The Type W Barge (Type WH Fuel Barge)

[robject]

The Type WH fuel barge is service barge for refueling ships in orbit. It's designed to fill its tanks from a world surface, then slowly lift into orbit. When its fuel levels are low, it reenters, refuels, and lifts back up. A sufficiently advanced TL could automate this with a sophisticated computer. Alternately a ship's brain could be installed to operate the ship. Or it can simply be flown by wire. Or a pilot could fly it up and then debark into an orbital station. And so on.

This example model has a flotation hull and landing legs, so it can do water landings as well as downport landings. Airframing makes it easier to handle in an atmosphere -- which is very helpful since it relies on lifters only, with neither maneuver drive nor power plant. Its fuel intakes allow gulping-and-refining water from seas or rivers at 1000 tons per hour. It has a Model/1 computer; a spacious bridge for three crew, ten spacer niches, and a bit of common space. It's still cramped, and is not intended for trips further than orbit (and then transfer off-ship).

Round trip time is nominally one standard day: 8 hours (plus or minus) to de-orbit, a few hours to refuel, optional hours for ground maintenance, and 8 hours back to orbit (plus or minus).

It holds up to 2000 tons of fuel and 250 tons of cargo. The extra spacer niches and cargo are for incidental transfer to and from orbit.

With maneuver-boosters (sold separately), this barge could conceivably cross interplanetary distances.

There is NO room for passengers.

MCr 250 for this model. There are a bazillion other versions of it.

Fuel Barge WH-ZA00 MCr250.8

Actual volume: 2385 tons
Crew comfort: -2
Passenger demand: -5

   Tons     Component                                MCr    Notes
-------     -----------------------------------    -----    --------------------
   2400     Airframe Hull, lifters, 24 a/l free      170    A, lifters, 24 a/l free
     24     Landing legs with pads                    24
     24     Flotation hull                            24
     50     25x Fuel Intakes with Purifier          27.5    #25 40 t/hr
      1     Computer Model/1 std                     1.5
      1     Life Support Standard                      1    10 person-months
      6     Spacious Bridge                          0.4    1cc 2op 0ws
      1     Crew Common Fresher                        1    10 crew
     10     10x Spacer Niche                           1    #10 1 crew
     16     4x Crew Commons                            0    #4
   2000     Cargo Hold Bulk Liquid                     0
    250     Cargo Hold Basic                           0
      2     Cargo Lock                               0.4

 

[robject]

Scale according to your needs. If your orbital setup requires 2,000 tons of fuel ready on-demand 24/7, then you should have three or four of these barges, and two or three pilots on standby.

If you find you need more than a couple dozen of these, then you might have to think about other options... I'm not sure if you want 20,000 ton hulls landing and launching a lot... although your mileage may vary.

 

[AnotherDilbert]

Landing legs (with wheels) are already included in Airframe configuration.

Lifters can't generate much lateral speed, so wings and fins will not have any airstream to work against, hence Airframe should not provide any benefit.

Any system with a defined TL should be possible to make Generic ("Certified" in previous versions) to be cheaper and have consistent quality. Perfect for a dependable civilian design. Applicable to e.g. Purifiers.

A M Drive-1 would cut the time to orbit from hours to minutes, increasing the ROI of the rest of the ship, at least if you actually need a steady stream of fuel.

The ship should have some communicators and sensors, and probably some more consoles to control them.

 

[AnotherDilbert]

I would make it something like this; TL-10, 2100 Dt cargo, MCr 258:

TL-10  F-ZA10                        Ergo 2   Comfort 4    Demand 0        Agility 1
       Freighter                     Total:           0         258        Stability 2
SYSTEM                                    #        DTON        COST    
                                                                       
Hull                                              2 400                
Config: Airframe                                                158    
Structure: Plate Dense         AV=10 ( 100 vs Blast, 2000 vs Heat/Beam, 100 vs Pres, 1000 vs Rad, 0 vs EMP )    
Coating: Reflec                AV= 0 ( 1000 vs Heat/Beam  )    
Armour Std Anti-Rad                       1                          AV=10 ( 100 vs Blast, 1000 vs H/B, 1000 vs Rad, 0 vs EMP )    
Landing Wheels Wilderness                                              
Wings Incr Perform                                                      
Fins Incr Agility                                                      
Floatation Water Landing                             24          24    
Lifters Installed                                                12    
                                                                       
Gen M Drive B7  1 G, 1260 EP              1          21          21    
Gen P Plant P  P 1, 1260 EP               1          43          22    
                                                                       
Fuel, Power  4 weeks                                 26                
Purifier                                 25          25          13    
Water Intake                             25          25           1    
                                                                       
Console, Control Gen C+S=9                2           4           0        Brain: INT=4, EDU=2
Console, Operati Gen C+S=9                5          10           1        Brain: INT=4, EDU=2
Computer Gen m/0                          1           1           0    
                                                                       
Sensors                                                                
Mod AR Surf Commu-10 +12A+7 PA(           1                       2      
Gen AR Surf Radar-10 +10A+7 PA(           1                       2        ACS S=6
Gen AR Surf Scope-10 +10A-- P(P           1                       2        ACS S=4
                                                                       
Crew:                                     4                            
Stateroom for 1                           2           4           0    
Freshers Shared                           1           1           1    
Common Areas                              4           4                
Life Support:                                                          
Med Console                               1           1           1    
Life Support, Standard 200%               1           0           0        120 person-days
Escape Capsules 200%                      1           1           1         10 people
                                                                       
Standard Air Lock                        24                            
                                                                       
Cargo                                             2 187                
Spare Space                                          24                
                                                                       
                                                                       
                                       Crew    Consoles      Panels    
Crew                                 2                7          12    
Bridge Crew                          1    0                            
    Pilot                                 1           1           2    
    Sensor Ops                            0           2           3    
Engineer                             1    0                            
    Engineer                              1           3           5    
Service Crew                         0    0                            
    Operations                            0           1           2

 

[robject]

Those are EXCELLENT thoughts Dilbert.

The M-Drive (and P-Plant) suggestions are worth it, as your design sheet shows. Do you use a spreadsheet for that?

The default sensor suite should be fine. No need to install better ones. The Default Package, Book 2, p139.

 

[robject]

I guesstimate that one of the Lifter-Only barges would service around 30 ACS in orbit per week. That's guesstimating fuel needs quite a bit.

Dilbert is right: this thing needs an M-drive. With the M-drive, the barge could refuel every day if it had to, and so could serve a couple hundred ACS per week.

Worth it.

Add to that a capability to serve as an interplanetary barge.

Yeah, put an M-drive on it.

 

[AnotherDilbert]

Do you use a spreadsheet for that?

Sure:
https://www.travellerrpg.com/index.php?threads/t5-10-shipmaker-spreadsheet.40404/

The default sensor suite should be fine. No need to install better ones. The Default Package, Book 2, p139.

OK, I guess. It would cut detection range of an ACS from S=6 (250000 km) to S=2 (50 km) and of a small craft to S=1 (5 km), basically nothing. It would need constant supervision by ATC (STC? [Space Traffic Control]) and not be quite capable of independent ops.

I would still consider a basic commo and sensor package to be worth it, its only a few percent of ship cost.

The default commo and radar would still be devices needing panels and consoles to control them.

 

[Spinward Flow]

I would still consider a basic commo and sensor package to be worth it, its only a few percent of ship cost.

Agree.
Making an orbital craft entirely dependent upon offboard sensors is a first order mistake.

The default sensor suite should be fine. No need to install better ones. The Default Package, Book 2, p139.

You can pull that kind of stunt with an XBoat that doesn't need to maneuver in space.
Any craft (of any size) that needs to maneuver under its own power "at speed" in space really needs more sensor capacity like @AnotherDilbert is saying. Just simple basic orbital and interplanetary navigation would demand it for safety (if for no other reasons).

 

[robject]

OK, I guess. It would cut detection range of an ACS from S=6 (250000 km) to S=2 (50 km) and of a small craft to S=1 (5 km), basically nothing. It would need constant supervision by ATC (STC? [Space Traffic Control]) and not be quite capable of independent ops.

It is interesting that his Standard Sensor Packages table (which btw is later than the text) has the default as

Basic LR Surf-Mt Comm-9 Mod=0. MCr3.5. S=09.
Basic AR Surf-Mt Radar-9 Mod=0. MCr1.5. S=07.
Basic AR Surf-Mt Scope-9 Mod=0. MCr1.5. S=07.

Which is plenty long.

The original text, which severely limits the ranges, is older, and it looks like Marc changed his mind about that.

I'll have to ask.

 

[Grav_Moped]

Dilbert is right: this thing needs an M-drive. With the M-drive, the barge could refuel every day if it had to, and so could serve a couple hundred ACS per week.

Worth it.

Add to that a capability to serve as an interplanetary barge.

Yeah, put an M-drive on it.

Not necessarily, but it's a good idea. Use the airframe hull to maneuver on the way down -- probably wouldn't help much on the way up though.

 

[Spinward Flow]

Not necessarily, but it's a good idea. Use the airframe hull to maneuver on the way down -- probably wouldn't help much on the way up though.

Actually, you'd want the airframe on the way up too so as to help generate lift through forward motion (not just vertical) on the way to orbit when the barge is loaded with fuel and therefore "heavier" than when it is descending. Give the engineering a bit of extra margin for mass tolerance.

 

[AnotherDilbert]

It is interesting that his Standard Sensor Packages table (which btw is later than the text) has the default as
...
The original text, which severely limits the ranges, is older, and it looks like Marc changed his mind about that.

Standard ≠ Default.

Default is the minimum no-cost option.

Standard is a decent package that a standard ship might have, and comes at a cost.

 

[AnotherDilbert]

Actually, you'd want the airframe on the way up too so as to help generate lift through forward motion (not just vertical) on the way to orbit when the barge is loaded with fuel and therefore "heavier" than when it is descending. Give the engineering a bit of extra margin for mass tolerance.

With only lifters (as discussed) there is very little horizontal speed, so no airflow over the wings, so no lift from the wings.

Glide-flying on the way down, helped by the lifters, should work a treat.

 

[robject]

Standard ≠ Default.

Default is the minimum no-cost option.

Standard is a decent package that a standard ship might have, and comes at a cost.

I've re-checked, and the Default in the chart (first column) is a decent package. The Default in the text (2nd column) is older and pretty useless.

The Defaults are available even in small craft and life pods.

First column, p139.

 

[AnotherDilbert]

Hm, yes... Some confusion seems to be involved...

B2, p139, Col 2:
What Sensors Should A Ship Carry?
By default, any ship has automatically installed (and at no specific cost) the following sensors:

The Default Package
Comms. One R=7 C Communicator-8.
Radar. One R=7 R Radar-9.
Vision. Several R=6 Portholes. ...

The default installed Sensors cannot be modified. They can be supplemented with new Sensors. If other sensors fail, or are damaged, the Sensor Operator can almost always turn to the default package and try to make it work instead.

As you note, pretty useless. But the price is right: nothing.

B2, p139, Col 1:

...

The text about default is repeated.

I suspect there is just some confusion about labels here. Or possibly two versions conflated?

I have some difficulty believing that two sensor packages, each costing MCr ~6.5, additionally requiring two consoles, are default, even on small craft.

I would interpret this as three things (in large part to preserve my sanity):

Default sensors (p139 col 2).	The minimum for spacecraft.
Standard sensors, depending on TL (B2 p139 col 1).	Presumed Normal sensors for starships.
Standard default sensors, regardless of TL (B2 p139 col 1 bottom).	Minimum for starships?

I would certainly not hand out expensive range-enhanced commo or sensors for free.


My normal package would be cheap reliable Gen sensors of normal range, with an added Neutrino Detector that can actually detect spacecraft at some range.

 

[Drew]

Dumb question - how will the fuel be transferred from the barge to a vessel in orbit? Will it be a boom with an operator in the barge extending to the orbiting ship? I would look at an automated collision avoidance software that could be overridden by the pilot (boom operator) when transferring fuel. Would potential eliminate the requirement for a third person on the barge.

 

[robject]

Dumb question - how will the fuel be transferred from the barge to a vessel in orbit? Will it be a boom with an operator in the barge extending to the orbiting ship? I would look at an automated collision avoidance software that could be overridden by the pilot (boom operator) when transferring fuel. Would potential eliminate the requirement for a third person on the barge.

NOT A DUMB QUESTION.

Before we even get to logistics, I see that I hadn't added Fuel Transfer Pumps into the Barge design.

 

[robject]

I would interpret this as three things (in large part to preserve my sanity):

I suspect this is my fault. At one point I suggested "standard packages" that grouped up sensors in reasonable ways as shortcuts to the design process. The idea was "simple", but the result is errata that you see.

I would certainly not hand out expensive range-enhanced commo or sensors for free.

I would allocate a standard budget according to e.g. what a typical merchant is likely to have, then let the designer do something else if he wants. So MCr 6 (or whatever) for a set of basic and generic surface sensors, give the most common example of what sensors are used, and stop there. Easy to tag the funds, easy to Let It Be for the typical merchant, and easy to Do Something Else.

My normal package would be cheap reliable Gen sensors of normal range, with an added Neutrino Detector that can actually detect spacecraft at some range.

Yeah -- that's what the Beo design has. The Neutrino Det is Basic, while the other three are Generic.
No idea where he cooked up his prices, though.

 

[AnotherDilbert]

I suspect this is my fault. At one point I suggested "standard packages" that grouped up sensors in reasonable ways as shortcuts to the design process. The idea was "simple", but the result is errata that you see.

The idea is good, the implementation spread over several chapters is a bit confusing. Giving some basic expectation of what a ship should have is good, so we don't get too many ships without e.g. communicators...

I would allocate a standard budget according to e.g. what a typical merchant is likely to have, then let the designer do something else if he wants. So MCr 6 (or whatever) for a set of basic and generic surface sensors, give the most common example of what sensors are used, and stop there.

MCr 6 is a lot for a Free Trader... Unfortunately we are not getting away with much less...

Yeah -- that's what the Beo design has. The Neutrino Det is Basic, while the other three are Generic.
No idea where he cooked up his prices, though.

The prices on B2 p45 are correct, as far as I can see. MCr 1 / 2 for the sensor + MCr 1 for the mount = MCr 1.5.

The prices on B2 p139 are correct, as far as I can see. E.g.: Basic LR Surf-Mt Comm-9 Mod=0. MCr3.5. S=09.
MCr 1 / 2 [Basic] for the sensor + MCr 1 × 3 [Range] for the mount = MCr 3.5.

 

[Drew]

I suspect this is my fault. At one point I suggested "standard packages" that grouped up sensors in reasonable ways as shortcuts to the design process. The idea was "simple", but the result is errata that you see.


I would allocate a standard budget according to e.g. what a typical merchant is likely to have, then let the designer do something else if he wants. So MCr 6 (or whatever) for a set of basic and generic surface sensors, give the most common example of what sensors are used, and stop there. Easy to tag the funds, easy to Let It Be for the typical merchant, and easy to Do Something Else.


Yeah -- that's what the Beo design has. The Neutrino Det is Basic, while the other three are Generic.
No idea where he cooked up his prices, though.

I was thinking that a "station keeping" software (on the assumption that there are thrusters that could do microbursts) to keep the barge in sync with the receiving ship.

I was thinking that the proboscis used in midair refueling would work best. Making the assumption that a cubic foot of liquid hydrogen weighs approximately 4.4 pounds; one could transfer from the barge set at higher PSI than the gaining ship which would be set at a lower PSI. Since liquid hydrogen freezes at 14 degrees Kelvin, the fuel temperature would have to be in a set parameter range. Would the barge be able to refuel collapsible tanks?