Forestay tension in a blow

[Jim Coleman]

Hello Everyone and a Happy New Year.

During my 1st year sailing the Sprint I have got on well sailing it with the loose set up as it was when I bought it from a very good Sprint 15 sailor; ie, 3rd hole down, a loose forestay, and mainsheet blocks going block to block in the middle with a strong pull when on shore. When I sailed with this set up in a few strong winds I was well on the pace in a straight line, although dreadful through the tacks, which I will work on.
But it seemed to make sense to use the rig tensions for stronger winds in the “Tips” articles "Sailing in a Blow" by George Carter and "Stay Tooned" by Paul Smith. So in the last two F5/F6 outings sailing Unarig I set the shrouds (not quite) to the tension recommended by them, ie “…to the point where it is difficult to deflect the shrouds inwards by pushing with your finger ends….” However with that set up I found on the beat that it was very difficult to get the boat to accelerate. If I set traveller well low and bore away to get speed it took me miles off the point, and velocity made good (Vmg) was poor. The alternative was to keep the traveller in a bit, accept the lower speed and point up, as that seemed to give reasonable Vmg. Is that the way to go? On the reaches and runs I found the stiff set up was very good.
I must admit I liked the loose set up on the beat and will go back to it if necessary. But do the articles by George and Paul refer to Unarig and/orSport mode or both? No particular mode is mentioned in the articles. And can someone please enlighten me about sailing on the beat with the stiffer rig. I should add that weight is not the problem as I’m about 86 kilos in the kit and I know a few lightweights who go very fast using the stiff set up.

[Brian Phipps]

Hi Jim,
Your thoughts I am sure are interesting to us all, as a coach I see many setups and ways of sailing the same craft all with similar results. In short what suits one sailing style / sailor may not suit another, what works in one sea condition may not be the fastest in another, what suits one crew weight may not suit another.
The important bit is you have these options in your sailing "tool box" , you understand the trade-offs and through testing them in training and none important events you build up and adapte your style of sailing to suit.

A simple example for myself was at the last Sprint 15 Nationals at Thorpe Bay. Having not sailed the Sprint 15 competitivly for a number of years it was an on water learning curve for myself watching other faster sailors performing and then going back to my personal sailing "tool box" to find the right combination to speed things up in my own style of sailing.
Experimenting on the race course is not the best way to test things out, which is why some form of club / class / group training-coaching session helps to fill up that tool box with options.
Not the answer you may be looking for, but what George says works for him, and an adaption of that could work for you!
Brian Phipps
Windsport Coach.

[Jim Coleman]

Hello Brian,

Thanks for the comments. And I do have the loose rig alternative in my 'toolbox' to fall back on. But it would be interesting to hear the views of other good sailors on the question of loose rig v tight rig.

Jim C

[Bob Carter]

Hi Jim
At Grafham we have the master of the loose rig brigade, Chris Black. He has the rig so loose that you can lift the mast off the ball without undoing the clevis pins. He is never the less very quick - especially when sailing by the lee downwind.
I always prefer the rig as tight as it will go while allowing the mast to rotate 90 degrees to each side. In practice this is not very tight as the shrouds have to wind a bit around the mast to turn the mast this far. Greasing the ball helps the mast spin freely and enable the shrouds to be a bit tighter. On strong wind days there is more force available to spin the mast so you can tighten up the forestay more to allow for this. I make all adjustments using only the bit of line on the forestay. Once I have found the optimum hole in the shroud adjuster plates I use that position, irrespective of the wind strength. I do not believe in raking the mast back in stronger winds on a Sprint 15 which is correctly set up because it results in the main sheet going block to block and a loose leech - the last thing you want when going upwind in a strong wind. I know it is a common approach on other classes but they probably have a different geometry of sail/mainsheet which allows raking the mast back without loosing the ability to sheet in hard. It just so happens, in my view, that the optimum mast rake on a Sprint 15 (even in light winds) is when the mainsheet is on the verge of going block to block with the mainsheet swivel removed (I'm pretty sure that Philip Howden will have already taken it off 1939).
This is probably pretty much the same as George says in his article
Cheers
Bob

[Robert]

That's interesting, Bob. I have a long shackle underneath a swivel and still have difficulty getting block to block unless I really try hard in stronger winds, so I guess my mast is raked fairly well forward. I think I have a standard forestay and my ideal stay tension is two shackles from the furler to the eye on the forestay and this still allows the mast to rotate to 90 degrees. I think that this all allows for a bit more power to make up for my extra weight and helps downwind. My mast ball might be a bit low, contributing to forward rake (I use hole 4 on the shrouds) and the wear pin is slightly proud (DIY job), allowing easy rotation but the base of the mast might not always be dead centre.

Recently I've taken to sailing sport mode with the idea of not being so far down the pack if possible - it's less depressing that way and you get to see what the experts are up to at the front.

I was very interested to see the new DX sails. One argument used against Multihulls being Olympic "equipment" was that there was not seen to be a clear path of development for younger sailors through this branch of the sport. It was also reasonably argued that many of the leaders in the field are not so young as one might have expected. Should the experimental rig be taken further, then the Sprint 15 could become a very affordable route for parents to support their offspring through the different stages of competitive cat sailing. The prospect of beginning with an inexpensive but competitive second-hand platform and progressing through crewing/helming two-up > una rig > sport rig > DX rig would get a keen youngster a long way in the multihull training game before moving on to the twin wire and very fast stuff.

Just a thought. By the way, does Draycote SC have access to a decent ice-breaking vessel (other than a pint glass)?

[Bob Carter]

Robert,
With the old blocks you must have the swivel - the newer black plastic blocks had the swivel built in but the Laser Centre never removed the swivel. The best that you can do is to dump the shackle and use the swivel to fix the main sheet to the traveller. It is ages since I sailed with the old blocks and I'm not sure how long they are when block to block so my advice is more useful for people with boats from about 1560 (Race colours) onwards that were fitted with the new blocks

On the matter of icebreaking, it would be a good idea for one of the Draycote guys to put a post on this website Friday to tell us if the lake is frozen. Any takers?
Cheers
Bob

[Steve Willis]

Robert,

I have sent you a private message with some information re wear plate and mast height with my e-mail address.

I have some measurement information for a range of boats that results from an exercise I did with regard to forestay length that may help you.

Best wishes

Steve

[Andrew Hannah]

On the subject of mast rake, I'm often asked what hole the shroud is fixed to, on the shroud adjuster. My answer is always the same.

I reply by posing further question. "Where did you buy your shrouds from?" Usually, the reply is "Don't know!"

The remedy is to buy a replacement wire set from Windsport who will have the exact measurements. It is only then, that we can discuss which hole to use.

Robin Leather once told me he replaces his shrouds every two years. I follow his example and always buy from Windsport.

[Jan]

Hi All,
Web Cam for Dr te , looks "warm" at the moment!!
I have neve seen it frozen over but it has happended a long while back.

If any of the other inland lakes , Graffam, Stewartby, Carsington freeze then we may have a problem.

I doubt it though....

See you Saturday

Jan

http://www.draycotewater.co.uk/weather/index.htm

[Robert]

Robert,
...With the old blocks you must have the swivel - the newer black plastic blocks had the swivel built in but the Laser Centre never removed the swivel. The best that you can do is to dump the shackle and use the swivel to fix the main sheet to the traveller. It is ages since I sailed with the old blocks and I'm not sure how long they are when block to block so my advice is more useful for people with boats from about 1560 (Race colours) onwards that were fitted with the new blocks...

Thanks Bob

After checking my boat today I realised that my statement about the swivel is mistaken. I have the newer style blocks now and therefore there is no swivel, just the long shackle (about 35mm I think, but I haven't measured it) so the forward rake is less than I had indicated. My shrouds are not from Windsport and so Andrew's comments may be pertinent because the forward rake is a little more since I replaced them.

I'm happy with the boat's performance - it's me that needs to improve. I could be tempted to drop the shrouds one hole and use a pretty tight rig in a heavy blow but I'm trying smaller tweaks first (like being at the start line on time).

Thanks to Steve for the useful message and advice.

I guess that Charles Watson has to be the Guru for the old style blocks so I'll see if I can sneak up on him on Saturday to see what he's up to, though I doubt if there'll be sufficient wind to make any observations valid.

[Steve Willis]

When I did my measurements of all Seasalter boats (17 boats from 191 to 1978) several things of note came out:

Shroud length on all the boats except one was 4300mm+/- 5mm one boat had 15mm less (that boat performs very well upwind but not so well downwind - third hole on chain plate like moast of the others)

Bridle wires were 1190+/-5mm on Dart15s and 1185mm on the Sparks
I did not tip any boats over so I do not have any values for the short top strop. The height of the bridle centre above the deck was 725-730mm but on one was 735mm. Obviously it is important for both bridle wires to be of equal length (all the boats had the mast foot central).

All furling drums were 65mm overall and all chain plates measured the same above the deck +/-1mm.

One thing I did notice is that boats with the older 1.5-2mm bridle hull plates had the plates bent backwards and twisted to some extent (the newer 3mm plates did not suffer that problem.

The Spark Fun and Spark Sport had different forestay lengths in the original manual (total length of forestay on the Sport was 50mm longer) it appears that the original design was for the mast to rake back if a jib was to be used.

Steve

[Bob Carter]

Robert,

On the matter of icebreaking, it would be a good idea for one of the Draycote guys to put a post on this website Friday to tell us if the lake is frozen. Any takers?
Cheers
Bob

Pete Slater just called me - Draycote Water is NOT frozen so it is all systems go for Saturday. He said that Carsington cannot get out of a thrashing that easily...............

[Charles]

Halifax isn't frozen, so nowhere else will be, though top temp according to windguru will be 1C on Sat at Draycote, brrrrrrrrrr.

Hope the low comes through quicker than forcast, more wind & warmer.

Re old blocks: I have my shrouds on 3rd hole & mast just twisting to 90 degrees, I find I can then oversheet the main & often have to let it off a couple of inches to stop the leech from closing & depowering the sail, so I guess the old blocks are shorter than the new ones.

Good commentary re Sprint multi format offering Robert, I agree it's just what the market needs, let's hope the market finds out !!

[Jim Coleman]

Bob,
Thanks for the info.
I'm not sure what you mean by the swivel being removed at the mainsheet blocks (and it's too cold to go to Grafham to check the details at the minute) but from memory my system doesn't look exactly like the one in the Parts Manual. And I think the blocks and the ropes between spin round the axis of the system.
Cheers
Jim

[Robert]

It's been another balmy night at Draycote I see (more than 5 degrees!). I'm a bit confused about the time of sunrise and sunset though.
http://www.draycotewater.co.uk/weather/index.htm