom-shaped aluminum level winds maintain correct orientation from full up to full down positions. The forward end of the pipe passes through the watertight bulkhead separating the main cabin from the cargo hold on a third Delrin bearing. The drive for the lift pipe is a 1 hp DC motor transmitted through two reducers: an oil-bath, right-angle drive reduction gear and a 12” bronze gear driven by a worm gear. Total lift or lower time is about 45 seconds.
A hinged Lexan cover on the keel trunk allows immediate monitoring of the raising/raising process and direct access to the lifting lines and bearings. I change out the lifting line every 5 years or so, though they have never shown signs of significant wear. This is facilitated by four locking pins – machined ¾” diam. ss bolts that screw into the trunk walls and support the keel underneath its top flange so the lines can be released. The top of this same flange holds two 1 ¾” sch 80 ss lock downs rods for blue water crossings. These fold horizontally onto the flange when not in use. After the keel is fully lowered, they can be rotated to vertical and locked into place on the underside of the support beams. This ensures the keel remains rigidly down in the unlikely event of a full rollover. There are two control switches for the lifting gear – one at the helm, for quick adjustment of the draft (“Shoal ahead!”) and one at the forward end of the trunk for observation with the Lexan cover raised.
Anchoring
I’m an ardent believer in reliable and versatile ground tackle. I carry five anchors, from a 45 lb spade to a 100 lb Danforth storm anchor. Anchor rodes are 350 ft of 1” plaited Dacron and 200 ft of 3/8” galvanized chain. I trust the pair of 4’ long oak 4x6 Samson posts extending two feet below deck and secured to a watertight bulkhead far more than any deck-fastened cleat. It is infinitely safer and faster to belay a running rode under a load around a vertical post at knee level than a cleat at deck level. But the unique item is the windlass.
The original anchor windlass is a massive, solid bronze manual-only beast by Lunenburg Foundry.. I was unimpressed by the available electric alternatives, especially their options for manual backup. I didn’t want to give up the Lunenberg’s power and reliability. So, I electrified the winch while maintaining its manual system. I inserted a 60:1 reduction gear used in commercial crab boats between the rope gypsy and chain wheel. The 1-hp reversing electric drive motor hangs vertically under the gear, completely dry under the deck. It can pull in 90 ft/min of chain at 525 lb.
Más
