Escape to bumpy ride

[chengkp75]

Google it to see Escape 136 feet and Getaway 172.8 at lifeboats

 

The figure for the Escape is the "waterline" beam (the width of the hull itself), while the Breakaway shows 130' as "beam" (or waterline) and 172' at lifeboats. The beam at the lifeboats has not a single thing to do with the stability or the sea keeping performance of the ship. The motion of a ship depends on the height difference between the center of gravity and the center of buoyancy. The center of gravity only depends on how high the weight is, not how wide it is. The center of buoyancy depends on the shape (length and beam) of the hull that is in the water, not even the width of the hull above the water, or the width of the lifeboats. The figure given for the Breakaway at the lifeboats is "extreme breadth (or beam)" and is important for clearance in shipping channels, at docks, and in drydock. On some ships, there are balcony "bump outs" that are actually the extreme beam controlling factor, and these have no affect on ship motion.

[chengkp75]

And thank you I have sailed on both.

 

And unless you have sailed on both ships on the same day, in the same location, there is no way to accurately compare which ship is "bumpier". There are hundreds of variables that affect ship motion, and any one of these can adversely or positively affect motion.

[Tbucs19]

Fair enough thank you cheng.

[KeithJenner]

Fair enough thank you cheng.

 

 

Yes, thanks cheng for reiterating what I said back in post 6 of this thread and we've been repeating since. I'm glad you didn't get grief for it too. :)

Edited November 28, 2015 by KeithJenner

[barnacle_boy]

Hi chengkp75! For comparison, Breakaway has GM of 4 meters while Escape's closer to 2.5 meters.

[chengkp75]

Yes, thanks cheng for reiterating what I said back in post 6 of this thread and we've been repeating since. I'm glad you didn't get grief for it too. :)

 

Just to confuse things a bit more, Breakaway has a narrower beam than Escape, but Breakaway's extreme breadth is greater by about 1 meter. So, the lifeboats or balconies hang out further on Breakaway than on Escape.

[KeithJenner]

Just to confuse things a bit more, Breakaway has a narrower beam than Escape, but Breakaway's extreme breadth is greater by about 1 meter. So, the lifeboats or balconies hang out further on Breakaway than on Escape.

 

 

Do we know why? Are the lifeboats on the Escape narrower, or are they held further out from the ship? The former would seem more logical, but surely the lifeboat capacity on the Escape is more than the Breakaway, so it isn't obvious.

[chengkp75]

Do we know why? Are the lifeboats on the Escape narrower, or are they held further out from the ship? The former would seem more logical, but surely the lifeboat capacity on the Escape is more than the Breakaway, so it isn't obvious.

 

Really couldn't say. The difference in lifeboat capacity between the two wouldn't make much, if any difference (generally the boats get longer with increased capacity), but the davits may be different.

[chengkp75]

Hi chengkp75! For comparison, Breakaway has GM of 4 meters while Escape's closer to 2.5 meters.

 

Hey, barnacle. Some of your data amazes me. You must really smooze the officers. :D

 

That data would tell me, that without stabilizers in action, the Breakaway will roll less, but with a quicker and snappier roll, while the Escape will roll more, but with a distinctly slower roll period. Of course, stabilizers will change the equation, and how the stabs are programmed is another of those vast variables to ship motion. And in the OP's defense, "bumpier" ride is pretty subjective, and certainly means something different between the general cruising public and myself.

 

The fact that the OP reported the ship heeling for an extended time, agrees with the reduced GM and "wind heel", and possibly not having enough capacity in the anti-heeling tanks to counteract, so they start to use potable water, and move this around to trim up the ship, but this is very slow method of "ballasting".