The SpitZfire 8.5 is a new design that fits into the NZMYC 8.5 Metre Box rule, and is based on my experiences both building and racing the Firefly 850 One Design. Hull shape is similar but with a lighter design displacement to make benefit of the fact that the “on the water” racing weight will be 200kg less at around 1200 kg including crew. Construction is in foam sandwich with a fairly robust layup that will result in a weight for the boat ready to race at the 900kg minimum weight required under the 8.5 Metre rule.
As with the Firefly, the hull has a mild flair that increases the interior volume while providing reserve buoyancy forward with the deck round reducing overall windage. The design has 3 main large diameter alloy beams that provide the basis for a stiff and strong structure. It is not necessary to incur the extra cost of carbon beams as the weight saving down low in minimal. The rig is ideally the All Yacht Spars 200 Wing section. With the air draft requirement of 12.6 metres, the mast height is 11.6 metres off the deck.
The SpitZfire 8.5 has a sit in cockpit rather than a sit on cockpit as on the Firefly. This configuration is better for longer coastal races where the crew weight is better positioned in the cockpit in moderate to strong conditions. In lighter conditions the crew will usually find themselves moving their weight forward and to leeward. The SpitZfire 8.5 cockpit configuration allows the sails to be trimmed from sitting in the cockpit in moderate to strong conditions or from the tramp in lighter conditions.
The interior of each hull has a largish bunk forward, which will mainly only be used at anchor. Under the cockpit is a narrow sea bunk where a crew member can escape the elements on an overnight or passage race. Access to the interior is provided by a standard deck hatch. Just inside this hatch there is a seat on the outer side and a bench and stowage unit on the inner side that can have a butane stove in one hull and a nav area in the other hull.
The 8hp outboard in mounted on a central lifting bracket although could be mounted on a bracket on the inner side of the hull if preferred.
Although designed primarily for the New Zealand Open 8.5 metre rule the SpitZfire 8.5 could carry a more powerful sail plan on lighter carbon fibre hulls if not conforming to the Open 8.5 Rule.
Plans
Plans for the SpitZfire 8.5 are extremely comprehensive and include:
- Construction Plans Book of detailed drawings and instructions
- Fabricated Fittings Book of drawings for fabricated fittings
- Full Size Patterns for Hull and Deck Sections and for Rudder and Daggerboard Sections
- Full Size Patterns for Bunks, Bulkheads and all flat panels.
- Detailed and Accurate Materials Lists for Foam Sandwich Construction
- Equipment Lists
- Harken Fittings List
Specifications
| LOA | 8.5 m (27’ 11") | Draft | ||
| BOA | 5.76 m (18' 11") | Hull | 0.26 m (10") | |
| Hull BWL | 560 mm (1' 10") | Rudders |
0.65 m (2' 2") | |
| Hull LWL : Hull BWL | 15.1 : 1 |
Daggerboards |
1.65 m (5’ 5”) | |
| Displacement | Heights | |||
| DWL |
1220 kg (2299 lb) |
Mast Height above deck | 11.6 m (38’ 1") | |
| Empty | 900 kg (2090 lb) |
Air Draft |
12.6 m (41’ 4”) | |
| Headroom | 1.6 m (5’ 3”) | |||
| Working Sail Area | ||||
| Main and Jib | 43.1 m2 (464 ft2) | |||
| Spinnaker | 72 m2 (775 ft2) |