Kiss*
posted by John & Phyllis
Web Site
I always learn something, or have my existing thinking clarified, when talking with other experienced voyagers. The latest pearl of wisdom came my way when chatting with a fifteen-year live-aboard and voyager with many thousands of miles of experience. We were discussing the challenge of trying to keep our boats technically simple while still functional and comfortable. The subject of what equipment should be electrified and what should not be came up. He said “well there are two things that should not be connected to the battery: the crapper and the sails”. I could not sum it up better myself.
* Keep It Simple, Stupid.
Labels: Rants and Musings
Are spade rudders suitable for ocean cruising?
posted by Colin Speedie
Web Site
Evidence of crevice corrosion and metal fatigue
As I mentioned in a previous posting, one of the most attractive features of our new OVNI is the protected rudder, which we think is an essential feature for a long distance boat. However, the three cruising boats I have owned over the last twenty five years were all equipped with balanced spade rudders with no supporting skeg. And as in the last of the three I had covered over 60,000 miles with no problems, I had, in fairness, few reasons to doubt their strength and fitness for long distance cruising.
This last boat, like all commercially registered boats in the UK, has had to undergo a full, out of the water, structural survey every five years, and in the most recent survey the rudder and its fittings received an A classification. With the rudder being balanced, the immense and repetitive loadings it is constantly subject to are seldom felt through the wheel, but we know they exist, so each year we have conducted a careful examination of the shell looking for cracks caused by stress. In addition, every few years we have dropped the rudder, to examine the stock, the bearings and neoprene stuffing gaiter, but we have never found any evidence of deterioration or stress. So when we lost our rudder off the South Cornwall coast this summer, it was, to say the least, a shock.
As we were within half a mile of the shore, the priority was to gain some sea room. Fortunately we have prepared for such an eventuality, and with our flexible cutter rig have always managed to work out a combination of sails and warps to make progress in the right direction. So we furled the Yankee, backed the staysail, and using the main to bring her head up, we turned her out to sea. With the wind being light we were making little progress, so we started the engine and brought our speed up to 3 knots. Although we were swooping around rather a lot, the combination of backed staysail and pinned in main worked effectively, so we didn’t need to trail a warp. A VHF call to the Coastguard to explain our predicament ended with the reassuring message that the local Lifeboat was being launched – with passengers aboard they were taking no chances.
The Lifeboat arrived and confirmed that our rudder was, indeed, missing – just as we had suspected. They passed us a drogue to be towed astern, and then a tow line and we were off. We had already dropped our sails as instructed and so had no way to balance the boat, but at a towing speed of five knots or more we were really swinging around on the limit of control even with the big drogue out, making it abundantly clear just how tricky it would be to handle a boat without a rudder at higher speeds.
Two days later she was out of the water, and we could see for the first time the extent of the damage. The 4” rudder stock had sheared off about 6 inches down from the hull, inside the rudder blade where no amount of inspection could have discovered a problem. Eventually a surveyor visited on behalf of our Insurers, and after some deliberation drew attention to two faults. One was that there was evidence of crevice corrosion at a weld where the shaft had been sleeved to allow the rudder to taper, which was where the stock had sheared. The second was the unmistakeable sign of “beaching marks” indicative of metal fatigue plainly visible on the sheared stock. So our claim was rejected on the grounds of “wear and tear/metal fatigue” – another shock.
Many yachtsmen are unaware that stainless steel is not corrosion free, and should not be constantly immersed which can cause the surface oxide layer to break down allowing crevice corrosion to gain an entry. GRP rudders are notorious for becoming waterlogged, and in the anoxic, polluted solution inside the shell, corrosion will soon go to work on even the best marine grade stainless steel. Ally that to the metallurgical changes that the weld itself would have caused, the fact that the step down in size would have effectively created a “hard spot” (and thus a weakness), coupled to the continuous loading and flexing inherent in this type of rudder where it exits the hull, and you have, over time, a recipe for disaster. The remarkable thing with ours may be that it lasted as long as it did.
So now I’m convinced that spade rudders are unsuitable for long distance offshore voyages, not just because many new production boats have stocks made in unsuitable materials (which they undoubtedly do), but also because there may be a potential time bomb waiting to go off even in a well built older cruiser. And whilst we were lucky, and all went well, I could think of a thousand occasions in the past when the consequences might have been very different – and that simply rules them out for me.
Happy Holidays
posted by John & Phyllis
Web Site
The Attainable Adventure Cruising blog will be one year old in a few days. It has been an interesting experience trying to come up with something to write about on a more or less regular basis. One thing that we have noticed is that the process has clarified and focused our thinking on many aspects of this strange sport, pastime, lifestyle, or whatever voyaging offshore in sailboats qualifies as. Thanks to all of you from some 30 different countries that follow along with our musings. All the best for the holidays and we wish you a new year filled with whatever voyage you wish to make.
The full sized version of our Christmas Card
Our voyage account for 2007
Labels: Rants and Musings
Heavy Weather Gear and Strategies #6—Survival Storms
posted by John & Phyllis
Web Site
In the last five posts in this series I have been writing about the techniques that have worked well for us on “Morgan’s Cloud” in gales and strong gales at sea. That is up to Beaufort Force 9 (41-47 knots). Next I’m going to write about our thinking on how to handle a storm of Force 10 or above that would threaten our very survival.
I'm happy to say that I did not take this photograph at sea, but rather from the shore after tropical storm Noel.
But before I get to that, I want to make clear that the waves generated by gales and strong gales, particularly if they are apposed to even a low velocity ocean current, can, if she is not properly equipped and handled, roll the average cruising boat completely over and injure or even kill her crew. I say this because I have noticed that many sailors exaggerate the wind speeds of gales that they have experienced and therefore give the impression that a Force 8 gale (34-40 knots) is no big deal. Usually they quote the top gust they registered, which is pretty meaningless, particularly since wind instruments are notoriously inaccurate once the wind gets over 30 knots. What matters when gauging the severity of heavy weather at sea is how strong the sustained wind is and how long it has been blowing for. (For more on this see “Liars, Damned Liars and Sailors”.)
Before I get into writing about survival storms, I have an admission to make: despite about 100,000 miles of offshore sailing experience over nearly 40 years, I have never been in one. On a few occasions I have experienced winds in excess of 50 knots, and on one memorable occasion, what I think was 70 knots or maybe a little more, but these blows did not last long enough to produce truly huge breaking waves. In each case I was on strong well equipped boats with experienced crews and my survival was not at risk unless we did something stupid.
Having said that, let’s all remember that a sustained wind of just 30 knots blowing against the Gulf Stream can turn into a survival storm if you handle it badly. Some years ago I got caught out in the Gulf Stream off Cape Hatteras in an unforecast rapidly intensifying low (bomb). The winds were blowing against the Stream at a steady 40 knots with gusts in squalls of 50 knots or so (verified from ship reports). The waves were huge, steep and starting to break. We rode it out by slowly jogging to windward with storm jib and trysail set. It was not a survival storm for us because I had a very strong and experienced crew of six aboard who were able to carefully steer over every wave for two days. But for a couple without an adequate strategy to manage these conditions without having to steer, it would have been a very dangerous situation. The point is that what constitutes a survival storm is as much about you and your boat as the weather.
Up to now in the series, I have been writing from experience. Now I’m getting into conjecture. But it is important conjecture. Despite the advances in modern weather forecasting, and taking into account the more frequent and intense violent weather we are seeing in recent years, there is a real chance that, if Phyllis and I go on sailing offshore, particularly in the high latitudes, we will get caught in a multi-day storm with sustained winds in excess of 50 knots that will be a survival storm for us. If that happens I want to make damned sure that we have a plan and the best possible gear to execute it.
So what about just staying heaved-to, perhaps with the drogue off the bow, as we have written about in the last three posts in the series? Would that be safe with the sustained winds over 50 knots and 30-40 foot breaking seas with the possibility of a 60 footer around? I don’t know for sure, but I think it might be. And I’m not alone in that surmise: Some months ago I had an interesting email exchange with Lin Pardey. She and Larry firmly believe that heaving-to, with a sea anchor if necessary, is the ultimate heavy weather strategy. She also quoted an interview she did with the late Sir Peter Blake who seemed to believe the same, and backed it up with a story of going through a true survival storm that overwhelmed another boat nearby, while heaved-to. Lin, Larry, and Sir Peter, between them, have wrung more salt water out of their socks than I have sailed over, as the old saying goes, and probably they are right. But, what if they’re not? What if the mast breaks and we can’t set any sail? What if…?
Bottom line, I’m a belt and suspenders kind of guy, and I want an alternative. Next post, we will talk about non-heaving-to storm survival systems: our old one, the new one we replaced it with, and why.
Earlier Posts in the Series
#1 Goals
#2 Heaving-To
#3 When Heaving-to is Dangerous
#4 Options When Heaving-to is Not Working
#5 Stopping Wave Strikes While Heaved-To
If you want to make sure that you don’t miss the next installment in this series, without having to keep checking this blog, subscribe to our feed or automated notification e-mails, both available on the side bar. You will then receive a short notice when the next post comes up. Of course we will respect your privacy and will never divulge your e-mail address or shower you with junk. If you don’t like the feed you can unsubscribe in a moment.
Labels: Seamanship
Limits to complexity
posted by Colin Speedie
Web Site
The new and the old both have their places
We are now at the final stage of selecting our navigation systems, and as new products are being launched all of the time, have decided to wait until the last minute before committing.
But to some degree the choices are being made for (or taken away from) us, as so many of the manufacturers are moving towards integrated systems, reducing the available options for those of us who like to pick and mix the best kit from different stables. For example, it is now virtually impossible to buy a stand alone radar, as everyone is moving towards combined radar/plotters using their own Ethernet type connectivity.
Since the 90’s I have professionally skippered my own yacht on research projects, and have for the last six years used a laptop linked to a GPS for all basic navigation. Being only modestly computer literate has never been a major shortcoming, and although they have simply been fixed to the chart table with Velcro, we have never lost one to damp or rough handling. If you are used to computers at all, they are quick and intuitive to operate, and their large screens offer a good view of the charts. By comparison, I recently skippered a boat with a brand new plotter, and didn’t like it at all – the screen was too small, and the operation was clumsy and slow. And having recently watched two experts trying to sort out a problem aboard a boat with an Ethernet link between instruments and plotter – two sets of software, and by their own admission, a tendency to crash on a regular basis – I wonder whether this is really the way forward?
Of course PC’s can go wrong, too – we carry a spare as back up, as well as up to date passage charts and pilot books, just in case. And as I learned to navigate long before we had any electronic luxuries, if I have to go back to dead reckoning in an emergency it should not a big deal. But with our laptop we can integrate weather files from the internet, AIS information, tidal streams and Navtex at far lower cost than a half way decent plotter. And we’ll stick with an NMEA interface which at least will allow some basic diagnostic tests to be run should it go down 1000 miles from the nearest dealer.
The one thing we have committed to is an Echopilot forward looking echosounder. We used an Interphase Twin Scope for the last seven years, and found that the ability to scan for depth and obstructions ahead of the boat was indispensable, especially in poorly charted waters. But Echopilot sensibly offer the option of a custom transducer housing made from solid aluminium billet (essential for us with our aluminium hull) which will enable us to pull the transducer prior to taking the ground, one of our main reasons for choosing an OVNI. Having heard nothing but good reports of their products, this was an easy choice to make.
And while we’re on the subject of holes in the hull, we think the fewer, the better, so we’re not having a through hull speed/log unit. Paddle wheel logs are unreliable, and often tricky to calibrate accurately, and as a Furuno WAAS GPS reads speed as fast as a log that we shall use a repeater in the cockpit as a speedo, and the trip facility as a log. We are well aware that this is “over the ground”, but we can compensate for that if needs be. And if all of the electrics fail, then we have a lovely boxed Walker Knotmaster towed log that has followed me from boat to boat over the years. There should be a limit to complexity!
Labels: Equipment
Heavy Weather Gear and Strategies #5—Stopping Wave Strikes While Heaved-to
posted by John & Phyllis
Web Site
As we have discussed in post #3 in the series, heaving-to is only safe as long as the boat does not forereach out from behind her own slick. It is the slick that causes waves to break before they reach the boat. In post #4 we looked at some alternatives to stop the wave strikes we were experiencing while heaved-to in a gale but that we rejected because they did not meet our goals for a heavy weather strategy.
In this post we will look at what we eventually did, how it worked and how it has become an integral part of our heavy weather strategy—I know, some of you thought I would never get to the payoff.
Having watched “Morgan’s Cloud”’s behavior for a while after the wave strike, I realized that all we needed to do to solve the problem was to slow her down just a bit and keep her bow just a bit up to windward. Large measures like our huge sea anchor really weren’t called for. However, the staysail was already rolled right in and the triple reefed mainsail centered, so we had done all we could with the rig to keep her bow up to the wind. (Learn about our heave-to method here.)
What we needed to do was to add some drag and give the bow a bit of a tug to weather to keep it from falling off the wind. While still heaved-to, I shackled 250 feet of 7/8” nylon line to our Galerider drogue and then struggled forward dragging the substantial weight of gear behind me. After passing the bitter end through our well-rounded bow fairlead, I cleated it off and then slid the Galerider down the windward side of the hull some 10’ aft of the bow (I did not want the drogue blowing off to leeward where the boat could reach over it) and into the water. This was surprisingly easy to do with the wind holding the drogue against the hull. Once the drogue was immersed, the boat slowly forereached away from it while I paid out the line. There was none of the high loads or fast run out of the line that you get with a drogue deployment over the stern when running off.
As soon as all the line paid out, the result was immediate and miraculous. The boat slowed to a virtual standstill from the 1-2 knots she had been making and the bow no longer fell off to leeward when a gust hit after a lull. We lay heaved-to like this for 18 hours very comfortably with no further wave strikes.
The great thing about this drogue technique is that, unlike with sea anchors, the loads were very low. The rode was quite often slack and I would estimate the highest load as lower than that you would get on an anchor rode in a 15 knot breeze. In fact, the gear could have been much lighter than I actually used, or what would be required for a sea anchor on a boat our size. ("Morgan’s Cloud" displaces 26 tons.)
In the morning I was occasionally able to see the drogue in a wave face to windward. Despite it only being set on 250 feet of line, the Galerider showed no signs of pulling out of a wave face or being tumbled. Again, I think the secret here is that the low loads on the drogue allowed it to sink well into the water thereby reducing this danger. Originally I said that if I did it again I would use 500 feet of line, but having thought about it some more, and in light of the above, I think I would be happy with 300 feet.
When the wind started to ease, we easily recovered the drogue, using the anchor windlass. Even though it was still blowing near gale, I would estimate that the load on the windlass was less than that when pulling up our anchor and chain on a calm day, because the boat was still heaved-to and we were not trying to sail away from the drogue.
It is important to understand that although the goal and result of this use of the Galerider are the same as Lin and Larry Pardey’s technique of setting a sea anchor on a bridle while heaved-to, the positioning and deployment of the drag device is very different. In our case the drogue ended up to windward and slightly aft of the boat with the rode making an angle of about 130 degrees to the bow and there was only one line to rig, instead of two.
Please read this, it’s important.
There are a couple of cautions with this technique:
- It specifically violates the Galerider’s instructions in which the manufacturer says that it should never be deployed from the bow of a boat.
- If the boat should tack through the eye of the wind with the Galerider deployed in this way, I think there is a chance that the boat could sail over the rode and perhaps the drogue. In a gale at sea, this could definitely ruin your whole day. “Morgan’s Cloud” showed no signs of tacking. In fact, I would be hard put to see how she could have tacked since the drag of the drogue was stopping her getting up enough speed to get her bow through the eye of the wind, nor was the drogue exerting enough pull to drag her bow through the wind—sort of a self limiting system. But if you have any fears that your boat might tack while set up like this, I would strongly suggest you use Lin and Larry’s technique instead. Finally if you limp into a harbour I’m anchored in with hundreds of feet of line and a Galerider wrapped around your rudder and prop, I will not be taking the blame for it or diving in the water to cut it off!
Since that day in early 2000 we have not had occasion to use this technique again, but it is really comforting to have it in our back pocket. By using the Galerider in this way, I’m confident that we can stay heaved-to safely in sustained strong gale or even storm force winds.
But what happens if it blows even harder and the waves get truly mountainous and breaking? What would we do then if heaving-to, even with the drogue, stops working? That will be the subject of the next post in the series.
Earlier Posts in the Series
#1 Goals
#2 Heaving-To
#3 When Heaving-to is Dangerous
#4 Options When Heaving-to is Not Working
If you want to make sure that you don’t miss the next installment in this series, without having to keep checking this blog, subscribe to our feed or automated notification e-mails, both available on the side bar. You will then receive a short notice when the next post comes up. Of course we will respect your privacy and will never divulge your e-mail address or shower you with junk. If you don’t like the feed you can unsubscribe in a moment.Labels: Seamanship
