Ship Design Philosophy

Discuss the Traveller RPG and its many settings
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Fri Dec 22, 2017 10:27 pm

Space Stations: (In)Dentured Bridges

First of all, can you install smaller bridges? It's not mentioned, and seems unlikely.

It's mentioned that you could mix and match components between spaceships and stations, and the bridge component seems the first candidate, especially since it's five times cheaper, the volume being relatively irrelevant.

Though there's a case to be made for ten tonnes for five hundred tonne hulls, compared to the default twenty tonner. Twenty tonnes for a five kay hull, hard to say it makes a difference.
baithammer
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Re: Ship Design Philosophy

Postby baithammer » Sat Dec 23, 2017 6:24 am

Have a feeling the station should've been 1.0 Mcr per 100t.
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Sat Dec 23, 2017 6:24 pm

Thing is, with a Tigress, cost should not be an issue.

Wouldn't bother getting a default bridge, I'd install three command bridges, since they act as ordinary ones, and give a bonus.
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Re: Ship Design Philosophy

Postby Condottiere » Sat Dec 23, 2017 11:06 pm

Or if money is an issue, space station bridge, default bridge, and space station command bridge.

You don't need the default bridge, if jump and full throttle manoeuvre drives are controllable from a space station bridge.
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Sun Dec 24, 2017 9:21 am

Spaceships: Double, double toil and Hulls

One appeal of the double hull, is that for smaller warships, you could present a broadside to the enemy, since you don't need to point the nose at them.

A double hull could present the entire weaponry at an enemy target as it rotates, but it also can make it more difficult to actually penetrate armour, as the armour itself becomes a moving target.
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Re: Ship Design Philosophy

Postby Condottiere » Sun Dec 24, 2017 7:54 pm

Image

Happy X Mass Bomber!
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Mon Dec 25, 2017 5:41 pm

Spaceships: Dogfighting and Reactionary Acceleration

When you're up close and personal, reactionary bunkerage would become fractions of thrust hours, six hundredths I believe.

That six seconds of afterburner could position your vessel in an advantageous position, on regard to a fighter that might not have that extra juice.

Also, what I assume is meant by High Burn Thruster in this edition.
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Re: Ship Design Philosophy

Postby Condottiere » Tue Dec 26, 2017 9:18 am

Spaceships: Engineering, Reaction Drive, and Auxiliary Chemical Rocket

As I read it, whether in Mongoose First or Second, it's implied that Reaction Drives burn hydrogen, while it's stated auxiliary rockets burn chemical fuel.

From Scoundrel:

To determine the effects of the thrusters, choose a Manoeuvre Drive that produces the desired speed. (For example, to get six gee acceleration on a two hundred tonne ship requires a Manoeuvre Drive F.) The high–burn thruster weighs twenty percent and costs twenty percent of that Manoeuvre Drive (2.2 tons and 4.8MCr, in the case of a Manoeuvre Drive F).

Thrusters require fuel depending on the thruster’s drive number. Fuel equal to twenty five percent of the mass of the drive gives enough for one full hour of operation (ten space combat turns). Fuel costs 10,000 Cr./ton. A high–burn thrusters may not operate for more than one hour before requiring a shut–down period equal to the duration of operation.


I don't see any specific definition in Mongoose Second, making it about as useful as your appendix.
baithammer
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Re: Ship Design Philosophy

Postby baithammer » Tue Dec 26, 2017 10:07 am

Hydrogen is a chemical and rockets require no power in order generate thrust in exchange fuel consumption is greater and can generate more thrust of a comparable m-drive.
Sigtrygg
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Re: Ship Design Philosophy

Postby Sigtrygg » Tue Dec 26, 2017 11:18 am

If its a chemical rocket your hydrogen is also going to require oxygen. Note a chemical rocket can not be the model for the MgT reaction drive - fuel requirements are way way way too low.

If all you are doing is using the hydrogen as reaction mass having heated it using a nuclear reactor then it is a nuclear powered reaction drive and not a chemical reaction... once again the fuel requirements are ridiculously low for the stated performance.
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Re: Ship Design Philosophy

Postby Condottiere » Tue Dec 26, 2017 8:31 pm

I don't think that the original Classic conception conceives of mixing oxygen in the thrust fuel.
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Re: Ship Design Philosophy

Postby Sigtrygg » Tue Dec 26, 2017 9:17 pm

The Classic Traveller maneuver drive was a fusion rocket - it said so in first edition High Guard,
baithammer
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Re: Ship Design Philosophy

Postby baithammer » Tue Dec 26, 2017 11:48 pm

Going over my copy of CT HG has no mention of fusion rockets or rockets period.
phavoc
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Re: Ship Design Philosophy

Postby phavoc » Wed Dec 27, 2017 1:03 am

I've been reading Conway's History of Ships - Eclipse of the Big Gun. It's a pretty detailed book on the many aspects of naval architecture, ship types, even fleet trains. It's a great book if you'd like a reference or just something to give you ideas on historically how warships were designed and deployed from 1906-1945. There are other books covering modern ships.

https://www.librarything.com/work/108617
Sigtrygg
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Re: Ship Design Philosophy

Postby Sigtrygg » Wed Dec 27, 2017 8:38 am

baithammer wrote:
Tue Dec 26, 2017 11:48 pm
Going over my copy of CT HG has no mention of fusion rockets or rockets period.
You don't have the original version of High Guard then.
GDW High Guard first edition 1979 page 40:
Fusion Drives as weapons: Any ship may use its maneuver drive as a weapon...
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Re: Ship Design Philosophy

Postby AnotherDilbert » Wed Dec 27, 2017 9:04 am

Sigtrygg wrote: The Classic Traveller maneuver drive was a fusion rocket - it said so in first edition High Guard,
CT 1st edition in 1977 had reaction drives. CT 2nd edition, from High Guard 1980 (i.e. most material), had reaction-less drives.
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Re: Ship Design Philosophy

Postby Sigtrygg » Wed Dec 27, 2017 10:45 am

Not necessarily.

There is no additional information in 81CT LBB2 or HG80 to overwrite the fusion drive description in HG79.

The descriptive text of the maneuver drive in LBB2 both editions is similar, as is the descriptive text in 79HG and 80HG - in fact the text on page 17 of each book regarding the maneuver drive is identical.

We know two things for certain:

MegaTraveller changed it to a reactionless drive

Frank Chadwick insisted that TNE go back to a reaction drive as it was originally intended to be.
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Re: Ship Design Philosophy

Postby Condottiere » Wed Dec 27, 2017 12:29 pm

When is a battlecruiser not a battlecruiser?

When it's too costly to lose.
AnotherDilbert
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Re: Ship Design Philosophy

Postby AnotherDilbert » Wed Dec 27, 2017 12:44 pm

Sigtrygg wrote: There is no additional information in 81CT LBB2 or HG80 to overwrite the fusion drive description in HG79.
The "Fusion Drives As Weapons" attack is only in HG'79, not in LBB2, removed in HG'80.
HG'80 does not extend HG'79, it replaces it. There is no need to countermand any information in HG'79.

Manoeuvre drives are not detailed, but only in LBB2'77 might they use reaction mass. In later books, even HG'79, they do not use reaction mass.


1977:
LBB2'77, p6 wrote: A fully fuelled power plant will enable a starship an effectively unlimited number of accelerations (at least 288) if necessary to use the maneuver drive during the trip...
So we can accelerate two days (or more), presumably limited by consuming reaction mass.


1979:
It's a strange kind of fusion rocket in HG'79:
HG'79, p17-18 wrote:Fuel consumption for starships is inconsequential, and assumed to be part of the power plant consumption, regardless of the degree of maneuver undertaken.
...
A power plant uses fuel equal to 1% of the ship's tonnage every four weeks, regardless of actual power drain; this usage is primarily to maintain the fusion bottle and other housekeeping functions. Other fuel requirements are considered inconsequential.
It uses no reaction mass.


1980:
HG'80, p17 wrote:Fuel consumption for maneuver drives is inconsequential, and is assumed to be part of the power plant consumption, regardless of the degree of maneuver undertaken.
Still no reaction mass.


1981:
LBB2'81, p15 wrote:Power plant fuel under the formula (10Pn) allows routine operations and maneuver for four weeks.
So we can accelerate for the full 4 weeks the PP has fuel, without using reaction mass.
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Re: Ship Design Philosophy

Postby phavoc » Wed Dec 27, 2017 1:14 pm

By the example cited, the maneuver drive isn't reaction less. If fuel use is inconsequential that means it IS being used, but at a rate that has little effect to your overall fuel consumption. Which makes sense as all illustrations show ships and small craft with engines in the rear of the ship.

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