Keel base plate

The keel base plate is made from a solid piece of 12mm thick steel about 6 meters long and around 40cm wide, it weighed hundreds of kilos so was moved with chain block and rollers etc.

The photos show keel base plate preparation work. Making sure the bottom of the keel is leveled off for the plate to fit on top, so the welding gap is correct all the way around.

 Moved up to large oxy-acetylene tanks for cutting steel hull plates (small ok in the frame building stage). The 12mm base plate cutting needed large cutting tips and alot of gas. It may be possible to provide a full-size template to a steel fabrication shop and they could plasma cut the keel base to shape.

This photo shows the keel profile shape. It is a NACA designed foil section. A 4" hollow pipe on a raked back angle forms a nice oval leading edge shape horrizontally. The keel has 6 compartments with 5mm plate bulkheads. These bulkheads extend to floor level inside the hull making the keel very well braced for extreme sideways forces. Moving front to rear the first 3 compartments house the ballast. The 4th and 5th are water tanks and i made the final thin compartment a sealed void (others use it as a tank, its a stove-kerosene tank in Nicks plans). The first 2 ballast bulheads have 45 degree cutouts on the corners, it should elliminate the chance of metal fatigue cracking where 2.2 tons of ballast gets thrown around by the sea. The 2 separate water tanks (25 gallons and 45 gallons) are fully sealed at the corners.

Sorry no photos of the plate making or raising. But i used a standard masonite template as the other plates were done. The keel base plate was about 10mm wider than the keel sides, sits ontop with  T joins to the keel sides. This join is probably strongest and is per design. 

(Also it allows the optional keel winglets could be attached..that a story in itself - to cut a long story short, i started building the 5" winglets, got the lower side in place on both sides but after awhile realized it was all too much time and work, and decided to "keep it simple" so oxy-cut them off and reground the ragged base plate edge smooth again. If you want to win the Ammerica's cup or something like that then build the winglets, i don't think they'll be necessary on the 4'3" draft keel version, (useful on the 3'9" draft keel version though, eg wylo35 Mahina ))

So the base plate was cut out and edges ground with the 9" grinder. (sorry cant remember peening it, if i did it would need a sledge hammer).  A strong angle steel was welded to one side of the hull and braced to take the 1/2 ton chain block, then it was raised into position and tack welded on. Shade cloths went back up. Final edge measuring, scribing and grinding followed.

Hull plating (3mm)

3mm thick,  mild steel plates were used for the hull from the lower chine to gunwales. The stock sheets were 6m long. They are not much heavier than the small 8x4 5mm sheets.

 2" diameter pipe rollers on angle iron rails was the method used to move the sheets across flat but lumpy ground into the boatyard from where the truck dropped them off. It was best with 2 guys hauling them along with a rope, (but one had to take the pic). It took an hour or so to move them about 15m. Thanks to Kim for the hard work put in that day. 

Templated Hull sheets were 6m long if possible which made only 4 vertical joins to worry about in the hull length. The 3mm was put on the topsides of the hull and between the chines. The vertical joins were also staggered to give greater strength.

Although larger, the 3mm plates were easier to bend and fit than the 5mm plates. A bit of gardening was also going on provide a foliage screen to keep the council happy.  The above photo shows a tyre pond, it was soon demolished due to mosquitos and in any case a boat yard should have vast ammounts of flat clear access space around it if possible (for work, vehicles, big trucks and even cranes etc).

The 3mm plates are faired up and tacked on. Prep work begins on the keel base.

It was well worth getting the largest sized 3mm sheets available (6 x 1.5m = 20ft x 5ft). Any handling difficulties were far outweighed by smooth and fair plating.

Hull Plating (5mm)

 The plating began with the 5mm bottom plates. The first plate was at the aft quarter . A half ton chain block was hung from some angle steel set around the keel line. A pair of well tightened 4" G-clamps in the middle of the plate substituted for a plate dog. Just made sure not to stand anywhere below it while raising.

 It's easier and faster to make a Masonite template for each plate. Masonite is a soft 6mm wood pulp sheet. Pieces of masonite were fitted to the hull frame, tek screwed together and clamped into position on the frames/chine bar. A pencil marked the outline of the sheet on the masonites painted side. Masonite is soft and it was easy to use a wood jigsaw and plane the edges to shape on the ground. The template was re-fitted to check, alter the outline, then replaned.

The template was then overlaid on an 8x4ft steel sheet and the outline scribed onto the steel. Oxy-acetylene gear was used to cut the steel sheet a few mm outside the scribe line. 9" and 5" diameter angle grinders then removed the few mm of steel to the scribed outline.

The oxy-acetylene cutting process causes some shrinkage distortion (curving) of the steel plate so the edges were peened flat. Peening involved placing a small anvil under the sheet edge then hitting the edge above the anvil with a small steel mallet. The anvil was moved and process repeated right around the edge of the plate. The edges of the plate, chine bars and adjoining plates on the hull were beveled to allow for better weld penetration later. Finally the plate laid flat on the ground ready for raising.



The third bottom plate is being raised amidships.

The plate fit exactly into the gap between lower chine, garboard and aft plate. C-clamps aligned the plate to chine and bolts with washers held adjoining plates into alignment. After everything looked fair and smooth. It was tack welded to the hull framework. A small 1mm gap was left at all joins. The templating pays off at this stage. Its far harder to move the heavy plate around than the lightweight template.

I followed the building methods and techniques recommended by the designer Nick Skeates and others of the era such as US boat-builder Gilbert Klingel and US Designer Thomas E Colvin (refer the books side bar). The building plans supplied by Nick come on 4 , A2 sized sheets, plus some building notes.

A 4" diameter pipe was fitted to form the leading edge of the keel.  The 40x10mm fore foot bar was faired into the hull.

The bottom plates were done first so that a solid surface is made to walk around on for work on the keel. It also allows access and keeps it drier below.

The keel side plates are fitted next. The aft plate has the propellor aperture cut out. Small steel steps were tack welded to the transom for easy access onto the hull.

 Note plate-plate joins have small bolts and washers, drilled through, to hold joins into alignment. Short flat bars help with hull fairing.

Framing up the hull

The frames were stood up, aligned and tacked onto the jigs angle steels. Its a great feeling to see the 3D shape of the hull for the first time. A string line down the centerline and the spirit level on centreline angle irons (plus plumb-bob) are good tools here. This stage is when you find out if your earlier lofting floor work was accurate or not.

Nicks building jig had angle irons going into cement footings. The hull must be held down onto a secure building jig to resist any plating-up and weld shrinkage forces during hull weld up later on. Initially i thought the heavy railway sleepers might do, but given the expanding clay soil i decided to play 100% safe and make 2 cement footings per sleeper as shown above. The vertical angle iron of the footing is welded to the jig frame and tek screwed into the sleeper. Mixed cement in the barrow. Station wagons shouldn't really be used for this, but it was an old beast with a rusty tailgate.

The transom is set up. This took a bit of bush-geometry and stake into the ground. The transom was pre-fabricated at the frames stage. After oxy-cutting, it wasn't edge peened (like all the other plates were to be) in order to have a natural compound curve left in it. In retrospect it should have been edge peened, to make the sheet flat. The sheet should curve in one dimension only, across the hull. The sheet should be flat to line up with the 2" flat bar end of the keel. (straight angle iron tacked on centreline). In summary I strongly suggest - peen the transom sheet flat before it goes up.

The 40x10 mm stem bar was aligned and tacked into place to form the bow shape. See photo below

Next the 2x 1/4 " flat bar chines were fitted and tacked welded on. I had saved 3.2mm weld rod leftovers for use as spacers between the chine bar and frames. This is done because later on during hull weld up, massive contraction sets in, so the spacers are knocked out as the compressive forces begin. If it were not done the frames would get hugely compressed and start buckling under the load. 

Another problem with flat chine bars is they dont bend too well edge-ways. To bend them like this run a weld bead on the side of bar edge you want the overall bend to go. Suddenly quench the hot weld with water and a curve will form.

 1" flat bar stringers fit into their slots, also with 3.2mm weld rod spacers. All longitudinal framing should have fair curves. If a stringer or chine is too far in,  a small spacer can be tacked on to hold it out to a fair curve.

As soon as the hull framework was strong enough, 4 shade cloths went up over a large bamboo ridge pole. Several angle irons tacked to the keel plates held the ridge pole up. Two more long bamboos held the outer edges.

The stringers and chines were pulled into the transom by tie wires.

The hull shape takes form. The cabin ends at frames 2 and  8 are a little over 20 ft  (6m) apart.

The 1" stringers are located where 3mm thick plates are to go. No stringers were needed to support the bottom plates, at 5mm thick the bottom plates are strong enough on their own. No bilge stringers means fewer potential internal rust traps in this area.

Setting up the wyloyard

Utilities

The wyloyard started with installation of a powerpole and box  with  40m overhead powerline in from the street pole, at a fair price. Then the 50m water main trench was dug and the heavy duty 25mm PVC water main laid from the front water meter, along the boundary line, then some 20m of 25mm heavy duty PV main in from the property boundary to the  caravan site.

Site accomodation

The caravan site was raised above the flat claypan with a truckload of decomposed granite or "deco". Once the 14 foot 2nd hand caravan was in position it had to be held down to cement footings with heavy gauge wire, this is to prevent the van blowing away in a cyclone. The van was past its roadworthy lifespan so was inexpensive but they can get long and useful retirement life on project blocks like this. The water main supplied the caravan's sink and an outside tap on a riser. The wash room was a few paperbark poles augered and cemented in with a poly tarp wrapped around. Figured the small van would be about similar size to living on the boat so would do for a start. A power lead from box to van had the lights, fridge and hotwater jug on.

Tool shed

Next a 6x3m garden shed was delivered, later to become the tool shed. (it was a fraction of the cost of a 6x6m garage) A 100mm thick concrete slab was built. I did the preparation, gravel and sand base laid, 4x2" timber formwork using stringlines, leveled the sand, laid black plastic liner, then reinforcing mesh cut to fit, laid on bar chairs so it was 50mm below the formwork tops. The concrete pour involved a bunch of friends, a load of concrete mix gravel-sand, a petrol driven cement mixer and bags of cement and shovels and barrow. Its not the easiest thing to do. A friend was good at concrete finishing, leveled it off with a straight edge and gave it a brush finish with a broom for non-skid. Watered it with a tarp cover to cure the slab slowly.

The shed went up in a few days and came with assembly instructions. Panels screwed together. Cyclone reinforcing beams and portal went inside the walls. Tek screws held alot of it together with smaller screws on other spots. A windward shed ventilation window was cut and hinged from the top, a good arrangement as it keeps the rain out when open. Spare steel C sections made window studs inside and a simple locking system made.

If you have more budget a 6x6m or larger car garage would be better sized for the tool shed. It can later become the wood and equipment storage shed as the project expands into fittout stage. In Qld, the highset style house makes a good base for boatbuilding activities, the ground floor covered workshop area is immense.

Strongback construction

Wylos need a strong building jig before frames go up. In my case of unstable clay soil alot more work needed to be done.

A "Deco" base was spread out first, then a sand layer on top of that was leveled off.  Paperbark posts were augered into the ground to make steel sheet standing racks around the boat site (they wouldn't last long laying flat on this reactive soil). Poly tarps ready to cover the sheets.

Hired a truck and a friend with a truck drivers licence drove it to pick up the frames from the interim shed and first load steel   A load of 14ft hardwood railway bridge sleepers also came. (i had found them cheaply at the railyards in town, hired a big trailer to get them to the interim shed earlier).

A driveway made of "deco" was also built from the front gate to the boat yard. So vehicles wouldnt sink into soft clay during the wet. Most of this stage was done in the dry season when the ground dries hard.

A bunch of friends helped unload the first steel shipment, about 2 tons of   flat bars, heavy angles, heavy 5mm thick 8x4' hull plates. The 14' heavy railway sleepers were also bought in and carried into rough postion. Many thanks for the help to all who were there, sorry the photo's a bit faded.

The railway sleepers, one for each frame station, are carefully positioned and then leveled. This system was done in lieu of a huge expensive concrete slab. Steel plates are stacked upright against paperbark poles and covered with black plastic to reduce rain induced corrosion.

 Below is another angle of the early yard. A brown shade cloth garden fence is up and the deco driveway extends to the caravan site.

2 heavy steel angles are laid fore-aft and coach screwed to the railway sleepers to complete the building jig or strongback. The first frame, F8 companionway, is stood up! I don't know why but it seemed like a real milestone, tangible progress. A hull centerline stringline and the frames' centerline angle iron help get the position right. The frame is tack welded to the 2 long heavy angle irons of the building jig.

The grey 40x40mm square section aluminium straight edge (center of jig) about 3.3m long is a very usefull piece of gear. It was first used to level the shed slab and screed the concrete flat. Then in conjunction with a spirt level, it was usefull to help level the sand and building jig components. It's usefulness extended into  all stages of the hull and decks construction, like checking levels across the hull framework. Aluminium is lightweight enough to handle easily and it hasn't lost it's straight edge after years of use.

A tarpaulin annexe awning was added to the tool shed and the workbench placed there. This was a good position for it astern of the hull. I figured it was an equal distance to trolley the welder or oxy gear out on each side of the hull, usually it stayed on one side all day. Some builders prefer the hull parallel to the tool shed.

Wylos are usually built upside down and rolled over later. This makes it much easier to lay the heavy steel hull plates in position and the first phase of external welding can be done down hand, far easier for learning the art of welding.

I had bought the land before realising that the soil would not support a building jig as Nick describes it. So if you have to select land, make sure the soil is not reactive (expanding) clay type. Probably a sandy-loam or sandy soil is far more stable. Ask locals what they think about their soil type first.

Ideally, a flat concrete slab (with roof) exists to build the jig upon. A different method could be used.  Large 20'x5' - 3mm deck sheets could be laid down first to form part of the strong back base. The frames with 1" flatbar deckstringers would be tacked downhand onto these. During hull weld up the deckheads 1" long intermitent welds would  also be done downhand. I'm not sure if anyone has tried this method yet, but it certainly avoids the overhead deck stringer welding that i went through later on.

My budget was pretty basic and being single the location didn't matter so much at the time. I wouldn't entirely recommend trying to do it as i did.  The ideal yard situation is to have long-term use of a fully established property with house and sheds already built, located close to town with employment and facilities. This may also cover many other life situations that can occur during a build.