Terrapin sprit update....

[paxfish 5]

We are in the depths of winter here.   Had a blizzard 10 days ago resulting in a meter of snow and 50 knot winds.   Most of it has melted.  Fortunately, my wife and I were in CostaRica!

 

Despite that, I've made some progress on Terrapin while she's in the yard.  A friend of a friend built me a nice sprit.   He machines the ends and has them anodized.  It has a hole on the end for a spinnaker tack which runs inside the sprit and out that slotted fitting on the other end.   The hook is for a furling screacher.   The socket has a nice delrin insert and the socket "collar" is nicely machined to fit the profile of my forward crossmember.

 

Next up is to drill the holes for the bobstays.  The stem is about 100 mm wide, and should make a nice mounting point.

 

Here's a couple of shots:

 

 

[paxfish 5]

I am having a bushing machined out of G-10 as well.   This will be inserted into a hole bored in my stems.

 

Looks like this:

 

[Marshy 30]

The stem idea is pretty nice!

Just concerned the hook in the end of the prod will catch the foot of the gennaker in a gybe and rip it?

[paxfish 5]

Good thinking, and I will watch it closely.  There will be a furling drum right above the hook, and I'm betting that will keep a gybing sail away.  But you're right, anything can happen in the heat of battle! 

 

Also - the hook is immediately above the tack for a spinnk/gennaker, and there is typically several layers of strong cloth at the tack.   Fortunately, the hook is ground pretty smooth and should not catch cloth.   The bend of the hook will be somewhat crowded anyway, with furling gear and a line to the seagull striker.

 

Here is what it will look like properly rigged up:

 

[paxfish 5]

Here's the latest, Gents!  As always, I solicit your comments with respect.

 

As interest, the stopper knot is a stevedore as recommended for SK-75 by Colligo.   The tail will be trimmed a bit, and the outer surface will be covered by a decal.  Line diameter is 6mm.

 

The bushing is machined out of G-10 and offers about 8 square inches of adhesion/bearing surface in the stem.

 

 

 

[RushMan 31]

What stops the furler from unhooking?

[ScottiE 174]

Quite a different set up to the 8.5's here.  I'm guessing that the furler stays hoisted when out for a sail?  In which case it looks like you just rely on halyard tension to hold the furler shackle in the hook - might unhook in a decent seastate?  In Auckland most of the 8.5's will drop the furler especially upwind.

[paxfish 5]

Thanks for you comments guys - I really do appreciate it.

 

My intention is to generally raise it at the beginning of the day and leave it up unless racing.   I may use a bit of shockcord or a polyurethane washer or something as a keeper.

 

My friend who built the sprit fittings hasn't had a problem with it unhooking, though it is a bigger cruising cat (St. Francis 44), and he does not race it.

 

This morning I just measured the Luff at 38'9"  ( 11.8 meters)   - That sail is gonna be a whopper!

 

[Adrianp 119]

One thing we have learnt is to not tie the line that holds the prod up onto the seagull striker, but to the forestay and with a small weak link of rope as a fuse. One day, you going to mess up a kite drop and its going to fall in the water, at which point the prod is going to have a lot of down force on it. The last thing you want is for it to bend the seagull striker forwards. If its tied to the forestay, then it will hold up better until the load is huge, at which point the little bit of rope breaks the the prod falls of  and will drag in between the hulls from the water stays.

 

We're just revamping Freedoms prod arrangement from almost exactly what you have here, to a bobstay and sidestays arrangement, mainly to get rid of the drag of the stays in the water. The new arrangement certainly loads things up a lot more!