The graph shows estimated hours for a one off catamaran or trimaran. Trimarans require more time on the structure but usually have less detail in the interior fitout and there’s only one hull with liveable spaces. Accordingly we can assume the total build time is similar for cats and tris and other factors come into play rather than the number of hulls.
In one respect trimarans are easier to build than cats. Everything is at a suitable working height for most of the project and the beams and floats can be easily moved around the factory space. A cat calls for a lot of climbing once you’re working at wing deck height.
Aside from the comments above a trimaran optimised for performance with a spartan interior could come in well under the build time of a similar sized cat especially if using a lot of panels in the construction
Putting the catamaran or trimaran issue aside, build time varies between different projects for a number of reasons. Preparation, organisation, and experience are significant factors. Other factors include build method and level of technology, level of skill and quality of finish required, extent of fitout and equipment, the tools and equipment you have at hand, how much work you subcontract out, and the building information provided by your designer.
Using flat panels can significantly reduce build time, possibly by around 20%, maybe even more.
One designer claims his 38’ LOA cat can be built from a DuFlex kit in 4000 hours. This may well be the case but I expect it applies to a well planned project using experienced workers.
For a 40’ cat using a kit I would generally expect more like 6000 to 7000 hours. Without a kit and using more conventional methods probably more like 8000 hours.
To give some idea of the variablity that’s possible, a well organised and experienced professional builder can complete a 60’ cat to a high standard in about 16000 hours using a lot of flat panel construction.
In contrast it is common for a large professional yard using female moulds and infused laminates to estimate between 40,000 and 50,000 hours for a similar boat, usually including quite a bit of clear finished carbon, sophisticated electrical systems and possibly hydraulics as well.
The combined Newsletter for Grainger Designs and Rocket Factory Trimarans
Our DuFLEX kit systems streamline the construction process for amateurs and professional yards alike. More details here…