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LandL · 01-11-2010, 10:16

Cruise ship barely squeezes under bridge - CNN.com

I'm impressed.

Any captain with the apendages (and skill) to rev the speed up as you approach a potentially deadly bridge crossing where you limbo under with a foot to spare has my admiration.
If I were to ever meet him the first one would be on me.

I think the pucker factor on that one has to be near the top of the scale.

**David M** · 01-11-2010, 10:20

Another factor not mentioned is air temperature. Bridges sag more in higher temperatures. The amount of traffic is another factor.

In looking at the picture, it looks like the clearance was much more than a foot. It also looks like the ship did not pass at center span where the bridge would be highest for a suspension bridge. Just guessing, but that's how it appears.

**James S** · 01-11-2010, 10:26

Just saw a news blurb on it...they said it was 20 inches.....I'm impressed.

sailvayu · 01-11-2010, 10:32

Damn the torpedoes! FULL SPEED AHEAD!
I'll give them credit but I am guessing the measured at least twice lol

avb3 · 01-11-2010, 13:25

The recently built "Allure of the Seas" shows how its done. For those of you using the ICW, listen to the captain speaking, "When operating in confined waters, speed up, as it causes the boat to lower".

Hmmm... so... do YOU want to take a chance and when leaving the mast up, speeding up and clearing it by as little as he did in the videos?

Just a thought to ponder.

aquarian · 01-11-2010, 21:05

Gutsy!!

SailFastTri · 01-11-2010, 21:43

NO way that was 20 inches. They had at least 5-10 feet to spare from the way it looked to-scale. Yes it was tight and it took guts. You can bet there was a team of engineers who planned that and checked every measurement of the bridge and the boat. There was no option of screwing that up.

It was good PR though.

SvenG · 01-11-2010, 22:54

That foot must have belonged to the Jolly Green Giant's much much bigger brother !

If there had actually been any question at all that it would not clear they would have closed down traffic on the bridge.

Still, a good publicity stunt.

-Sven

**hummingway** · 02-11-2010, 00:13

Impressive. I wonder what the tides are like there?

maytrix · 02-11-2010, 07:30

If it really was that close, then I'm not impressed and don't think it took guts. It took stupidity. That's my opinion based on how its written. It seems the way its written that there was some possibility that they could hit.

What exactly would the result of them miscalculating be? Taking out the bridge worst case? Damaging it so it needed to be closed?

Seems like a stupid stunt that risked damaging not only the boat but more importantly the bridge and anyone on it at the time.

**GordMay** · 02-11-2010, 07:31

Quote:

Originally Posted by maytrix

If it really was that close, then I'm not impressed and don't think it took guts. It took stupidity...

Indeed!
I don’t believe that “squat” can be precisely calulated; only very nearly estimated.
The "squat effect" is the hydrodynamic phenomenon by which a vessel moving quickly through shallow water creates an area of lowered pressure under its bottom that causes the ship to "squat" lower in the water than would otherwise be expected. This is due to a reduction in buoyancy caused by a downward hydrodynamic force created by flow-induced pressures. It is caused by similar forces as lift in aircraft, except that the low pressure area is beneath the hull. It can lead to unexpected groundings and handling difficulties.
Squat is believed to have been one of the causes of the 1992 grounding of the Queen Elizabeth 2 (QE2) off Cuttyhunk Island, near Martha's Vineyard. At the time of the QE2's grounding she was reportedly traveling at 24 knots (12 m/s) and her draft was 32 feet (9.8 m). The rock upon which she grounded was an uncharted shoal later determined to be 34.5 feet (10.5 m), which should have given her room to spare, if not for the "squat effect." NTSB investigators found that the QE2's officers significantly underestimated the amount the increase in speed would increase the ship's squat. The officers allowed for 2 feet of squat in their calculations, but the NTSB concluded that her squat at that speed and depth would have been between 4.5 and 8 feet.

**David M** · 02-11-2010, 07:35

Quote:

Originally Posted by maytrix

If it really was that close, then I'm not impressed and don't think it took guts. It took stupidity. That's my opinion based on how its written. It seems the way its written that there was some possibility that they could hit.

It's more likely the case that the press is not quite correct. It's been my experience that most reporters have very little knowledge pertaining to ships or other maritime related matters.

maytrix · 02-11-2010, 07:39

Quote:

Originally Posted by GordMay

Indeed!
I don’t believe that “squat” can be accurately calulated; only very nearly estimated.

Even if it could, you can't calculate other factores. Engine failure for example. If the engine failed for some reason or there was some other failure that caused them to lose propulsion, they'd continue to move but would slow and rise because of it.

I agree David, probably not completely accurate and sensationalized for media purposes.