I just read some comments in another thread about Tandem windsurfers and thought I would start a new thread on tandems, just in case anyone is interested.

One sailors tandem trip:

I started mucking around with Tandems in the late '80's when we came upon a derelict white Waylar that seemed to us to have huge volume. The talk around the campfire was that this thing was so big you could put 2 rigs and people on it. It became a sort of alcohol induced pact so the next day we literally screwed a couple of mast bases on to it, plugged in two 6.5m rigs and drifted off down the inlet in 5 knots of wind. We had a ball falling in, laughing at each other and generally being out of control. We soon decided that we should build a 'proper' tandem. At that time, our small band of sailing addicts had been building quite a few slalom, wave and speed boards and we set out to investigate. There did not seem to be any polyurethane blanks anywhere near big enough for what we had in mind and Styrene/epoxy seemed like just too much trouble so we stalled a bit right there. The idea was planted but it just needed the right fertilizer to grow. It came soon after from slight tangent. Peter Smith had picked up an old Angulo Pan Am race board a few years before (polyester/polyurethane) about 12’ 6” long. We had sailed it a few times but soon found it was uncompetitive with the then current long boards in light to moderate conditions. It was quite narrow and clearly built for high winds. It had sat under a tree out the back for a while but Peter suddenly had the wild idea that, since it looked like an oversized speed needle, we should make a tandem speed board out of it. One non windy afternoon soon after, we got it out and took to it with a pail of resin, some fibreglass matt and some foam bocks to plug up the centreboard case. We screwed a couple of strips of aluminium plates to the deck to attach the mast bases. A few foot strap inserts later and we had ourselves a tandem. We knew it would take a lot of wind to get it going so we tried it in the next 20 knot easterly. Peter on the front and me on the back. We stepped on, immediately got it up and planning and ploughed through the chop for a couple of runs. Surprisingly we had fluked the balance of the rigs and foot straps about right. Just as we were starting to get the hang of it we slammed into a wave and there was a loud crack as the 13” fin and ‘A’ box rolled out of the board. Oh well, that was fun while it lasted but now we were hooked!

We immediately made plans for a speed tandem based around what we had learnt from the converted Angulo Pan Am. We drew an outline on the bottom of the now finless board and decided that we didn’t need all that nose up front. We found that a 10’ 8” polyester blank was available from Burford and they even had one with a flatter rocker. Perfect! We ordered it and got to work. The result was a speed tandem 10’8” long (3.25m) and 20” wide (50cm). We had done a bit of deep thinking about it and realised the fin (‘A’ box – highly reinforced) had to be in front of the back sailors rear foot to balance the Centre of Effort with the Centre of Resistance. We also decided that we needed to get the two sailors as close as possible to the rear of the board when up and planing to closely replicate the situation on a single rider board and get the minimum wetted surface at speed. We reasoned it would be difficult to get started in that position so we needed two rolling mast tracks. We would get going with them forward and pull them back when up and planing. A couple of Tyronsea race board tracks did the trick.

To solve the foot strap position problem for the front person, we attached the back strap to the rear mast track just in front of the mast. This way it moved back with the mast as the front sailor moved back. Somehow there was never any question about who would go where. Peter was on the front and I was at the back. Peter decided we would wait until after a shakedown run before we fitted any front straps for him. I decided all I needed was two straps right on the centreline. My back strap is as close to the tail as is physically possible.

We also put a lot of thought into the rocker line and bottom shape. There is virtually no vee but there is a step chine on the sides of the bottom through the widest part of the outline which is designed to reduce wetted area when planing. The rocker is quite flat overall and seems to work very well.

Sailing the Tandem. It is definitely not a floater for two people and it takes a fair bit of wind and power to get it going. Initially we really only sailed it with 4.5m sails and smaller in 30+ knots of wind. Step on starts are the go but timing the jump on is a bit of a trick. If you don’t get it right one sailor can easily miss the board and get dragged, stopping proceedings quite quickly. We found that it often helps to take a step to get the board moving, just like starting an individual speed needle but timing is everything. We have managed to waterstart a few times but it is very difficult as well because the front sailors sail tends to kill the rear one. This results in the front sailor getting up and the back sailor getting dragged which gets you nowhere. I have actually had Peter grab my mast with his back hand in this situation and physically haul me up on board. This only worked when I was almost there and was just enough to make the difference. In really strong winds with the smaller sails it is a bit easier.
Once underway it is possible to move the tracks back but they are not the easiest rolling tracks around and we usually find it easier to set them up for the speed run before starting if there is enough wind. We always move them forward for upwind. With the tracks back the rigs overlap quite a bit. We quickly found that this had the same effect as the Jib and Mainsail on a yacht. There is a noticeable increase in the power generated by the front sail and we always ran a smaller sail on the front. Typical sizing in 30-35 knots of wind was 4.2m on the rear and 3.7m on the front. We ran it in one speed trail in only about 20-25 knots with a 5m on the front and 5.5m on the back. This is the largest combination we have successfully used but we are talking early ‘90’s sails here. With the modern KA Koncepts we could almost certainly go a size larger.
Getting the mast tracks in the right place is critical to keeping everything balanced, the sail drive symmetrical and maximising the power. If the front track is too far forward the sail rakes back too much and is very awkward. Sheeting angles are also critical. If the front sailor over-sheets he kills the power for the rear sailor, a scenario that can easily lead to the terminal speed wobbles. With the tracks right back and using small sails, we occasionally found the middle of the front boom ‘tapping’ the rear mast. The best idea seemed to be to keep at least a few inches of gap between them. On a few occasions in this situation, Peter removed his foot from the back strap and hooked it behind the rear mast base! He never did get around to putting a front strap on the upwind side. He just thought he didn’t need it! We did discuss the need for a strap behind the mast but he just shrugged and said hooking his foot in was fine. I think he just wanted to be in a position to eject quickly if the need arose.
Roll stability was an issue from the start. It is very natural to try to use your feet to stabilise the board if it wobbles or rocks. This can easily lead to each sailor overcompensating for the other. The dreaded speed wobbles are the result. The first thing I say to new partners is to completely relax the ankles and let the board rock as much as it likes. Luckily, it is very smooth and stable at speed but it needs a delicate touch with the feet. Everyone who has ridden it has commented on how smoothly it rides the corrugated chop. It is extremely stable in pitch and we often run quite a bit further from the bank than we would on a single board without even noticing the chop at all.
Stopping: This is a bit tricky. When this thing is wound up it feels like a runaway freight train. When you back off the power it just keeps going and it is very easy to get the wobbles. One way we often stopped on the upwind run was to drag our bums in the water. Another way was to just drop the rigs and fall in on a signal. As we get more confident we learnt to round it up and lose speed in the normal way but it does require a lot of room and this method is not really an option if you are running close to the bank.
How fast does it go? That is hard to say because we didn’t have GPS’s back in the early ‘90’s. We did have a Speedwatch and at one stage and we saw a peak speed of over 37 knots on it one stormy 30-40 knots day. This was with 3.2 and 3.7m speed sails! We are not sure how accurate the Speedwatch was but we strongly suspect it read a bit slow because we ran it through the timing gates one day and it was 1 -2 knots slower than the gate speed. We did get clocked at 35 knots through a 250m course at one speed trial with the 5m and 5.5m sails in 20 -25 knots of wind, a pretty satisfying result that bettered most of the individual sailors running in that session. I am pretty confident that it has 40 knots potential in good conditions, maybe even more. The problem is finding someone who will do it with me. Peter has drifted out of windsurfing and it is hard to get enough experience with any other partners. Craig Hollins has done a few runs with me and is starting to get the hang of it but we have always left our tandem time until late in the afternoon when we have decided that we no longer have a chance to push our individual PB’s. By then we are too tired to do it justice and the best conditions are past. To get the best out of it we would have to make the commitment to run the Tandem for the whole session and go for it in the best conditions available.
For years we tossed around the idea of building a ‘Slalom’ type of tandem. Something large enough to gybe and tack. Something to blast around on in 15 knots of wind and take everyone for rides. The blocker was just that we couldn’t get over our deep seated aversion to working with polystyrene and epoxy. We flirted with the idea of selling our worldly possessions to buy a Cobra tandem, and later, we very nearly tracked down an F2 tandem that was rumoured to be in the country. Alas, this was one dream we have not been able to make come true. But all was not lost. When Starboard invented the modern Formula board my tandem orientated brain immediately realised the possibilities. Why not a Formula tandem? It would plane in light wind and the would be plenty of room on it to tack and gybe. I knew it would be just a matter of time before the fertile imaginations in the Starboard skunk works saw the same light. And do you know what? I was right. Taadaaaa….. Gemini! You know what is coming in my Christmas stocking!

I just know this is going to be lots of really relaxed fun, and I am sure we will crack 30 knots on this monster on a good day but, well, I still have these dreams of the ultimate modern speed tandem capable of pushing towards 50 knots. Aaaah….., maybe one day I will get around to it……….

I don't know anyone I like enough to want to do it with.

Maybe Toni Peron... If she was at the front. But i'd get bored of that after two minutes..

i just got off the phone to peter who made the one at the windwanderers meet.

he made about 7 in total, including a threesome...

i've sailed his tandem with him but i'll wait to see what he has to say.

he is talking about making another 3m long wide style

Mr G.
can you get a pic of Pete's board up.
Would be interesting to compare with Sailquik's board - dimensions, mast locations etc.

Andrew, got a plastic fantastic TC Spacer Nova in the garage 3.55m x .66m.
Could that be a starting point for a trial tandem board??
Not much good for anything other than learners - and there's better options for learners now anyway

Hi Matt. My order is definitely in!! Don't let me down now!

Hey Mat. Be sure to bring you stack hat and a healthy disregard for you own safety!

quote:

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Originally posted by sailquik

When Starboard invented the modern Formula board my tandem orientated brain immediately realised the possibilities. Why not a Formula tandem? It would plane in light wind and the would be plenty of room on it to tack and gybe. I knew it would be just a matter of time before the fertile imaginations in the Starboard skunk works saw the same light. And do you know what? I was right. Taadaaaa... Gemini! You know what is coming in my Christmas stocking!

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For those interested, here is the reference:

http://2004.star-board.com/forum/askteam/read.asp?ID=3280&t=5%2F4%2F2004+5%3A57%3A43+AM

You can blame sailquik for this *board monstrosity...!

www.boardseekermag.com/equipment_reviews/equipment/starboard_tandem_07.htm

hi guys,

i asked pete to contribute and he tried but couldn't sort out his password. user error.

so he sent me an email and this is what he had to add.

Hi Justin having read the bit about tandem on seabreeze i hope you can post my reply i build the first tandem in 1978 which were 6m long with three sail stations including a centreboard like on the windsurfer , brand only one to copy, the guy in the middle was responsble for raising and lowering it . going about was a bit of an art as you can imagine he basically had to lay his sail down for the forward and rear sail to tack once this was done it was his turn we soon dispenced with the middle station and leaving the centreboard at home as it did not need it relying on the rail line and mastrack in its rear station to go to windward yes this board slots cut out on the deck like a windsurfer so you had to pull your mast base out of the board and move it to the rear ,mind you we never moved it if it was windy as it wanted to go to windward on its own, my brother and i sailed it mostly when i was still in Tassy .I eventually sold it to sombody in Hobart so came the next one still 6m long , I build 4 of the 6m ones and sold them 2 in tassy one in Melbourne one in QLd where i moved to in 1980 and build the last long one there from the experience i had with tandems is that the placing of the stations is verry critical and basically ballancing the sails over the lenght of the board working out the center of effort to the latteral resistance if you ar looking at a planing board is different to a long tandem as we found out once i build shorter ones the last tendem by me were 4.6m long and was build in 1988 which i still have one at that stage this board had build in rolling mast tracks and were state of the art at that stage for front and rear .The process for going about was the front sailer eased off and the rear sailer sheeted in to initiate the tack for a gybe it worked the opposite with a bit of a ballancing act , to do this we moved the stations apart and the repositioned them either off the wind forward and upwind back a smaller sail in the front worked the best also the best sailer should be at the rear otherwise the front one gets clobbert with the mast in a catapult from the rear > At the present moment iam thinking of building a shorter version which had been on my mind for a while as the interest was rekindled after sailing the old one on the weekend and thy are great fun just cruising in Morton Bay and can also be used as a teaching aid for shortboard learning which i had used one when we had our windsurfing school on Bribie island just make sure that the person you sail with is under your command otherwise you might not get anywhere Peter Nitschke owner of Caloundrawind andsurf and Manta NXS sailboards, Kiteboards with 34 years in the windsurfing business


p.s. wineman, i will get photos next time i am at the factory and upload them.

quote:

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Originally posted by king of the point

Posted a few pictures SPEED BOARD from early 1990 9'6" x16' x 3'

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I'll take it!!!! (If I can uphaul it!)

My water-ski's nearly bigger than that!!! Great pic!

Windsurfing is not really a team sport, but the tandom changes all that! Daffy brought out his new Starboard Gemini for us to play with... Really lots of fun! Posted some pics of Daffy and Kato...

www.seabreeze.com.au/gallery/gallery.asp?imageid=5430
www.seabreeze.com.au/gallery/gallery.asp?imageid=5431
www.seabreeze.com.au/gallery/gallery.asp?imageid=5432
www.seabreeze.com.au/gallery/gallery.asp?imageid=5433

And for those of you that like specs, go here:

http://www.star-board.com/viewpage.php?page_id=28

Short video of this weekend's tandom runs. Sailquik on the back, Kato on the front. Sails are both 5.8 Koncepts.