Most Efficient Ship by TL for Cargo to X Parsecs

[Grav_Moped]

I, of course, use LBB2 hulls for LBB2 ships.

Streamlining in LBB2 is not +10%, but MCr 1 per 100 Dt (LBB2'81 p15).

For custom hulls, they're equivalent.
Hull: MCr0.1/Td unstreamlined.
Streamlining: MCr1/100Td=MCr.01Td.
MCr0.1/Td+MCr0.01/Td=MCr0.11/Td.
0.11/0.1=1.1 (+10%)

Not equivalent for standard hulls, no. And very non-linear.

Tons   Nonstreamlined  Streamlined  
          Cost (MCr)   Cost (MCr)   % cost
 100Td        2            3         +50%
 200Td        8           10         +25%
 400Td       16           20         +25%
 600Td       48           54         +12.5%
 800Td       80           88         +10%
1000Td      100          110         +10%

The standard 600 Dt hull in LBB2 costs MCr 48 (but takes 22 months to build).

So a streamlined standard 600 Dt hull costs:
MCr 48 _ Base hull (LBB2'81 p22)
MCr _6 _ Streamlining (LBB2'81 p15)
=========
MCr 54 _ Total

It's just MCr 12 cheaper than a custom hull, which is nice, but not "an INSANE bargain".

Fair enough. Misread build time as cost; +10% for streamlining and got 41.8MCr savings... now that would have been worth wasting 50 tons of cargo for.... But no. LOL

At 600Td, the 50Td wasted isn't worth saving MCr 12 on the hull. Will need to recalc costs for the TL-9 J-1 800Td ship and slot that in again.

 

[Grav_Moped]

@ GravMoped - enjoying your analysis. Looking forward to seeing J4-J6.

Will you share your spreadsheet?
How are you confirming these are optimal; is this a manual search?!?

@ AD - will you share your trade volumes spreadsheet?

Sure, if a MS OneDrive link will suffice.
It's a hacked mess though. It's the quick-and-dirty hack spreadsheet tab I use to build ships one at a time, with salary and cost stuff bodged in. No macros, no lookup tables -- it's pretty much manual plug-in-all-the-numbers rather than pick a hull size and performance numbers and let the spreadsheet do the rest. For example, weaponry is two line items: "hardpoint" at MCr0.1, and "turret" at 1 Td and MCr2 (both typed in manually).

I replicated it a couple of dozen times, once per ship, then linked a summary sheet to the cost per parsec section of each tab.

The summary sheet then lays out each ship's cost-to-x-parsecs table (where X is 1-6) and finds the lowest cost option for each TL and distance, then looks up the ship from the header row that has that cost and lists it.

Honestly, it's embarrassing and, as-is, is really only useful for this one project.

But sure, if you want it I can post it.

 

[Grav_Moped]

...
I have experimented with robots, but I just end up with fully automated ships, possibly with a token sophont supervisor.

But that defeats the purpose of a RPG largely set in space, so I use the crew requirements strictly. There might be robots doing the actual work, but there is also a sophont crew herding them by law, custom, or prejudice...

Or just maybe small virus outbreaks have happened before, so fully automated ships are strictly banned?

IMTU (basically OTU), the 3I does not allow robots to control a starship's offensive weaponry, maneuver drives, or Jump.

Defensive weaponry and screens can be bot-controlled.

Maneuver drives can have autopilot functionality, but only with sophont guidance (the autopilot can't pick its own destinations).

 

[Grav_Moped]

UPDATED TO CORRECT FOR ENGINEERING CREW COMPUTATION ERROR (see below.)
(Also, the TL-11 J2 ship was mistakenly shown as 800Td, not 1000Td.)

Ok, I think I'm done. Just need to package it so it makes sense.

Let's start by going over the common characteristics of the ships I'm working with:

Jump Drives and Power Plants are sized to the required Jump Number.
Maneuver Drives are 1G.
Hulls are per LBB2, streamlined, and custom unless otherwise noted.
Drive space left over after drive installation in standard hulls cannot be used for any other purpose.
Computer is the minimum (least expensive/smallest) needed to support the required Jn.
Armament is one triple turret, armed with Beam Laser, Missile Launcher, and Sandcaster
Crew assigned as per LBB2.
All crew are skill level 1 in their position except supervisors.
Skill level and supervision salary bonuses (+10%) do not stack.
Engineers assigned at 1 per 35Td drives rounded down, minimum 1 except in 100Td ships.
"Extremely large ships..." (LBB2'81 p.16) needing 10 crew per 1000Td are those 4000Td and up.
If their positions are required, the CO's salary is Cr7K/Mo., the XO's is Cr6K/Mo., Admin get Cr1K/Mo.
Generic crew added to meet minimum crew size for large ships are paid Cr3500/Mo. average.
All crew are in single 4Td staterooms.
"Payload" is space left over after accounting for all of the above. It can be used for cargo, staterooms (with additional allowance for steward staterooms if desired), weapons (which will require gunners), computer upgrades, or carried vehicles and small craft. Non-revenue-generating payload will increase the cost per ton per parsec of the remaining revenue-generating payload.

Operational assumptions:
Ships jump twice per month, for a total of 50 Jumps per year including annual overhauls.
Ships burn 2 weeks of power plant fuel (half the monthly allocation) per Jump.
Refined fuel is always used. If refined fuel is not available, cargo rates will increase to reflect the additional risk.

Financial assumptions:
Stated ship costs include 10% discount for multiple ships.
Ships are self-financed; no down payment is required, but payments are still 1/240 of the ship's cost for 480 payments (40 years). The additional 100% of the ship's cost (the "interest" on the "loan") is the owners profit on the investment. (This simplifies calculations of cost per cargo ton per parsec.) I neglected to include port fees of Cr100/week. This may introduce an error of 1Cr/Td/wk/Pc in small ships over longer distances.
EDIT TO ADD:
Ship costs incorporate 10% discount for volume production.

TL-9
                           Class
Jn  Tons    Drives Payload Cost    Notes:
1    800      D      619    68.39
2    400     D,B     204    99.99  Std hull. Wastes 9Td. Would be 400Td regardless.
3    200     C,A     40     92.79
Jump-4+ is not possible at TL-9 due to computer TL limitations. 


TL-10
                           Class
Jn  Tons    Drives Payload Cost    Notes:
1   1000       E     793   208.44
2    800      H,D    493   235.44
3    400      F,B    175   133.74  F is smallest that gets J3 in 400Td @ TL-10. 
4    400      H,B     74   210.24  (Larger drive, same hull.)
Jump-5+ is not possible at TL-10 due to computer TL limitations. 

TL-11
                           Class
Jn  Tons    Drives Payload Cost    Notes:
1   2000      J,E   1605   394.29
2   1000      H,D    635   292.14
3    600      J,C    206   202.32
5    400      K,B     57   256.14            
TL-11 does not enable construction of a Jump-4 ship larger than at TL-10.
Jump-6 is not possible at this TL due to component size limits.

TL-12
                           Class
Jn  Tons    Drives Payload Cost    Notes:
3    800      M,D     366  313.29
4    600      M,C     156  299.79
TL-12 does not enable construction of a Jump-1 ship larger than at TL-11.
TL-12 does not enable construction of a Jump-2 ship larger than at TL-11.
TL-12 does not enable construction of a Jump-5 ship larger than at TL-11.
Jump-6 is not possible at this TL due to component size limits.  

TL-13
                           Class
Jn  Tons    Drives Payload Cost    Notes:
1   3000       Q    2417   617.49
3   1000      Q,E    480   386.19
5    600      Q,C    61    361.89
TL-13 does not enable construction of a Jump-2 ship larger than at TL-11.
TL-13 does not enable construction of a Jump-4 ship larger than at TL-12.
Jump-6 is not possible at this TL due to component size limits. 

TL-14
                           Class
Jn  Tons    Drives Payload Cost    Notes:
4    800      R,D    238   389.34
TL-14 does not enable construction of a Jump-1 ship larger than at TL-11.
TL-14 does not enable construction of a Jump-2 ship larger than at TL-11.
TL-14 does not enable construction of a Jump-3 ship larger than at TL-13.
TL-14 does not enable construction of a Jump-5 ship larger than at TL-13.
Jump-6 is not possible at this TL due to component size limits. 

TL-15
                           Class
Jn  Tons    Drives Payload Cost    Notes:
1   5000       W    3973   959.49
2   5000      Z,W   3439  1009.89
3   4000      Z,W   2288   914.49
4   3000      Z,W   1348   795.69
5   1000      W,E    201   508.59  Why bother? It's cheaper to J-5 the J-6 2000Td... 
6   2000      Z,W    425   671.94

 

[Grav_Moped]

Table has been updated to correct an error in calculating Engineering crew.
(The formulae now round up to the nearest 35 tons of drives instead of rounding down; raising ship purchase costs by a trivial amount, but increasing overhead costs and reducing payload. This does not change relative efficiency, the same ships are still most cost-efficient.)

Now, the annoying table with everything:
(I'll break it down by Tech Level in subsequent posts.)

Cost per ton to a distance of X parsecs by available TL
Includes the ship used to acccomplish the task, number of jumps, and the length of the Jumps.

Dist 
 /TL-9  Ship  TL-10   Ship  TL-11   Ship  TL-12   Ship  TL-13   Ship  TL-14   Ship  TL-15   Ship                          
1  684  T9 J1   648  T10 J1   614  T11 J1   614  T11 J1   614  T11 J1   614  T11 J1   614  T11 J1
2 1368  T9 J1  1242  T10 J2  1185  T11 J2  1185  T11 J2  1185  T11 J2  1185  T11 J2   826  T15 J2
3 2052  T9 J1  1945  T10 J1  1842  T11 J1  1842  T11 J1  1842  T11 J1  1842  T11 J1  1181  T15 J3
4 2736  T9 J1  2484  T10 J2  2370  T11 J2  2370  T11 J2  2370  T11 J2  2370  T11 J2  1652  T15 J2
5 3420  T9 J1  3242  T10 J1  3069  T11 J1  3069  T11 J1  3069  T11 J1  3069  T11 J1  2271  T15 J3
6 4104  T9 J1  3726  T10 J2  3556  T11 J2  3556  T11 J2  3556  T11 J2  3556  T11 J2  2362  T15 J3

 

[Grav_Moped]

Table has been updated to correct an error in calculating Engineering crew.
(The formulae now round up to the nearest 35 tons of drives instead of rounding down; raising ship purchase costs by a trivial amount, but increasing overhead costs and reducing payload. This does not change relative efficiency, the same ships are still most cost-efficient.)

This is the cost in credits to carry 1 ton of cargo to a given number of parsecs (Dist) via the least expensive means, by Tech Level.

Dist                    Cost to distance by TL
          TL-9     TL-10     TL-11     TL-12     TL-13     TL-14     TL-15
  1        684       648       614       614       614       614       614
  2       1368      1242      1185      1185      1185      1185       826
  3       2052      1945      1842      1842      1842      1842      1181
  4       2736      2484      2370      2370      2370      2370      1652
  5       3420      3242      3069      3069      3069      3069      2271
  6       4104      3726      3556      3556      3556      3556      2362

Note that this is just alternate columns from the above table.

 

[Grav_Moped]

Corrected: the TL-11 J-2 ship is 1000Td, not 800Td as shown previously.
These are the ships which get used to carry the cargo in the preceding table:

Distance      TL-9       TL-10       TL-11      TL-12      TL-13      TL-14     TL-15
(Parsecs)   Jn, Tons    Jn, Tons    Jn, Tons   Jn, Tons   Jn, Tons   Jn, Tons   Jn, Tons
    1       J1, 800     J1, 1000    J1,2000    J1, 2000   J1,2000    J1, 2000   J1, 2000
    2       J2, 400     J2, 1000    J2, 1000   J2, 1000   J2, 1000   J2, 1000   J2, 5000(Z)
    3       J1, 800     J1, 1000    J1,2000    J1, 2000   J1,2000    J1, 2000   J3, 4000
    4       J2, 400     J2, 1000    J2, 1000   J2, 1000   J2, 1000   J2, 1000   J2, 5000(Z)
    5       J1, 800     J1, 1000    J1,2000    J1, 2000   J1,2000    J1, 2000   J3, 4000
    6       J2, 400     J2, 1000    J2, 1000   J2, 1000   J2, 1000   J2, 1000   J3, 4000

These are the other alternate columns from the first table.

Observations:
Until TL-15, odd distances are always cheapest by the largest Jump-1 ship that the available TL provides for.
Until TL-15, even distances are always cheapest by the largest Jump-2 ship that the available TL provides for.
Both of these max out at TL-11 until TL-15 (Strangely, the TL-13 3000Td J-1 ship is less cost-efficient than the TL-11 one -- probably due to crew size.)
At TL-15, J-3 is cheaper for 3 and 6 parsecs; J-2 is cheaper for 4 parsecs.
Also at TL-15, there is no reason for the Jump-5, 1000Td ship with W drives to exist. Not only is it cheaper to use the Jump-3 4000Td ship jumping twice to get J-5, it's also cheaper to use the Jump-6 2000Td ship at Jump-5 to do it. Z drives, man...

 

[Grav_Moped]

I'm going to need to calculate average cost per Jump for each distance and TL to see how far the rules-as-written per-jump payment diverges from actual costs.

Really, though, it looks a lot like a per-parsec rather than a per-jump model is the best fit for non time-critical cargo.

I'll also break down costs to 1-6 parsecs for each ship, but that will be a bit more of a grind.

 

[AnotherDilbert]

For custom hulls, they're equivalent.
Hull: MCr0.1/Td unstreamlined.
Streamlining: MCr1/100Td=MCr.01Td.

Not quite, custom hull have a minimum cost of MCr 20, so any hull <200 Dt will break the 10% relationship.

 

[AnotherDilbert]

Engineers assigned at 1 per 35Td drives rounded down, minimum 1 except in 100Td ships.

If we go by the ships in LBB2, crew requirements are rounded up.

Example: Sub Liner has 83 Dt drives, so has 83/35≈2.371 rounded up to 3 engineers.

 

[AnotherDilbert]

Until TL-15, even distances are always cheapest by the largest Jump-2 ship that the available TL provides for.

You should check out the three week 2 × J-1 carrying fuel for both jumps cycle. Except for Z drives, it seems to be slightly cheaper.


With your chosen criteria, bigger ships are basically better, as you have found. At any lower TL a J-1 ship with fuel for two jumps will be larger and more efficient than a J-2 ship.



To take an extreme example:
TL-11, J-2, cost Cr 1157 per trip:

MT-A2212R1-030000-10001-0        MCr 293       1 000 Dton
bearing     1     1   1                            Crew=7
batteries   1     1   1                             TL=11
                       Cargo=635 Fuel=220 EP=20 Agility=1

Single Occupancy    LBB2 design                     635       325
                                     USP    #      Dton      Cost
Hull, Streamlined   Custom             A          1 000          
Configuration       Cone               2                      110
Scoops              Streamlined                                  
                                                                 
Jump Drive          K                  2    1        55       100
Manoeuvre D         E                  1    1         9        20
Power Plant         K                  2    1        31        80
Fuel, #J, #weeks    J-2, 4 weeks            2       220          
                                                                 
Bridge                                      1        20         5
Computer            m/1bis             R    1         1         4
                                                                 
Staterooms                                  7        28         4
                                                                 
Cargo                                               635          
                                                                 
Mixed Turret        Full                    1         1         1
  Weapon            Missile            1    1                   1
  Weapon            Pulse              1    1                   1
  Weapon            Sand               3    1                   0
                                                                 
Nominal Cost        MCr 325,10           Sum:       635       325
Class Cost          MCr  35,76          Valid        ≥0        ≥0
Ship Cost           MCr 292,59                                   
                                                                 
                                                                 
Crew &               High     0        Crew          Bridge     2
Passengers            Mid     0           7       Engineers     3
                      Low     0                     Gunners     1
                 Extra SR     0      Frozen         Service     1
               # Frozen W     0           0          Flight     0
                  Marines     0                     Marines     0
                                                                 
                                                                 
Estimated Economy of Ship     Standard                                     
       Ship price     Down Payment         Mortgage       Trips/year
       MCr 292,59       kCr 58 518        kCr 1 219             25,0
                                                                 
Expenses per jump                       Revenue                  
Bank                Cr 585 180          High           Cr       0
Fuel                Cr 110 000          Middle         Cr       0
Life Support        Cr  14 000          Low            Cr       0
Salaries            Cr  12 960          Cargo          Cr 508 000
Maintenance         Cr  11 704                                   
Berthing            Cr   1 000                                   
                                                                 
Summa              kCr     735                        kCr     508
                                                                 
  Cost per trip per Dton cargo     Cr 1157

TL-11, J-1×2, three week cycle, cost Cr 1068 per trip:

MT-B211112-030000-10001-0        MCr 395       2 000 Dton
bearing     1     1   1                           Crew=12
batteries   1     1   1                             TL=11
                      Cargo=1405 Fuel=410 EP=20 Agility=0

Single Occupancy    LBB2 design                   1 405       439
                                     USP    #      Dton      Cost
Hull, Streamlined   Custom             B          2 000          
Configuration       Cone               2                      220
Scoops              Streamlined                                  
                                                                 
Jump Drive          J                  1    1        50        90
Manoeuvre D         J                  1    1        17        36
Power Plant         J                  1    1        28        72
Fuel, #J, #weeks    J-2, 4 weeks            2       210          
                                                                 
Bridge                                      1        40        10
Computer            m/1                1    1         1         2
                                                                 
Staterooms                                 12        48         6
                                                                 
Cargo                                             1 405          
Demountable Tanks   J-1                     1       200         0
                                                                 
Mixed Turret        Full                    1         1         1
  Weapon            Missile            1    1                   1
  Weapon            Pulse              1    1                   1
  Weapon            Sand               3    1                   0
                                                                 
Nominal Cost        MCr 438,80           Sum:     1 405       439
Class Cost          MCr  48,27          Valid        ≥0        ≥0
Ship Cost           MCr 394,92                                   
                                                                 
                                                                 
Crew &               High     0        Crew          Bridge     7
Passengers            Mid     0          12       Engineers     3
                      Low     0                     Gunners     1
                 Extra SR     0      Frozen         Service     1
               # Frozen W     0           0          Flight     0
                  Marines     0                     Marines     0
                                                                 
                                                                 
Estimated Economy of Ship     Standard                                     
       Ship price     Down Payment         Mortgage       Trips/year
       MCr 394,92       kCr 78 984        kCr 1 646             16,7  (= 50 w / 3 w)
                                                                 
Expenses per jump                       Revenue                  
Bank              Cr 1 184 760          High         Cr         0
Fuel              Cr   205 000          Middle       Cr         0
Life Support      Cr    48 000          Low          Cr         0
Salaries          Cr    37 440          Cargo        Cr 1 124 000
Maintenance       Cr    23 695                                   
Berthing          Cr     2 000                                   
                                                                 
Summa            kCr     1 501                      kCr     1 124
                                                                 
  Cost per trip per Dton cargo     Cr 1068

Obviously my calculated numbers are not exactly the same as yours, but the difference is marginal. E.g. berthing costs are insignificant.

 

[Grav_Moped]

Not quite, custom hull have a minimum cost of MCr 20, so any hull <200 Dt will break the 10% relationship.

Fair enough. I haven't ever done serious work (other than "will it fit?") on ships under 200Td, so I missed that.

If we go by the ships in LBB2, crew requirements are rounded up.

Example: Sub Liner has 83 Dt drives, so has 83/35≈2.371 rounded up to 3 engineers.

Fair enough. I'll redo the math -- it might move the numbers a little.


Just bumps up costs across the board, doesn't change which ships are most profitable.

I'll revise the preceding tables accordingly, and make a note here when I've done it.

 

[Grav_Moped]

You should check out the three week 2 × J-1 carrying fuel for both jumps cycle. Except for Z drives, it seems to be slightly cheaper.


With your chosen criteria, bigger ships are basically better, as you have found. At any lower TL a J-1 ship with fuel for two jumps will be larger and more efficient than a J-2 ship.



To take an extreme example:
TL-11, J-2, cost Cr 1157 per trip:

Spoiler:

MT-A2212R1-030000-10001-0        MCr 293       1 000 Dton
bearing     1     1   1                            Crew=7
batteries   1     1   1                             TL=11
                       Cargo=635 Fuel=220 EP=20 Agility=1

Single Occupancy    LBB2 design                     635       325
                                     USP    #      Dton      Cost
Hull, Streamlined   Custom             A          1 000          
Configuration       Cone               2                      110
Scoops              Streamlined                                  
                                                                 
Jump Drive          K                  2    1        55       100
Manoeuvre D         E                  1    1         9        20
Power Plant         K                  2    1        31        80
Fuel, #J, #weeks    J-2, 4 weeks            2       220          
                                                                 
Bridge                                      1        20         5
Computer            m/1bis             R    1         1         4
                                                                 
Staterooms                                  7        28         4
                                                                 
Cargo                                               635          
                                                                 
Mixed Turret        Full                    1         1         1
  Weapon            Missile            1    1                   1
  Weapon            Pulse              1    1                   1
  Weapon            Sand               3    1                   0
                                                                 
Nominal Cost        MCr 325,10           Sum:       635       325
Class Cost          MCr  35,76          Valid        ≥0        ≥0
Ship Cost           MCr 292,59                                   
                                                                 
                                                                 
Crew &               High     0        Crew          Bridge     2
Passengers            Mid     0           7       Engineers     3
                      Low     0                     Gunners     1
                 Extra SR     0      Frozen         Service     1
               # Frozen W     0           0          Flight     0
                  Marines     0                     Marines     0
                                                                 
                                                                 
Estimated Economy of Ship     Standard                                     
       Ship price     Down Payment         Mortgage       Trips/year
       MCr 292,59       kCr 58 518        kCr 1 219             25,0
                                                                 
Expenses per jump                       Revenue                  
Bank                Cr 585 180          High           Cr       0
Fuel                Cr 110 000          Middle         Cr       0
Life Support        Cr  14 000          Low            Cr       0
Salaries            Cr  12 960          Cargo          Cr 508 000
Maintenance         Cr  11 704                                   
Berthing            Cr   1 000                                   
                                                                 
Summa              kCr     735                        kCr     508
                                                                 
  Cost per trip per Dton cargo     Cr 1157

TL-11, J-1×2, three week cycle, cost Cr 1068 per trip:

MT-B211112-030000-10001-0        MCr 395       2 000 Dton
bearing     1     1   1                           Crew=12
batteries   1     1   1                             TL=11
                      Cargo=1405 Fuel=410 EP=20 Agility=0

Single Occupancy    LBB2 design                   1 405       439
                                     USP    #      Dton      Cost
Hull, Streamlined   Custom             B          2 000          
Configuration       Cone               2                      220
Scoops              Streamlined                                  
                                                                 
Jump Drive          J                  1    1        50        90
Manoeuvre D         J                  1    1        17        36
Power Plant         J                  1    1        28        72
Fuel, #J, #weeks    J-2, 4 weeks            2       210          
                                                                 
Bridge                                      1        40        10
Computer            m/1                1    1         1         2
                                                                 
Staterooms                                 12        48         6
                                                                 
Cargo                                             1 405          
Demountable Tanks   J-1                     1       200         0
                                                                 
Mixed Turret        Full                    1         1         1
  Weapon            Missile            1    1                   1
  Weapon            Pulse              1    1                   1
  Weapon            Sand               3    1                   0
                                                                 
Nominal Cost        MCr 438,80           Sum:     1 405       439
Class Cost          MCr  48,27          Valid        ≥0        ≥0
Ship Cost           MCr 394,92                                   
                                                                 
                                                                 
Crew &               High     0        Crew          Bridge     7
Passengers            Mid     0          12       Engineers     3
                      Low     0                     Gunners     1
                 Extra SR     0      Frozen         Service     1
               # Frozen W     0           0          Flight     0
                  Marines     0                     Marines     0
                                                                 
                                                                 
Estimated Economy of Ship     Standard                                     
       Ship price     Down Payment         Mortgage       Trips/year
       MCr 394,92       kCr 78 984        kCr 1 646             16,7  (= 50 w / 3 w)
                                                                 
Expenses per jump                       Revenue                  
Bank              Cr 1 184 760          High         Cr         0
Fuel              Cr   205 000          Middle       Cr         0
Life Support      Cr    48 000          Low          Cr         0
Salaries          Cr    37 440          Cargo        Cr 1 124 000
Maintenance       Cr    23 695                                   
Berthing          Cr     2 000                                   
                                                                 
Summa            kCr     1 501                      kCr     1 124
                                                                 
  Cost per trip per Dton cargo     Cr 1068

Obviously my calculated numbers are not exactly the same as yours, but the difference is marginal. E.g. berthing costs are insignificant.

Something that might matter in my interpretation is that ships already carry two jumps of power plant fuel (because the pp burn rate is per month and ships jump twice a month). This makes a difference for the smallest ships. Looks like you've taken that into account, but for an over-tanked back-to-back jump I'd say the power plant used 3/4 of a month's fuel rather than the whole month's fuel.

LBB2 is all about "bigger is better" at least until the minimum crew size kicks in, then after that the Z drives blow everything away.

I was really surprised that 3xJ1 beat 1J3 (again, except for Z drives). If the ships had to carry all the fuel for multiple-parsec, multiple-jump runs, it'd look a lot different.

Another thing worth repeating (that I left out of my repetition of the operating assumptions) is that all the multi-jump trips are done in the same ship. That is, 3 parsecs in a J-2 ship includes one Jump-1 in that Jump-2 ship. This cuts fuel costs but not the fixed expenses, so that J-2 ship is really inefficient on the short jump by comparison to a J-1 ship. Apparently that inefficiency is worse than incurring the fixed costs multiple times for the slower alternative.

This is pretty much what you're getting at with the over-tanked multi-jump option you're talking about, without the extra cost of the higher-rated drives and cargo space lost to extra fuel tankage.

 

[vegas]

Operational assumptions:
Ships jump twice per month, for a total of 50 Jumps per year including annual overhauls.

There is a typo there, I don't which way; is it
1) jump twice per month for a total of 24 jumps per year, or
2) one jump per week for 50 jumps per year?

I'm re-using all your good work...

 

[Grav_Moped]

If over-tanked back-to-back Jump-1 beats Jump-2 on cost, then everything goes by Jump-1 by default until TL-15.

And that means the base cargo rate has to be on a per-parsec basis, and the per-jump rates in the rules are broken. We knew that, but now I know why.

The follow-up questions are how much are shippers willing to pay for faster delivery? Or, working within the construct of my analysis, how much extra would they have to pay to get their cargo there faster?

I still need to check to see whether High Guard ships change this math, and double-check by building High Guard ships with LBB2 drives.

 

[AnotherDilbert]

I was really surprised that 3xJ1 beat 1J3 (again, except for Z drives).

Me too, I have made this kind of calcs before, but never with LBB2 ships.

If the ships had to carry all the fuel for multiple-parsec, multiple-jump runs, it'd look a lot different.

You lose a little cargo space, but you save a week of mortgage and salaries.

Losing the cargo space is not too bad for a J-1 ship, but carrying fuel for two jumps in a J-3 ship would about halve cargo space.

 

[AnotherDilbert]

There is a typo there, I don't which way; is it
1) jump twice per month for a total of 24 jumps per year, or
2) one jump per week for 50 jumps per year?

Presumably a typo.

Normally a ship can jump 25 times per year. 52 weeks in a year, 2 lost to maintenance leaves 50 weeks, one jump every two weeks is 25 jumps.

 

[AnotherDilbert]

The follow-up questions are how much are shippers willing to pay for faster delivery?

Depends entirely on type of cargo. Hard to model.

I still need to check to see whether High Guard ships change this math, and double-check by building High Guard ships with LBB2 drives.

Cost is lower, slightly cheaper hulls and bigger standard discount makes the ships cheaper. No "extremely large" ships crews. Drop tanks makes high jump ships possible. J-6 costs are dramatically lower.

 

[Proneutron]

If over-tanked back-to-back Jump-1 beats Jump-2 on cost, then everything goes by Jump-1 by default until TL-15.

Everything that has no time constraints put on its delivery time by the shipper. Otherwise no.

 

[Grav_Moped]

Presumably a typo.

Normally a ship can jump 25 times per year. 52 weeks in a year, 2 lost to maintenance leaves 50 weeks, one jump every two weeks is 25 jumps.

Yep, that's it. Not a typo, I just blurred twice/month with 50/52 weeks in operation.