Is there a limit to Breakaway modularity?


Cosmic Mongoose
Is there a limit RAW to how breakaway hulls fit together?

Assume a standard shape hull of 200 tons. This is your core module. Everything will be done in 200 ton units.
The Core modue has 200 tons, Power plant and Jump drives the Thrust 1, Jump 1. The Core unit will have the 5 extra tons of Jump drive on it.

A Supplemental unit will have Thrust 1, Jump 1 and fuel for the 200 ton module, plus power to provide enough power to the Jump drive for the 200 ton unit. It will not have a bridge, since it will be controlled by the Core unit once connected. It may have a Bandwidth 5 computer and Virtual Crew software to drone the unit into place and mate with the Core unit, or maybe they will be connected at a Highport facility.

RAW has 2% total volume being used as connector, so there will be 8 tons of connector tonnage to connect the 2 units together.
So combining the Core unit with the Supplemental unit gives us a 400 ton ship, with power and Jump drives for 400 tons (with the extra 5 tons of Jump drives needed in the core unit.) Now it does not say how the 8 tons of connector units work but I would argue for 4 tons on the Core unit and 4 tons on the Supplemental unit, equal tonnage, to connect the two pieces together. This seems logical to me.

This system would allow for different configurations of the Supplemental units. One unit could be cargo based, another filled with staterooms for passenger runs, another for lab work or medical bays.

That is all well and good. Here is where I want to stretch the rules. (Literally)

Assuming 4 tons of connectors allows a breakaway unit to mate with another breakaway unit with 4 tons of connectors, could a breakaway ship design be built that did not have an upper limit on hull size? At least until the ship reached 1001 tons and RAW needs another 20 tons of bridge to prevent the -1 on all checks, which could allow 2000 ton ships if you were not worried about the -1 since you can run one bridge size smaller and live with the -1.

Going to the Core unit again, the ship has 4 tons on the starboard side that allows the connection with the Supplemental unit. This would mean the Supplemental units have connections on the Port side to connect the ships together.

What if you doubled the tonnage on the ships to be 4% of the total, and allowing for units to connect on both sides of the ship. So the Core unit would have connector on both sides of the ship. The Supplemental units could have connectors on both sides as well. The Core unit could be the center of the ship and the Supplemental units connect on either side until the preferred size of ship is built.

If you are not using the Connectors the tonnage is wasted space, but it allows ships to be configured to meet various needs and situations. If there is more cargo at a port, a cargo module could be taken. If there were more passengers a passenger module could be taken. The key is twofold. THe ability to build a ship of varying tonnages to meet a need, or to leave a unit behind if it is not needed, saving fuel needs for not having to move the tonnage into Jumpspace.

The only minimum would probably be ten tonne hulls, and in regard to jump drives, the five tonne overhead per separate independent module.

You're probably trying to account for the required surface area to integrate each breakaway hull: High Guard ignores this.

I should add that my solution was to make those hulls hexagonal.
Hmm, a re-read of the Jump Drive section in Highguard says a Jump drive must be 10 tons minimum. J1 is 2.5% so 200 tons would be 5 tons of Jump drive, plus 5 extra for the Core is the minimum Jump drive at 10 tons. The Secondary units would be 10 tons and could be larger than 200 tons, a 400 ton module with the Core being smaller? That seems odd to me. The extra modules would not be Jump capable in and of themselves, unless you added in an extra 5 tons, 7.5 MCr per Secondary module. And then you get into the scenario of always having too much Jump drive that you are paying for and not really using. Or you leave the Secondary unit at 200 tons, with 10 tons of Jump drive.

The Jump calculation would be 400 tons of ship, with 20 tons of Jump 1 Drive. 400 tons of ship would need 10 tons of drive and 5 extra for 15 tons. This means the Jump drive could move 600 tons of material. How to add on 200 more tons of cargo, without adding in another module that would add more Jump drive. You could add on a third dimension and add a Docking Clamp for 5 tons onto each unit. This would let you clamp on a cargo pod to maximize Jump drive capability. This would increase flexibility as well.

That would work. Each breakaway hull is its own ship, but can link together to create a single unit to move extra cargo in pods clamped to the side, or towed in a Jump Net, maybe there is external cargo mounts on the modules.

Then you get the snag of extra bridges being paid for, unless you skip the bridge part for the Secondary units and let the Core be the command center for the Jump drives. That could work.

Back to the spreadsheet to crunch some more numbers and tonnage.
Would Voltron constitute a workable break-away vessel? :)

I guess one question would be what is the purpose behind what you are trying to build? In some ways it sounds like the battlerider concept, where a ship not burdened with having jump drives and the associated fuel would be able to convert that tonnage into something else. So are you looking to create smaller battleriders and have the core engineering hull take care of the jump tasks?
I am looking at the possibility of making a commercial battle rider concept as the idea evolves. A secondary unit that contains a lot of Jump drives and fuel could allow several pure cargo pods to be mounted, or pods with Docking clamps to carry non Jump capable ships. There are RAW possible ways of pushing the limits of performance and profitability.

The simpler version is a tinker toy linking of various units to build whatever ship you want. A crew could start off with a Core unit and make simple runs. As they can afford to upgrade their ship, rather than buying a new ship they can add a module to their ship, and run the larger ship as a single entity. Their 200 ton ship now is a 400 ton ship for example, because they added 200 more tons to the ship. So as the company grows rather than having a flotilla os smaller ships needing half a dozen crews they have a single larger ship.

Such a system, of linkable ships would allow smaller crews to run around in smaller modules and be the tramp traders, but able to expand their business as they grew, literally, in size.

I am just trying to sort out the Core module with a bridge and the non core modules that might not have a bridge, but do have Jump drives and M Drives enough to move the secondary unit around. It's not the cost of the bridge that is bothering me, it is the 10 or 20 tons of space it takes up that I want to have as a profit making volume. If you link 2 units together to have an 800 ton ship with 2 20 ton bridges in it. You only need 1 bridge, so the extra bridge is wasted space. This is 20 000 credits a Jump worth of lost income per Jump for freight work, and possibly millions of lost volume on spec freight lost, per trip.
I don't see much problem with the concept. Economically the cost of the breakaway connectors (4 Dt / MCr 8 per 200 Dt section) is steep for a cheap trader.

Each 200 Dt expansion section could get away with a 6 Dt small bridge.

Virtual Crew can probably not be used to obviate the need of a bridge since Virtual Crew can't replace Engineers or Astrogators and must replace the entire crew to remove the need of a bridge. Engineers can presumably be replaced with Expert software and Repair Drones.

Sections smaller than 100 Dt (technically small craft) can use Virtual Software to replace the bridge.
Well you could have Engineers and Astrogators assigned to the secondary units, and use the software to replace the crew the software can replace. The description of the Virtual Crew software package includes this:

"Indeed, ships can be designed without a bridge, relying purely on this software package in order to function as a drone." (page 64)

Now including some living crew to maintain the secondary unit is an option. And to be honest I am less concerned with having the secondary unit be a functioning ship in and of itself. The drone ability is to simply get the ship piece to be able to travel to the Core piece of ship and connect. If this was done at a Highport the breakaway piece might not have to be autonomous at all. The Core piece might be able to do all the maneuvering to connect. The cost of a computer 5 is only 160 000 Cr, so does not increase the cost of the ship all that much in comparison to the cost of the hull.

What I am aiming at is that the additional pieces of ship be able to provide the power, fuel, and Jump drive volume to move that piece of ship once connected to the Core piece. So this means the secondary unit has fuel, M-drive, Jump drive and power plants capable of providing power to the hardware to Jump the volume of ship it represents.

I could push the design and have the infrastructure part of the secondary units be the same: M-Drive, power plant, fuel, Jump drive. Then have the rest of the ship be modular in nature to give the extra flexibility of load-out design. This increases cost, but would provide a standard shell of hull volume and allowing a new ship section to be designed and fitted out however the party desires. Cargo modules, cabin modules, whatever the ship needs could be placed within the modular, breakaway hull section.
So basically like the LASH concept that originated in the 60s, but instead of barges that have to be towed, each module could have it's own set of M-drives, power plant and a small bridge so that it was self-sufficient enough to drop off anywhere in a system and it could make it's own way to it's destination? There was also a TNE ship that transported cargo ships between systems, something along the lines that you are proposing. Though one difference, I think, is you are trying to allow for organic growth. But I think that you would have the same issue that any ship does - the more tonnage you add the bigger your power plant, M-drive and J-drive need to be. Those aren't really plug and play, so your initial ship of 200 tons would have to have equipment sized for 400 tons per your example, unless I'm mis-reading that.

The TNE model works, but the transport ship starts assuming a maximum tonnage and allots it's engineering equipment and such using that as the baseline. I understand the desire from a design point to make a starship as plug and play as possible to maximize it's carrying capacity and costs, however those sorts of designs typically can only be successful in certain conditions. Kind of like ships using drop tanks - works great as long as every place you go has them available and the availability and pricing remain constant. The LASH concept seemed great on paper as well until they had to start taking into account the costs of operating the LASH lighters as actual vessels. Plus the containerization industry started hitting it's stride and LASH could not compete on costs.

I'm interested to see what you come up with.
That's the thing with breakaway hulls, it literally is plug and play.

There are three methods to achieve this goal:

1. External cargo, whether towing, nets, docking clamps and/or racks.

2. Breakaway hulls.

3. And, apparently, pods.

Bridges would be in a grayzone, since their cost scales, as compared to cockpits, where their cost is absolute.

My suggestion is to reverse engineer from the end product.
Each unit would have enough Power plant, M Drive and Jump drive to be able to operate that unit. This brings up a RAW issue.

Since Jump Drives are minimum 10 Tons and J1 is 2.5 % of Volume Jumped the 10 ton minimum would be a 400 Ton capacity. Note that this ignores the "+5 tons" in the RAW, since the extra 5 tons is held in the Core module. So my 200 Secondary Unit has 10 tons of Jump Drive in it. This would allow the 200 ton unit to Jump alone. But the design will have 200 tons of external cargo mounts on the ship to allow 400 tons to be Jumped. This increases profitability.

This does mean that the M Drive will need to be 4 tons to move 400 tons at Thrust 1, unless I accept the ship will not be mobile and load the ship at the Jump point. This could save 2 tons of space and 4 million credits. M-Drives are pricey.

Power plant would need 40 points for a Jump 1 of 400 tons, plus 20 points of Basic power, plus M-Drive and computer, sensors etc. But throw a few tons of power plant, and maybe 1 ton of battery to cover all the bases and power is not an issue.

So the Core ship has the extra 5 tons of Jump drives and a bridge, and the Secondary units can be run without a bridge if you spend the million credits to use the Virtual crew. Each add on would allow 400 tons of volume to be moved, with the internal cargo space being fuel/cargo containers from the Deep SPace exploration handbook. This loses 5% of cargo space, but allows the internal cargo space to be used as fuel supply when the external mounts are fully loaded.

Core Unit
Hull 200 tons
Breakaway tonnage : 8 tons (double amount to allow ships to be added both sides.
Jump Drive 15 tons Jump 1, allows 400 tons J1
M Drive: 4 tons. allows Thrust 1 at 400 tons
Power Plant: 8 tons TL 12 120 points power
Battery: TL 12 1 ton stores 60 points
Fuel: 8 weeks: 2 tons
Fuel, dedicated storage: 20 tons (J1 for 200 Tons)
Bridge 20 tons. Holographic controls
Computer TL 9 Rating 10
Sensors Civilian
2 Triple Turrets, 6 Pulse Lasers
Systems: Ships Locker
Fuel Scoops installed
Fuel Processors 40 tons per day
Medical Bay
200 Tons external cargo mounts
8 Staterooms, 8 tons common area 4 Low Berths
65 Tons Fuel/Cargo container capacity. Takes up 68.25 tons

Power Needed: 131
Power Generated 120: Note 24 points needed for Pulse Lasers. If in a Laser battle use the battery to provide power to lasers, and recharge if not using the Jump drive

Cost is 84 million credits which means the CER is 2.6, which is not ideal.

Secondary Unit has
200 ton hull
10 tons Jump drive
4 tons M Drive
8 tons power plant
1 ton battery
2 tons fuel
20 tons dedicated Jump Fuel
TL 9 Rating 10 computer
Civilan sensors
Cargo Crane 3 tons
130 Tons Fuel/Cargo container. Takes up 136.5 tons
200 tons external cargo mounts
120 Cargo/Fuel container

Cost is 73.61 MCr 300 tons of cargo. CER is 4.07
No Bridge
3 Staterooms

Combining the 2 units the cargo is just over 500 tons of cargo and a CER of 3.2. At freight rates.
You pay a heavy price for the limited flexibility. A conventional 400 Dt design would only cost about MCr 100 for the same carrying capacity:

400 Dt freighter with J-2/M-2 or J-1/M-1 with 400 Dt external cargo:

Note that breakaway connectors are 2% of the total combined ship, so a 400 Dt ship would require 8 Dt and a 600 Dt ship (Core + dual Secondary) would require 12 Dt.
That is why I was looking at a standard core unit and standard Secondary Units.

Imagine something like the flying brick shape of the shuttle ship in Flatlined. The breakaway hull system could be a linking series of those bricks. Each brick lines up and connects nicely to the brick next to it. Have the M-Drive and J drives at the rear of the ship, and fuel tanks etc in the same places. With the brick shape as standard the airlocks and such could line up. Cargo leaves from the front.

To build a larger ship just connect something onto the side of the next piece in line, like lego linking together.

That was my thought anyway. A flexible standard system of shipbuilding.
You can place the power plants or the fuel tanks anywhere, as long as the plumbing exists to connect them.

With drives, you have to account for the centre of gravity of the ship for manoeuvring, and synchronize the hyperdrive modules when you want to drop down the rabbit hole.
PsiTraveller said:
To build a larger ship just connect something onto the side of the next piece in line, like lego linking together.

That was my thought anyway. A flexible standard system of shipbuilding.

I agree that it is an interesting idea, but you should also keep an eye on cost, especially for commercial ships.

I tried something vaguely similar a few years ago, but failed to make it economically competitive as far as I can remember.