Some Observations 10 June 2005

 

The usual caveat – these are specific to Berrimilla but almost certainly applicable to other similar boats. They are not prescriptions and should be read after looking at the photo of Berrimilla out of the water, to be found in the ‘Preparations’ document on the website and my description of our NZ roll-over in the log for (I think) 19th Jan. 2005  Berrimilla has an exceptionally deep keeled displacement hull and is unusually stiff – her point of vanishing stability occurs at 146 degrees. This means she can roll almost upside down before she will stop resisting and invert, and it also means that she is unlikely to remain inverted for more than a few seconds, as long as she does not fill with water. We think that the NZ roll-over took her to about 140 degrees of roll and about 70 degrees nose down, with an almost instant recovery.

 

Berrimilla’s hull speed is about 7 knots – much slower than the big waves in the southern ocean. The problems of handling heavy weather in this type of boat are quite different from a faster, planing hull that travels as fast and often much faster than the waves.

 

It is also worth remembering that the waves last long after the wind has eased and they don’t lose their ferocity immediately. The NZ rollover was caused by a double wave combination that occurred some time after we thought the worst was over and we were both tethered on deck setting more sail. As it turned out, this was lucky – the heavy icebox lids and all the contents (about 60 plastic bottles of home brew) took flight across the saloon, bounced off the coachroof half way along and ended up at the base of the mast and in the forepeak. Not a migration to try and prevent with one’s head.

 

I have already written about inadequate cockpit drains – just s reminder!

 

Storm sailing: What follows are observations related to sailing Berrimilla. They are the result of experience, and they may not be applicable to other boats. The only way to find out is to try it yourself preferably when the wind is less than storm force and circumstances are not critical, or talk to someone who has tried it in your type of boat - and then try it yourself.

 

Most of you reading this will not be planning to follow us, but for those who are, it goes without saying that you must do all the other things necessary in heavy weather – sails off the deck and stowed below, everything tied down on deck with double lashings if you really don’t want to lose it, stormboards in, hatches and ventilators closed etc. 

And months before you even think of leaving the dock, spend a quiet hour sitting in the boat on a calm day with a notepad and imagine the boat inverted. Scary but you must. Is it watertight with everything closed and are the stormboards strong enough? Those little plastic dorade vents will gush water – can you block them? What will end up on the new floor if it isn’t tied down or latched into a cupboard? Shelves become useless and gravity becomes your enemy – flying toolboxes are lethal as are icebox lids and anything made of glass. Under bunk stowage must have lids that can be fixed or screwed down and the nav table lid needs to be tied closed. That’s just a start. What about your anchor chain? Anchors? Are your bilge pumps adequate and accessible – and your buckets? Are your batteries sealed and strapped in? Your floorboards?  Your fuel tank? Chances are, any inversion will only last a few seconds, but that could be enough to spoil your day rather severely. And there will be a wave out there that could do it – there always is. If you are unlucky enough to meet it, you may be very glad you prepared the boat. We were, and even though we got some of it wrong what we did was enough to allow us to keep going.

 

Heaving to: Really easy in a Brolga – Berrimilla will heave to without a headsail with the tiller lashed down about half way and she rides slightly into wind or directly abeam and fore reaches ahead at 2 – 3 knots – depends on the conditions. Try it some time if you haven’t ever done it – good fun and works if you need a quiet meal in 20 knots too. Not always a good option but great if you’re totally stuffed and need a few hours rest. Can get swamped in really big seas and better to sail if possible. We’ve done it now several times in anger and it has worked every time. Make sure the main is tightly lashed to boom with a lashing every foot or so – we use a continuous line and blanket-stitch it. If you leave any gaps, the water will get in and rip the sail, as happened in our NZ barrel roll. Up to you whether you leave boom up in normal position or down and lashed to coachroof – I think up is best although more windage but allows most of big green waves to flow underneath. Either way, it must be lashed so that it doesn’t move.  Depending on where you are it may be very wise to be brightly lit – nav lights at least - and to keep a lookout. We will double lash our liferaft in future too, with a sharp knife attached.

 

Bare poles: 50 knots and up! This is an extreme form of sailing, definitely not a heave to. Almost no strain on the rig and you can steer. Works fine and you will go directly downwind or up to about 15 degrees off if you steer the boat (we use the self steering or the autohelm – the latter needs battery though and you may not have sufficient reserve). We were getting up to 7 knots off big waves near the Horn with some freak takeoffs at about 12. Scary and if you are out in these conditions you have to accept that it’s dangerous and cope as best you can

 

Storm jib: we set ours on a strop about a metre long to let the greenies go underneath. The car position must be moved back a bit - and it helps if you have a hank or snap shackle in the tack cringle to clip to the forestay to stop the sail pulling away on the strop and stressing the lowest hank. St J can be set on the forestay or the inner – not much influence if on the inner, but less aggravation if really windy.

 

Trisail: Truly useful bit of gear – allows you to point in all but the very worst conditions, easy to gybe, allows all the green stuff to pass underneath and can be fine tuned by using both sheets together. Set on its own or with a headsail to provide balance.  Must be small enough - it is not a 4th reef but an emergency lifesaver and should be treated as such. With the trisail on its own, we were able to get to 60 degrees off the wind in big waves in 1998 and the boat sailed on at 4 knots – several near knockdowns but no difficulty with the sail and good steerage way. Make sure you know instinctively how to set it, mark the tack strop at the correct length (a bit of vb cord through the weave can be felt at night) and if possible have a second track on the mast so that you don’t have to take the main out of its track. It may be possible to make a gate above the lowered mainsail to feed the trisail slides into. We have a long tape on the head of ours with slides every metre or so, so that the halyard shackle is at the masthead and the halyard not stretched down the mast and flogging itself and the head of the sail to death. Works exceptionally well but adds a bit of hassle to setting the sail – must keep the twist out of the tape etc.

 

Both set together: We’ve had up to 7 knots to windward with this combination but tricky to tune. Nice snug safe balanced rig as long as it is not taking the boat too fast into the seas – often the biggest problem in high winds and big seas. Minimal heel and very little stress on the rig itself.  Trisail also works well with #5.

 

Handling in heavy seas: Observations for Berrimilla only – your storm sails may be different, your rig is almost certainly subtly different - not likely to make big difference but these notes are for guidance only. We used the Fleming self-steering for most of this and watched in awe as it all happened.

 

Upwind: the real killer is a short steep sea @ 3+ metres and wavelength about the same or a bit more than the boat length. Pounds, leaps, crashes, stops – most uncomfortable and very hard to make progress (cf our heave to in 2004 S2H) Reduce sail and speed and try to ride the waves and head down by enough to make progress possible.

In really big – warehouse sized – seas, if not breaking, the boat will go quite well to windward as long as speed not too great and doesn’t leap off the tops – if breaking, need to be slower and we found best about 60 degrees off the wind – need both storm jib and trisail to make progress to windward, but this combo probably too fast so trisail only if not too big. Breaking crests can be avoided sometimes if hand steering, but windvane can’t see them so get swamped. Make sure cockpit drains clear, all gear stowed below, liferings etc off the pushpit and below, lifejackets and harnesses on and tethered. Stormboards in and latched closed – must be able to open from inside and out – need small hatch at very top too, for communication, pee buckets etc.

 

Abeam: not recommended – very uncomfortable, big rolling motion and open to the big breaking wave that’s out to get you. The boat handles it well – it’s the crew that have the difficulty.

 

Downwind: Again, depends on sea state and wind strength. We have found that two poled out storm jibs is very effective but only allows dead downwind to about 20 degrees off – sometimes just enough to ride down the faces of big waves at a reasonable angle. Much the same with bare poles. The storm jib on its own gives a wider angle, from abeam back to more or less dead downwind. The best angle is governed by whether the waves are breaking (or whether the boats passage causes them to break) – straight down the face doesn’t work – we’re not fast enough and there’s not much to stop the bow going under at the bottom – we have found that about 20 – 40 degrees on the quarter works best and allows a big breaker to run across the boat, perhaps fill the cockpit but pass by.

 

And it’s astonishing the size and steepness of some of the really big ones that the boat copes with quite easily. You see a vertical slab of water astern rearing into the sky, with the turbine line spearing into it at almost right angles – the stern rises and is usually slewed sideways up to about 60 deg, the boat levels off at the top rolls the other way and slides back down the back of the wave, sometimes slewing back again. Really smooth, but very uncomfortable because of the range of movement. Different if it’s breaking. The NZ roll-over wave was directly abeam, very steep and just starting to break before it lifted us and rolled us forward with it, pushing the masthead down into the water. Quite a gentle experience but very dangerous. It was probably the combination of two cross waves giving it more height and a different direction. We might have avoided the aggravation if the angle had been ok. The Montevideo wave that took the liferaft with it felt to be much the same – we were both below and stuff started to fall off shelves and we could hear the water crashing around us. All seemed ok – the boat recovered very quickly from just past the horizontal – and I only realised something was wrong a few minutes later when I felt the vibration from the liferaft painter, towing a ton or so of water in the raft.

 

Leeway: Significant when hove to - at least 45 degrees depending on conditions. With a sail up, surprisingly little. Storm jib alone takes the boat ahead with about 10 degrees of leeway. Both together is just like normal sailing, but in either case, leeway depends on conditions. Bare poling is mostly all leeway anyway.

 

Trials of the turbine: There are some bear traps associated with towing a turbine to turn a generator. Keeping the turbine attached to the towline, not snagging it on the bottom in shallow water and keeping sufficient speed to charge the batteries are the obvious ones. Less obvious but worth remembering are the need to pull it in every now and again to check for chafe at each attachment point, which means almost stopping the boat, and keeping the associated twists and kinks in the line under control (impossible if the boat is moving too fast) and finally, the chance that it will snag itself on the self steering gear especially in slow, rough beam seas.  This happened several times to us and is potentially a show stopper as the result could be the loss of both turbine and at least part of the self steering. None of this is hard to manage, but managed it must be.

Instructions for our Ampair say tie a fisherman’s bend at each end of the towline to attach to turbine and generator body. Ok except that knots are eccentric and cause vibration. If you do use knots, then tape or whip the bitter end to the line so it doesn’t flail. We don’t use a knot – we just put the line thro the attachment eye and shackle and then twist the tail around the line in the right direction, and then tape it up with two layers of duct tape. Twist must be against direction of rotation so that rotation tends to tighten the twist rather than unwind it.