The art, science and bluff of ship handling

Two recent incidents at sea have drawn unfavourable attention to the business of moving a large objects around on the water. The first was an error large enough to be visible from space and bunged up a canal that carries a significant percentage of global trade:

The second, fortunately, was only visible from The Sun:

Commentary on incidents such as these, particularly the Suez one, tend to draw out a mawkish humour but with undertones of ‘how do professional mariners allow this to happen?’ Hopefully this blog will help explain how. Incidents at sea can be amusing if you get away with them; catastrophic and tragic if you do not – and it’s a very fine line.

Ship handling has always been described as part art, part science. This is true.

First, you need to know what effect the conditions will have on your vessel so that you can anticipate (science). Second, you need to be able to see/feel/judge what is actually happening (art). Third, you need to know how your vessel manoeuvres so that you can adjust accordingly (science). Finally, with all those in place, you then need the confidence to actually do it, particularly when it’s going wrong (art).

Needless to say, this curious mix of art and science makes it a topic as prone to exaggeration, legends-of-yore and bluff as any. Hopefully this blog won’t add to this, but rather explain why ships occasionally get it wrong (noting that most of the time they get it right). My qualifications include over 20 years driving all manner of warships as well as command of four very different vessel types, notching off 100s of ‘alongsides’ in the process which in my view was the hardest thing to do. And of course, I was amazing at it; never took tugs, never damaged the paintwork and didn’t even spill my G&T…

In days gone by (here we go) ones ship handling was judged by your ability to sternboard into (say) The Grand Harbour, Malta at 12 knots, pirouette around your anchor and park perfectly outboard of three other ships in time to hoist the gin pennant. (This is only partly anecdotal and there were definitely instances where the Commander in Chief Mediterranean sent ships back out to sea for not driving with enough panache). However, times change and throughout my years in the Navy, despite what the occasional unconscionable ‘good old days’ bore would have you believe, there was only one real metric for a good ship handler:

Can you get from A to B without impacting on yours or anyone else’s programme?

If that sounds a rather soulless metric then it shouldn’t. There are endless opportunities to drive your ship hard when out at sea, or to ‘drive it like you stole it’. indeed, this forms an essential part of being able to fight. If it sounds risk-averse in terms of berthing then again, it shouldn’t. ‘Could I do this manoeuvre without tugs if we’re at war and they’re not available?’ was always in the back of one’s mind, and besides, quite often you had to anyway. But if you’re not at war then pragmatism rules and the business becomes more one of process and asset management. The key was knowing where your safety margins were at all times. Stay within those and you’re ‘managing risk’. Exceed them and you’ve strayed into the gambling zone and bad things happen there.

The business of managing your safety margins I have discussed a couple of times before. The first was in my blog rebutting those who criticised HMS Queen Elizabeth’s decision not to sail from Portsmouth Harbour in high winds in September last year. The second was another blog looking at what happened to MV Ever Given when she spectacularly failed to manage her margins earlier this year.

Back to my original four points on what is required to successfully drive a ship.

You must know what effect the conditions will have on your vessel so that you can anticipate (science).  

From the commentary seen after incidents it seems that many people equate driving a ship with driving a car (whist conveniently forgetting that cars crash far more than ships). There are, however, some major differences. The main one is that a car goes where you are pointing it. Imagine if it didn’t and that even a modest side wind caused you to drift across the road. Or if the tarmac all looked the same but sometimes had a dramatic effect on your ability to steer straight. Or if you got too close to the side, you suddenly veered dramatically across the other lane. (Incidentally, this is likely to be what happened to the MV Ever Given when she grounded in the Suez Canal). And then finally, when it’s all going wrong and you want to stop, there is a 20 second delay between stamping on the pedal and anything happening, and maybe minutes before you’re actually stopped. So really it’s nothing like driving a car at all because of the number of external factors that influence where you are actually going. Understanding these external factors is key to driving a ship because you can then either counter them or avoid them. The problem is, the science is never exact.

Being able to see/feel/judge what is actually happening (art).

So now you have to be able to judge what’s actually happening to you. Using berthing as an example, there are often a lot of visual cues to help you as you make your approach. Picking something in the distance that lines up with where you are aiming (a natural transit) is a good start as this will tell you more quickly than any electronic aid if you are being set one way or the other. But even that isn’t exact because if, say, it’s the wind that is causing you to drift, then it’s going to get worse the slower you go. So in the final few yards, when the large solid object you want to park your thin-metal ship against is getting awfully close, the wind (or tide) effect reaches its maximum just as your control over the vessel reaches its minimum. And if you’ve got it wrong, the few sickening seconds when collision is inevitable but your options are zero are no fun at all. Sometimes you might even have time to discuss with your second in command what your Line To Take could be for not taking tugs.

Knowing how your vessel manoeuvres so that you can adjust accordingly (science).

Knowing how your ship will respond both to your inputs and the external influences is key. As I said before I was lucky enough to have four different attempts at this, in ships that carried very different manoeuvring characteristics, outlined here in reverse order of difficulty:

HMS Endurance was a large red plum of a ship but was comfortably the easiest to berth. Her shrouded propellor made deceleration slow (by warship standards), and she would sheer quite violently as you did so in a direction of her choosing, but once below three knots, her bow and stern thrusters meant you could turn on a sixpence. It was like carrying your own tugs everywhere – bliss. In addition, the four inch thick ice-strengthened hull meant it was the jetty you worried about, not the ship.

HMS Dulverton, a Hunt Class minehunter of the same type mentioned in the Sun story above, was in theory an easy ship to handle. In practice, often less so. Two propellors and a bow thruster gave you lots of options but you needed them as you were inevitably asked to squeeze into tight spots and tugs were rarely available. There were other difficulties. For a start, they may be the best sailing vessel the navy has ever produced. Slab sided above the water but rounded and shallow below meant that any more than six knots of wind on the beam and you had to adjust your approach. Failure to do so could result in one coming alongside some distance short of your allocated berth. This is unfortunate if there is a ship already there as I discovered one windy day up in Faslane. The good news back then was that when this sort of thing happened, the ship’s company’s priority was repairing the paintwork, not ringing a national newspaper… The shape of the propellors meant that reducing headway took a while. Conversely, at slow speeds, a combination of the prop design and the minimum speed you could set on the engines meant you leapt down the jetty like you were on fire (which given the Deltic Diesels back then, you quite often were). Finally, as HMS Chiddingfold discovered, although the GRP hull was designed to absorb a mine detonation that is a load shared along the length of the ship; its ability to absorb point impact is very poor. You could do some neat tricks such as walking the ship bodily sideways, but for me at least, the fragility of the hull took much of the fun out of driving one.

HMS St Albans was the most ‘standard’ warship I drove. Two large fixed-pitch propellors meant you had bags of power but no bow thruster meant that you could quickly run out of options if you got your setup wrong. The large GRP bow dome made her sluggish to turn and certainly prevented you from using any trickery with the anchor. The thinness of the steel was always a concern as well. Built to save weight (and money), these are not strong ships. One was also aware of how taut Type 23 programming was across the class of ship. They were very busy – one serious bump by you could affect the programme of three or four in quick succession and for that, there were no prizes.

Here is a short clip of it going well. We’d been in the Kiel canal for about 12 hours at this point when as I made my approach to the northern lock. The plan had been to berth starboard side to, astern of the red vessel but as we made our approach, the pilot informed me that we were to go alongside port side to between it and the wall. The video doesn’t do justice to either how tight that gap was or how windy it was, but by driving hard against a tug pulling from dead astern, I was able to (just about) control the bow as we squeezed in there:

Conversely my best looking alongside was also the closest I came to disaster. Rounding Fountain Lake Jetty at night (it’s always at night) I was going too fast. Either I’d been doing this too long now and was overconfident or I got my cues wrong because it was dark. Probably both. Then, at the critical moment, and as I was using increasing amounts of power to dig myself out of a rapidly growing hole, I gave an engine order to the wrong shaft. My second in command, who was experienced enough to have internal alarms going off already, spotted the error and immediately and almost silently asked me if that’s what I meant. I didn’t. He knew I didn’t. Reversing the order now with even more power applied we screeched to a halt about 6 inches from the jetty. To the external viewer it was a perfect and very punchy alongside in the dark and in poor conditions. To me, it was a terrible use of my safety margins compounded by an error. It cost me a lot in whiskey as well because the XO was very thirsty that night for some reason.

HMS Lindisfarne was a hilarious ship to drive. One prop controlled by a single stick connected to the control room by a bicycle chain and no bow thrusters (although annoyingly the space and tubing was there – they just weren’t fitted…to save money). This made her handle much like many merchant vessels which, of course, she was. A relatively deep draft compared to her sail area meant low windage. The single screw generated considerable paddlewheel effect (where the stern will literally walk in the direction the screw is turning) which could be used in your favour but could also be a pain. In sum, you had to own it which invariably meant applying large gobs of power whilst very close to the jetty – exactly what you want to avoid most of the time. For the feint-hearted it was not. On the plus side, the steel hull was thick so you could do this with confidence and if you did bump it you just had to remember to initial the dent at the next opportunity.

The confidence to actually do it (art).

And now the final bit. You know what should happen, you can see what is actually happening, you know how your vessel responds, now you just have to get on and do it. Sounds pretty straightforward, and most of the time it is. But just occasionally it isn’t. Maybe you misread the environment and the wind is stronger than forecast, or there’s a tidal stream that wasn’t expected, or it’s dark – everything is way harder in the dark – or there is a mechanical issue of some sort that effects your manoeuvrability, or a tug comes barrelling in with every intention of doing the exact opposite of what you want despite your internationally recognised gesticulations from the bridge. Or maybe you’ve just got it wrong. But when it’s unravelling, and everyone on the bridge turns to face you, that’s the moment where you have to dig deep. Indecision or lack of confidence at that point will certainly make things worse. Hundreds of people and millions of pounds can make those few seconds quite lonely.

To sum up, I’ve tried to explain how driving ships around works. It’s a vast subject with masses of source material but one that doesn’t translate particularly well unless you’ve done it. Hopefully this helps a bit. One thing I can guarantee is that when it does go wrong, every mariner in the world raises a metaphorical glass saying ‘there but for the grace of God’ immediately followed by a grossly exaggerated anecdote about when they did exactly the same thing but got away with it! With the merchant marine pushing increasingly large ships into ever tighter spaces and warships forever operating at the limit, it’s testament to the professionalism of the 1000s of mariners out there right now, today and every day, that this doesn’t happen more often.

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