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Spindrift: leaving the mast up whilst afloat


Aphers
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I've been really enjoying sailing my S11N. It's not built exactly to plan, I modified some parts from other dinghies to cut costs and build time.

 

The mast is from an OK, and seems quite heavy at around 7kg. The sail is from a 420 which does seem like a good fit. And the boom is an old length of broken dinghy mast with fittings added.

 

I've found that in stronger conditions my limitation is not wind strength for sailing, but sea conditions for rigging and de-rigging. Last time I was out I really thought I was going to lose my grip on the mast as I unstepped it, which would likely have destroyed the foredeck due to the leverage. Not good!

 

So I'm trying to think of a way of tackling this problem. Some options might be:

a) convert to a tabernacle arrangement. It would be easier to lower the mast slowly than to have to lift it right out. But will that compromise strength at the partners?

b) get a lighter rig? E.g. from a laser. Would that be light enough to remain stable with the boat afloat? It would at least be easier to unstep.

c) something more radical like a gunter rig. Yes it's probably more weight aloft whilst sailing, but I think with the yard, sail, and boom down the much shorter mast would be far easier to handle. Ideally it would make the boat stable enough to leave afloat with the mast in place.

 

I'd be very interested to hear what people think might work best, and especially any similar projects that people have already done.

I'm living on my yacht now, using the Spindrift as my tender, so I have very limited access to workshop facilities etc. My best bet is to keep my ear to the ground as I travel, and hopefully pick up useful stuff as I go, e.g. from dinghy schools.

 

Cheers

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3 hours ago, Aphers said:

 

 

I'd be very interested to hear what people think might work best, and especially any similar projects that people have already done.

I'm living on my yacht now, using the Spindrift as my tender, so I have very limited access to workshop facilities etc. My best bet is to keep my ear to the ground as I travel, and hopefully pick up useful stuff as I go, e.g. from dinghy schools.

 

Cheers

It doesn't take much of a shop to build a Spindrift mast to plans.

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Since you've already got a rig and sail that works I don't see why you should build a Spindrift mast to plan necessarily. I think you'll still have some difficulty stepping it alongside the mothership. I think what I would do is build and install a fiberglass tube or even use a PVC pipe to connect the top and bottom mast partners. It would not be load bearing under sail so it could just be slipped underneath the foredeck hole and over top of the existing mast step i.e. don't cut the foredeck hole larger to receive the pipe so as not to weaken it. Then you'd epoxy it in place and apply a fillet to the outside which should be strong enough to hold it in place if you get a bit off balance. You won't have to worry about landing the mast in the mast step. A fiberglass tube would be lighter and more elegant. If you scroll to the end of this video on how we make our glass tubes you'll see it being installed as a guide tube for the Core Sound 15 mizzen mast which serves the purpose i'm describing above. https://www.youtube.com/watch?v=JO_-sbbBRBM

 

Another option would be to modify the foredeck partner with a removable section of the actual mast support collar specifically the aft half of the collar could be hinged to rotate 90 degrees and allow the mast to be set into the bottom step first and then rotated up into the top partner similar to a tabernacle action but with still some balancing required. Then with the mast vertical the aft section is rotated shut and a pin secures it. The S12 at our workshop actually has this setup I believe with an aluminum reinforcing plate top and bottom (i think) I can get another picture tomorrow but here is one from Graham's Trip to Sail Oklahoma in 2013 where you can just make out the aluminum part. andrewlinn.com/2013/131010_ok/03spin.jpg 

 

Of course a lighter mast would be easier. A balanced lug sail could be an option such as what we have on the Amanda dinghy but it will likely have lee helm with no change to the mast location. You want to try to keep the center of area of the sail as close to the designed location as you can. 

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19 hours ago, Hirilonde said:

It doesn't take much of a shop to build a Spindrift mast to plans.

 

Maybe not. But I'm not even sure where to buy the right kind of wood (this was hard enough back home- I ended up getting it from 700 miles away). No car or postal address doesn't help either.

 

How much lighter would a wooden mast be, if any? At least it would be much less of an inversion risk if I did capsize...

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9 hours ago, Alan Stewart said:

Since you've already got a rig and sail that works I don't see why you should build a Spindrift mast to plan necessarily. I think you'll still have some difficulty stepping it alongside the mothership. I think what I would do is build and install a fiberglass tube or even use a PVC pipe to connect the top and bottom mast partners. It would not be load bearing under sail so it could just be slipped underneath the foredeck hole and over top of the existing mast step i.e. don't cut the foredeck hole larger to receive the pipe so as not to weaken it. Then you'd epoxy it in place and apply a fillet to the outside which should be strong enough to hold it in place if you get a bit off balance. You won't have to worry about landing the mast in the mast step. A fiberglass tube would be lighter and more elegant. If you scroll to the end of this video on how we make our glass tubes you'll see it being installed as a guide tube for the Core Sound 15 mizzen mast which serves the purpose i'm describing above. https://www.youtube.com/watch?v=JO_-sbbBRBM

 

Another option would be to modify the foredeck partner with a removable section of the actual mast support collar specifically the aft half of the collar could be hinged to rotate 90 degrees and allow the mast to be set into the bottom step first and then rotated up into the top partner similar to a tabernacle action but with still some balancing required. Then with the mast vertical the aft section is rotated shut and a pin secures it. The S12 at our workshop actually has this setup I believe with an aluminum reinforcing plate top and bottom (i think) I can get another picture tomorrow but here is one from Graham's Trip to Sail Oklahoma in 2013 where you can just make out the aluminum part. andrewlinn.com/2013/131010_ok/03spin.jpg 

 

Of course a lighter mast would be easier. A balanced lug sail could be an option such as what we have on the Amanda dinghy but it will likely have lee helm with no change to the mast location. You want to try to keep the center of area of the sail as close to the designed location as you can. 

Thanks, lots of interesting options there.

What I had in mind for a pivoting mast is to just lash it in place to prevent it from being able to move back. Would need a strong point further forward, e.g. on the bow knee or the fillet below it, which would find other uses too I'm sure.

I'm very daunted by the idea of cutting a chunk out of the foredeck so not going to rush in to anything.

 

A tube is a very interesting idea, I would never have thought of that.

 

I've sailed dipping lugs before, very practical rig in certain ways, very cumbersome in others! A balanced or standing lug could be interesting. I do think a gunter would allow the sail plan to remain reasonably faithful to the design. Of course modifying sails will not be easy for me given my limited access to equipment.

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I think Alan's idea to install a FG tube between the upper mast partner and the mast step is good, might make the most improvement for the time and effort. My mast partner is too tight so it tends to bind unless I have it aligned just right. My S 10 mast weighs less than half of yours which I think could make a difference. The stock mast is constructed from three pieces of 6068? aluminum tubing which I think will ship UPS. The upper section of my mast is hollow birdsmouth but that is a lot of work for minimum weight saving. The most difficult part of constructing the stock mast is making the FG bushings to join the mast sections which are of decreasing size and I think will nest inside each other. I  can not think of the gentleman from Northern Virginia who built a S 10 last year or so and has lots of good info.

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Yes I was forgetting that the stock mast was aluminium! Perhaps not so difficult to source after all.

 

The mast I'm currently using is a rather strange design. It's from Needlespars, and has a tapered upper, with the lower portion made of separate sections, permanently joined by internal sleeves. I think it has a pretty thick wall, plus the sleeves, which explains the weight. This design made it relatively straightforward to do a 'cut and shut'. I chopped it in half at a 45 degree angle just above a sleeved section, then very carefully removed the outer section only for a few inches (took a very steady hand with the grinder!). So the existing sleeve became the joining piece. I cut at an angle to ensure that the mast track, which is riveted on, lines up.

 

It works really well when I'm sailing, it's just not that practical in a choppy anchorage to get the rig up and down.

 

In my defence I was out of time and money. I now have a bit more of both, but very limited facilities...

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Here is a shot of the mast partner on the S12 here at the shop. Graham would know the story on it probably. It does not hinge like I thought but does allow for stepping the mast starting at the bottom and rotating it up so at least you don't have to balance it as high up in the air but perhaps not really worth it for an S11 with the lighter stock mast. This one has wing nuts underneath so would be a chore to open and close very often.  We have never opened it. 

 

s12 with opening mast partner.jpg

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5 hours ago, Hirilonde said:

Joe: 3 aluminum sections for an S10?  My S9 has just 2 plus a smaller wooden top section.  I used a DF closet pole for mine.

 

Yes my S 10 mast is just over 17 feet in three sections. I don't have access to the plans but I think stock is three sections of aluminum, but you could do it a number of ways depending on storage or transport issues. Two sections of aluminum and douglas fir CP is good.

 

I like Alan/Graham's idea of having the mast partner swing out of the way, then you could pivot the mast up and secure it by swinging the partner closed.

 

 

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Just returning to this topic. The boat is in a yard for repairs (see other thread) and it will be the ideal opportunity to modify the mast partners.

I'm considering cutting a slot leading aft from the existing hole in the foredeck, to allow the mast to be pivoted in to place.

I would then install a cleat on the foredeck, and use a webbing strap to lash the mast in place. Not quite as neat as a proper mast gate but much easier to make with limited resources.

 

Assuming this would not compromise the strength of the foredeck and partners, the only real downside I can see is that the foredeck would be left with sharp edges which could snag on ropes etc.

 

I'm really reluctant to get the saw out... the poor boat has suffered enough... but I will regret missing this opportunity to make the modification and not being able to safely rig/derig on choppy days is preventing me from actually going sailing...

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I'm not crazy about the webbing strap for keeping the mast forward I think it will be too hard to keep it tight. I drew up a gate that would work and swing open. Some 1/8" aluminum scraps top and bottom through bolted through the cutout section make the swinging part. A couple of radiuses are made to allow it to swing open. I can send you a 1:1 paper template if you want to get the size. 

 

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On the dipping lugs that I learnt to sail on, we had an iron strap forming an eye on either side of the mast, with a big wooden pin that you hammered in to place. One side would be a smaller eye than the other, so once the pin was carved to a slight taper you could get a really snug fit.

But a wee bit chunky for a boat like the spindrift, I think.

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