Bayraider20 - Strong wind sail.

[Andy Dingle]

'The BayRaider is a two masted ketch and has the huge advantage over a single mast rig of allowing  a quick and massive reduction of  sail.  Dropping the mainsail completely takes only moments, leaving her well balanced, very stable and able to tolerate virtually any weather - even making to windward under jib and mizzen alone'.


So the designer/builder of the Bayraider20 tells us on their website and when admiring her in the comfort and safety of boat shows etc.

We all nod sagely and agree. Yes, in theory such a huge reduction in sail will be a huge safety factor. But is she really as manageable with just a jib and mizzen as we are told, and very importantly in strong winds - by which I mean F7 plus gusting up to F9. Higher than the design spec of the RCD cat C (Wind speed upto F6, significant wave height of 2m), possibly the sort of conditions you may be unfortunate enough to be caught out in. There is only one way to find out..

The opportunity arose at Rutland Water on Monday 28 January 2013 to test Matt's confidence in his boat.
The weather was for a good F4-F5 SW, sunny, temp at 4-5 degrees C until about midday. The wind strength forecast then to increase through the day to an expected F9 (50 plus knots) later, with heavy rain.

After a deal of careful consideration Peter Cockerton and I decided we would rig his Bayraider (GRP) 'Joybells' with just Jib and Mizzen and launch with full ballast tanks.
We fully appreciated that we were taking a risk, but it was a considered risk. We were both confident in each other's sailing abilities and are fairly experienced in heavy weather in a Bayraider up to and over F6. Peter's boat is well founded and equipped. We both were wearing suitable heavy and cold weather clothing and life jackets.

We were able to slip into fairly sheltered water and the first test was to beat south into the main body of the lake. After the initial sorting out of the boat after slipping, we found that with the wind well forward of the starboard beam we were still able to make progress upwind. Clearing the lee of the land we were hit by the full force of the wind and we eased downwind slightly into a beam reach. We were happy that with our combined weight and that of the ballast there was little risk of capsize. Wave height was about a metre.
We quickly found the sail combination to be well balanced and we were making good progress fairly comfortably, to be honest, more comfortably than I had expected, to the extent we soon felt relaxed and fairly confident.
Allowing plenty of sea room - as we knew leeway would be considerable - we attempted to tack, and failed!
Try as we might she just wouldn't go through the wind, ending up in irons at each attempt.
As anticipated we were being blown downwind at some rate so we managed to gybe around without any drama to reach off away into open water.
Analysing what was going wrong with the tack we surmised, correctly it turned out, that the Mizzen was to blame.
We again headed up wind, alternatively pinching and bearing away with the gusts to maintain speed, we found that as claimed, it was possible to make progress up wind, even in these conditions (I estimated about an F7-8, gusts slightly higher, unfortunately our anemometer had failed). Time to try a tack again, bearing away to pick up speed we turned into the wind, this time we reckoned, by pulling the Mizzen windward as we went through the wind, the stern would be blown around, swivelling on the centreboard and pushing us through the wind. Success! She went about as easily as you could want.
To prove the theory we did it again, and again. Problem solved. We were happy that she could handle the wind conditions and safely tack, gybe and sail on all points quite happily with the reduced sail plan even in these very strong conditions.
Our confidence in the boat and and our somewhat bizarre enjoyment levels were high and we settled into taking advantage of the conditions and sailed confidently around the lake for the next few hours.
The lakes rescue RIB buzzed around us on a couple of occasions (we were the only ones out - again - needless to say!) but seeing we were ok he disappeared with a cheery wave.
As predicted the wind strength continued to build in the afternoon and it began to rain. We had proven our point - or rather Matt's point - and turned to head in. On final approach we furled all the sails and were blown down wind to the slip on bare poles!
Not an exercise to be undertaken lightly but I do not think we were being foolhardy. Nothing had been damaged, neither the boat or us.
You have to bear in mind that wave action was not as extreme as it could have been at sea, but it was a fair test I think, in any case it is unlikely that many Bayraider sailors would be in open sea in those conditions. And we were able to find shelter in the lee of trees that grow up to the shore line - where we stopped and rested for lunch! I probably wouldn't have done it at sea but certainly if the worst ever happened and I was stuck out I would feel a lot more confident in my own and the boats ability, that's why we thought to share it with other owners.



Andy Dingle BR20 'Psalter'
Pete Cockerton BR20 'Joybells'


Jonathon - I'm not sure if this should go in the Library area for others information or on the forum - please feel free to move it if you think fit. Andy

[Graham W]

Good stuff! How wet a sail was it?

I particularly liked Colin's analogy with the tailfin of an aircraft in this old posting http://www.swallowyachtsassociation.org/smf/index.php/topic,427.msg2342.html#msg2342  It is useful in reminding me which mizzen sheet to pull when tacking.

[Andy Dingle]

Graham.

Surprisingly enough it was a fairly dry sail. Yes, we had the occasional shower of spray over us. (The helmsman generally being protected by the crew!)
The boat stayed pretty well upright with little heeling that you would expect with the main, even deeply reefed, bent on. After the initial anxiety she really was easily manageable, the helm had to be on the ball at all times but it was far from being a white knuckle ride.
Had we taken the trouble to research the forum beforehand we would have been aware of what to do with the Mizzen, and indeed we did on a couple of occasions end up sheeting it in the wrong way!  But once we got the hang of it was no problem at all. In retrospect Colin was absolutely correct.. His discourse pertains to light winds, but the principle equally applied to heavy weather - and made absolute sense when applied in practise.

What I didn't make clear - and in fact I do not think it would make the slightest difference - is that Peter's mast is the wood full length version - ie not the usual gaff set up, nor the 'american' style fat head. But the jib and mizzen are rigged just the same - the hounds being the same height on his mast as the top of the mast would be on (for example) my gaff rig BR.


Andy

[Rob Waller]

Thanks - sounds really useful. I tried a similar experiment and also struggled to go about. But I also found that jib and mizzen didn't give really me enough power to beat the tidal flow in Chichester Harbour, and resorted to my engine.

[Colin Lawson]

I have been avoiding telling this story out of embarrassment but in view of this topic I had better bite the bullet.

Last summer in Poole Harbour with a decent breeze I was experimenting with sailing under jib and mizzen alone in my BR20.  Everything was going fine - I was able to sail modestly to windward and tack by pulling the mizzen to windward to help the boat go through the wind. This was going so well that I started getting confident and more ambitious with the tacking when, as I pulled the mizzen to windward, the mizzen mast snapped at the point where it enters the deck fitting.  I managed to drag the mizzen etc on board and get the outboard started before being blown onto a lee shore (the jib alone was not going to help me). 

Reviewing what happened I think that I must have been too enthusiastic in pulling in the mizzen to windward. As the sail angle increases the attachment point of the mizzen sheet to the mizzen boom tends to move over the deck fitting and the sheet tends towards the vertical, pulling the mizzen boom down and hence putting sideways bending force on the mast.  I guess I just pulled too enthusiastically (the wind probably didn't help but I suspect the breaking force came from me).  I was probably looking ahead at the time rather than watching the angle of the mizzen.

Anyway the lesson for me is to avoid pulling the mizzen more than 45 degrees to the boat. Obvious really.

As sailing under mizzen and jib is a fall back technique for when things get serious it is worth bearing in mind that the mizzen mast is not indestructible.  And you certainly won't sail to windward with the jib alone 


Colin  BR20 'Spray'

[Julian Swindell]

I saw you without the mizzen mast last year, but you didn't tell me how it broke! I have a fairly thin rope loop around the mizzen boom that the mizzen sheet clips onto. This has broken once and I replaced it, but thought that maybe I should use a thicker rope. Having heard your story I think I will stick with the thin loop. Easier to replace than a whole mast!
But I am surprised that you could snap a carbon fibre mast by pulling on a simple sheet. Was the mast defective at all?

[Peter Cockerton]

Reviewing what happened I think that I must have been too enthusiastic in pulling in the mizzen to windward. As the sail angle increases the attachment point of the mizzen sheet to the mizzen boom tends to move over the deck fitting and the sheet tends towards the vertical, pulling the mizzen boom down and hence putting sideways bending force on the mast.  I guess I just pulled too enthusiastically (the wind probably didn't help but I suspect the breaking force came from me).  I was probably looking ahead at the time rather than watching the angle of the mizzen.

Colin  BR20 'Spray'

Colin

Can't quite get my head around how the sidewise force was being exerted on the mast from the mizzen boom perspective. My boom is attached to the mast with one of those fancy prosaic loops if that’s how you spell it, so the boom being pulled down by the sheet should only result in the mast end pointing up as it's loose in the loop. I can see huge forces being applied the mast from the sail if pulled at right angles to the wind and the point of breaking if it was to break would be the top of the fixing as it would not be able to flex at that point. Perhaps a conversation with Matt on whether this force is reasonable and if the mast should be able to take this. I have a suspicion you may have had a fault on that mast.

Having considered this whilst poo shoveling the dog's mess (too much information i know) i guess the downward force exerted on the sail leech is how the force was being applied the mast, (silly me).

Peter

[Colin Lawson]

I did not explain myself very clearly and perhaps I am not right anyway, but I figured that with the mizzen boom pulled round by more than 45 degrees the sheet is tending towards pulling vertically downwards on the mizzen boom which means that the leech of the sail will be pulling the top of the mast sideways (and down) and hence, as has been said, putting extra stress on the mast at the point where it enters the deck fitting.  This is a stress that would not be present at smaller angles.

As Peter has mentioned there is also the issue of the wind force on the sail at this angle and clearly the failure of the mast will be partly due to this but my best guess is still that I gave the mizzen sheet too much welly in my enthusiasm for a quick tack through the wind.

As far as prior damage to the mast is concerned, this will have to remain an open question. I had sailed the boat for four months prior to the failure and had never noticed any damage or fault but I probably did not look that closely so a small flaw might have gone unnoticed.

In response to Julian, I was also surprised that the mast broke, particularly at the moment it happened.  For those who haven't broken a mast before it is not a clean break. It just splits into strips at the point of failure losing all bending strength and simply flopping over.  This has the advantage that the mast and sail are still attached to the boat and can be retrieved (but is still embarrassing).


Colin BR20 'Spray'

[Colin Lawson]

Here is a photo of the mizzen mast. I could not see any obvious flaw or defect. There are some wear marks where the mast rotates in its socket but these do not seem to correspond to the fracture.

[Julian Swindell]

One further thought. This ability to pull the mizzen to windward to aid a tack shows the advantage of the Swallow Boat approach, using a boomed mizzen with two part sheets. I used to have a Drascombe Dabber, with a loose footed mizzen controlled by a single sheet from the end of a long bumpkin. There was no way to pull this to windward. This made it effectively impossible to tack with just the jib and mizzen. The same problem would apply to a single sheeted mizzen boom, which I have seen some do on Bayraiders. This might give finer mizzen control when using all three sails, but would be detrimental to sailing with just the jib and mizzen.

[Clem Freeman]

Another mod to make to my S17. I've got a single sheet and failed to tack under jib and mizzen, the harbour master was passing at the time so only a small amount of embarrassment.

[Michael Rogers]

Hi Colin

That's a CF mast isn't it? It would be interesting to have Jeremy's comments, if he still looks in on this forum. He has written before on the types of stress that CF deals particularly well, and not so well, with.

(Hope I'm not unknowingly belittling the scientific/engineering know-how of other contributors - if so, in no way intentional!)

Michael

[Matt Newland]

Hello All. Very interesting post.
Regarding the mizzen breakage. We discovered this was too weak some time ago and as a result we put solid timber bungs in the mizzen where it passes through the deck. This prevents the huge localised crushing loads and increases the bending strength significantly. We also stopped cutting the tubes down to length from the bottom, which because they are tapered, reduced the diameter slightly.
This happened from boat 34 onward. I believe Colins boat to be number 25.
We do not have accurate contact details for all our early owners but if you do have an old boat and would like to strengthen the mizzen, we are happy to provide the necessary parts and instructions free of charge, to do the job. Please get in touch directly.
Matt

[david]

I recently also experienced a situation where the wind came up while sailing. Started off around 10 knots then picked up gusting over 25 knots (according to our local windsurf site). I did not have ballast and had one crew. We dropped the main and happily sailed on jib and mizzen at around 5 knots. I felt safe and under control. I was also in a bay. Not on the ocean.
David

[Brian Robertson]

Yes, strong wind condition in a bay and the open sea are very different!  I tested my BC 20 under jib and mizzen in an estuary in F6 and she behaved impeccably.  I later got caught out in a F6 (gusting 7) in open water and the steep waves (2+m) had a noticeable effect pushing the bow round, making any progress to windward difficult.

On a related point, one issue I have found is that in heavy winds I cannot fully furl the jib. The pressure on the sail causes the jib luff wire to twist and it will not fully furl and ends up flogging madly.  I have about as many turns of line on the furler drum as it can reliably take without jamming.

In these conditions the only thing I have found works is to hoist the main and use it to shadow the jib while going downwind. But hoisting the main in a F6/7 isn't my idea of fun!

Would welcome suggestions for alternative strategies.