T5 Book 2 Big Ships

[robject]

Doable -- "legally" to around 190,000 tons, realistically around 100,000 tons, but theoretically to any tonnage.
And there's at least two ways to do it:

(1) Calculate things. There are formula. Some are easier than others. A spreadsheet can help (a lot).
Using formula lets you calculate any hull size and any drive requirements.

(2) Scale. It is possible to scale without a lot of inefficiency.
This limits you to maybe 100,000 tons or so.


Kiloton Freighters

The easiest big ships are things like the Tukera AT and the Mora World-class transports: they're only 3,000 tons.

The trick is to leverage hull and drive multiples. Keep them all in sync and scaling becomes easy.

I'll build the 3,000 ton J4 M1 freighter frame using the 1000 ton hull (K).
J4 M1 P4 on the K hull are drives V and E, and V respectively.

Now scale all four up.

• Hull = 3K

This is the way I write the 3,000 ton hull. I think it's convenient.

• Jump = 3V
• Maneuver = 3E
• Power = 3V

 

[AnotherDilbert]

I have three methods to build large ships, and you just introduced a fourth...

a) Subhulls & EP calculation, it's even RAW.
b) Extend the drive and hull tables. Since they are based on simple formulae, it's simple.
c) Use custom drives of just the right size, based on the drive formula.

Example: A jump drive is size 5 + 5 × letter, or 5 + 5 × EP / 100 = 5 + EP / 20.

So if you need a jump drive with 120 EP, it would be 5 + 120 / 20 = 11 Dt.

 

[Magnus von Thornwood]

For the Shackleton I just mashed two 2500-ton hulls together and doubled up on the drives and such. So, it looks like I tend to use Rob’s method.

 

[AnotherDilbert]

Technically, T5 ACS only goes up to 2400 Dt hulls, so presumably you used a scaled by formulae method, then added two hulls together?

 

[Condottiere]

Catamaran, trimaran.

 

[robject]

Catamaran designs have been completely, unfairly ignored!

Ok there are reasons.

But still, they're totally doable, and I can see an aftermarket effect of welding a couple of old hulks together to build a larger ship.

Heck, weld a gas tank onto a ship's boat and you could get a jump-capable craft.

 

[mike wightman]

Not without also rigging the hull with the jump cables or plates needed to maintain the normal space field in jump space. And installing a larger bridge/control panels...

 

[agorski]

Sounds like a "Flight of the Phoenix" scenario where your ship is dead in a Sargasso Sea area of other abandoned hulks.

 

[Condottiere]

Tee Five has jump bubble option.

 

[robject]

Tee Five has jump bubble option.

And you technically don't need a bridge. It would make for a challenging ship though. Flight of the Phoenix indeed.

 

[Condottiere]

Computationally, the ship's computer could run the whole show.

 

[mike wightman]

You still need cables or plates to maintain the jump field - regardless of whether it is a bubble or conformal. Non-starships lack the cabling, hull grid or plates.

 

[Condottiere]

Not that I recall, which I think was the point of the bubble.

 

[mike wightman]

No, you still need hull cabling or plates to maintain the bubble. Here is what a certain MWM has to say in his jumpspace article.

Starship hulls contain as an integral part of their structure a network of wiring which maintains the jump field around the ship...

Breaks in the protective network within a starship hull are a primary cause of the loss of ships in jump...

The need for this network in a ship hull also indicates what happens to matter ejected from a ship while in jump.

 

[Condottiere]

A Jump Bubble creates a spherical field around the ship and centered on the jump drive. Jump Bubble is the standard for generating a Jump Field; it does not interfere with armor and produces a standard jump flash.

Jump Bubble allows a ship to vary its effective tonnage from mission to mission (which makes Drop Tanks and Variable Jump Container Ships possible).


I tend to interpret this as foregoing the excessive wiring and cabling.

 

[mike wightman]

So you are saying that MWM is contradicting himself?

The jumpspace article is common to JTAS 24 and MgT JTAS1.2

The jump bubble and the conformal field both require a network of cabling in the hull to maintain the jump field. There is no contradiction, just a lack of clarity in T5.

 

[Condottiere]

I find that I write contradictory posts.

A closely-conforming Jump Grid channels jump energy through a mesh of conduits and cables embedded in the hull. Jump Grid allows a reduced safe jump distance, making it possible for a ship to jump closer to a gravity source. On the other hand, the Jump Grid reduces the strength of armor and increases telltale jump flash.

Difficulties. Damaged Jump Grids are difficult to repair. (Jump Plates are bolted on to repair gaps in grid coverage, which converts it to Jump Plates).

 

[AnotherDilbert]

The jump bubble and the conformal field both require a network of cabling in the hull to maintain the jump field. There is no contradiction, just a lack of clarity in T5.

No lack of clarity: T5 requires the main hull to have a jump drive if jump bubble, or all hulls to have jump wiring if jump grid.

You are only considering the jump grid case.

T5 B2, p113:
Jump Bubble
Without any additional mechanisms, the Jump Drive creates a quasi-spherical (often an egg-shaped oblate spheroid) bubble.
...
Jump Grid
A Hull equipped with Jump Grid has a mesh of jumpfield conductive wires just below its surface; the Jump Drive effect is channeled through these elements to create an efficient field which closely conforms to the shape of the hull.

T5 B2, p52:
Jump Field. A parent hull equipped with a Jump Bubble automatically envelopes any attached Pods or Subhulls within that bubble. Otherwise, a Pod or Subhull must be equipped with Jump Plates or Jump Grid if its parent hull is to carry it into Jump.

MWM hasn't contradicted himself in this case, as far as I can see. Not that he isn't capable of doing that, but in this case he has only added detail.

 

[mike wightman]

His jumpspace article, which i consider definitive, states that the hull needs a network of cables, nothing in T5 contradicts or overwrites this.

 

[aramis]

His jumpspace article, which i consider definitive, states that the hull needs a network of cables, nothing in T5 contradicts or overwrites this.

T5 trumps JTAS 16. At least for canonicity in the OTU. YTU may be different, but the OTU is fields or hull grids, designer's choice. (And with minor variations in function.)