Bowsprit ideas

[JoeWalling]

Hi all

I seem to remember, some time ago, promising to describe HUSH's bowsprit. Here goes.

The pole is a standard 2 inch aluminium scaffold pole, about four feet long. I don't know what our Colonial Cousins call this - it the kind of pole used in the construction industry to erect temporary and usually external building platforms. My local yard turned a couple of white nylon bushes which finish off the exposed ends. A lick of grey paint and you would never know the pole's humble origins. It is very light, strong and will have cost next to nothing to make.

The pole normally sits 28 inches proud of the front of the central hull. It is anchored at the back through another standard scaffold fitting which is screwed to the deck. An allen keyed grub screw allows for the pole to be retracted and resecured. An oversiszed O shaped stainless ring has been welded to the port side of the bow roller housing and the pole slides through that, with a rubber O ring compressed inside the stainless ring - this allows some shock absorbancy.

You can see that there is a ring screwed into the starboard front end of the pole. To this is attached a clip on shackle and block, which I can reach from the pulpit. When the asymetric is not going to be deployed I can unclip this assembly and relocate it to the pulpit, leaving no line attached to the bowsprit. This is useful when mooring - so as to not snag the pickup buoy or chain.

A line is fed through the block attached to the clip on shackle. One end of the line is attached a snap shackle which in turn attaches to the tack of the asymetric, the other is taken back past the mast to the clutch assembly mounted on the coachroof above the saloon doors. This way, the tack can be close hauled to the end of the bowsprit or played further away from it, without leaving the cockpit. The asymetric halyard is also led back to the cockpit.

You can also see another block attached to an eye on the starboard side of the bow roller housing. This used for a line to send and return the asymetric snuffer.

That's about it. There is no bobstay, by the way.

[petrel]

Joe
Thanks for the photos and information on your bowsprit. I now understand that instead of stays it is attached to the foredeck. Cantilevered 28" from the bow. My bowsprit is not cantilevered. Hence it requires two whisker stays and a bob stay. I am part way through the project having set up the bow bracket. Next are the pad eyes and swaging new stays. When finished it will protrude about 48 inches from the bow.

With your set up you have the advantage of being able to withdraw the sprit. Whereas on mine it is fixed. I think it is going to be a bit scary getting used to that proboscis. I like your method of being able to adjust the height of the tack and will probably do the same with my old sail. When I get a new one I intend for it to have its own roller furler.

Thanks again
Geoffrey

[Dan]

Hush's setup is pretty similar to the setup on the Telstar 28's, but the Telstar 28's setup is integral to the hull and the bowsprit is inside the anchor locker and head compartment. I'm adding a bobstay to mine, to help offset the loading on the bowsprit when using the screacher. The lower anchor point for the bobstay will be the boat's boweye that is used for trailering.

[petrel]

Dan,

I find it interesting, and am curious as to why your boat's canter levered sprit needs an additional bobstay to offset the forces from the screacher sail. Is your screacher standard? Also what are its dimensions? And lastly how far from the bow is the screacher tacked onto the sprit? Dave Bierig will be making the screacher for my 8m which will probably have a slightly smaller in area than the standard T 28 sail.

I am in the design and build stages of both sprit and sail at present so any input would help.

Thanks
Geoffrey

[Ron]

Geoffrey,

I regard the bobstay on the 28 as optional and totally dependent on conditions. In lighter air (<12 knots) you're perfectly OK without it, but get above 15 knots, especially with the screecher going into the wind, and you could be easily overstressing the sprit. If there is any chance of exceeding this wind speed, I will set the bobstay BEFORE I leave the dock. I carry a pre-measured low-stretch line on board with a hook on the bottom and a loop on top. I just dangle the hook onto the trailer U bolt, attach the loop around the sprit forward of the bail holding either the screecher drum or spinnaker pennent, and extend the sprit forward making sure the hook stays in the U bolt. When the sprit is extended as far as possible, the line is exerting significant pressure on the sprit.

I believe the 28's manual warns about using the bow sprit and screecher upwind in anything above 14 knots. I've done about 18 aleady with the above bobstay in place. This was not exactly planned - it just happened. The upper limit is something like 18 knots on any point of sail. I've probably exceeded that as well (with the bobstay).

[petrel]

Ron,

Thanks for your reply and info. So both Dan and Ron find that in addition to the canter levered support the T28 bowsprit needs an additional bobstay! Very interesting. The bowsprit that I will be using was originally made for an F-24 which is designed to carry a larger screacher than I will. It is not canter lever supported like your T28 bowsprit and will have a bob stay and two whisker stays. I intend to use it only for the light airs that are typical on the Chesapeake Bay during the hotter months. Even if it means the boat is only sailing at 3 knots I prefer that motoring

What are the details of the T8's screacher (area) and bowsprit(length from bow) and does Dave Bierig make the screechers for the T8?

Thanks again
Geoffrey

[JoeWalling]

I had previously shown some pictures of the bowsprit with the tack line deployed. Here are a couple with the tack line removed from the bowsprit. One picture shows the shackles before they are 'parked' - the shinier snap shackle, with the block attached, is the one thats clips to the bowsprit eye. The other clips onto the tack itself. The other picture shows the two shackles as they normally sit when the chute is not being used - they both clip to a ring on the starboard side of the bow roller assembly. You can also see the block which is used to return the snuffer uphaul/downhaul line. They are a couple of bits of old string in the photo - they need to be removed.

[petrel]

Joe,

Thanks for the additional info and photos. Having a bowsprit that is retractable has the advantage of being able to easily attach sails and lines to the end while it is retracted and then extend it to its working length. With my non - retractable sprit design I will not be able to do that and have to work out a different system.

Would you please provide more details on the size and type of your spinnaker.

Thanks again
Geoffrey

[JoeWalling]

Hi Geoffrey

Well, I don't have a spinnaker. It's called over here an asymetric cruising chute and maybe your equivalent is a screecher? I'm not sure because I've never heard the term screecher before, apart from on this website. Anyway, its shaped quite like a spinnaker, made of really lightweight spinnaker material, can be rigged like a spinnaker but can also be rigged as a genoa so I imagine it has a shallower cut than a full bellied spinnaker. It can be used with a pole although I don't have one because I find it's best value is when used as an upwind genoa. Wow - does it make the boat go to windward. Of course, I have the variable tack positioning so I can fly the chute way outboard and high of the bowsprit in light downwind airs, for example.

I use quite light sheets with the cruising chute - I'm guessing 6mm or 8mm and they are led aft to a cleat aft of the main jib cleat, so I can fly both jib and chute together. Currently, the chute sheets are led via a block attached via a short line to an eye at the bottom of the midships guardrail stanchion posts on either side, thereby creating a rather wide slot (the width of the wing deck effectively). This seems to work fine and does not interfere with the airflow to the jib but I might at some point 'play' with an adjustable arrangement, maybe like a barberhaul, so that I can alter the address of the clew for even better upwind performance.

The only way I can describe better the chute is to refer to the invoice paid for it by the previous owners. It jusr says cruising chute - 32ft by 18ft.

[Ron]

Joe -

A "screecher" over here is actually a Code 0 asymmetric spinnaker. It's flat enough that it can be rolled up around a wire or line embedded in its luff, using a drum at the bottom and a swivel at the top. It also is normally built from a little heavier weight cloth than the other asymmetrics, which are usually nylon in .75 or 1.5 oz weights. The flatter surface works best on a reach or somewhat into the wind. Code 1 thru 5 asymmetrics are not as flat, would be difficult to roll up, and work either on a reach or downwind. The various numbers indictate wind angle and wind strength. None of these require a pole but can be used with one.

As I recall the "code 0" screecher supplied by Bierig on the 28's is approximately 400 sq feet while the asymmetric spinnaker is around 650. I'd guess that this 1.5 oz rip-stop nylon sail would be better classified as a Code 4 (heavier air, downwind). A little flatter would change the designation to a code 5 (heavier air, reaching). But it could be a compromise (a 4.5 ????). 0.75 oz nylon would probably make it a Code 2 (lighter air, apparent wind angles above 90 true).

Some of the newer asymmetrics sold by various lofts as cruising spinnakes are closer to being Code 0's. They are designed to be rolled up.