Tanielle is built entirely in
Stainless Steel grade SAF 2205 (Duplex).
She is a 24 mtr Ketch by Hoek Design, and built to Lloyds.
She is set up for short handed cruising – electric winches, bow thruster etc, as well as expedition – super strong hull, sonar etc.
As the ultimate cruising yacht she is perfect for world cruising with 2 couples.
She can also race – 11 berths, efficient sail plan etc, but would need strong conditions.
Tanielle was designed by Andre Hoek as a Truly Classic 79.
Length Overall – 23.98m
Length at DWL – 18.24m
Beam – 5.88m
Draft – 3.2m
Sail Area – 330 square metres
Lightship Displacement – ca 56t
Ballast – 15t
Stability (STIX) – 62
Hull Speed – 10.38 knots
Displacement Length – 269
SA/Displacement – 22.14
Comfort Ratio – 60
Why SAF 2205 Stainless Steel
- High resistance to stress corrosion cracking in chloride bearing environment.
- High resistance to general corrosion pitting and crevice corrosion.
- High resistance to erosion corrosion.
- High fatigue strength.
- High mechanical strength.
- Good weldability.
The practical alternative was 5083 Aluminium so a comparison is useful.
From the chart it can be seen that the SAF 2205 plate is 3.0 x stronger than the 5083 plate but the welds are 4.4 x stronger.
The weight however is 2.93 x heavier than the 5083.
Therefore SAF 2205 is 21% stronger for the same weight.
It is also 3.3 x harder so ice and reefs would cause little damage. It will survive a collision with a container that would rip open the 5083 hull.
The sailplan was modified to utilise the stronger stay attachments afforded by the bulkhead and the bow. At the same time we reduced the mast height and moved the forestay forward to finish up at the same 330 square metre sail area.
The accommodation has been designed to be very flexible. She can be used as a luxury cruiser for a couple, or perhaps 2 couples. Crew are easily provided for in the crew cabin adjacent to the galley. They would use the day head. She can also be used as a long distance racer as there are bunks for 11 if we include the setees. Because of her extremely strong hull, she would be suitable for polar use either as a private expedition or undertaking scientific voyages.
Hoek Design had all the rigging analysed so all hardware and lines would be adequately sized.
The deck layout had input from the mast maker and various marine consultants as well as Hoek Design. An overlapping staysail gives greater speed while not as convenient as a self tacking sail. Similarly a traveller allows greater sail control than a fixed point. The mizzen traveller is moved with a line drive operated from the aft helm.
The build began in April 2008 with an empty shed. The MDF template panels were the first to arrive. These were direct UV printed with the frames cut files as a guide to check the laser cut steel frame pieces.
My son Michael and Art standing on lofting floor. The lines plan was enlarged to the full size and their lines reduced in thickness to 1mm. These were then given a 300mm square grid as a check on the floor accuracy. This was then printed by a UV flatbed printed to 20mm MDF sheets to create the 6m x 4.8m lofting floor. We used this to lay out the frame pieces and weld them together.
The frame is finally taking form.
Early days and here Phil the welder in foreground and Jos the boatbuilder discussing either plate ordering or the bowthruster tunnel. All hull plates were laser cut to .1mm accuracy, but they needed to be nested as we had to pay for a 6m x 3m plate. At the same time the plates on the hull were different thicknesses and we had very limited storage. We could not find a 300mm ID pipe with 8mm wall for the bow thruster, so had to roll one and weld it up.
The yacht was designed by Hoek Design with engineering by a Sydney firm One Two Three. All plans were submitted to Lloyds for approval and here we see some of their comments in red as well as their plan approval stamp.
Hull plating in progress. The square plate around the skeg is 10mm thick and the remainder is mostly 6mm. The keel was built in situ to ensure it would fit later as she would be too high to transport with the keel fitted.
This is looking forward from the engine bed in the foreground to the saloon and into the forward cabin.
Phil the welder is a good mate that helped out when he could. Altogether we used 37 kilometres of welding wire. The welders had to be approved by Lloyds using destructive testing, as well as all the materials. The final welds were X-Rayed and we bought a Ferritescope to test the welds for phase change.
Here the plates are tacked on after rolling. The large hole is for the bow thruster tunnel. Art can be seen in the foreground. A pleasant and patient plasma cutter, lathe operator etc.
Here Phil is griding the welds smooth. The noise of 3 nine inch grinders together made ear muffs mandatory.
She was turned over in 2010 using 250t and 90t cranes. The crane scales measured her at 13.15 t.
My first look at her lines. The photo also gives a sense of scale but a pity we left the furniture blanket inside. We used these to absorb noise. She is not yet faired and the grey paint is a glass flake paint from Jotun.
Now the decks are on and we are modifying again. We raised the doghouse by 200 mm so we could see over the deck from the inside helm. We also moved the back of the aft coach house and its bulkhead, so the the rudder was in the lazerette, instead of under the bed in the aft cabin. At the same time we are now able to accommodate a 300mm larger dinghy on the aft deck.
Here all the deck hardware is installed and leads trialed before removing to sandblast and paint.
Anchor roller detail. Roller for chain has captive swivel box which is self launching. Roller for line is nearest. Block is for adjusting tack line on mps.
The keel is also in SAF 2205 with 15 t of lead in the bulb with a fuel tank in the fin. We increased the original draft from 3m to 3.2 m for increased stability while at the same time reducing the lead required by 2.2 t.
This is the fresh water manifold. It can draw from the port or starboard tank as needed and each outlet can be closed off so the remainder of the system is not impacted. There is a duplicate pump to port giving redundancy. The water can also be pumped from one tank to the other acting as ballast. All waterlines are in 316 ss with short runs of food grade 20mm tubing. There are 2 watermakers of 100 ltrs an hour each, one 240V and the other belt driven off the generator. The photo shows these fitted but they are removed before sandblasting and painting. The box is for a recessed anode which is isolated from the hull and fixed with an insulated bolt which is the earthed to the hull internally via a current limiting diode. The hole is for the depth sounder transducer.
Phil and Jos fitting the 2 steering systems. From the bottom we see the stuffing box and then a support plate with a radial thrust bearing to take the 780 kg weight of the rudder and fittings. Next are the steering arms for the hydraulic rams fixed to the 110mm solid duplex shaft with twin SS taper locks. Further up the 900mm radius duplex quadrant is also fixed by twin SS taper locks. The quadrant is fixed in place by temporary brackets to ensure the correct placement for the cable pulleys.
Fitting both wheels as well as the winches and stand up blocks. Sail tracks are welded to decks. Bronze mushrooms are half of the engine air inlets.
The 215C Perkins from the day head. This is the only engine I could find that doesn’t have a computer involved.
Amy and her friend Toke taped up the polished stainless with 3 layers of gaffa tape getting ready for sandblasting which was necessary to get the paint to adhere properly. The girls also helped out with the painting. They would work all day then work at a pub at night. On a night off from the pub they would party till 2 or 3, and very occasionally they would crash and have a catch up sleep. Great workers and fun company.
The rudder also has to be fitted after transport. We modified the rudder to be a half skeg instead of a full skeg to give better speed, (the rudder acts as a brake) and to be more effective. The bumps divide the water flow and accelerate it between them. This gives greater flow attachment and means the rudder stall angle is improved from around 15 degrees to around 30 degrees.
Testing the teak decking glue. We tried a few different brands and settled on Fixtech, as it is flexible, but strong enough to tear the teak plank apart, rather than the glue letting go. Here an American brand failed on 2 out of 6 test pieces.
The galley showing 75mm of closed cell insulation, the porthole attachment and the SAF 2205 tubing for the hydraulic bowthruster and anchor winch. The wiring is for the bow nav lights.
Showing the Marine Air unit with the soft start. The red hoses are for the hydronic heater, yellow for sea water cooling for the aircon and the yellow cable 240V for the aircon. The white pipes are for the hydraulic bowthruster and anchor winch.
The foredeck is waiting for the teak decking. Each dorade has a mushroom vent underneath so the airflow can be adjusted. The winches are Andersen 72 electric. We made the sail tracks and welded them on, so no leaks. The pads are bases for turning blocks again welded to the deck.
The aft cabin is now clad in teak, the winches are fitted and wired up. The 300mm inset on the rear timber, to allow for a longer dinghy, is not very noticeable.
The forward head has an electric Tecma toilet, a separate shower with glass door, 12V and 240V outlets as well as USB sockets. The door opens to give privacy to the cabin and there is a watertight door as well. There are multiple light configurations with 3 switches as well as the bunk lights. The lights are LED and incorporate a red option as well as dimming. The red lighting is necessary if the front cabin is in use so the helmsman doesn’t lose night vision.
The forward cabin has a writing desk with storage, 2 dorades and 3 hatches. There are 2 bookshelves, 8 lockers as well as more lockers in the head. Air-conditioning is fitted as well as hydronic heating.
Still in the forward cabin. The shelf covers the bowthruster and above you can see a glass “pineapple” which lets in a beautiful light.
Anderson winches and Antal stand up blocks.
The traveller is welded to the support beam and was designed to flex 3mm with the calculated sheet load of 4.5 t. The car is a Lewmar 8t.
The forward deck house is now completed.
Painted in Awlgrip Matterhorn White. Rubbing strake is Duplex ss pipes welded to hull and then faired with gold insert. Anchor is 135kg to 16mm studlink chain to Muir 8000 windlass. Those anchor roller cheeks are 10mm thick SAF 2205 stainless with a 20mm bar around to give extra strength as well as a round surface for any side loading. The anchor rollers are 316L with grooves for the 16mm stud link chain and a plain roller for the line. The lug just above the waterline is to locate a block through which the snubber will be led. This moves the anchor point from the bow to the waterline and so shortens the room needed to anchor by a boat length and a half. The box on the port bow holds the anchor stock firmly against stops and swivels up against other stops to trap the stock. Below the cove boot top you can just make out the bowthruster doors which articulate to be parallel to the hull.
This is the lazarette storing the diesel hydronic heater which serves 5 fan radiator units. The unit can operate at a sailing angle of 30 degrees and the exhaust is at deck level so it can be used while sailing.
Steering gear now in place. Polished stainless tubes protect the ram rods as they exit and are angled down as the rams articulate upwards as they move aft, the rudder being swept back.
The cockpit has been designed to allow a folded chart on port, with nav rollers etc, and chart screen with radar to starboard. An Icom M605 Euro VHF is outside the screens, and the NKE instruments are over the companionway.
Inside protected steering while outside steering looks over the coach house roof.
This shows book matched Blue Gum figuring highlighted by the 9 coats of gloss varnish.
Petrol Stowage. Self draining locker for 60 lets petrol and 2 outboard motor tanks of 25 and 13 Litres. Second motor is Mariner also 9 hp which is stored on pushpit or in lazarette after running it dry. Each of these items have their webbing tie downs.
Gas Stowage. Hold down for 4 off 9 kg tanks and 1 off 4 1/2 kg tank for the portable BBQ. Shown is the valve and air connection to test the 10mm SS schedule 80 tubes for leaks. The tubes were threaded then joined, then the join TIG welded. Bottom is 3mm rubber and locker is self draining.
Master cabin done except floors & doors. Starting on head and engine room.
Aft cabin head. Plumbing almost done. Stainless steel pipe where there is no future access, then hot cold hoses to shower head diverter and hot cold control. Pump out diverter to deck fitting and overboard.
Duplex Sea Chest and water maker pump installed.
Starting on engine room. The two pipes are 80mm cockpit drains. Engine is Perkins 215c and generator 10 Kw Northern Lights. As each area is complete, it is painted with International 820 primer before fixing the double insulation. The generator will not have a sound cover to allow better access.
Aft Head complete with Bath Tub and Washing Machine.