Torpedo Dimensions?

[SSWarlock]

Has anyone reverse-engineered the most likely dimensions of a single torpedo? I'm trying to lay out the deckplans for both small and large torpedo bays and have searched the Traveller forum but no joy.

 

[barnest2]

My best bet is about 7-7.5 metres long, with a diameter of somewhere between 1 and 1.5 metres...
So if you say 7.2x1.2x1.2 you would probably be about right...
(on deckplans, thats 5 squares by 1 )

 

[rust]

High Guard page 99 has a Torpedo Boat, its 2 torpedoes take 5 dtons of
space, and if you look at the deck plan you get the dimensions of a tor-
pedo, five hexes long and one hex wide.

Edit.:
Ah, of course "square", not "hex" - I was just working on a different game.

 

[SSWarlock]

Oh my. Then my calculations are way off. Or Mongoose's is (likely mine though). If you all don't mind, how did you arrive at a length of 7m for a diameter of 1.5m? Other than looking at Mongoose's deckplans, that is?

I tried using the formula for the volume of a cylinder (pi * r squared * h) and arrived at the following.

-- Assumptions --
1) Torpedo shape is roughly a cylinder.
2) Volume of 1 displacement ton = 14 cu. m.
3) Displacement of a single torpedo = 2.5 dtons, so
4) Volume of a single torpedeo = 2.5 * 14 or 35 cu.m.


Evaluating the formula (cylinder volume = pi * r squared * h) for h gives a formula (I think) of

h = cylinder volume / pi * r squared

Therefore,
Torp diameter = 1.5m
giving
Torp radius = 0.75m and radius squared = 0.5625m.

Plug in the numbers in the formula evaluated for h ends up with

Torp height (i.e. length) = 35 / pi * 0.5625 = 19.8m

19.8 meters long?!? Can't be but I haven't had to do this kind of maths for a few decades. So..where did I go wrong?

 

[SSWarlock]

Huh. Could it be that a torpedo is actually an ovoid-shaped cylinder (if that makes sense) in the same fashion as a Star Trek photon torpedo? If so, anyone know the formula for calculating the volume of such a critter?

"Dammit Jim! I was a business major, not an engineer!"

 

[barnest2]

I don't know. I just made an odd guess from the deckplans.
On a deckplan, a torpedo is 5 squares by 1.5.
A square is 1.5 by 1.5
5x1.5=7.5
so I reduced that slightly to add loading systems and cradles and stuff.
Gives me 7.4x1.2 or so
No fancy calcs, just a bit of good guessing

Now: vol=pi x r squared x h
is: h= vol/ pi x r squared
is: h= 35/ pi x 0.5625
is: h= 35/ 1.7671 (and lots more figures)
is: h= 19 metres....
hmmm... your math looks about right, I think your cubic volume is off...
lets see...volume should in fact be
7.5x1.5x3=33.75.... buggery...

I think my maths is bad too. I'm not sure how, but it is. Wait! half that volume, because a ton is 3 metres tall, while the torpedo is only 1.5 metres tall... so volume should be:
7.5x1.5x1.5=16.875
So:
H= 16.875/1.7671
H= 9 metres long.
Still a little off, but much closer.

Lets do it the other way:
volume= pi x 0.5625 x 7.5
volume = 13.253
There you go. Volume of a torpedo is it is 7.5 metres long and 1.5 metres in diameter.

Ouch... I have done too much maths today... and I'm a history student

 

[barnest2]

It could be, but I don't like it.
I just think the rest of the volume is filled up with mounting cradles, reloading systems, and shock absorbers so that the enormous missiles don't explode when the ship is hit

 

[SSWarlock]

I don't know. I just made an odd guess from the deckplans.
On a deckplan, a torpedo is 5 squares by 1.5.
A square is 1.5 by 1.5
5x1.5=7.5
so I reduced that slightly to add loading systems and cradles and stuff.
Gives me 7.4x1.2 or so
No fancy calcs, just a bit of good guessing

Ah ha! Shame on me for leaving out my fifth assumption (which I just realized existed). That is,

5) The 2.5 dton displacement is taken up by the entire torpedo.

And there's nothing anywhere that states this as fact.

*slaps self* Mea culpa, mea culpa.

7.2 x 1.2 x 1.2 with the rest of the 2.5 dtonnage being taken up by storing/trolley gear works for me.

Thank you both.

 

[barnest2]

No worries
I secretly love maths
just today I worked out the kinetic energy a 500 pound missile would have upon impact with the earth, going from 20,000 kilometres, along with its TNT equivalent and blast radius... the answer is not as big as I would have liked

 

[DFW]

I don't think it has to be slender at all. There no streamlining issues to deal with. Logically it would spherical or egg shaped as that gives the smallest surface area to volume.

 

[rust]

Logically it would spherical or egg shaped as that gives the smallest surface area to volume.

Think of the logistics, tubes require less space in storage than spheres or
eggs. :wink:

 

[barnest2]

I don't think it has to be slender at all. There no streamlining issues to deal with. Logically it would spherical or egg shaped as that gives the smallest surface area to volume.

Doesn't have to be, no. But that's easiest for a) deckplans, and b) describing to players (i.e. "it look's like a really big naval torpedo")

 

[SSWarlock]

I don't think it has to be slender at all. There no streamlining issues to deal with. Logically it would spherical or egg shaped as that gives the smallest surface area to volume.

True. But as barnest2 and rust pointed out, published deckplans help define the volume a torp takes up. And I'd completely forgotten that some equipment is necessary to store and move the ordinance to the launcher.

 

[barnest2]

True. But as barnest2 and rust pointed out, published deckplans help define the volume a torp takes up. And I'd completely forgotten that some equipment is necessary to store and move the ordinance to the launcher.

Indeed. Or at least some space for the indentured lackey's to grab hold and lift as they work in teams to move these rather ridiculously enormous weapons into firing position.

(wow... sounds 40k-ish, if a little small)

 

[DFW]

I don't think it has to be slender at all. There no streamlining issues to deal with. Logically it would spherical or egg shaped as that gives the smallest surface area to volume.

True. But as barnest2 and rust pointed out, published deckplans help define the volume a torp takes up. And I'd completely forgotten that some equipment is necessary to store and move the ordinance to the launcher.

Yes, it probably masses 75% of the listed value.

 

[SSWarlock]

And the best thing of all about having a tubular/cylindrical torpedo measuring 7.2 x 1.2 x 1.2?

It'll fit through one of the Ancients ship-board portals from SotA. Anyone for a ordinance magazine the size of a planet?

Munchkins, unite! :lol:

Of course, if the portal ever takes a hit.... :shock:

 

[barnest2]

Seeing as we just had a discussion in the PBP about where to fit more torpedoes for an extended tour aboard an 8000 ton ship... I wants one for the Swiftsure dammit!

(p.s., we finally shoved some in the troop sections of the ships many boarding craft... the marines are not happy)

 

[rust]

To give unhappy marines a lot of torpedoes to play with is rather ... ah ...
brave. :shock:

 

[barnest2]

I can only assume, as the GM and technically also the captain, that the gunnery officer has declared those craft with torpedoes aboard off-limits until they can be unloaded into the magazines (i.e. until some are used up)... at least I hope he has... This could lead to some amusement as the marines play ride the bomb... or decide to trigger a couple whilst 'larking about'... anyway, what's the worst that could happen?

 

[SSWarlock]

Heh. The trick to using those portals to save space on a ship is to grab as many of the portals as possible from the Ancients ship but actually use as few portals as possible while armoring the area they're in as much as can be afforded.

And have a small amount of backup on board for whatever is stored in said portals.

Actually, they don't save that much space because they're such an Achilles' Heel.