[Shipyard] Tukera AT-Class Transport - [Designing beyond 2400 tons]

[robject]

This is a brief set of notes on building ships larger than 2400 tons.

Classic Traveller has a few Book 2 starships which break the 2,000 ton mark -- the Tukera AT Transport (3,000 tons), the Tukera Hercules-class Freighter (5,000 tons), and the Al Morai World-class Transports (3,000 tons).

If I hope to convert these ships to ACS, I need to use the rules in creative ways.

I'm going to focus on the Tukera Type AT Transport. It is a jump-4 transport that carries -- if I recall correctly -- a minimal crew (a dozen-plus people), up to 36 passengers, a lifeboat, and a lot of cargo.

The Hull The Type AT has an unstreamlined hull. The easiest way by far to get a hull cost using T5 is to flip to page 333, pick the 1500t Unstreamlined hull (Hull Q, MCr 47), and double the cost (MCr 94).

A more "correct" way is to reverse engineer the actual equation. However, I recommend the easiest way.

Hull fittings, Jump field, and Armor are handled without modification.

Drives Flipping ahead to drives (p.337), I can use formula to determine drive size. The Type AT is Jump 4, Maneuver 1, Power Plant 4.

Jump volume = (Hull x JumpNumber / 200) x 5 + 5.
= 3,000 x 4 / 40 + 5
= 305t
Jump price is (page 338) MCr1 per ton, for a total of MCr 305.

Maneuver volume = (Hull x ManeuverNumber / 200) x 2 - 1, (round up)
= 3,000 x 1 / 100 - 1
= 29 tons.
Maneuver price is (page 338) MCr2 per ton, for a total of MCr 58.

Power Plant volume = (Hull x PowerPlantNumber / 200) x 3 + 1, (round up)
= (3,000 x 4 / 200) x 3 + 1
= 181 tons.
Power Plant price is (page 338) MCr1 per ton, for a total of MCr 181.

Fuel is calculated without modification.

Everything else is added and managed per ACS rules.

Transport T-Q2U14 AT-Class Transport MCr697.8 [Tukera]

Owner: Tukera

Overtonnage: 13 tons
Crew comfort: +2
Passenger demand: +2

    Tons Component                          TN     MCr  Notes
-------- ---------------------------------- -- -------  --------------------
    3000 Unstreamlined Hull                 12      92  U
       0 AV=13. 1 Kinetic Plate             13       0  
    1200 Jump Fuel (4  parsecs)             12       0  J4, 300t/pc
   107.9 Plant Fuel (one month)             12       0  one month
     305 Jump Drive-4 (V3)                  13     305  J 4
     181 Imp PowerPlant-4 (V3)              13     181  P 4
    9.57 Adv Maneuver Drive-1 (Q)           13      58  1 G
       3 Vd T1 Beam Laser (3)               11       2  #3 
       3 AR T1 Missile (3)                  11     1.2  #3 
       3 Vd T1 Sandcaster (3)               11     0.9  #3 
       4 Computer Model/4 std               17      18  
       8 Squad Barracks (2)                 13     0.4  #2 (5) R1 R1 R2 R2 R3
       4 Life Support Long Term (2)         13       4  #2 40 person-months
       2 Life Support Adaptable (2)         13       2  #2 10 sophonts
       3 Life Support Luxury (3)            13       3  #3 10 high passengers
      18 Standard Controls                  13       0  
      24 Crew Stateroom (12)                13     1.2  #12 1 crew
       2 Crew Common Fresher (2)            13       2  #2 10 crew
      60 Crew Lounge (15)                   13       0  #15 
       2 Cargo Lock                         13       0  
     800 Cargo Hold Basic                   12       0  
      72 Standard Stateroom (36)            13     3.6  #36 1 passenger
       4 Common Fresher (4)                 13       4  #4 10 passengers
     176 Passenger Lounge (44)              13       0  #44 
      20 Launch                             13      16  
       2 Grapple Set Single                 13       2  up to 35t

 

[sporegnosis]

the ACS rules make assumptions about size and systems around the 1000t mark

you can skew the rules a bit and push that up to 3-4k tonnes.

you need a completely different scaling system for ships x10 x100 x1000 kilotonnes.

have a look at GURPS ships for such a system...

 

[Licheking]

or Megatraveller, or the generic Vehicle Design System from BTRC

 

[savage]

2400dt

During the creation of T5 was there an explanation given for the 2400dt limit beyond the original small ship universe philosophy? Or is there a plan for a large ship followup product (TCS?).

I suppose creating tables won't be too hard. It's easier to select a small ship universe that to create a larger ship universe.

 

[robject]

During the creation of T5 was there an explanation given for the 2400dt limit beyond the original small ship universe philosophy? Or is there a plan for a large ship followup product (TCS?).

I suppose creating tables won't be too hard. It's easier to select a small ship universe that to create a larger ship universe.

The idea is that 2400 tons is (conceptually?) the largest ship that a group of player-characters can crew without help. Beyond that you get Big Ships that always require a large-ish crew (i.e. more than just a set of player characters).

 

[Reban]

BCS or Battle Class Ships is supposed to be the follow-up product for 2400ton+ ships but it also focuses on squadron and fleet engagements that don't include any or many small ships.

Hopefully it'll add some more interesting crunch like reaction drives that are missing from ACS.

 

[savage]

Crew size

The idea is that 2400 tons is (conceptually?) the largest ship that a group of player-characters can crew without help. Beyond that you get Big Ships that always require a large-ish crew (i.e. more than just a set of player characters).

Ok. I get it.
Thanks Reban for your input too!

However, it leaves those with Large Ship Universes hanging until BCS.

o:

 

[Murdoc]

However, it leaves those with Large Ship Universes hanging until BCS.

Only if you really need the exact stats for such ships. I don't usually find them that relevant on a PC level, unless they are commanding the thing, and are all bridge crew like in Star Trek. If so, then yeah, I can see that. Most of my games though don't have that, but still plenty of big ships. If the PCs encounter one at all, it's either because their ACS runs into one, in which case, it's just BCS wins the encounter (hence the PCs either surrender or jump out), or they are on board the BCS, perhaps fighting their way out, or just visiting. I think of it like in Star Wars, Ep 6 or 3, where the PCs do their small-scale missions (flying fighters or rescuing the chancellor) while the big ships slug it out in the background.

 

[savage]

Big Ships

Only if you really need the exact stats for such ships. I don't usually find them that relevant on a PC level, unless they are commanding the thing, and are all bridge crew like in Star Trek. If so, then yeah, I can see that. Most of my games though don't have that, but still plenty of big ships. If the PCs encounter one at all, it's either because their ACS runs into one, in which case, it's just BCS wins the encounter (hence the PCs either surrender or jump out), or they are on board the BCS, perhaps fighting their way out, or just visiting. I think of it like in Star Wars, Ep 6 or 3, where the PCs do their small-scale missions (flying fighters or rescuing the chancellor) while the big ships slug it out in the background.

Or ships systems for combat. There are several approaches to large ship combat. I agree but I tend to put players into these situations. I was also a bit surprised about it and I still have a lot of reading to do having received "the book" a few weeks ago.

 

[robject]

the ACS rules make assumptions about size and systems around the 1000t mark

you can skew the rules a bit and push that up to 3-4k tonnes.

you need a completely different scaling system for ships x10 x100 x1000 kilotonnes.

Well, I have some thoughts about this as well. Traveller5 already assumes we can gang the drives for higher power. So why not "gang" the hull codes too? Especially for those "grey area" hulls that are too big for ACS but not really "big time" BCS hulls, it seems to work fine.

 

[Draconian]

This is a brief set of notes on building ships larger than 2400 tons.

I am ship-starved. I want to design a T5 campaign but the skies are empty (and the surface road grids, for that matter.)

Your notes and designs are highly appreciated, sir!

 

[robject]

Updated to include a full draft design of the Tukera AT-class Transport.

 

[daltoncalford]

Perhaps using ACS hull sizes as hull sections - with a small amount of overhead.

For example, a private or small commercial vessel would be constructed of only a single hull.

commercial carriers would have 2 - 3 hull sections ie a 3000tn ship would be comprised of 3 1000 tn hulls.

Military ships would intentionally have many sections ie a 2000 tn destroyer would have 8 250tn hull sections.

The concept would be that in combat, you could damage and or destroy one section, while the rest are still viable. Each hull section would have it's own damage table.

There would need to be some limits and a structural value/cost/tonnage assigned for combining the various elements.

Drives/Engineering would be by formula while everything else is ACS.

 

[Reban]

Military ships would intentionally have many sections ie a 2000 tn destroyer would have 8 250tn hull sections.

The concept would be that in combat, you could damage and or destroy one section, while the rest are still viable. Each hull section would have it's own damage table.

ACS already has compartmentalization of hulls, why add another layer on top of that in the way you propose? Whats the added value?

 

[robject]

Military ships would intentionally have many sections ie a 2000 tn destroyer would have 8 250tn hull sections.

The concept would be that in combat, you could damage and or destroy one section, while the rest are still viable. Each hull section would have it's own damage table.

This is more or less exactly how space combat manages damage in Traveller5. The volume of a section depends on the volume of the hull.

 

[daltoncalford]

ACS already has compartmentalization of hulls, why add another layer on top of that in the way you propose? Whats the added value?

The separate armour values for different compartments, basically just an extension of existing material vs a different set of rules.

BCS would just be ACS with defined multi-hull.

Other than more BCS weapons/defences/fittings, it is no different from the ACS system and thus, nothing new to learn for players and could be done in very short order.

 

[daltoncalford]

This is more or less exactly how space combat manages damage in Traveller5. The volume of a section depends on the volume of the hull.

Yup, only thing is, you would have defined section sizes based upon the size of the sub-hulls.

You could have sub-hulls that are their own life pods for the larger ship etc.

You could even have standardized sub-hulls in pre-done sizes for the use of the military - easier to tear out and repair whole sections of the ship. The reason a particular governments fleet looks the same is they all use the same standard parts.

For those who hate formulas, whole lists of dedicated sub-hulls could be done up in 250 or 500 tn sizes (flight deck, fuel, engineering etc) so a player would select a range of units, and a chart could list engine/size etc to overall tonnage to get performance.

Basic idea, use what you have, from existing rules to existing lists to create the next level of complexity.

For the players, it would be an evolution and thus friendlier than an all new approach.

 

[Reban]

The separate armour values for different compartments, basically just an extension of existing material vs a different set of rules.

BCS would just be ACS with defined multi-hull.

Other than more BCS weapons/defences/fittings, it is no different from the ACS system and thus, nothing new to learn for players and could be done in very short order.

Thats a lot of extra complexity for a Ref or Player to track. You now have several compartments in each sub-hull to assign and resolve damage in and you have to allow for damage to migrate along some path to other hulls.

While I like the idea of different armor values different compartments, Space Combat doesn't use facings and assumes (rightly imho) that any part of the ship is reachable by weapons fire so it makes more sense to have a uniform armor value. Even if we had different armor values for different parts of the ship compartmentalization means that once damage penetrates in one part of the hull it may overspill into adjacent compartments.

Armor belts make sense for surface ships but not for spaceships. Armor around specific components might make better sense, but I'd use a different mechanic to armor value such as giving a redundancy roll to save an "armored" component like a jump drive.

Yup, only thing is, you would have defined section sizes based upon the size of the sub-hulls.

You could have sub-hulls that are their own life pods for the larger ship etc.

You could even have standardized sub-hulls in pre-done sizes for the use of the military - easier to tear out and repair whole sections of the ship. The reason a particular governments fleet looks the same is they all use the same standard parts.

For those who hate formulas, whole lists of dedicated sub-hulls could be done up in 250 or 500 tn sizes (flight deck, fuel, engineering etc) so a player would select a range of units, and a chart could list engine/size etc to overall tonnage to get performance.

Basic idea, use what you have, from existing rules to existing lists to create the next level of complexity.

For the players, it would be an evolution and thus friendlier than an all new approach.

You can actually do most of these things in ACS. Ships are assumed to have Payload which is undifferentiated and can be fitted out. With ships of BCS size you could build "modules" for operational, cargo and crew spaces and drop them in.

Rather than standard sub-hulls you could have standard hulls and drop in redesigned weapons and sensor packages.

I can see where you're coming from but I just feel you are designing in an un-needed level of complexity for BCS ships when ACS does everything required. What BCS needs to do is 1). provide the formulas behind ACS tables. 2) guide the designer through the special considerations for big ships 3). provide components like launch tubes and spines 4). provide rules and a combat system for large scale squadron and fleet battles.

I don't think BCS will provide different weapons/defence systems other than spines. Most likely it will provide rules for building and describing batteries made up of ACS weapons.

 

[robject]

While I like the idea of different armor values different compartments, Space Combat doesn't use facings and assumes (rightly imho) that any part of the ship is reachable by weapons fire so it makes more sense to have a uniform armor value. Even if we had different armor values for different parts of the ship compartmentalization means that once damage penetrates in one part of the hull it may overspill into adjacent compartments.

Though it doesn't use facings, it does allow moving armor layers around to shield some areas better than others -- I think.

As far as BCS, in addition to spine building rules, I think it will need rules for massing sensors into batteries.

 

[Reban]

Though it doesn't use facings, it does allow moving armor layers around to shield some areas better than others -- I think.

As far as BCS, in addition to spine building rules, I think it will need rules for massing sensors into batteries.

Moving armor around? I'm not sure I can see any way of doing that in a single hull. We could design pods or subhulls to carry particular components and give them distinct armor types and layers.

If the 4% layer is uniform all over the hull how do you move some of the AV from the back to the front? Does a layer become 6% at the front and 2% at the back?

The easier way is to build two subhulls, make one the armored bow section and the other the lightly armored stern.


Re: BCS sensors. How should sensor batteries work? I'd say, assuming sensors of the same type, the resolution should increase (that would resolve objects at one range band closer for each improvement?). The other thing BCS should bring to sensors is some survey sensors and rules to use them.