Previous PageNext Page

IconUK News: Weir Wood 23-24th May 1997Icon

Bob Downhill

Normally at this time of year I go to Weymouth to familiarise myself with the equipment I use at Weymouth Speed Week in the Autumn. (This year's dates will be Saturday 24th September to Friday 3rd of October at the Weymouth Sailing Centre in Portland Harbour.)

This year Nick Povey suggested as Weir Wood was closer to Eastbourne than Weymouth why not go and do the business there. As the mileage from Eastbourne to Weymouth is 160, compared with about 35 to Forest Row it was no contest. The local sailing club was contacted (Nick is a member) and they made the right sort of noises so we agreed to try the venue.

Weir Wood reservoir is where speed sailing all started in, I believe, 1965 when the Amateur Yacht Research Society held their meetings for "experimental boats". In 1972 the RYA. and the AYRS collaborated to make the speed trials happen at Weymouth. I was too young for those days but from pictures I have seen of the events they were well attended and enjoyable. For experimental boats it is a good location. It is a man made lake some 400-500 metres wide and some 4-5 kms long with the water bounded by gently sloping tree-lined banks. It certainly is a beautiful location with an excellent clubhouse serving tea and coffee with delicious cheese salad rolls, hamburgers.

So there I was on the 23rd with Nick, equipped with "Joddy boxes", computers, radios and all the bits and pieces needed to endeavour to put on a mini speed trial on the 24th. As we had no budget for this particular adventure one or two things were missing - most important, we had no laser tape, and my radios, or rather the batteries, were getting a bit old.

We arrived at the club and set the computers up - no problems. We then addressed the problems of laying a course. I brought the tape measure and sextant which could be used as a last resort, but Nick favoured using a 500 metre bit of string. Looking the radio batteries in order to make sure they lasted longer than the 1½ hours we had the last time we tried the Joddy boxes, Nick decided to go and make an interface so we could use the 12 volt batteries the model aeroplane people use.

While the discussions were going on Torix Bennett turned up with his boat. This has been modified since last September from an asymmetric design to a symmetric one. He wanted to assemble it the first day with a view to wetting the bottom and be ready for the next day in case we were lucky enough to get a course laid.

After lunch Nick and I reviewed the situation and decided we had to address the problem of the course. At Weymouth the situation is easy to address. We know that the course is difficult to lay and accurately measuring it is even more difficult and this is where money comes in useful. We have radios and big-ish boats plus a laser-tape. The laser-tape is a wonderful piece of equipment. It is a monocular (half a pair of binoculars) and is self focusing in addition to being a range finder accurate to half a metre. Operation of this bit of kit is easy. You first find your target, which incidentally does not have to be co-operative, then press the button, and hey presto the distance to the target appears some 0.3 second later. The best part of this kit is it has two ranges - up to about 700 metres and to 2000 metres - and the illuminated area is about 1 square metre at 600 metres. This is significant, as it makes it easy to acquire the target from a rolling boat.

We tried the laser guns the police use - the Laser Technologies LT 20/20 - but the maximum range we could read was 515 metres, and it took up to half an hour to hold the spot on the target for the required 0.3 of a second. The LTI 20/20 accuracy is better at 0.1 metre compared with the 0.5 metre for the laser-tape. I mention police equipment because I am always being urged to look at their stuff. It is higher quality but shorter range which more or less rules it out for Weymouth.

Anyway back to Weir Wood. We hummed and hawed and finally Nick rushed off and came back with 500 metres of 30lb twine on five plastic reels all connected together. We got the sailing club rescue boat out and loaded up with a couple of buoys with anchors. About 50 metres offshore one of the buoys went over the side and we tied one end of the twine to it. Then came the tricky bit. By holding the spool of the twine the boat could move and the twine would unroll from the spool. Unfortunately at the 100 metre point you had to change reels rather quickly. We only lost 100 metres of line when the spool shattered but we got the hang of it and successfully ran out 360 metres before we lobbed the second buoy in. I am not too sure what we would have done if the course had gone over the 400 metres. Luckily we had crossed the lake before that happened.

Torix had meanwhile put his boat in the water and while sorting himself out drifted down wind a fair distance. We towed him back and then all went home at about 6.00 p.m. I recharged all the batteries and after a sleepless night I rose at 7.30 a.m. (and that is really early for me), had breakfast and headed back to Weir Wood.

I pulled into the carpark at 9.25 closely followed by Nick and we set up again. We were fortunate enough to borrow radios for general communications from the club so with a shore base, and the club committee boat at the other end of the course, we were set up for the day. As it was now 12.30 we broke for lunch and restarted timing at 1.45. One of the big problems with doing trials such as these unless there is a surplus of people it makes it hard for the timers. They want to be out on the water and especially on a lovely day like this Saturday turned out to be. No matter!

Torix got rigged up and seemed to be zipping from one location to another, sitting there for a bit, then heading off to another location. The club officials were most concerned that he might drown, but I pointed out that Torix was only really in trouble when he was upside down. I think they took a dim view of the spirit behind the safety aspects. Torix is one of the most stalwart supporters of speed sailing. He is either there or sends his apologies. He turns up with his friend with his latest creation normally on a massive trailer. He is plagued with the fundamental problem of minor structural failures. This time he broke his mast and was towed back.

His boat in its present form is a planing triscaph (2 floats at the rear and one at the front) held together by a well-made aluminium space frame. The hulls are perhaps 4feet long and 2feet wide each with a pointed bow, squared off stern, and are flat bottomed with directional stability being provided by a number of Windsurfer skegs. I am not sure how it was steered. There are three sails: 2 mains in an A frame configuration and a quite small jib. All the sails were unbattened and in consequence the jib had difficulty in doing its job. I suggested that perhaps some stiff battens in the jib may help.

If I can muster up some help I would like to go back to Weir Wood and do some towing trials on Torix's boat to produce credible speed/drag figures then tether the boat and see how the power of the sails measures up to the power required. That sort of thing is very time consuming but very worthwhile. To do it you need lots of rope, spring balances, speedos, and at least one reasonably powerful boat.

Mark Tingley turned up and volunteered the information that he had a model in his car. He was persuaded to bring it into the clubhouse and assemble it. The design is a trimaran with a sliding gunter sprit. The interesting feature about this design is the variable geometry outer hulls which are adjustable vertically and horizontally using an ingenious combination of skewed rods for the vertical movement and sliding joints for the horizontal movement. Completion of the full size article is still some way off. I have booked Mark a place in the 2000 Weymouth event.

Timing finished at 4.30 p.m. with the day being rated a success. The course length was 360 metres with one end sighted from the bank and the other from the club committee boat. We used the Joddy boxes and recorded 59 runs from seven competitors (or eight, if you include Torix who did not make the course). The maximum speed recorded was 21.7 Knots from a wind speed of 15 knots rising to 17Knots down the course. I made a mistake by not taking my printer and in consequence had to produce the results later. I drove back up to Weir Wood from my home the following day to give Nick a copy and to pin the results on the notice board.

The venue is an ideal place for the sort of experimentation that AYRS is for. They have a co-operative club committee, and we should endeavour to develop a working relationship with the club.

Previous PageTop Of PageNext Page

This Web page was produced using a Beta version of HTML Transit 3.0