How to Squeeze a Huge Ship Down a Tiny River

http://www.wired.com/2014/09/conveyance-quantum-of-the-seas/

by sveme • 12 years ago

112 38 12 years ago

ColinWright2• 12 years ago

I once assisted getting a barge into a port. Technically it was a barge, because it didn't have its own engines, but it was an FPSO[0] and it was 310 metres long and 80 metres wide - you could fit three football fields in its footprint.

My job was to provide real-time live radar from the land-based VTS[1]. It had been decided that only relying on GPS was a risk, and that independent radar images would be necessary to confirm position, course, and speed. We were transmitting live radar from Port Control over a 19.2k baud VHS data link to my laptop on the barge. Using the radar data we re-calibrated and cross-checked the GPS positioning to make sure there was no drift, error, or distortion. There was some interesting math going on underneath.

Modern radars sample at 50 MHz, giving a 3m inter-sample distance. Getting that 50 MBytes/sec data down a 19.2k bits/sec channel was a challenge. There were some easy gains (inter-pulse dead-time, blanking) but we still needed a radar image the pilots and captains could rely on, especially coming in from open water.

There's a picture of it coming in to the river[2] and a video[3] of the vessel, having been fitted, leaving the river. When it came in it didn't have all the super-structure, and the highest point was the heliport, which is where I stood for much of the time.

An interesting job.

[0] http://en.wikipedia.org/wiki/Floating_production_storage_and...

[1] http://en.wikipedia.org/wiki/Vessel_traffic_service

[2] http://www.ship-technology.com/projects/bonga-fpso/bonga-fps...

[3] https://www.youtube.com/watch?v=wKLXiHPNu8A

mjb• 12 years ago

Cool story!

Modern radars sample at 50 MHz, giving a 3m inter-sample distance. Getting that 50 MBytes/sec data down a 19.2k bits/sec channel was a challenge

Surely you would do the processing for target extraction on the radar's side of that link, and send much less frequent samples from the estimated track over the slow link? Tracking on scanning radars can be tricky, but I suspect that would something so big and so slow the processing would be quite simple. It's also a bit surprising that ports don't do this with secondary radar (like airports do). Using the ship's signals with PCL or similar technology would definately be feasible.

Radar is a technology with great promise. The advances in computing power, signal processing, and radio technology over the last decade or so is a radar revolution waiting to happen.

ColinWright2• 12 years ago

  > Surely you would do the processing for target
  > extraction on the radar's side of that link,
  > and send much less frequent samples from the
  > estimated track over the slow link?

That's the obvious thing to try, and it works well in ideal conditions when there are only large targets, and no clutter. Lots of people track at the radar head and only send what they believe to be the stuff that matters.

We work in contexts where there can be personal water-craft in areas of moderate clutter, and plot extractors have a very poor record and even worse reputation for finding the real targets that are most at risk of being run down by vessels.

We transmit the actual radar video so the operators can put the Mark I eyeball on the image. Customers like that, and we regularly out-perform our competitors at getting customers to find and identify small targets at risk.

sveme2• 12 years ago

There is a second story to it: about a decade ago, the shipyard owners realized that they had already reached the maximum ship size that they could transfer from the shipyard to the sea. So they announced that they would transfer the shipyard to the city of Eemshaven downstream the Ems river - a sensible decision you might think, however, Eemshaven is unfortunately already in the Netherlands. The state government, not wanting to lose a major employer in a rather poor area of the state, built a storm surge barrier to the tune of around 400 mio Euros, arguing it would be for flood prevention. Conveniently, it also allows blocking the outgoing tide, leaving the river at high tide for more than a couple of hours, allowing for larger ships to travel to the sea. At apparently quite an ecological cost.

Well, surprisingly the shipyard stayed in Lower Saxony. So much for European integration.

But it seems like they reached maximum ship size yet again, wondering what they are coming up with next.

qwerta• 12 years ago

It does not always go as planned. In 2006 boat caused major blackout in Europe, more then 15M people were without electricity.

https://en.wikipedia.org/wiki/2006_European_blackout

jug6ernaut2• 12 years ago

I regularly visit Port Aransas Texas, often fishing the shipping channel that goes to Corpus Christi. The channel can not handle the biggest of tankers, the supertankers. But even so, i can not overstate the size of these ships. It never ceases to amazes me. When you are in the channel you have to take into account them coming through the channel, and i dont mean simply getting out of there way, the channel is plenty wide to hold two(as they go both ways) with much space on both sides. I mean the effect they have on the channel, specifically when they are coming in (full of cargo). When full they draft a full 10-15' more of water. Displacing this much water causes mini tsunami in the channel. If you are to close to the bank you could either find yourself beached or slammed against something.

Its really a spectacle when they come by, even after seeing it hundreds of times i still stop and watch.

One thing not mentioned in this article which is a HUGE factor with moving these large ships is wind drift. Any boat /ship will act as a sail, but the bigger you get the harder it is to control. As anyone who has piloted any vessel can tell you it only takes seconds to get out of control. When moving these huge ships through such tight quarters i can only imagine how difficult it is to control.

gk1• 12 years ago

I once got to experience the other end of that: Being on a ship while it's going through a tiny canal. In my case, it was the Kiel Canal in Germany.

(When you're standing on the deck of a ship, you can't see the small gap -- between ship and land -- unless you stretch your neck over the rail and look down.)

So imagine this: You've spent many days on the open sea, with nothing but water in every direction. It's become so normal to you that you forget there's other life out there, beyond the steel hull.

Then one morning you wake up from a deep sleep and step outside, and... You're surrounded by land! You can't see the canal beneath you, but you can see the beautiful park you're in, with joggers, mothers with strollers, and couples holding hands.

It's very bizarre, and I'm not sure I'd get used to it either.

tcopeland• 12 years ago

Even transiting the Panama Canal in a smallish (210 foot USCG medium endurance cutter) is kind of weird. One day you're underway making way in the Pacific, the next day you've got mules pulling you through locks.

frenchman_in_ny• 12 years ago

Other major consideration, especially in a narrow channel, is squat -- see http://en.m.wikipedia.org/wiki/Squat_effect

Someone• 12 years ago

That takes balls:

"The second largest cruise ship in the world, Oasis of the Seas, used this effect as a contributing factor to pass under the Great Belt bridge, Denmark, 1 November 2009, on her voyage from the shipyard in Turku, Finland to Florida, USA.[5] Without the presence of the squat effect, the ship wouldn't have been able to clear the bridge safely - the margin would have been very slight. However, travelling at 20 knots (37 km/h) in the shallow channel, Oasis experienced a 30 cm squat, allowing sufficient room to clear the bridge safely."

So, you are captaining this brand new billion dollar cruise ship, and the deck of the bridge is too low to pass under it. Now, order your crew to speed up as much as they can, and trust physics to do its thing.

dmoo• 12 years ago

Not quite the same but big ships in the Corinth Canal in Greece just look fantastic

http://www.youtube.com/watch?v=R6xOPAetZuQ http://hhvferry.com/blog/wp-content/uploads/2009/05/orientex...

sveme2• 12 years ago

A nice time lapse video can be found here: http://www.youtube.com/watch?feature=player_detailpage&v=PHJ...

jhallenworld• 12 years ago

The article reminds me of the "fitting a ladder around a corner" problem that I saw in numerical analysis class years ago. Expanded forms of this problem include the food trolley and sofa problems... take a look at

http://www.researchgate.net/publication/220154823_Moving_a_F...

johnohara2• 12 years ago

“Everything is unusual on this trip,” says Bernard Meyer, managing partner of the firm.

Meyer is the great-great-great-grandson of Willm Rolf Meyer. He founded the company in 1795, choosing a spot in Papenburg so construction projects would be safe from storms.

In his wildest dreams, I doubt Willm Rolf Meyer could have ever imagined this as a legacy. Or that his family business would survive 219 years and apply its experience this way. Remarkable.

junto• 12 years ago

I assume that this firm counts as one of the German "Mittelstand".

http://en.wikipedia.org/wiki/Mittelstand

johnohara2• 12 years ago

Interesting read. Thank you for posting it.

RyanMcGreal• 12 years ago

a full moon (or no moon) is ideal to ensure the water was at its deepest.

Here's a fun word: syzygy.

http://en.wikipedia.org/wiki/Syzygy_(astronomy)

xenophonf• 12 years ago

That's odd. I typed it in and nothing happened.

emjaygee• 12 years ago

You have to type it three times.

IanDrake2• 12 years ago

It is a beast of a ship, 1,141 feet long with room for more than 4,000 passengers

"I want to be crammed on a ship with 4,000 other people" said no one ever.

I wonder how these cruise ships make money between the cost of fuel, food, and expensive mishaps.

ceejayoz• 12 years ago

With all the decks, it's likely roughly as much square footage per person as a mall or a resort.

mcguire• 12 years ago

Judging from my experience on a cruise several years ago, the only major issues are arriving on/leaving the ship in port (and they somehow managed that process so that it wasn't that big of a deal) and scheduling dinner in the evening (there were two or three seatings and, by god, you had to be there on time).

Fomite3• 12 years ago

Shipping is massively fuel efficient, and enjoys economies of scale

Food is built into the cost of the cruise itself.

Mishaps are insured, and relatively rare. Insuring ships is a very old industry.

IanDrake2• 12 years ago

Shipping is massively fuel efficient

That's interesting.

Mishaps are insured

The cost I was thinking of was the bad PR. Ships running aground with people dying, mass strandings at sea with people living in squalor unable to flush toilets, and general sickness run wild.

idlewords• 12 years ago

Reminds me of the A380, every one of which has to be squeezed through the tiny French town of Levignac on its way to assembly. http://www.cnet.com/pictures/tiny-french-village-meet-giant-...

adnam2• 12 years ago

Unrelated, bit it irks me that in 2014 there are three countries left that have not adapted to the metric system: Liberia, Burma, and the United States. So when I read

"1,141 feet long with room for more than 4,000 passengers"

I have to mentally translate it to:

"348 meters long with room for more than 20-score passengers"

Fomite3• 12 years ago

The magazine that published the article is based in one of those countries.

napoleond• 12 years ago

20-score passengers

I'm with you on the metric, but... 20-score? Really?

i_cannot_hack• 12 years ago

He's joking.

hughdbrown2• 12 years ago

A score is 20 so 20-score would be 400, not 4,000. Is that the joke?

adnam2• 12 years ago

Yeah I meant to write 200-score but using mobile and fat-fingered it.

pkaye• 12 years ago

I'm guessing the joke that that a "score" is an obscure unit of measure.

drzaiusapelord• 12 years ago

Scroll down to the Medusa Challenger navigating the Chicago river in 72.

http://galleries.apps.chicagotribune.com/chi-20131028-st-mar...

Talk about a tight fit. That must have been incredibly stressful.

How to Squeeze a Huge Ship Down a Tiny River

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