It can't be Boaty McBoatface. It's Shippy McShipface

[Recursion]

http://www.independent.co.uk/news/boaty-mcboatface-could-be-the-name-of-200m-research-vessel-after-public-vote-a6942551.html



That clearly has three masts (if you know what to look for), and I've worked on enough vessels to assure you it leans out from its turns rather than into them. It is not a boat. It is a ship.

It's Shippy McShipface.

[fleur-de-lisa]

1. I prefer 'Boaty McBoatface' . . .

sounds a lot like South Park's 'Scrotie McBoogerballs'.

[flamin lib]

2. As a sailor myself I've always held to the definition of a ship as

a vessel large enough to carry a boat and a boat as a vessel small enough to carried by a ship.

Either way, the heli-pad qualifies this as a ship.

[Recursion]

3. The list with the turn is the only one I've found to be fully consistent

Even the largest submarine leans into her turns, and all submarines are boats.

But, yeah, the carrying another vessel rule is another good one, though a cutter can carry a dinghy.

[MowCowWhoHow III]

4. So it's a multi-dimensional trolling

Last edited Mon Mar 21, 2016, 12:26 PM - Edit history (1)

Top notch



https://twitter.com/JamesHand

[OriginalGeek]

5. I L'd OL

when I heard them say "Boaty McBoatface" on NPR this morning.

It's not often I LOL at NPR.


I just want to say I love England for that being the current front-runner.

[So Far From Heaven]

6. How much you want to bet,

that there is a really good chance the real winning name can't be used?

[jmowreader]

8. That it's stupid as fuck?

[So Far From Heaven]

11. Or worse. Don't let the children vote for a name!!!

[Thor_MN]

7. It does not appear too big for this:

So.... Boaty McBoatface is not out of the running.

[KamaAina]

9. I read that as "McShitface"!

That would be the Exxon Valdez.

[Blue Dalek]

10. I damn near shipped my pants

when I first heard this.

[eppur_se_muova]

12. Ummm OK -- *why* does a ship lean out from its turns ?

Is it just something that can't be prevented ? Too small a keel for its mass ?

[Recursion]

13. A ship's center of mass is above the waterline and a boat's is below it

(Well, really strictly, a ship's center of mass is "within the freeboard", but 9 times out of 10 that just means "above the waterline&quot . This has to do with size. If you double the scale of a vessel you've octupled its volume, which means given the same materials you've quadrupled its buoyancy (again, generally), so it sits much higher in the water, proportionally.

The friction from the water in a turn pushes the vessel's center of mass against the turn direction. For a boat where the center of mass is underwater, that makes it lean in to the turn (or stay flat); for a ship where the center of mass is above the water, that acts just like a simple lever and pushes it outwards.

[eppur_se_muova]

14. Thanks, I learn all kinds of info I'll never use on DU !

I just can't predict which I'll use and which I won't. Best to save it all.

[Recursion]

15. Hopefully my ASCII art will make more sense than my description:

Last edited Wed Mar 23, 2016, 12:06 AM - Edit history (1)

This is a cutaway from behind of a ship and a boat turning port (left)

Ship:

|
|
|
|
|* (center of mass)
|~~~~~~~~~~~~ (waterline)
|<----- normal force as momentum of ship continues forward
|<-----
|<-----

That means the ship's hull is slamming in to the water on its starboard side while turning port, and since the center of mass is above the water, that tilts the whole ship to the right.

Boat:

|
|~~~~~~~~~~~~ (waterline)
|<----- normal force as momentum of boat continues forward
|<-----
|<-----
|<-----
|* (center of mass) <-----
|<-----
|<-----
|<-----

In the boat's case, the hull is slamming into the water on its starboard side while turning port. This can result in a lot of things, but in the general case there's more hull between the center of mass and the waterline than below the center of mass, with the result that the pressure between the center of mass and the waterline leans the boat into the turn.

I feel like I'm still not explaining this well, but I thought the graphic might help.