15 March 2016

Getting Run Down

Eternal vigilance is the price of safety -- U.S. Navy (among others)

I've been making a list of things I can do to to mitigate the risks of participating in the transatlantic Jester Challenge.

If you review the top-level list, you'll notice I have added a new risk category which I will drill down into today: Minimize the risk of getting run down.

The risk of getting run down by a bigger boat or ship is undeniable. Practically every sailing narrative includes one or more harrowing tales of near misses. Sailors who are actually run down, of course, don't get to write about it. They just disappear, since the ships that run them down either don't notice they've done so, or don't want to fill out the paperwork.

However, I've always assumed the risk of getting T-boned by a freighter has gone down since the 1960s and 70s, simply because the world is less dependent upon old-fashioned merchant shipping and thus there are fewer ships roaming the ocean waves. Right?

Wrong. When I went looking for actual facts, I discovered there are more merchant ships than ever!


The blue line in this graph is number of ships. In 1966, the number of merchant ships was roughly 40,000. In the fifty years since (what!? that must be a mistake... I remember 1966 like it was yesterday), the number of ships has more than doubled to over 100,000.

Not only are there more ships, they are bigger. Not that it really matters whether you are run over by a big ship or a little one.

More details on the number of ships at sea at this link, and this.

Beyond mere data, Helena and I have first-hand experience with crowded seas. On our sail down the coast of a commercially booming Brazil, keeping watch was no formality. We encountered a half-dozen ships a day, at minimum, and several nights seemed filled with huge ships lit up like Christmas trees, small fishing boats showing a single white light, and oil platforms that looked like small cities.

So much for the motivational part of this post. What can be done to mitigate the risks? After thinking about this for a week or so, I've boiled it down to three elements, prioritized in the order below:
  1. Seeing Other Ships
  2. Avoiding Collision
  3. Being Seen By Other Ships
My fundamental strategy is to take responsibility for detecting other ships, and to stay out of their way. If other ships happen see me and take evasive action, that's a bonus, but I won't ever depend on it.

Money, time, and electricity always being in short supply, it makes sense to apply it where it will do the most good. Therefore, I will prioritize acquiring tools, techniques, and technology that will help me detect other ships or to avoid collision, over being seen by other ships.

As always, if you have though think of something else to add to the list, please comment below or email me directly.

* * *
SEEING OTHER SHIPS

When the weather is clear and the water relatively calm, there is no problem seeing other ships and boats, providing someone is keeping watch. Especially at night, it is possible to see the lights of even a small boat miles away, and even during the day its relatively easy to spot them, as long as you are vigilant and your view isn't obstructed by a deck-sweeping genoa. The Blue Moon has a high-cut jib, so the view ahead is unobscured.

Complications arise in fog, or rain, or when small boats are hidden in the trough of large seas -- or when the solo sailor is sleeping and thus not keeping watch. 

In the old days single-handers avoided shipping lanes, crossed them at right-angles when they had to, set alarms to wake them up frequently enough to take peeks around, or simply consigned their lives to Fate or Luck when they simply had to get some sleep. 

Interestingly, Robert Manry didn't even try to sail when he wasn't on watch. He took down his sail, threw out his sea anchor, and tucked himself into bed, trusting that the chance of getting run down while asleep was small (which it is.)

As technology has provided automated helmsmen (autopilots & windvanes) and navigators (GPS), so it has provided reasonably adequate watchmen in the form of AIS and Radar-based collision alarms. Neither are perfect. 

AIS only helps you see other boats if they are transmitting. Yachts, small commercial craft, and fishing boats might not be equipped, and even large commercial or navy ships may not want to broadcast their location, for various reasons.

Radar doesn't depend on the other guy for detection. Newer units allow you to set up a 360 degree 'guard zone'. If it detects anything entering that zone, it rings an alarm. I've always assumed a radar would consume more electricity than we could generate on the Blue Moon, but new models can operate in a low-power standby mode, periodically waking up for a quick look around. This might be the ideal automated watch-stander, if it's not fantastically expensive. Need to do more research.

Despite the small risk that a ship encountered at sea will have it's AIS transmitter turned off, an AIS receiver is probably the single most effective automated watch-keeper available today, particularly for a small boat with limited electricity. It's #1 on my list of electronics to install.

* * *
AVOIDING COLLISION

Once you've detected another vessel, the next step is to determine if the risk of collision exists. This is easy to do if you have a hand-bearing compass. The trick is to take a bearing on the other ship as soon as you spot it. Then periodically take additional bearings. As long as the bearing keeps changing, there is no risk of collision. If the bearing is constant, then the risk exists.

If I ever sail off shore on someone else's boat again, I will pack my own hand-bearing compass. There wasn't one aboard Fiona when we sailed down the coast of Brazil and across the Caribbean with Eric Forsyth, and this caused me much unnecessary nail biting. 

According to the rules of the nautical road, you might be the stand-on vessel in a potential collision. Strictly speaking, you should then hold your course and allow the other vessel to maneuver out of your way. This assumes the other vessel sees you and cares whether you live or die. It's safer to stay out of the way in all cases.

There are two simple ways to avoid collision: 
  1. Stop
  2. Make a huge circle away from the other vessel, then come back on course
I'm assuming open water here. The problem is more difficult in restricted waters like harbors, but I'm only concerned here with mitigating risks on the high seas.

Besides the bearing, its nice to know which direction the ship is moving, as early as possible. To see this, you need a decent pair of binoculars. This is another piece of equipment I will pack on all future voyages. Eric's were old and misaligned from being banged around for 20 years. It's very difficult to make out the running lights on a big ship at night. Big ships are generally lit up like Christmas trees, with hundreds of bright white lights obscuring the running lights. With a good pair of binoculars, you might be able to pick them out. This is impossible with foggy or mis-aligned binoculars, believe you me. During the day, you can use the various masts and structures on a big ship as range markers. If the range markers move relative to each other, then you are not on a collision course. If the ranges are steady... watch out!

Another piece of equipment I'd carry on the Blue Moon, if I had radar on board (or some other means of determining distance), would be a maneuvering board. This low tech navigation tool enables you to plot the relative course of the other ship, and thus determine how close she will pass. 

In fog, without radar, you must fall back on listening for the low-tech fog horn. Do big ships reliably blow their fog horns at sea? I don't know. Must do more digging on that.

* * *
BEING SEEN BY OTHER SHIPS

It seems suicidal to depend on other ships seeing and avoiding me, but it can't hurt to do everything possible to be seen. You never know. It might help.

Again, AIS is the biggest technological advance in this area, recently. A Class B transmitter (used by small ships and yachts) will tell other ships in the area that you are there, how fast you are moving, what your speed is, etc. Sounds great, except big ships aren't obliged to monitor AIS screens. Furthermore, big Class A ships can filter out Class B traffic, so even if the bridge crew is looking at their screen, you might be filtered out. Bummer if you are sleeping.

Likewise, a yacht-size radar reflector might make a blip so small that you won't be noticed. Or the ship's radar might be adjusted to filter out 'background' noise -- including your tiny reflection. And in big seas, the reflector could be obscured by waves.

Newer technology is an active radar reflector, which picks up and returns amplified radar pings. These are more effective than passive radar reflectors, but pricy.

The brightest possible LED running lights are not only required by law, but the simplest technology for being seen. Masthead running lights are the best at sea, because they are not as easily obscured by waves. Some sailors use a mast-head strobe light, though strictly speaking a flashing light indicates distress, I believe.

Along the same lines, some sailors use a bright 360 degree white light at the masthead. This is not strictly legal, but it is the most visible kind of light to display. 

In fog, the pathetic bleat of your fog horn probably won't be heard on the deck of an oil tanker 3 miles away. Or even 300 yards away. Or 30. In such conditions, I might regret not paying for the active radar reflector!

Probably the best tool for being seen is one of those multi-million candlepower spotlights now available from your friendly chandlery. Forget about shining it on your sails like the old-timers did. Point one of those babies at the bridge of an on-coming ship and give them a split-second flash, and you probably will be seen. I say split-second, because you don't want to blind the crew on the other vessel. You just want to be seen at a goodly distance. Emergency use only!

Bottom line, it's better to see them first, and get out of their way, than to depend on being seen. 

Any other ideas on minimizing the risk of getting run down? Please note them below or send me an email

Next Up: Staying Onboard


10 comments:

  1. "AIS only works if the other boat is transmitting." Not so - AIS only works if YOU are transmitting, and the other vessel is receiving. Last year delivering a yacht to the Med from the UK, I triple blessed our little black AIS box, which gave us an enormously clearer sit rep than any binoculars could deliver, as it could "see" over the horizon. It made crossing the English Channel so much easier, because we could see where ships were, their intentions, and where they would be when it got critical. Admittedly, off the Spanish coast we were confounded by a rowing boat with AIS (really), and 150 ton trawlers without… Mid-Atlantic though, I'd be very surprised to hear of any ship running without their (compulsory AIS) on, in open seas mode (without filters). During that Channel crossing, we were gratified to see an 80,000 ton bulk carrier make a course correction 8 nm from us to ensure we passed clear. AIS is not a guaranteed panacea, but it is a huge improvement on a radar watch. The big issue is how to keep an AIS unit working on BLUE MOON both in terms of Watts and environment….

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    1. Michael, I've edited my post to make what I was trying to say more clear: "AIS only helps you see other boats if they are transmitting." Thanks!

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  2. I think you'll find AIS on most ships. Fishing baots are more the hazzard, although at night they are most linkely working and lit up like a Christmas tree. Fishing boats are more of a hazard during daylight hours.
    Regarding the stand on vessel, I don't believe there is any case in which you in your boat would be stand on, nor would I ever temp fate by trying to insist on that in a converging path situation. I alwayw believe in making a very obvious maneuver to give way to make my intentions clear.
    I don't consider radar on either your boat on on commercial shipping to be an effective defense: AIS is much more accurate and reliable.
    Finally, at night I always run a masthead strobe. Best of luck in your adventures.

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    1. David, Obviously, I did a poor job talking about AIS by focusing too much on its limitations. I've revised my post to make it clear that AIS is the best bet for an automated watch keeper. Thanks for your comments.

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  3. One more comment. In heavy fog you can plainly hear and "feel" an approaching ship. I've crossed the Strait of Juan de Fuca a number of times in pea soup fog and fairly big wind. The shipping channel there is one of the busiest. Radar was less help than I had expected, but sound was a good measure of position and direction. Speed was less important since all shipping was steaming faster than my sailboat. Not to put too fine a point on it, but on a container ship the radar is elevated so high that in reasonably close quarters a small boat isn't in the cone and it is almost guaranteed that the watchstander on the bridge is not looking for anything that small (if they are looking at all).

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    1. Sounds like it's safest to assume big ships are running on autopilot, and to just stay out of their way. That's why I'm prioritizing active avoidance.

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  4. Interesting post, thanks John. I was at sea in the merchant service 1968 to 1975. Fog horn used? Then, yes, but be aware that a low level mist is not seen to be fog by big ships, even though it might hide Blue Moon. They will judge by sight from the level of the bridge.
    I don't see how continuing to sail, or stopping hove to or lying to a sea anchor would make any difference to the chances of being run down. It would all be happenstance anyway and depend on the three factors you identified, 1,2,3.
    Bright lights festooned all around? Well, when just left port, or approaching port, there will be deck working lights. Passenger ships are always lit up like your Christmas tree. Otherwise, cargo ships far from land might well not be, but they will always have running lights.

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    1. A couple of people have said that they turn the lights off once they are out at sea. That's good to know. And that makes sense, since they would be visually blind, otherwise.

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  5. Thanks John:

    All merchant ships run AIS and they do not use to filter AIS B reports (what for?). Exceptionally in some zones of piracy they may switch it off although it is not recommended. Therefore AIS B is a very good way to be easily detected by a ship but obviously it has its price in terms of electrical energy. A good alternative is to switch on transmission in bad visibility conditions and keep "reception only" at a fraction of power consumption or even switch it off in good visibility.


    You will find merchant ships with little illumination in the accommodation area and no lights at all in the rest of the length. Exceptions are the cruiser ships, which sometimes is so hard to find their navigation lights and therefore their relative aspect. Also the ships at anchor or stopped at sea (solving mech problems for instance) normally switch on all the illumination on deck and turn off the navigation lights.

    My experience as Master Mariner is that unless your hull is steel you will be detected by radar only in favourable conditions. As it is repeatedly said in the specialized publications, "in radar detection size matters". If you look at a buoy radar reflector you will find that it is in the order of ten times the size of a current yacht radar reflector. A buoy is a small target in a ship's radar screen, you can imagine how weak a sailing boat radar reflector is presented. Very often it is completely hidden in the sea clutter.

    Agree with you.The absolute best way of being detected by radar without any doubt in an "active radar reflector".

    Fog horn, although is compulsory, is normally used only in high density traffic areas or in known fishing grounds.

    You will not blind the crew of a ship if you switch on pointing on them your spotlight (unless your are literally on top of them). It is the best way to be seen. I always have a kind of spotlight at hand when sailing at night.

    I agree what has been said about the importance of the sounds in every condition but specially when wind and sea are relatively calmed.

    Please keep on these well organized risk analisys!!!



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    1. Wow, a lot of useful information. I read in one of my books that merchant ships filter out AIS B traffic in busy areas, just because of the clutter, and then sometimes forget to turn it back on. Probably rare, but I'm trying to at least think about all the possibilities. Thanks so much for your feedback.

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