Maori DE-1913

[Korpen]

You got no weight for the electric engine itself, just the generators. I suspect the engine itself will be quite heavy.
A 1925 electric locomotive weight in at 80 tons, and that one have an 1840kW engine. It seems reasonable to assume that maybe ¼ of the weight of the locomotive is the engine itself (wild guess, but seems reasonable), that would put the electric motors for the close to 11 000kW you want in the destroyer close to a hefty 120 tons. :(
I think that is the reason F1 cars do not have electric engines.

How do you think it would look to mount the engines along the booms to the outriggers, and have one propeller each, like a huge rack of outboard engines?

[Valles]

Hm. Well, one advantage to my using lightweight steam engines rather than IC is that they're more scalable at this point in history... but it seems kinda unsporting to play up that aspect when I'm already doing so much utterly weird shit.

Ah, well. Cross-linked direct drive systems do exist (a la V-22 Osprey), and I'd always intended that the airships used direct drive shafts from a single centrally mounted engine...

[Sachmle]

Machinery:
   No fuel, Internal combustion motors,
   Electric motors, 2 shafts, 13,780 shp / 10,280 Kw = 30.00 kts
   Range 5,000nm at 10.00 kts
   Bunker at max displacement = 91 tons

So what, they run on trash or something? Where did you put the flux capacitor?  :D

[Valles]

That would qualify as my not correcting a weird artifact of SS. ^_^ The fuel is something about like kerosene or jet fuel - a dense, hot-burning petroleum derivative more filtered and refined than conventional steam-plant fuel oil.

[P3D]

Have you calculated the wave resistance of the two outriggers? :P

[Sachmle]

That would qualify as my not correcting a weird artifact of SS. ^_^ The fuel is something about like kerosene or jet fuel - a dense, hot-burning petroleum derivative more filtered and refined than conventional steam-plant fuel oil.

Like "super-diesel"? How did you sim fuel weight in the SS Report?

Distribution of weights at normal displacement:
   Armament: 13 tons, 4.0 %
   Armour: 3 tons, 0.9 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 3 tons, 0.9 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 0 tons, 0.0 %
   Hull, fittings & equipment: 156 tons, 46.9 %
   Fuel, ammunition & stores: 66 tons, 19.8 %
   Miscellaneous weights: 95 tons, 28.5 %

No Machinery weight? And that 66t for "Fuel, ammunition & stores" is ammunition & stores in this case.

[Carthaginian]

And that 66t for "Fuel, ammunition & stores" is ammunition & stores in this case.

But SS states that "Bunker at max displacement = 91 tons".
Seems that some fuel is included.

[Sachmle]

Now that's just weird.

[Valles]

Very weird...

Hm. Lemme try it with SS3.

Ooh. New version has 'relative weight performance' slider for engines. Doesn't work yet, though, pity. 'Calculate speed for power', ditto and ditto.

Ah, well, that's no good. This version doesn't work even as well as the last.

Anyway. Things like this and hydrofoils are on my list of 'to be developed later' items.

As to 'outrigger drag', no, I've not done anything with that. Would be a lot of very thorny math, there, and, while I'm willing to go to the trouble if I'd actually be allowed to build the nightmare things, I don't actually know how.

[P3D]

The simplest, somewhat crude way is to simulate the outriggers as separate ships - length, beam, draught, BC speed would give you a power requirement that you need. Only first approximation, of course.

But then, then the same outriggers would influence stability too much, and comes the question that what size of outriggers you need for a given ship.


...
Selecting no fuel apparently makes SS2 think the engine is missing.

[Valles]

That was the idea, since SS's engines are all an order of magnitude or so heavier than what I had available to install on the ship.

[The Rock Doctor]

So I guess we need to resolve four broad questions:

-How do we accurately simulate an outrigger with SS?

-Is an outrigger of this size and speed technologically possible in our time period?

-How do we accurately simulate the machinery set-up?

-Is the machinery set-up feasible and technologically possible?

[P3D]

So I guess we need to resolve four broad questions:

-How do we accurately simulate an outrigger with SS?

-Is an outrigger of this size and speed technologically possible in our time period?

-How do we accurately simulate the machinery set-up?

-Is the machinery set-up feasible and technologically possible?

- Outrigger cannot be simulated by SS only. Extra SHP need yes, stability/steadiness no.
- Without any naval engineering background I cannot tell how large outriggers have to be  to be effective. It should be mention, that the additional resistance of two outriggers would make a trimaran slower than a monohull of the same displacement. The usual problems of SS2 and small fast hulls is still there.
- machinery set-up cannot be simulated by SS2.
- without electric motors, yes. Of course you need adequate engine technology.

[Sachmle]

Would you really WANT one? What happens to performance when one of the outriggers is damaged by shellfire/torpedo/mine? Will the ship still be stable enough to be useful? How much damage could an outrigger sustain?

[Valles]

I don't think that convincing Springsharp to do something with more than the vaguest resemblance to the proposed layout and performance is possible without cutting and pasting together two or three different sims... which was what I did. I suspect that a multihull that suffered a sudden increase in drag on one of its outriggers (as for a hit below the waterline) or a sudden loss of structural strength (ditto for a bracing arm) at speed would rip itself apart quite messily. On the other hand, they are immensely stable for their weight and they're mostly empty space, so the odds of that happening aren't actually all that bad.

My choosing a trimaran layout for this design had much more to do with the fact that SS2 puts all misc weight above the waterline than with my interest in having a multihull. I tripled the beam to account for the outrigger's positioning, grabbed the stability figures, and then dropped them into the original sim.

If I were to try and create something like this that I was serious about building, it'd probably be a relatively wide single-hull - a true planing design rather than a displacement hull.

But that would open its own can of worms, of course.