Oasis and the Verrazzano-Narrows Bridge

[chengkp75]

1 hour ago, xpcdoojk said:

 

Chief, can a ship consistently “squat” the same amount, and if a ship failed to “squat” wouldn’t that mean that a bridge could get wiped out since the ship would be at high speed.  This just seems crazy dangerous for the bridge.  

 

JC

Pretty much.  Its a factor of the distance between the bottom of the ship and the bottom of the river. If this is narrow enough, a Bernouli effect happens, where the pressure drops and the water is sucked out from under the ship causing the squat.  For a given stretch of a river, as long as the channel doesn't get any deeper over time, the squat will be pretty consistent.  And, "high speed" is relative.  The ship won't be going more than "full ahead", which is about 12 knots, but the stopping difference between 12 knots and the "normal" bridge passage speed of "half" or "slow" (6 knots or 4 knots) is not that much.  Given that all that is going to hit the bridge is the exhaust pipes, that is what will get cleaned off.  I've seen a video of a ship that steams under a bridge that cleans the entire funnel structure and all masts above the bridge off.  Sparks everywhere, but little damage to the bridge.

[xpcdoojk]

2 minutes ago, chengkp75 said:

Pretty much.  Its a factor of the distance between the bottom of the ship and the bottom of the river. If this is narrow enough, a Bernouli effect happens, where the pressure drops and the water is sucked out from under the ship causing the squat.  For a given stretch of a river, as long as the channel doesn't get any deeper over time, the squat will be pretty consistent.  And, "high speed" is relative.  The ship won't be going more than "full ahead", which is about 12 knots, but the stopping difference between 12 knots and the "normal" bridge passage speed of "half" or "slow" (6 knots or 4 knots) is not that much.  Given that all that is going to hit the bridge is the exhaust pipes, that is what will get cleaned off.  I've seen a video of a ship that steams under a bridge that cleans the entire funnel structure and all masts above the bridge off.  Sparks everywhere, but little damage to the bridge.

 

 

OK that makes sense.  The smokestack is just relatively thin metal and it smashes down or breaks off, but the ship keeps sailing on at 12knots and the bridge does a shudder.

 

Of course, the captain gets fired.... the media goes bonkers, and horrified citizens of Brooklyn  and Staten Island are terrified to leave their homes because the bridge is not safe.

 

jc

[mo&fran]

Wouldn't you think that if there was an issue, the USCG  and underwriters would have said no way.

Edited December 21, 2018 by mo&fran

[Ocean Boy]

4 hours ago, BillOh said:

Has Symphony specifically had issues with the Aqua theater?

I don't know. Oasis was plagued with problems during one of our cruises.

[JAMESCC]

I'm sure RCI did a boat load [pun intended] of research and engineering before making this announcement. I'm sure they had their engineers, and the ship builders engineers go over this for probably a year before this announcement. 

[philpcruiser]

2 hours ago, chengkp75 said:

 Sparks everywhere, but little damage to the bridge.

I wouldn't want to be driving my Chevy in the right lane on the lower level of the VZ when it hits!

[BillOh]

1 hour ago, Ocean Boy said:

I don't know. Oasis was plagued with problems during one of our cruises.

 

I remember the Rising Tide had lots of problems. I do remember seeing problems on Oasis in the Mighty Cruise Ships show when she first came to the US.  

[do_not_spindle]

10 hours ago, HBE4 said:

Maybe spend 7 days sailing in circles around the Statue of Liberty? Sail up and down the Hudson river between the George Washington and Verrazzno Bridges.

 

I was thinking "sails up the scenic Hudson River to the Poughkeepsie Bridge where it turns around..." (old Circle Line Alexander Hamilton TV ad...)  Although the Tappan Zee bridge might also be in the way!

[boscobeans]

23 minutes ago, do_not_spindle said:

 

I was thinking "sails up the scenic Hudson River to the Poughkeepsie Bridge where it turns around..." (old Circle Line Alexander Hamilton TV ad...)  Although the Tappan Zee bridge might also be in the way!

 

138 foot clearance for the new Tappen Zee

[HBE4]

33 minutes ago, do_not_spindle said:

 

I was thinking "sails up the scenic Hudson River to the Poughkeepsie Bridge where it turns around..." (old Circle Line Alexander Hamilton TV ad...)  Although the Tappan Zee bridge might also be in the way!

 

I remember sailing on the old Alexander Hamilton. Well, not really. I was a baby at the time. But my parents would always say "Remember when we took you on it"? I'm like, "No, I was 2". I do remember her replacement, The Dayliner.

[HBE4]

12 minutes ago, boscobeans said:

 

138 foot clearance for the new Tappen Zee

 

The drydock after next is when they install the retractable decks 10-15.

 

Also, I'm glad you referred to it at the new Tappen Zee. I refuse to call it by the new name. It'll always be Tappen Zee Bridge to me.

[boscobeans]

20 minutes ago, boscobeans said:

 

138 foot clearance for the new Tappen Zee

 

North of 59th street the channel depth goes from 32 to 200 feet the rest of the way to Albany.  

[xpcdoojk]

Ok,,not a NYer, but all the way to Albany.... that is a long way.....

 

OK, ignoring that post.

 

jc

[PhoenixCruiser]

7 hours ago, xpcdoojk said:

 

Of course, the captain gets fired.... the media goes bonkers, and horrified citizens of Brooklyn  and Staten Island are terrified to leave their homes because the bridge is not safe.

 

jc

 

Awesome summary! 

 

Just need to add - and CruiseCritic goes nuts and back to when we had an app level of participation with "I told you so", "what is Royal going to do for us", "my cruise is in three months, I hope this is fixed by then" and "our vacation was ruined, Ruined!"