Renewing the steel skeleton; bringing in the timber
The first set of new ribs installed in the boiler room; fabrication of floors and reverse frames is underway.
The massive project of renewing the steel skeleton of the hull continues with the engine and boiler room (the centre compartment of the hull) substantially complete: Frames installed from keel to deck, complete with floors and intercostals; side-deck beams and gusset plates installed; the engine seats and the tie-plates installed; and the longitudinal and transverse steel bulkheads, completed in new steel. Only two original bulkhead plates were sound enough to save, and were patched and refurbished. Bulkheads were hot-riveted in the traditional way, by steelwork contractors and volunteers. Much of the steelwork funding was by way of grants from the Lottery Grants Board and the ASB Community Trust. The steel bulb-angle for the new frames was funded by the Waitakere Licensing Trust.
Corroded frames, deck beams, gusset-plates & stringer-plate in the port wing, with rainwater-decayed deck planking & topside planking. Corroded coal-bunker bulkhead plate. P.J.McCurdy, Toroa Collection
The engine-room and boiler-room transverse bulkheads have been redesigned and rebuilt to be water tight—a requirement of current marine regulations—and water-tight doors installed, obtained from the decommissioned RNZN frigates Wellington and Canterbury, both now sunk as dive ships.
Heading picture: Fabricating the new engine-room water-tight bulkhead. The central plate will not be permanently fastened until reconstruction and machinery installation have been completed
Steelwright Andrew Macbeth of ADM Contractors Ltd, riveting the engine-room bulkhead. The newly riveted starboard wing bulkhead is in the background. Photo: Toroa Collection
Volunteer Brian Claney cleaning off new rivet points in the starboard bulkhead prior to sealing and painting.
The watertight door in the engine-room bulkhead to the right of the photo is from HMNZS Wellington .
Photo: Toroa Collection
The TPS thanks VT Fitzroy, MoTaT, Chris McMullen, and Ian Nielson Blacksmith for their generous loan of riveting and steelworking equipment.
Work on the steelwork of the forward and after void spaces commences, funded mainly by further grants from the Lottery Grants Board and the ASB Community Trust. All fittings measured, photographed and recorded, and the rusted frames and bulkheads begin to be replaced.
Driving out old keel bolts after removing corroded frames, floors & intercostals
Second stage of void space steelwork renewal. New frames, floors, fore-&-aft bulkheads and transverse bulkheads fitted. The bulb-angle frames towards the ends of the hull are much more complicated to bend to shape than in the machinery room—concave & reverse curvature and extreme bevel of the flange to fit the converging planking demand skilful shaping and sometimes several returns to the bending slab to get right.
Steelwork mostly completed in the after void space of the hull. The central plates of the transom bulkhead in the distance will be left out until the propeller post and apron have been replaced. The fore void steelwork has been similarly renewed.
Finding the timber
Toroa‘s backbone, planking and superstructure were from built from New Zealand heart kauri, Agathis australis, still plentiful in the 1920s. Of the 75 cu m of timber in the hull, some can be reused and some can be resawn for use elsewhere in the vessel, but much new timber is needed. These are large timbers by modern standards: keel 14” x 12” in three lengths, the middle length nearly 60 ft or 18 m long. The sheer strakes and the garboard strakes are of 12” x 4” in lengths up to 40 ft or 12m. The No.2 strake is 14” x 4” in 11 m lengths. Such sizes and lengths are difficult to obtain in any species of timber – the modern standard 6 m timber length would require far too many butt joints and laminating is not really a practical proposition on this scale – nor would it be authentic.
Initially the new timber was to be from Kaipara sinker logs surviving from the last era of wholesale kauri extraction in the district. However, the supplier ran into several difficulties and this source became no longer available. A decades search ensued, following every lead and investigating other species, with none of the prospects reaching fruition until very recently, when part of the timber requirement was sourced from an old forestry area. It must be stressed that this timber is from large trees that have been dead a long time, either fallen or dead on their feet – no live kauri has been used at all, and nor can it be, legally or ethically.
Because of the high cost, the difficulty of procurement and the environmental considerations, heart kauri will be used just for the main structural timbers—backbone, garboard strakes, sheer strake, covering boards—and other timbers of similar characteristics will be used elsewhere in the boat.
One of the timber baulks secured for the restoration of the 90-year-old steam ferry TOROA. This stick,
9.1 m long (30’ x 15” x 13-3/8” in 1925 numbers), will provide one quarter of the length of the new keel or one
complete plank the full length of the hull
2017-2018 Renewing the main-deck beams
The second to last last major part of the steelwork renewal is the replacement of the corroded main-deck beams in the void spaces. The original 3½ x 2½ angle section is no longer made so larger 100 x 75 x 10 has been used.
The beams were fabricated by Kim Henderson of IMEC Ltd, an ex-Alloy Yachts boilermaker and super-yacht builder. They were rolled to camber, drilled for deck-bolts and gusset-plate bolts, had bulkhead cleats attached. After sandblasting and painting they were threaded through slots in the gunwale and winched across the tops of the longitudinal bulkheads into place.
The old corroded beams were removed by the same route, after the careful and laborious removal of old deck bolts by Toroa volunteers, and were used as templates to mark out the new beams.
2018 Refurbishing the cabins
The fore-cabin on the main deck has been refurbished by volunteers Mike Walls and Barry Davis for use as a display and presentation centre for tours of the Toroa restoration, with the seating temporarily rearranged to suit this purpose. The after ‘smokers” cabin will be tackled once the deck-beam installation has been completed in the after void space.