Ship-Flipping for Evil Bricks

[Shaft]

According to the Ultimate Brick, you'd need a 110 STR to lift a cruise ship.

If you wanted to flip it to get a Poseidon adventure style result on the ship, how much STR would you need?

Note that the ship doesn't have to come out of the water- it just has to be rotated enough to be upside down.

I am assuming that the Brick can fly on his own and use his flight to brace himself.

[Beast]

probably 110 str
you should know that you will have to hold it there till enough water floods in to counter the ballast at the bottom of the ship that you are forcing out of the water

[Lord Liaden]

Well, since maximum "lifting" as defined by the game is just getting the object off the ground and staggering a few steps with it, I'd say that double the listed STR (in this case, going from 110 to 115) would be enough to flip it. Keep in mind the optional rule that one can add (#of Inches in Flight/2) of STR for lifting purposes.

[Shaft]

probably 110 str
you should know that you will have to hold it there till enough water floods in to counter the ballast at the bottom of the ship that you are forcing out of the water

Hmm, I guess it's effectively throwing an object that weighs *110 STR* and throwing it 0".

[Vulcan]

But most (if not all) large ships are not 'self righting' beyond a certain angle of list. Liners, which are often very tall in comparison to their draft, are (granted, only slightly) vulnerable to capsizing because of this.

Once you lean a liner over far enough that the majority of it's structure is outboard of the ballast tanks, it will tip over and not recover. It's just hard to do without a lot of force.

Unless someone passed regulations about liners needing to be 'self righting' that I didn't hear about...

[Sean Waters]

Go find something heavy you can't quite lift. Then flip it over. You probably can (unless it is bolted down). You need less STR to flip than lift.

You will definitely need less strength to flip a ship than to lift it over your head, but how much will depend on a lot of things. Imagine, for example, you put a blue whale on the side rail of the boat - would that tip it over? Maybe, I've no real idea. That only requires 60 strength (I know putting a blue whale ON the boat won't sink it, but we are looking at rotational forces here).

Ultimately the answer is probably somewhere between 105 STR (half the lift of 110) and, at the lower end, perhaps 60 STR, if you think the whale might do the trick. I'd certainly think if you plonked a loaded freighter on the side rail the thing would go over and that only requires 85 STR.

[Steve Long]

I'm no physicist, but I think any of us who've been aboard a small boat (like a rowboat) have observed that it's easy to move the boat with ordinary muscle power even if we couldn't ordinarily lift it, since water provides relatively little resistance.

Thus, assuming the ship you describe is in the water, *and* that the character has something to brace against, I'd think that flipping the ship would require significantly less STR than lifting it. Actually holding it upside down in the water, against the forces that want to right it, might take more than that.

But undoubtedly someone who knows more about physics will point out a flaw in these conclusions. ;)

[Maur]

As already pointed out, once a ship is flipped it really doesn't take anything to hold it that way. Flip your rowboat or canoe over and they stay upside down until you try and right it again. With larger vessels you have the same problem (as already pointed out upstream in this thread). Just getting it unbalanced is enough to send it over the rest of the way on its own. The question is, what is the brick braced against to utilize all that strength. You could be the strongest thing in the universe, but try and lift a whale while swimming and you'll find that all you'll accomplish is to push yourself further under as you are outmassed by the whale. Same with flipping the boat.

[CTaylor]

I'd argue that first, flipping a ship entirely over would take at least the strength to lift the ship, because they're designed to stay upright and stay in the water. In essence, they're gripping the water with their strength and trying not to turn over. Second, you have to displace an amount of water that the ship has in size to get it to turn over: it is already displacing the water that it is under already, you just have to get all the rest of that water out of the way. So it will either take a long time or a gigantic amount of strength to turn that thing over.

You can push them forward with very little effort, because they're designed to move forward and the water offers very little resistance. Ships are built so they have the smallest profile possible facing the water which keeps the displacement at a minimum and tends to move the water around the front end rather than pushing it away.

[Hyper-Man]

...The question is, what is the brick braced against to utilize all that strength. You could be the strongest thing in the universe, but try and lift a whale while swimming and you'll find that all you'll accomplish is to push yourself further under as you are outmassed by the whale. Same with flipping the boat.

As long as the character in question has some form of appropriate movement (swimming, flight, flight usable underwater) he is allowed to use his FULL strength for lifting purposes.

A brick with 60 STR and 4" of Flight can carry 100 tonnes while flying straight up @ 1" per phase. The amount of Flight only determines how fast he can move.

[Hyper-Man]

I'm no physicist, but I think any of us who've been aboard a small boat (like a rowboat) have observed that it's easy to move the boat with ordinary muscle power even if we couldn't ordinarily lift it, since water provides relatively little resistance.

Thus, assuming the ship you describe is in the water, *and* that the character has something to brace against, I'd think that flipping the ship would require significantly less STR than lifting it. Actually holding it upside down in the water, against the forces that want to right it, might take more than that.

But undoubtedly someone who knows more about physics will point out a flaw in these conclusions. ;)

I'm no physicist either but flipping over a boat seems a lot like trying to roll a weeble-wobble end over end. The center of mass (which I'm guessing is a significant portion of the total mass) is extremely off center in both cases and is essentially what we are talking about moving.

Determine the STR needed to shift the center of mass and you should have the answer.

[Sean Waters]

Speaking as a physicist (which, obviously, I'm not, but I'm pretty good at accents) this is a leverage problem, isn't it?

Centre of mass, how far away you are from it, how much you have to tip the ship to start flooding the upper decks and therefore change the centre of mass. God bless wikipedia:

http://en.wikipedia.org/wiki/Metacentric_height

However, speaking as a gamer (which I am despite the physicist accent), I'd say if it took 110 STR to lift the ship out of the water, it takes only 1/64th of that to roll it, or 30 less STR thatn 110 = 80*.

I have no idea if that is right, but it sounds like it might do in a pinch and there's a good chance of getting the game finished tonight.





*Or, if the villain I want flipping the ship has 65 STR, that will do. He was lucky. There was a big wave. And a blue whale desperate to take a cruise.

[Maur]

As long as the character in question has some form of appropriate movement (swimming, flight, flight usable underwater) he is allowed to use his FULL strength for lifting purposes.

A brick with 60 STR and 4" of Flight can carry 100 tonnes while flying straight up @ 1" per phase. The amount of Flight only determines how fast he can move.

That may be so, but the default swimming that all characters are given isn't enough... or if it is, then something is broken here...

[Vulcan]

As already pointed out, once a ship is flipped it really doesn't take anything to hold it that way. Flip your rowboat or canoe over and they stay upside down until you try and right it again. With larger vessels you have the same problem (as already pointed out upstream in this thread). Just getting it unbalanced is enough to send it over the rest of the way on its own. The question is, what is the brick braced against to utilize all that strength. You could be the strongest thing in the universe, but try and lift a whale while swimming and you'll find that all you'll accomplish is to push yourself further under as you are outmassed by the whale. Same with flipping the boat.

That's why the initial post stated "I am assuming that the Brick can fly on his own and use his flight to brace himself. "

[Vulcan]

Speaking as a physicist (which, obviously, I'm not, but I'm pretty good at accents) this is a leverage problem, isn't it?

Centre of mass, how far away you are from it, how much you have to tip the ship to start flooding the upper decks and therefore change the centre of mass. God bless wikipedia:

http://en.wikipedia.org/wiki/Metacentric_height

However, speaking as a gamer (which I am despite the physicist accent), I'd say if it took 110 STR to lift the ship out of the water, it takes only 1/64th of that to roll it, or 30 less STR thatn 110 = 80*.

I have no idea if that is right, but it sounds like it might do in a pinch and there's a good chance of getting the game finished tonight.

*Or, if the villain I want flipping the ship has 65 STR, that will do. He was lucky. There was a big wave. And a blue whale desperate to take a cruise.

It all sounds reasonable to me.

[Hyper-Man]

That may be so, but the default swimming that all characters are given isn't enough... or if it is, then something is broken here...

Moving and lifting are not connected to one another by the rules.

Take DCU's Flash or Marvel's Northstar (a running and flying speedster respectively). They both have incredible movement ability but relatively human lifting ability. Within HERO rules, Northstar could certainly use some of his excess flight to enhance his lifting ability. However, reducing his STR has no direct effect on his movement. And reducing his Flight has no direct effect on his STR and what he can do with it.

Let's take a couple of more relevant examples:
Aquaman & Namor

Both can swim fast (as fast as ANY sea creature - Namor can also fly) and are super strong (at least STR 60+ in HERO). They should have no problem applying their full STR in or under water since it is essentially their native environement.

Let's compare them to some other non-flying 'bricks' like Hulk or Thing.
I'm not even sure if Thing can swim or not if he can it's probably not much faster than a normal human (I would use the same scaling as his running which is not super-human). I'm pretty sure that Hulk can swim pretty fast and should be able to apply his STR. He just might not be as familiar with the water environment. I think HERO deals with this via Life Support (like zero G movement). Namor and Aquaman have this for water. Most other characters probably don't.

[Sean Waters]

That may be so, but the default swimming that all characters are given isn't enough... or if it is, then something is broken here...

Which is a very nice point.

Perhaps 6th ought to introduce the idea that movement is only moving yourself and additional weight slows you or renders the power effectively inoperable. You can then buy a 5 or 10 point adder to have your movement power apply at casual or full STR.

The rules should be consistent and this is a clear inconsistency.

IMO

[Maur]

Moving and lifting are not connected to one another by the rules.

Didn't think they should be directly. But they do have an effect on each other. Just because you're a fast swimmer with 60 STR doesn't mean that you should be able to lift up out of the water a mass greater than you per se as the water is a deformable material and will just give under the stress of you trying. Doesn't mean you can't throw that 12d6 punch...

[Alibear]

speaking as a physicist (which, obviously, i'm not, but i'm pretty good at accents)

:d

[BNakagawa]

The proper answer to the OP question is:

about 20 STR more than BIGBADGUY can muster.

That's why he has to go steal a embiggening machine from the absentminded professor at the PC's alma mater to buff himself to be able to tip over the ship, giving the PCs an opportunity to ruin his plans.

[Vulcan]

Why do people assume that to flip a ship over, you must push up from underneath? Two other types of forces flip ships in real life.

First, lateral forces applied to the top of the ship push the top sideways. Once the center of gravity moves beyond the ability of the ship to right itself, it will flip itself over.

Second, forces pushing down can flip a ship as well. That's why cargo ships are carefully balanced when they are loaded. If the weight (which is a measure of the force of gravity pulling down) of the cargo is all on one side, the ship is going to tilt to that side. In an extreme case, this can flip a ship all by itself.

In practice, both these forces usually work together to flip real ships. Uneven lifting from below will (usually) only flip small boats that run up onto an obstacle. Large ships tend to crush obstacles long before they are flipped over.

The 'bracing' issue is more problematic from a realism standpoint, but then again we're talking about super-powered beings. The very idea that a human-sized being could lift hundreds - or thousands - of tons in the first place is just as unlikely. So let the villian use his flight or swimming to do it, if it results in a more interesting story.

[Shaft]

Vulcan: I already repped you for one post on this thread alone, but I owe you rep for at least two other points that you've made. You've made a lot of good observations that I hadn't even considered. The next time I want to flip a cruise liner, I want you as my wingman! :D

(Thanks to Shawn Waters too for his math).

[prestidigitator]

It really depends completely on the characteristics of the ship. Let's assume for the moment that:


The cross-section of the ship if you chop it in half length-wise (so the two halves are front and back) is a perfect circle, and that the deck of the ship, which cuts the circle in half, sits at water level.
The load is distributed perfectly from left to right, so the center of gravity is in the middle.
Nothing will shift on the ship when it is tipped.
For some reason we have to tip the ship a whole 90 degrees to capsize it.
To maximize torque, we apply the force(s) to the very outside edge of the ship.


In this case, it becomes a pure sum of torques (since we can assume the buoyant force always effectively acts at the center of the ship, there is nothing other than weight couteracting the roll, etc.), and what is going to matter is the vertical position of the ship's center of gravity. If the center of gravity were above the water line, any tiny tip of the ship would actually cause the whole thing to capsize on its own. That's a pointless case we can discard. If the center of gravity were right at water level, it would take zero force to tip it. If the center of gravity were somehow at the VERY bottom of the ship, the maximum force needed (just before the ship is capsized at a 90 degree rotation), would equal the ship's weight. Obviously the case is actually going to be somewhere in between in our simple example.

It actually comes down to: F=W*(h/r) where W is the ship's weight, h is the distance below the center of the circle where the ship's center of gravity is, and r is the radius at which the lifter exerts the force to tip the ship.

However, re-examining the assumptions above:

Shape - The shape of the ship is obviously going to play a pretty big role in the problem, especially since the ship's cross-section is not going to be a perfect circle and at some point water is going to leak over the edge of the boat and add weight tending to help roll it a bit.
Load Balance - Probably a decent assumption, actually. Even if it weren't, any imbalance would help the lifter since we can assume (s)he would pick the more advantageous side from which to do the lifting.
Shifting of Load - Hey, for all I know they lash things down pretty well, but if anything shifted it would help, since the tendency would be for the shifting weight to shift to the downward side of the ship and help roll it. Unless there's some very strange and imaginative design actively doing the opposite, or a bunch of heavy passengers running over to the high side of the ship.
Angle - I doubt most ships would have to be tipped a whole 90 degrees to accomplish this goal. The maximum torque--and thus force at the edge--that will be required would be multiplied by the sine of the angle needed to capsize the ship. Thus if you only needed to tip it 10 degrees, you'd only need sin(10 deg)=17% of the force.
Position of Force - It is probably safe to assume the lifter starts at the very edge of the ship. Actually if the lifter had some kind of huge boom sticking way out (increasing r above) it would help a lot, provided the boom isn't very heavy compared to all the other forces involved. BUT if the lifter FOLLOWS the ship's roll, (s)he's actually going to start exerting some horizontal force that will cause the ship to start slipping sideways rather than rolling (eh, let's ignore that possibility, right?).


With the starting assumptions except a required angle of only 30 degrees, and with the ship's C.G. half-way between the water line and the edge of the circle, the lifting force would only have to be a quarter the weight of the ship. So Str 100 I guess. For each halving of the distance between the C.G. and the waterline, we could halve the force again (subtract another 5 Str). If the lifter could stick a boom out to twice the [EDIT: RADIUS, not width] of the ship, take off another 5 Str. Something like that anyway. ;)

Yes, it is true that a downward force would be equivalent to an upward one in this problem. A sideways one up on a mast or something would work too, but note the bit I mentioned above about the ship starting to slip sideways. I think the assumption is upward because it is stated that the character can fly, not swim. Heh.

Actually, what would require very little force is to set up an oscillating motion that, if driven at the proper frequency, would tip the ship eventually. That force would I believe just have to be significantly larger than whatever waves and such might also tend to rock the ship around. I believe Nikola Tesla could bring down a whole building with a small mass driven by a wind-up motor, or something like that. :)

[Outsider]

Didn't think they should be directly. But they do have an effect on each other. Just because you're a fast swimmer with 60 STR doesn't mean that you should be able to lift up out of the water a mass greater than you per se as the water is a deformable material and will just give under the stress of you trying. Doesn't mean you can't throw that 12d6 punch...

If we're talking about things deforming under stress, then the whole excercise of a super strong person grabbing a large ship, even with both hands, and flipping it is moot. Whatever small part of the ship that 110 STR was applied to would just deform under the pressure, leaving Mr/Ms Superstrong with a couple hands full of hull plating, and the ship with a couple hand sized holes.

[Vulcan]

Superhero genere, not superrealistic genre.

We're talking about a normal-sized guy who can lift thousands of tons, for christ's sake!

[Outsider]

Exactly. So worrying too much about physics at all is pretty silly. If you want it to take less than the STR required to lift the object, just make a ruling.

[prestidigitator]

Exactly. So worrying too much about physics at all is pretty silly. If you want it to take less than the STR required to lift the object, just make a ruling.

True. You could always just consider what your strongest PC is and make a dramatic ruling based on whether (s)he should be able to do it, or how (s)he should compare to this villain, or what kind of challenge the villain should present to the party, or whatever. And since the amount of force required, as I showed above, COULD vary anywhere from zero to the full weight of the ship, you can then arrange the physics to match the drama ("the freighter is top-heavy from its loading and enough weight shifted....") if you really get an argumentative player or something. :cool:

[prestidigitator]

Oh. There is one more thing very notable about shape. Say that our ship has a rectangular cross-section. In that case, as soon as the ship starts to tip from a LIFTING force, most likely it is going to tip up on the corner farthest from the lifter (sort of like it was sitting on hard ground), in which case the buoyant force shifts toward that corner (if it's the only place the water touches...) and torques have to be added up around that point instead of the center of the ship. In that case it's probably not going to matter much whether the C.G. is at water level or not; instead the lifting force will simply have to be about half the weight of the ship (assuming again that the ship is evenly loaded from left to right and the lifter pulls at one extreme edge).

So shape IS going to matter quite a bit. Flat-bottomed would PROBABLY tend to resist this kind of attack a bit better, though rounded ones could possibly be constructed deep enough to compete (like if the ship is deeper than a half-circle and capitalizes on it by REALLY loading toward the bottom and dropping that center of gravity).

[shadowcat1313]

what about coming from below and flipping it instead from above or the side?
or some kind of focused punch or large explosion?

thought being a sufficiently large underwater explosion or punch etc could snap the keel in effect and send it to the bottom instead, this idea comes from how some real torpedoes are supposed to work.

[Comic]

Ship engineering is an ancient art.

Ships have to use their engineered design cope with the STR of the ocean, which applies to every square minum of their hulls. In the case of a cruise ship, this STR is at least the 110 STR it takes to hold up the ship. One might even call this the ocean's casual STR.

And if the ocean is in a bad mood -- which I hear oceans can do -- it may PUSH.

And how often do you hear of a cruise ship being flipped by the ocean, really? So I'd rate the ship's STR applied against flipping by virtue of its engineering at 135 (110 + 10 for PUSH by ocean +15 to reduce the odds of flipping from even to under 3%) .

On the flip side //yes, I said it//, if the Brick (who may not be the ocean) has the Hoist or the Brick Tricks Power skill, or both, then he may counter the engineers' and ships pilots skill rolls and reduce the STR he needs to defeat the ship's design.

So, I'd say if we're being purely simulationist, having a minimum STR of 105 (half the STR needed to lift the vessel) and making a STR Roll against a difficulty of 9+135/5=36.

But if we're trying to build a balanced campaign with a ship-flipping Brick, I'd hope the Brick's pure STR doesn't exceed campaign guidelines (60? 75? 90? etc.) and the remainder of the STR comes from a McGuffin of suitable nature to allow heroic intervention.

[ghost-angel]

Having practice capsizing sail craft, I can say with a decent amount of authority that you can capsize a boat with far less strength than is needed to hoist in in the air - since I can't even begin to lift a 20ft sailboat.

And yes - I capsized two boats on purpose, both as part of exercises on how to Right said sailboats in case they ever capsize without you helping them.

That said, capsizing a sailboat and capsizing an ocean liner are probably wholly different animals. But I would imagine the technique might be the same. In the case of a sail boat somewhere around the time the mast is below a 45 degree angle off the water (and I will note I've gotten an near 90 degree heel, so sail boats don't go over easily - at least while moving) a couple guys jump onto the mast to provide just that last bit of weight to capsize it wholly.

The trick is to get momentum on your side. Rock the boat hard and fast enough and eventually you can use both STR and Momentum in your favor to roll it over deck side down.

Doing it in one go - probably not anywhere as so be so easy, but as a general rule of thumb since we're already in fantasy land, no more than the maximum amount of STR needed to lift it would be needed to Capsize it. Just grab onto one side and keep pushing. . .

[SteveZilla]

Ship engineering is an ancient art.

Ships have to use their engineered design cope with the STR of the ocean, which applies to every square minum of their hulls. In the case of a cruise ship, this STR is at least the 110 STR it takes to hold up the ship. One might even call this the ocean's casual STR.

And if the ocean is in a bad mood -- which I hear oceans can do -- it may PUSH.

Not to mention Haymaker with a Rogue Wave. :ugly:

[Sean Waters]

Ship engineering is an ancient art.

Ships have to use their engineered design cope with the STR of the ocean, which applies to every square minum of their hulls. In the case of a cruise ship, this STR is at least the 110 STR it takes to hold up the ship. One might even call this the ocean's casual STR.

And if the ocean is in a bad mood -- which I hear oceans can do -- it may PUSH.

And how often do you hear of a cruise ship being flipped by the ocean, really? So I'd rate the ship's STR applied against flipping by virtue of its engineering at 135 (110 + 10 for PUSH by ocean +15 to reduce the odds of flipping from even to under 3%) .

On the flip side //yes, I said it//, if the Brick (who may not be the ocean) has the Hoist or the Brick Tricks Power skill, or both, then he may counter the engineers' and ships pilots skill rolls and reduce the STR he needs to defeat the ship's design.

So, I'd say if we're being purely simulationist, having a minimum STR of 105 (half the STR needed to lift the vessel) and making a STR Roll against a difficulty of 9+135/5=36.

But if we're trying to build a balanced campaign with a ship-flipping Brick, I'd hope the Brick's pure STR doesn't exceed campaign guidelines (60? 75? 90? etc.) and the remainder of the STR comes from a McGuffin of suitable nature to allow heroic intervention.

With a STR of 110 and even 1" of flight you could pick the thing up out of the water and drop it back in however you like, so I can't accept you need more than the STR to lift to flip.

However, what you said about the strength of the ocean and what ghost-angel said about requiring rocking got me thinking. Perhaps, with an appropriate DEX roll you can time your pushes on the side of the boat with the ocean swell and with any previous rocking motion you might have induced. If you can move it at all, let it go and wait for it to return almost tot he point you let it go then it is further out of balance each time. You might decide, for instance, that someone with, say, 60 STR can move the boat two hexes before the mass is too hard to move, but when he lets go it rocks and somes out 1 hex before returning again. With a DEX roll he can push again when it is already rocked 1 hex out of kilter, and so on, using the principle every child uses on a swing. Subject to having enough strength to rock the thing at all, it is then just a matter of time.

Of course, by the itme you got it over all the passengers would have been flung overboard or squashed flat in their cabins :)

[prestidigitator]

However, what you said about the strength of the ocean and what ghost-angel said about requiring rocking got me thinking. Perhaps, with an appropriate DEX roll you can time your pushes on the side of the boat with the ocean swell and with any previous rocking motion you might have induced. If you can move it at all, let it go and wait for it to return almost tot he point you let it go then it is further out of balance each time.

That's actually just the natural (resonant) oscillation I mentioned a ways up.

[Maur]

That's actually just the natural (resonant) oscillation I mentioned a ways up.

Yep. Same way one can shatter a glass with sound. Find the resonant frequency of the material and just pour on the dB.

[Comic]

Sure, lifting the thing out of the water (assuming it didn't break under the stress), and turning it upside down, or rocking it repeatedly could flip a ship.

Heck, I could flip a ship with the strength it takes to unscrew the lid on a bottle of Jack Daniels and hand it to the skipper, if I pick the right crew at night close enough to a rocky coastline.

But flipping a cruise ship in the water -- where the resistance of the water is an issue -- as a half phase action by strength? That's the hard way, and I stand by my estimate for the difficulty of doing it that way.

Taking more time or using other methods of course wouldn't require anything like that level of STR.

[Utech]

Rather than hunting for a particular STR value required to flip the ship, you might want to go with a STR Roll. The roll can be modified by appropriate Skills, time, good roleplaying, weather, etc. as well as the difficulty for flipping a cruise ship . . . call it -10?

[SteveZilla]

That's actually just the natural (resonant) oscillation I mentioned a ways up.

It strikes me that for large ships that sit deep in the water with an flattened bottom (see picture (http://www.dkimages.com/discover/Home/Technology/Transportation/Ships-and-Boats/Commercial-Vessels/Ocean-Liners/Canberra/Canberra-2.html)), any rocking motion is dampened by the water itself. The larget the ship's bottom, the more water it has to push out of the way as it rights itself, causing the motion to be dampened.

Or is this line of thinking all wet? ;)

[Sean Waters]

I think your sig might have the answer: we don't need to worry too much aboutt he right answer, we just need an answer that is going to keep everyone round the table reasonably satisfied (good job WE'RE not round the table :)) Reality and game reality need not intersect so long as the bubble of disbelief suspension remains unburst.

That's an interesting point. I wonder how big the bubble has to be to suspend your disbelief, and, indeed, what strength you would need to flip it...

[lemming]

Sean has a very good point. What's the fun value? And hopefully at the table, there's agreement.

And different ships have very different values for flipping. I think cruise ships would be more difficult because IIRC, they're designed to not rock very much.