Most of you may be aware of the BF18 & the platform stiffness results that have made their way into many dicsussions & arguements on this and many forums on catsailor.
All the BS aside, the BF18 is very rigid & under any measurment scenario is much more resistant to torsion than any other catamaran that I have laid eyes on & tested.
Having owned & raced both the Reg White & Marstrom Tornado, I can tell you there is a marked differnce in the performance of the two boats when racing in a sea way. It is like chaulk & cheese. Dont Get me wrong the Reg White is a very well made boat, but the Marstrom is streets ahead in the construction department.
Given the experience from the Two Tornado's, we identified several areas on the Blade F18 that needed attention during the construction & this was not just targeting the hulls. The major areas of concern were the beam size & cross sectional area, how the beam is attached to the hull & its bedding & how well the load from the beam is transferred in to the hulls.
We used an oval section ( 150 x 100 x 3mm wall thickmess) beam that was double bolted to the hull at both sides of the hulls (ie// there were 16 bolts instead of the usual 8 bolts), the beams were fully bedded into the hull to the half way point of the beam. ( the bedding is very important as we conducted a torsion test before full bedding was complete & the torsion results were reduced by 300% once bedding was fully completed). The beam bolts were connected to some serious glass layup that continued in to the hull sides for maximum connection.
The hulls them selves were fairly standard using 4mm ply with stitched glass both sides, 4mm ply frames every 330mm & 4mm ply subdeck.
Generally there is no rocket science here, but just common sense as we knew that the F18 is a heavy bugger & we taylored the construction of the beams & hulls to suit the class rule. F18 rule suggests a manufacturer can get away with 45kg per hull & still be on min weight.
Now building a F16 to 25kg per hull will be little more challenging while keeping the platform rigid.!!
I have attached a photo of the BF18 on its first day on the water & will dig out some of the construction photo's over the next few days.
