Topic: pride of Rotterdam at 38kts? (Read 4514 times)

Stuart2007 · « **on:** October 05, 2011, 10:17:44 »

Following on from the bizarre topic about making por go at 38kts in the game, I wonder what the effect would be on the real one if it were physically possible to get it that fast (which it wouldn't be- unless you had probably 12 engines and 4 props)

But in terms of a displacement hull achieving 38 kts, would it manage to keep the bow out the water or would it plane down or up, or would the wash clean out the stern area where they forgot to build the rear?

danhill · « **Reply #1 on:** October 05, 2011, 12:32:01 »

I think it would technically be possible, but economically possible, no.

The bow probably would rise out the water, but they could add water too the forward ballast tanks to counter act this partially. The fuel bill would be huge tho, making a ship where the hull was not specifically designed to do those speeds, actually do those speeds.

Ballast · « **Reply #2 on:** October 05, 2011, 12:36:40 »

You just can't simply slap an huge overkill on engine power or in it to go faster. Due to the hull shape there is a maximum hull speed, regardless how many horsepower you put into it.

If you want to achieve something like that, the hull shape and the propellers have to be optimalized for that purpose.

danhill · « **Reply #3 on:** October 05, 2011, 12:39:35 »

This is not what i was taught. As long as the hull is strong enough.

However, the curve between speed and fuel burnt starts to to curve very very sharply after a certain point. Until, you get too the stage where stupid amounts of extra horse power will only give you a few extra knots. Due to drag and hull. Obviously you would need the correct props, or ever better, waterjets.

danny · « **Reply #4 on:** October 05, 2011, 18:59:22 »

Its possible!
and quite simple.
The solution? The mother of all "NoS" kits

That or give the ENTIRE engine dept Lots of energy drinks and caffine, however, If using the later method make sure to tie everything non-engine releated down as tight as possible, and that the door to the engineroom is firmly secured (with the engineer's inside). Otherwise hell will break free from the engineroom...
In all honesty,
I doubt the PoR could get up to 38kts, And even if it could the stresses on the hull would probobly result in catastrophic failure of the hull.

Captain Cadet · « **Reply #5 on:** October 05, 2011, 19:31:15 »

i want to stay dry if im on a ship
my boat diffrent.
but a 200 ship
ill stay dry

Quote from: Stuart2007 on October 05, 2011, 10:17:44

Following on from the bizarre topic about making por go at 38kts in the game, I wonder what the effect would be on the real one if it were physically possible to get it that fast (which it wouldn't be- unless you had probably 12 engines and 4 props)

But in terms of a displacement hull achieving 38 kts, would it manage to keep the bow out the water or would it plane down or up, or would the wash clean out the stern area where they forgot to build the rear?

where was this topic about the por going so quick

Stuart2007 · « **Reply #6 on:** October 05, 2011, 20:36:00 »

OK, I was trying to get to the aquadynamic effects of a displacement hull travelling at speeds that a SDH or a PH would encounter.

I got my own boat up to 11 kts and the bow started to ride up and then dive down- not to the point it was dangerous but it was noticable.

I remember the Superseacats how the bow used to ride up when at speed- obviosuly they were designed for the speed and were a deep vee mono.

Ballast · « **Reply #7 on:** October 05, 2011, 20:43:07 »

It that wouldn't happen, the boat would break

It also happens on 'real' ships as you can see on this vid.

http://www.youtube.com/watch?v=89Mw6L69b6Y

Captain Cadet · « **Reply #8 on:** October 05, 2011, 21:44:31 »

Quote from: Ballast on October 05, 2011, 20:43:07

It that wouldn't happen, the boat would break

It also happens on 'real' ships as you can see on this vid.

http://www.youtube.com/watch?v=89Mw6L69b6Y

god
im not going on that ship

Ballast · « **Reply #9 on:** October 05, 2011, 21:49:03 »

That's any ship.

Have you ever noticed the wings of an airplane during a flight? They also go wobly wably. If that wouldn't happen, they would break off.

Same goes for a ship.

Captain Cadet · « **Reply #10 on:** October 05, 2011, 21:51:28 »

Quote from: Ballast on October 05, 2011, 21:49:03

That's any ship.

Have you ever noticed the wings of an airplane during a flight? They also go wobly wably. If that wouldn't happen, they would break off.

Same goes for a ship.

ok...
i dont like planes due to a equlization problem with me so it pritty painful to go up (and down)
also i get sea sick on boats

Ralphy · « **Reply #11 on:** October 05, 2011, 22:11:00 »

Quote from: Captain Cadet on October 05, 2011, 21:51:28

also i get sea sick on boats

But I thought you were going to go into the merchant navy...also you have a boat of your own

clanky · « **Reply #12 on:** October 06, 2011, 15:11:34 »

Stuart, not sure what would happen if you could somehow magically up the power enough to propel a ship like PoR at 38 knots, to be honest I suspect that at that speed she would just go faster.

It would take a model test to really find out what would happen, but I think the mechanics of making the hull go faster and faster would work something like this...

- The bow wave would increase, thus increasing hull resistance

- if more power was applied the increased the bow wave would continue to increase to the point where it would actually be providing extra buoyancy forward, lifting the bow slightly and causing the stern to squat.

- this lifting of the bow would form a wedge of water under the ship which if enough power were added the ship would actually climb causing her to effectively rise up on her own bow wave and plane

- she would then capsize

All of the above is pretty much guesswork, but I don't think it would be far off, assuming of course that the propulsion method was changed to something which still allowed power to be applied when the ship was planing and that she didn't break in half at some point while climbing what would be a fairly monstrous bow wave.

Stuart2007 · « **Reply #13 on:** October 06, 2011, 17:42:17 »

Thanks Clanky- that was the sort of answer I was looking for. Perhaps my original question wasn't well enough thought out.

Simos31 · « **Reply #14 on:** October 06, 2011, 20:22:31 »

The beauty of ship simulator is that Pride of Rotterdam may indeed float at 38Kts, software physics is omnipotent and that drives even an old man like me crazy

That video, Ballast, looks scary but true! Iron is soft and too malleable above a certain length. In order to change that property you just quit using iron, you just switch to ceramic instead. There's so much silica on the planets mantle it only takes a little more ..... evolution?
After all above 35Kts aerodynamics are much more significant to the design than flow dynamics I guess.
I think I'll stick to my old nitro tweaked Esperanza at the end, smooth and skiddy as no other!
Whales put on your earplugs!

Captain Cadet · « **Reply #15 on:** October 06, 2011, 20:43:42 »

can i have the link to the video

Ballast · « **Reply #16 on:** October 06, 2011, 20:44:36 »

Quote from: Captain Cadet on October 06, 2011, 20:43:42

can i have the link to the video

It's the same video that you quoted....

Captain Cadet · « **Reply #17 on:** October 06, 2011, 20:45:51 »

Quote from: Ballast on October 06, 2011, 20:44:36

It's the same video that you quoted....

danhill · « **Reply #18 on:** October 06, 2011, 22:33:25 »

That video has nothing to do with this topic.

That video shows a large ship flexing in heavy seas, perfectly normal, and perfectly safe.

Ballast · « **Reply #19 on:** October 06, 2011, 22:42:00 »

If you would actually read what's written, you'd know that the video was used to show the motions of a ship on the waves which is one of the discussion points

2000 · « **Reply #20 on:** October 07, 2011, 11:45:11 »

Quote from: Ballast on October 05, 2011, 20:43:07

It that wouldn't happen, the boat would break

It also happens on 'real' ships as you can see on this vid.

http://www.youtube.com/watch?v=89Mw6L69b6Y

That's really cool.

MokMok · « **Reply #21 on:** October 10, 2011, 11:21:29 »

It is said that the MS Estonia didn't capsize due to bow door failure, but due to a leaking under water hull due to sailing too fast in rough seas.

More info:

http://heiwaco.tripod.com/e7.htm (http://heiwaco.tripod.com/e7.htm)

Stuart2007 · « **Reply #22 on:** October 10, 2011, 12:31:51 »

Ballast, that's an impressive sight. I guess that's only on super large ships- your average cruiser or ferry isn't going to encounter that- at least not to THAT extent???

MokMok, the author of that report is no doubt very technically able. However, he still lacks one credible thing- "motives"

Sorry: Motive was to hide the poor state of repair of the ship... by claiming it sank due to a faulty bow visor. Ah, that's OK then.

EDIT: His credentials seem pretty impressive. I'd be interested to hear what maritime professionals here have to say on this.

danny · « **Reply #23 on:** October 10, 2011, 13:14:24 »

Whatever way you look at it the estonia sank because she was going to fast. If the vessel had maintained a slow (5kts?) speed in those conditions the bow door shouldn't have "broke free".

Stuart2007 · « **Reply #24 on:** October 10, 2011, 19:55:52 »

Quote from: danny on October 10, 2011, 13:14:24

Whatever way you look at it the estonia sank because she was going to fast. If the vessel had maintained a slow (5kts?) speed in those conditions the bow door shouldn't have "broke free".

And your maritime qualifications and experiences are :-?

At5kts in such rough weather, I wonder what the effect on steering and stability would be. The point is with the Estonia that we don't really know what happened; whether the report linked by MokMok is any good or not, I don't know- but there certainly does seem to be some disagreement over the causes of the sinking.

Author Topic: pride of Rotterdam at 38kts? (Read 4514 times)