Knock-downs, capsizes, 360s, dismastings: boating accidents

Knock-downs, capsizes, 360s, dismastings: boating accidents

Image: Fastnet dismasting 2011

Article by Marco Nannini for Global Solo Challenge

Everyone who has gone by boat has certainly wondered what would happen if the boat overturned. Just think about how many times I have asked myself this before leaving for the Global Ocean Race. With a boat of just 12 meters, a Class40 the possibility is far from remote. In fact the probability of an overturning or capsize is proportional to the wave height. It usually occurs with a breaking wave.


A rule of thumb say that a capsize is likely with a wave of height proportional but even less than the length of the boat. A breaker taken sideways can not only lay us down with a knock-down but also makes us roll or capsize. Mini 650 sailors know something about this as a Mini 6.50s has a higher chance of meeting a wave of dangerous height. My co-skipper at the Global Ocean Race, Paul Peggs on two occasions in two editions of the Mini Transat has suffered an a full 360.


The first time he abandone the boat by helicopter, the second he managed to sail it under jury rig to Spain. Once ashore, he replaced the mast with that of a friend with an identical boat and set off again and concluded the race. However, I can only imagine his memory of those two episodes was still alive at the Global Ocean Race. After seeing the stormy sea of the roaring forties, I could sense a bit of gloom in his mood. He later decided not to carry on and Hugo Ramon of Spain replaced him for the following two legs.


What would happen in the event of a rollover
First, I make a brief digression knock-downs, which is when you are completely laid flat at 90 degrees by the wind. At the moment of the knock-down, the boat is in a very precarious situation of stability. If a wave hit us right then it would be easy to go over. Knock-down usually occurs in very gusty wind situations or when you are hit by a squall.


In fact, a thunderstorm cloud can produce very dangerous situations. The movement of air inside a large cumulonimbus can become our real enemy. The hot and humid air that rises in altitude feeding a cumulonimbus falls to the sides of it with violence. The wind is not horizontal but vertical, and has all the characteristics of the katabatic wind falling from the mountains.


Kock-down
To give you a sense of how a sudden burst can actually lay us down completely I recovered this video. We are in winter in the Gulf of Spezia in Italy. The wind is gusty, a north-westerly after a cold front. Moreover, the wind accelerates down from the mountain sides, so-called katabatic wind. On the boat we were with a full mainsail and jib with canvas for an average wind of 10-15 knots. Suddenly we were hit by gusts of 30-40 or maybe even more knots of wind. The sea was flat and apart from the fear there were no consequences.


On another occasion, on a Mini 650 prototype, with structural runners, I found myself in great difficulty. I was headed to Talamone in Italy for the Arci Mini 650 when we were surprised by very strong catabatic gusts coming down from the promontory. The boat was laid down until the spreaders were in the water. Everything was complicated by the proximity of the coast, we wanted to tack but with structural runners we could not even begin to tack in those conditions.


They were tense moments, the boat was at 70-80 degrees, and I clearly remember standing on the stanchions with the water reaching the winches. Water was also dangerously close to companionway, luckily there were no significant waves. In those conditions I was able to appreciate how little it would have taken to start taking in water. With waves I suspect the story would have ended differently. If we had been in the open waters with a breaking wave surely we would have rolled.


Capsize
On modern boats there you either run downwind in strong winds or on most boats you can also heave-to in extreme situations. The technique of running with no sails is not recommended because the boat would literally be at the mercy of the waves. Heaving-to you can keep the sea forward of the beam, whilst running the breakers come nearly from behind. Both situations can be dangerous, being overturned can happen in both situations.

In the event of inversion, the mast is almost always damaged. In many cases, the boat dismasts completely, in others a section of the mast is broken. We have to take into account that the pressure exerted by the water on the sails a thousand times higher than that of the air. Even if the sails gave way, the bare mast would still be subject to enormous forces. In the case of very wide and flat racing boats there is also an additional problem. In fact, the boat may self-right, and even if it has not lost the keel, it may remain upside down.

The shape of the stability curve of a boat tells us whether or not it can stay upside down after an inversion. For traditional boats this is unlikely, while for racing boats it is different. Of course, most capsizes happened in conjunction with the loss of the keel. Note, however, the enormous stability of hull shape of boats like the Imoca 60s where I remember at least Mike Golding who completed a Vendée Globe reaching the finish line without his keel.

Inversion test
This eventuality is far from remote for a Class40. So much so that, to be admitted to the Global Ocean Race, a real inversion test was mandatory. We had to shown that if the boat capsized and dismasted, we would be able to right the boat from the inside. In some ways, doing the test in flat water makes little sense. But then, if you can right the boat in those conditions you will certainly succeed with the help of waves.


To carry out the test we had to contact the designer Marc Lombard. By completing stability calculations, he confirmed that the boat would remain stable upside down. To right it, it would not have been enough to use the side tanks of the ballasts. We had to add an additional tank (sealed during the race) always lateral, but in the bow, of almost 1000 litres of water. In other words, to straighten the boat we had to embark 1750 litres of water to one side and then get to the tilting point where the we reached the inverted angle of vanishing stability.


On the Imoca 60s, where this test originates, the operation is very different. Once the boat has been turned upside down, simply the keel is let to cant to one side to make the boat right. On the other hand, since the test is mandatory for admission in the class, it is done on a new boat before installing all the electronics on board. In our case, however, we took a fully equipped boat and had to prepare for the test. It was not an easy thing, here is the video of the day of the test. Altogether it took us almost 40 minutes to load all 1750 litres of water and complete the inversion test.


Dismasting
Unfortunately, dismasting is not an event that occurs only in the event of a capsize. Failure of components standing rigging can happen for many reasons. From bad design to wear and tear to an accident, dismasting is never a nice thing. Unfortunately it happened to me three times, once on the boat with which I then did the OSTAR, two on my Class40. Only after the second dismasting I finally understood what the cause was. At the first dismasting the expert pointed to a defective part as the cause, which gave us a false sense of security after replacing the parts and not allowing us to understand the root cause.


My first solo dismasting
The first time i dismasted I did single-handed, I was training for the OSTAR. I had decided to go west for 3-4 days and then go back to get a sense of the first days of racing. Just as I was about to turn and go back, the attachment of the lower diagonal gave way.


The mast bent in half and ended up in the sea, there was nothing to do alone. I got rid of the mast, armed the emergency VHF antenna for radio and AIS and headed for Ireland. With diesel and a jury rig I reached land after about two days.


My second dismasting with a crew
On the Class40, a steel eye that held the forestay had failed, causing the dismasting. All this in the midst of the departure of Fastnet 2011.


The mast, which was brand new, replaced a few months before, its fall was slowed down by the sails. There were five of us on board and no one was hurt, not even the mast!


It was less than two months before the start of the Global Ocean Race, but the expert after an ultrasound analysis said that the mast had no damage. Four days later the boat left to go to Palma, completely repaired after dismasting.


The third dismasting, the most absurd
The third time I dismasted was in 2013, with no wind, under engine, while I was hoisting the mainsail. I was in the Gulf of Spezia and inexplicably the mast came down. This time too, one of the two eyes, part of the headsail structural furler , gave way. The first time it been the one at the top, this time the one at the bottom. After the first dismasting based on the advice of the surveyor the pieces had been machined differently and in fact this time it was not the eye to have opened. The pin snapped sideways and the one at the top of the furler was about to break too. Imagine that, just a few weeks earlier I had crossed Gibraltar with 50 knots wind on the nose.


It was then, however, that I fully understood the cause and the reason for the repeat dismasting. When sailing with Code Zero or with staysail the Code Zero anti-torsion cable or the interner forestay were put under tension. In doing so, the rolled-up headsail remained on the forestay but was not in full tension. This meant that the forestay slammed sideways on the waves, especially with the staysail. This constant banging was the cause of the final breaking.

 

The indication of the first expert had misled me, and with hindsight it would have been enough to change the two pins with a certain frequency or change for a dyneema lashing. Bear in mind that the parts had sailed 50,000 miles before letting go! It was certainly a dismasting that caught me off guard, luckily no one was hurt.


The capsize of the 2009 OSTAR
When I took part in the OSTAR 2009 we faced a bad depression. I chose to stay north of it and this forced me to sail in the middle of an area of known icebergs. The International Ice Patrol provides maps with the position of all known ice. I sailed 36 hours in thick fog knowing that there were icebergs, but nothing could be seen. I didn’t even see anything on the radar and I only remember the tremendous apprehension.

 

During the race there was an Italian competitor to suffer the worst consequences in that storm. In the area of Banks of Newfoundland, Gianfranco Tortolani capsized in his Citta di Salerno. As expected, he dismasted with a lot of damage to the boat. Fortunately, Gianfranco was recovered and rescued. His boat was recovered many months later still adrift in those waters.


The capsize of Matteo Miceli
Matteo Miceli, during his record attempt during a circumnavigation on a Class40, suffered a capsize. In his case it was not caused by the sea but by the structural failure of the keel. Matteo was rescued and in his case the boat was recovered, still overturned upside down, many months later. The boat is now back sailing having been fully repaired, so a happy ending to the story.

 

Isabelle Autissier and Giovanni Soldini
Isabelle Autissier famously suffered an overturning. When Giovanni Soldini helped her, the boat was at the mercy of the waves. Without satellite and EPIRB to give the exact position, Giovanni’s search was exhausting, during a storm. Giovanni did not give up until he was able to retrieve Isabelle.

 

Capsize on multi-hulls
Unfortunately capsizes on multi-hulls are a much more probable occurrence. The enormous shape stability of the multi-hull and its lightness allow it to reach incredible speeds. However, after a certain angle, the stability vanishes and the capsize is inevitable. On all trimarans sailed alone there is a sensor that automatically releases the mainsheet if the heel angle of the boat exceeds a certain angle.


However, the question is not that simple, in some situations releasing only the mainsheet may not be enough. For this reason, despite all the precautions, including technological ones, capsizes continue to happen. Especially with downwind sails, the sailor, at the helm, may have to ease both the mainsail but also the spinnaker sheet. Above all it may need to luff or bear away, it depends on the point of sail.


In fact, if we sailing close to the wind, bearing away worsens the situation and it is by luffing that depower the boat. If, on the other hand, we are sailing downwind, it is in bearing away that we decrease the apparent wind and we can hope to get out of the emergency situation unscathed.

Click here to view the following images and videos on the Global Solo Challenge website


Overturning - Imoca 60 Hugo Boss inversion test
Overturning - The Effects of a 360 - Sam Goodchild
Capsize - Jean Le Cam - VM Materiaux
Capsize - Tony Bullimore - Vendée Globe 1996
Capsize - Imoca 60 Hugo Boss inversion test
Capsize - Banque Populaire Trimaran
Capsize - Matteo Miceli
Giovanni Soldini and Isabelle Autissier
Capsize - Imoca 60 Cheminées Poujolat inversion test
Dismasting – Fastnet 2011 – Class40
Dismasting - British Beagle 2008 - Immediately after dismasting
Dismasting - British Beagle 2008 - The boom recovered to make a makeshift mast
Dismasting - Base of the mast - Class40 - Fastnet 2011
Dismasting - Fastnet mast ultrasound test 2011
Fastnet dismasting 2011
Dismasting - Fastnet 2011 - Class40 - Immediately after the accident
Dismasting - Class40 2013