Type AD Adventure class catamaran

[Maladominus]

Traveller(c) Starship Design
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Wanderlust (Adventure Class, Type AD)


The design of the Adventure class starship is a unique development. The Magyar sector has always been a cultural and technological backwater, despite its proximity to the highly civilized Solomani Rim. Although the sector has been settled since the final years of the Vilani Imperium, the Magyar sector was hit hard by the Long Night, thus throwing most of the sector backwards. Most of the Magyar sector is nominally governed by the Solomani Confederation, with a few worlds swearing allegiance to the Imperium, and many more under the stewardship of various pocket empires. As a result, the Magyar sector has always been a wild frontier region, a virtual haven for mercenaries, explorers, and adventurers.

With this clientele in mind, Uebelhor Shipyards Inc. comissioned the Adventure class starship in 1098, a 400dt catamaran based on a custom hull. The ship is unique among civilian vessels, as it is large enough to rival the size of many military frigates, patrol cruisers, and system defense boats. Nevertheless, the focus of the design was on flexibility and mobility. The Adventure class is lightly armed on purpose (2 hardpoints max), so as to remove any suspicion that the ship was intended as a rival to the military patrol ships and mercenary cruisers employed by local governments. Nevertheless, the Adventure class ship turned out to be an extremely popular design. Successful adventuring groups, nobles with disposable income, and wealthy fortune-seekers lined up to place orders almost as soon as the ship was announced. Uebelhor was only able to produce 3 ships a year during the first two years of production, but has promised to increase this pace significantly.


The Adventure class starship is based on a 400T, custom hull, of a general catamaran shape. It mounts jump drive F, maneuver drive F, and power plant F, giving a performance of jump-3 and 3-G acceleration. Fuel tankage for 150 tons supports the power plant allowing for 1 jump-3 and 4 weeks of operation. Adjacent to the bridge is a computer Model/4.
The ship has the following accommodations:
10 stateroom(s)
4 low berth(s)
The ship has 2 hardpoints and 2 tons allocated to fire control.
There are 2 ship's vehicles:
1 launch(s)
1 air/raft(s)
Cargo capacity is 60 tons. The hull is streamlined.

The ship requires a minimum crew of 7:
1 pilot
1 navigator
2 engineer(s)
1 medic
2 gunner(s)

The ship costs MCr232 (not including discounts and fees) and takes 16 months to build.


Ship's Name: Wanderlust
Ship's Class: Adventure class
Build Cost: MCr232
Design Fee: MCr2.5
Construction Tech Level: 12
Mass Production Cost: MCr208.05 (includes design fee)
Hull: 400T, custom (streamlined)
Jump Drive: F (jump-3)
Maneuver Drive: F (3-G)
Power Plant: F
Ship's Computer: 4 (capacity 8/15)
Ship's Accommodations: 10 stateroom(s), 4 low berth(s),
Cargo Capacity: 60
Available Hardpoints: 2
Mounted Turrets: none
Mounted Weapons: none


The Adventure class starship consists of an upper deck and a lower deck. The upper deck contains the bridge, crew quarters, staterooms, a sick bay, a spacious commons area and other accomodations. The lower deck consists of forward cargo bays (60tons total), the aft engineering section that houses the drives, and a centerline bay housing the 20-ton launch that nearly divides the lower deck, thus forming the catamaran sillhouette that defines the lower deck. Fuel tanks are also on the forward section on the lower deck.


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Generated using the Classic Traveller Utility
Ship design created by Maladominus for the Terra Incognita campaign.


*** Yes I am aware of FASA (decanonized?) publishing 2 products called Adventure Class Starships. But the "Adventure Class" refers to their Traveller products, it's not the actual class name of any starship they designed to my knowledge. Mine on the other hand, the "Adventure class" refers to a specific class of ship, Type AD. Just making sure no one is confused here.

 

[Maladominus]

I'd love it if a talented CCG deck plan-maker would attempt a deck plan for this design.... but with my luck, I'll end up having to make the deck plans myself.

 

[Berg]

Our next ship?...

or an adversary

 

[Maladominus]

Originally posted by Berg:
Our next ship?...

or an adversary

Both are possibilities, yes.

tho it will be a long time until this ship becomes playable... as I yet have to figure out what the ship looks like, and what the deck plans may look like.

 

[Jame]

This'd make a good blockade runner.

 

[deadlock]

Greetings and salutations,

LBB design?

[edit]I just saw the note at the bottom of the post. Sorry for wasting space.[/edit]

 

[far-trader]

Very interesting, I was just thinking the night before last "You know a catamaran hull spaceship would look cool."

Of course my next thought was "But there's no point. A cat hull grants no benefit to the design, it probably just makes it weaker and less volume efficient."

So I was very interested when I saw you had posted this. Right after repairing my anti-psi helm I came back here to post a challenge to you Maladominus, and the board in general:

What is(are) the advantage(s) of a catamaran hull for this or any spaceship design?

 

[Maladominus]

You are completely correct that a catamaran design is not a "sturdy hull" and will tend to waste a little bit of space.

Perfectly correct. Just look at my design, and I proved it. A 400-ton custom hull... and it only accomodates a crew of 7, with 3 passenger staterooms, and it only has a modest 80t cargo space remaining. And only 2 hardpoints.

So what's the advantage you ask? The logic of the catamaran hull is that this ship is FAST and STREAMLINED! What's the result? It justified my use of a custom hull so that I could build a 400ton ship with Jump Drive F, Maneuver Drive F, and PowerPlant F. (I used the CT Utility ship design thinggy as my guideline).

Had this been a "standard hull" type, according to the CT construction rules, a 400ton standard hull ship could NEVER have over 50 tons of drivespace (Type F Jump, Type F Maneuver, and Type F PowerPlant amounted to slightly over 50tons of drivespace that is allocated for a standard 400ton hull).

In conclusion: the reasoning for this type of custom hull was that "well, the catamaran hull type and hull sillhouette fully supports a much faster and maneuverable ship for its given hull size, but at the expense of everything else!"

When I look at the final stats for the Adventure Class, it dawned on me that this 400ton design comes fairly close to the stats of a CT 400ton Patrol Cruiser (Gazelle class). The main difference is that the Gazelle class is focused on being an armored military vessel but still a very maneuverable military vessel. Mine, on the other hand, is a civilian registry "adventure ship", and altho it cannot stand up and survive against heavily-armed 400ton patrol cruisers, the Adventure Class can certainly run away from any situation or trouble it gets into.

P.S. --- I forgot to mention that the Type AD has fuel scoops and a purification plant (which only makes sense)

 

[far-trader]

Yep, speed is the key reason for a wet catamaran hull iirc. Stability is another. You can also heel over on one hull and really fly in a sail cat. None of these really seem to apply to spaceships though, at least outside of surface aquatic situations which would be limited.

Still I wonder. What handwaves could we get away with?

Perhaps it could be a streamlined limited dispersed structure? Cheaper hull construction but still able to enter atmospheres.

Or maybe it could have a speed advantage (warning, the following is very heretical) in that the limit of 6G drives is due to hull dynamics and by putting your drives in seperate hulls, a catamaran or trimaran, you can put 6G drives in each hull and get 12G or even 18G! I'd limit it to trimaran, anything more than that is too much like a single hull with multiple drives and the interaction limits it the 6G max again. Of course with this handwave must come some balance or it would be done all the time. But my hand is tired so I can't throw that balance right now

 

[far-trader]

Hope you don't mind the tangent to your post Maladominus, I can move it elsewhere if you like but it relates to your idea.

OK, couple quick ideas on why more ships aren't built mulit-hull for the drive boost posited above:

Expense - Catamaran maneuver drives are 2x the total cost, Trimaran maneuver drives are 4x the total cost. The cost covers the extra care in balancing the drives and the power feed control.

Balance - If the maneuver drives or power plant are damaged in one hull the ship must reduce power to the other hull(s) to maintain control. So where a hit that would reduce a 6G ship to 5G in a single hull, the same hit on a 12G ship would reduce it to 10G. In the case of maneuver drive damage note which hull is reduced each time for actual damage as subsequent hits may not reduce available manuver.

Example 1: 1st hit is on hull 1 maneuver so power is reduced to hull 2 maneuver and overall perfomance degrades. 2nd is on hull 2 maneuver but it is already reduced and can still perform at the needed level so performance is not impacted. Both drives will have to repaired to restore performance.

Example 2: 1st hit is on hull 1 maneuver so power is reduced to hull 2 maneuver and overall perfomance degrades. 2nd is on hull 1 maneuver so power is further reduced to hull 2 maneuver and overall performance degrades further. Only the hull 1 maneuver drive will have to be repaired to restore performance.

 

[Maladominus]

Originally posted by far-trader:

Expense - Catamaran maneuver drives are 2x the total cost, Trimaran maneuver drives are 4x the total cost. The cost covers the extra care in balancing the drives and the power feed control.

I'm willing to agree with you on the increased cost of catamaran drives. However, if we are going on that logic.... then the ship also *saves* a few million credits of manufacturing cost because.... umm... because it uses up a LOT less metals and does not require as much construction "volume" as other bulky hulls.

Let's remember that a catamaran hull is not one solid block of metal.... it has some missing volume in the centerline of the ship! That amounts to a LOT of savings for the shipyard.

Like you said above, "cheaper hull construction" is definitely one advantage of this type of hull. I have not yet figured out the final cost for these factors.

Also let's mention one more hidden advantage of the catamaran that CT does not cover (but T20 does): the Agility advantage! Since this ship has a dual engine construct, it only makes sense that the ship's maneuverability and handling is a dream for the Pilot flying this thing. What would you rate the agility of a catamaran like the Adventure class?

P.S. -- I'm more than happy to collaborate on ideas for the Adventure class, since you seem to have some well thought out ideas on catamarans in the first place. Besides, I still do not have a definite idea of how this proposed ship will look on deckplan blueprints. It's going to take some effort to have this ship make sense on deck plans.

 

[Fritz_Brown]

Actually, Maladominus, a convoluted shape like a catamaran will require more material, as there is more surface area with which to contend. And, more surface area will mean more expensive construction methods, too.

I could go with the agility handwave, though.

 

[Maladominus]

For a catamaran hull, I was inspired mostly by the old Lyran CA (heavy cruiser) from Star Fleet Battles. This is not to say that the Adventure class looks anything like the Lyran CA.... but the general sillhouette is what I imagine most starship catamarans to look like.

Below is a hobby model of the Lyran heavy cruiser catamaran from SFB:

 

[Maladominus]

Edits made to the original Adventure class Type AD:

a) I downgraded the 30t ship's boat into a smaller 20t launch instead. It makes no sense for such a large 30ton craft to be taking up the volume of the catamaran centerline. A 10 or 20 ton small craft makes more sense.

b) Since the catamaran is a "space inefficient" design, I reduced the remaining cargo capacity from 80tons to 60tons. This is simply a 'reality adjustment', something that LBB2 and High Guard design rules never cover.

c) slightly adjusted the price to reflect cost factors: slightly more expensive architect fees because this is a complicated non-standard design, and took free-trader's suggestion that the maneuver drives would cost nearly twice as much for a dual-engine design, also reflected the cost for downgrading to the launch, etc.

 

[far-trader]

Not sure about the agility idea. That is something I've toyed with the few times I've played around with vectored thrust designs.

Speed for catamaran hulls, agility for vectored thrust hulls. Costs and such similar but for different effects.

My idea of drive stacking won't benefit this design (edit, see trimaran note below, I was wrong). It would, marginally if it were a 4G design. Twin D drives stacked would give 4G in 14tons while a single H drive for 4G takes 15tons. There is also the Book 2 TL chart so it could be built at TL9 if twin drive but have to be TL10 for single drive. Naturally this example shows one of the lower end comparisons. I think savings in tons and TL will be higher the bigger the ship.

Hmm, as a trimaran per my idea with three B drives you get 3G for 9tons, saving 2tons over the single F drive.

Also, now that I think about it, a trimaran could be balanced so that the central drive will work solo, in this case giving you 1G even if the other drives are toast. Or you could use your power plant for something else, like Double Fire by taking the outboard maneuver drives offline

Hmm, you could even use just the outboard maneuver drives and take the central one offline for the same effect and have 2G

 

[far-trader]

Very nice model. So, just curious, was Star Trek the main inspiration for doing a cat hull for Traveller? It does seem to be the norm in ST, with some techno-babble about warp field stability or something

...which is kind of how I see Traveller maneuver drives working. It's not so much just a Gee rating as also a maximum speed limit. Kind of like how an simple hull aquatic ship is limited to a top speed based mostly on it's hull length. Nicely eliminates the easy "near c-rock" problem.

 

[Maladominus]

Originally posted by far-trader:
Very nice model. So, just curious, was Star Trek the main inspiration for doing a cat hull for Traveller? It does seem to be the norm in ST, with some techno-babble about warp field stability or something

The Lyran Heavy Cruiser is from the Star Fleet Battles miniatures boardgame; and SFB has been a licensed Star Trek game for almost 20+ years. SFB is almost as old as Traveller. It goes back to the early 1980s.

Star Fleet Battles was always seen as "that violent shoot-em-up starship combat boardgame that hardcore violent Trekkie wargamers always loved to play". Many old school Trekkies dismiss SFB as a non-canon game, because it introduced non-canon and semi-canon empires and fleets such as the Lyrans, the Gorns, and the Orion Pirate fleets, etc.

However, SFB was not my inspiration for designing the Adventure class ship. The catamaran proposal was actually a last minute thought that I just wrote in! =) It might end up that catamarans simply will never work in the Classic Traveller universe of ship design. In that case, I will simply change the Type AD to a more traditional ship hull.... probably resembling a submarine-shaped design like the SDB or the Gazelle class patrol boats.

 

[far-trader]

Heck, "just wrote it in" is a perfectly good reason in my books

Don't take my meddling the wrong way, I like the thought exercise. I don't see a reason for not saying there are catamarans. The Gazelle is a classic example of outboard hulls.

And there doesn't have to be a rule to cover it either. Because it looks cool is all the reason CT needs and it's part of what I still love about the game. I've probably come up with wackier ideas

I wanted to get into SFB when it came out but the group was drifting apart and games were getting harder to set up so it never happened.

The thing that got me thinking about a Traveller catamaran the other night was a TV shot of a catamaran ferry. Why I linked it to Traveller then and not all the times before I don't know.

 

[robject]

It also got me thinking about a modular "outrigger" setup, with swappable modules for different missions. Supplemental maneuver, or more fuel, or a sensor module, or a bigger jump drive... or a big fixed gun.

 

[Straybow]

Talk about ST reminds me of separating the saucer section from the base. If it's to be a twin hull, why not make them separable?

Bridge, crew quarters, manuever fuel and drive, plus weapons on one section, everything else on the other.