Voyager Jumpship and Yardship

[Lagrange]

I'm trying to work out a standard jumpship for general transport and participation in a jump circuit, ending up with the Voyager below.  As always, I'm interested in any comments about how to improve the design.

The Voyager is similar in scale (100K tons), price (~500M), and collars (2) to the Merchant, but with much greater endurance.  The Merchant has sufficient fuel stores for ~1.5 months of station keeping and can't charge the jump drive off of fuel stores.  The Voyager in contrast has 8+ months of endurance or can charge the drive twice off the fuel store enabling a 90 light year transit through dead space or a 30 jump voyage with the light collecting sail.   30 jumps, for example, is slightly over the maximum radius of the inner sphere.

The cargo is divided into two bays.  The 100 ton bay contains all the spare parts and consumables necessary for 8 months.  The remaining 21 ton bay is free storage for anything else desired.  Relative to the Merchant (~650 tons) the quantity of free storage is much lower, implying a strong dependence on dropship->dropship or dropship->station->dropship transshipment rather than dropship->jumpship->dropship transshipment.

Like all jumpships, the Voyager class is a poor combatant.  It does however have two modest advantages.  Maximized Lamellor Ferro-carbide armor provides a bit over 3x the protection of a typical Merchant while Laser AMS provide a modest capacity to defend against missiles, particularly when linked into a grid with other ships.  Nevertheless, crews are likely to end up requiring the use of lifeboats should any serious combat situation arise.

A single smallcraft bay enables easy transport as well as a degree of modularity.  Two additional passenger quarters provide space for journeyman crew or a passenger.

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Voyager Jumpship
Mass: 99,000 tons
Technology Base: Inner Sphere (Advanced)
Introduced: 3145
Mass: 99,000
Battle Value: 1,864
Tech Rating/Availability: F/X-X-X-F
Cost: 517,857,500 C-bills

Fuel: 250 tons (2,500)
Safe Thrust: 0
Maximum Thrust: 0
Sail Integrity: 4
KF Drive Integrity: 3
Heat Sinks: 93 (186)
Structural Integrity: 1

Armor
    Nose: 13
    Fore Sides: 13/13
    Aft Sides: 13/13
    Aft: 12

Cargo
    Bay 1:  Small Craft (1)         1 Door   
    Bay 2:  Cargo (100.0 tons)      1 Door   
    Bay 3:  Cargo (21.0 tons)       1 Door   

Ammunition:
None

Dropship Capacity: 2
Grav Decks: 1 (95 m)
Escape Pods: 0
Life Boats: 2
Crew:  2 officers, 9 enlisted/non-rated, 5 bay personnel, 2 passengers

Notes: Mounts 55 tons of lamellor ferro-carbide armor.

Weapons:         Capital Attack Values (Standard)
Arc (Heat)   Heat  SRV     MRV     LRV      ERV    Class     
Nose (14 Heat)
2 Laser AMS  14    1(6)    0(0)    0(0)     0(0)   AMS       
FRS/FLS (14 Heat)
2 Laser AMS  14    1(6)    0(0)    0(0)     0(0)   AMS       
ARS/ALS (14 Heat)
2 Laser AMS  14    1(6)    0(0)    0(0)     0(0)   AMS       
Aft (14 Heat)
2 Laser AMS  14    1(6)    0(0)    0(0)     0(0)   AMS       
If a Voyager carries a pair of fully loaded Warmothers into combat the total cost is 4833M or ~121M/triad.

Tradeoffs:
Dropcollars What is the right number of drop collars for a jump circuit ship?  There are two metrics for a jump circuit: collar count and length.  If you have a fixed budget and care about only collar count, you end up making jumpships with 10 collars and have a short circuit since each individual node is very expensive.  If you have a fixed budget and care only about jump circuit length, you make long circuits with no collars.  If you instead care about both equally, you end up choosing 2 collars since a 2-collar design produces a circuit only 68% shorter (350M/517M) than 1-collar approach and has 72% (187M/collar / 259M/collar) of the collars of a 10-collar approach.

Range Jumpships normally can top-up supplies from carried dropships.  In a jump circuit, that may not be possible since there are only a few minutes before a dropship is passed on to the next jumpship in the line.  An extreme example of range is given by the Magellan which has 1200 tons of fuel lasting 600+ days, although notably with a single dropcollar and no grav deck.  The Voyager doesn't match that, but the 250+ day fuel capacity is slightly less than half that and over 5x a Merchant's range.  Amongst other jumpships, there are the Hunter (400 days, no grav deck, 1 dropcollar, Clan), Odyssey (250 days, 4 dropcollars, Clan), and the Leviathan (250 days, 8 dropcollars).  So no other canon jumpship manages greater range with 2 or more collars and everything with more range lacks a grav deck.

Luxuries? You can save tons by dropping grav decks, shifting to steerage quarters, or in a few other ways.  However, trading off an 8 month range with a comfortable crew for a 10 month range with an uncomfortable crew doesn't seem like a good tradeoff in large scale usage.

Defense? The investment in LFC armor, laser AMS, and double heat sinks is somewhat questionable on an essentially-noncombatant unit.  Nevertheless, I'm thinking of applications where a Voyager is treated as a disposable unit when it jumps into a contested zone with 2 Warmother dropships.  There, the Laser AMS protects the Warmothers as well as the Voyager itself, destroying White Shark and Antiship missiles when functioning as a member of a defensive grid.  The cost here is also fairly low (~1.5% of total) so it seems like an acceptable expense. 

Voyager, 3025

In a 3025 context, minor downgrades still produce a simple and capable jumpship.  The variations are below.

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3025 Voyager Jumpship
Mass: 99,000 tons
Introduced: 3025
Battle Value: 840
Tech Rating/Availability: D/X-E-D-F
Cost: 507,931,250 C-bills

Armor
    Nose: 7
    Fore Sides: 7/7
    Aft Sides: 8/8
    Aft: 7

Cargo
    Bay 1:  Small Craft (1)         1 Door   
    Bay 2:  Cargo (100.0 tons)      1 Door   
    Bay 3:  Infantry (Foot) (5)     1 Door   
    Bay 4:  Cargo (34.0 tons)       1 Door   

Dropship Capacity: 2
Grav Decks: 1 (95 m)
Life Boats: 2
Crew:  2 officers, 9 enlisted/non-rated, 33 bay personnel, 2 passengers

Notes: Mounts 55 tons of standard aerospace armor.

Weapons:     Capital Attack Values (Standard)
Arc (Heat) Heat  SRV     MRV     LRV      ERV    Class       
None

Voyager Yardship

A rare variant of the 3025 Voyager drops two docking collars, the grav deck, much of the cargo space, and much of the fuel capacity in favor of an unpressurized yard capable of supporting assembly,  repair, and transport of 107K ton vessels.  The variations from the 3025 design are:

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Voyager Yardship
Cost: 969,411,750

Fuel: 12 tons (120)

Cargo
    Bay 1:  Cargo (12.5 tons)       1 Door   

Dropship Capacity: 0
Grav Decks: 0
Crew:  2 officers, 9 enlisted/non-rated in steerage quarters

107K ton Unpressurized Naval Repair Bay.
The Voyager Yardship is only meant to be used in a well-supported environment where the crew can rotate off to use other gravdecks as necessary.  The two key capabilities provided are:

• The ability to repair any damaged element of the jump circuit, whether a Voyager jumpship, Cavern dropship, or Sloth Transport Station.
• The ability to transport a jump circuit from one system to another.  The Voyager and Cavern already transport, so the missing link addressed here is the Sloth stations.

The cost is about twice a standard Voyager, so just a few successful rescue missions pay off the costs.

[NomadicChronicler]

Will just comment on a single point to begin with;

Grav Decks are not a luxury but a dire necessity for a crew that will never be subjected to acceleration generated pseudo-gravity for 10 months per circuit mate.

Please disregard. I are illiterate.

[Lagrange]

Grav Decks are not a luxury but a dire necessity for a crew that will never be subjected to acceleration generated pseudo-gravity for 10 months per circuit mate.

I'm agreeing--that's why the Voyager has a grav deck.

My understanding is that ISS crew members are typically up there for 6 months, and some have gone for 10 month-or-so stretches.  It's doable but not great---people getting back to earth need  time to rebuild strength and it may damage long term health in some ways. 

[CVB]

...a Jumpship with 10 collars would necessarily be much shorter.

Shorter than what? Measured in which unit? Sorry, maybe I'm just too dense...

[Lagrange]

Shorter than what? Measured in which unit? Sorry, maybe I'm just too dense...

Yeah, that doesn't seem to have been very clear.   I tried to write out more carefully in the OP.

In essence, there are two metrics for a jump circuit: collar count and length.  If you care about only collar count, you end up making jumpships with 10 collars and have a short circuit.  If you care only about jump circuit length, you make long circuits with no collars.  If you care about both equally, you end up choosing 2 collars since you are about equally suboptimal in both metrics.

Clearer?

[NomadicChronicler]

Lagrange;
Sorry, a very "DUH!" moment. Completely misread what you wrote...

[Lagrange]

I updated the OP to include a 3025 version of things in relation to a general effort to figure out logistics for 3025.

Transporting 2 Cavern dropships provides 170k+ tons of transport of which 110k+ can be loaded and offloaded while a 2 hour docking process is underway in a jump circuit.

My expectation is that often there would just be 1 Cavern, with the other docking collar occupied by some special load (such as a military transport). 

Although the Voyager was optimized for use in a jump circuit, it also appears fairly useful in long duration voyages, making it capable of supporting peripheral colonies.

[Lagrange]

Added a Voyager Yardship variant, which enables assembly, repair, and transport for all elements of the jump circuit.

[Retry]

Quite a nice Jumpship design.  Would work well in most command circuits.

Luxuries? You can save tons by dropping grav decks, shifting to steerage quarters, or in a few other ways.  However, trading off an 8 month range with a comfortable crew for a 10 month range with an uncomfortable crew doesn't seem like a good tradeoff in large scale usage.

Interesting.  I actually went the other way here for an AU called Vela Corridor: The Jumpships in the Whittle Network (a special type of Command Circuit) stuff as many dropship collars and cargo as they physically can, packing practically no armor, armament, comfortable quarters or even grav-decks onto their hulls such that they're practically a bag of metal components floating in tight formation around a KF Drive (Well, more so than usual that is).  Instead, amenities such as protection, gravity decks & quarters for crew are offloaded to Zenith/Nadir space stations.  Net result, the Crew only spends a few hours per week on the actual Jumpship to perform the jump, and spend the rest of their time on space stations, which has far more comfortable living conditions than a standard Jumpship can have. (much more space, and bigger Grav Decks = higher quality artificial gravity (closer to earth G & lower RPM)

It helped that the network was fairly far away from both the Clans and Inner Sphere and thus didn't have factions-of-the-week razing each other's supporting infrastructure into the ground every other year.

[Lagrange]

Quite a nice Jumpship design.  Would work well in most command circuits.

Thanks 

Net result, the Crew only spends a few hours per week on the actual Jumpship to perform the jump, and spend the rest of their time on space stations, which has far more comfortable living conditions than a standard Jumpship can have. (much more space, and bigger Grav Decks = higher quality artificial gravity (closer to earth G & lower RPM)

This makes sense on a well-established and supported circuit.  I wanted a design that could go several stops unsupported for several reasons:

• The circuit becomes more easily mobile.
• The circuit can more easily support economically poor systems.
• A general purpose design enables non-circuit applications as well.  Basically, I think of the Voyager as a better (=cheaper, more serviceable, greater duration) Merchant.

There's a little more discussion here if interested.

[Lagrange]

Updated the yardship version to go up to 107K tons.  This seems to be a key capability, since it enables the repair and transport of stations with an energy battery.

Also updated the 3025 version to include an infantry bay.  This is marginally useful when jumping from station to station since it allows passengers.  This also provides the life support for visitors to benefit from the grav deck.

[Daryk]

Yeah, it's odd life support is just a C-Bill charge...