Looking for Jump 6

[Grav_Moped]

I'm arguing that you can't build a ship designed to operate in a configuration totaling over 200 tons that doesn't have a navigator, medic, and at least one engineer for the same reason you can't build a ship that has only two weeks of power plant fuel even though its mission profile would never call for more than that.

In other words, sure -- it'd work. It's just not allowed by the rules.

And the key to this is that letting one person operate a small ship alone is an exception to the rest of the crew size rules (and originally in LBB2, would have only applied to three possible ship designs: the Type S, the XBoat, and a 4G non-starship*).



*Give or take a stateroom or air/raft... there's just not that much room to play with in a 100 ton hull.

 

[Grav_Moped]

But then you must also argue that e.g. bridge size and service crew must be based on total tonnage including drop tanks? Eurisko says otherwise.

There is no special magic around 200 Dt; crew requirements are either based on total tonnage or hull tonnage, not sometimes one, sometimes the other.


You are saying these tonnages are not the same?

The special magic is that the rules say that the 200 ton threshold matters.

 

[Grav_Moped]

Then why would the same 50 Dt drives not require engineers when you remove the drop tank?

Why would 15 Dt of drives in a Scout take care of themselves, but the same 15 Dt drives in a Free Trader require an Engineer?

Because the rules say they do.

In-universe, it's because ships under 200 tons have an exemption from the requirement. That may mean that there's something special about the drives in the Type S (and there already is: they can handle unrefined fuel without risk), or that the risk tolerance for smaller ships is higher.

 

[AnotherDilbert]

The special magic is that the rules say that the 200 ton threshold matters.

The rules does not attach any special magic to 200 Dt. There just happens to be several cut-off around 200 Dt, and 1000 Dt. There is absolutely nothing that says that the 200 Dt limit applies to drop tanks, but other limits does not.

Navigator: Each starship displacing greater than 200 tons must have a navigator.

For starships of greater than 1000 tons hull mass displacement, the crew should also include a commanding officer (or captain), his executive officer, and at least three administrative personnel. Extremely large starships should have at least 10 crew members for each 1000 tons of mass displacement.

The Bridge: All ships must allocate 2% of their tonnage (minimum 20 tons) ...

 

[AnotherDilbert]

I'm arguing that you can't build a ship designed to operate in a configuration totaling over 200 tons that doesn't have a navigator, medic, and at least one engineer for the same reason you can't build a ship that has only two weeks of power plant fuel even though its mission profile would never call for more than that.

So, you can attach a 100 Dt drop tank to a Scout without changing the crew requirements, but if you design a new class of 100 Dt ship with a 100 Dt drop tank crew requirements does change?

That makes no sense whatsoever to me.

 

[Grav_Moped]

Because the rules say they do.

In-universe, it's because ships under 200 tons have an exemption from the requirement. That may mean that there's something special about the drives in the Type S (and there already is: they can handle unrefined fuel without risk), or that the risk tolerance for smaller ships is higher.

Which gives a really good in-universe explanation:

You can build a Type S with all of the crew positions (pilot, navigator, engineer, medic, gunner) in single-occupancy staterooms, but you have to give up the air/raft. The Scouts didn't want to give up the air/raft, so they got a blanket waiver for all ships under about 200 tons allowing single-person operation. (As I noted, in LBB2 "under about 200 tons" is basically just the Type S and the XBoat.) It worked for them, since they had access to better Size A drives than everyone else (and if it comes to it, there's always Jack-of-all-Trades skill to fall back on).

Everyone else is just taking their chances...

 

[Grav_Moped]

So, you can attach a 100 Dt drop tank to a Scout without changing the crew requirements, but if you design a new class of 100 Dt ship with a 100 Dt drop tank crew requirements does change?

That makes no sense whatsoever to me.

The point (from my preceding post) is that the Type S really should have had a full 4-5 man crew, but they got an exception written into the regulations. Build something under 200Td and you're within the exception. Build it any bigger and you don't qualify for the exemption.

 

[AnotherDilbert]

(As I noted, in LBB2 "under about 200 tons" is basically just the Type S and the XBoat.)

You can build lots of different ships under 200 Dt with LBB2, they are just inefficient (largely due to standard hulls).

Example:

MN-1211111-000000-00000-0       MCr 47,5         190 Dton
bearing                                            Crew=1
batteries                                           TL=12
                       Cargo=120 Fuel=29 EP=1,9 Agility=1

Single Occupancy    LBB2 design                   120        47,5
                                     USP    #     Dton       Cost
Hull, Streamlined   Custom             1          190            
Configuration       Cone               2                     21,9
Scoops              Streamlined                                  
                                                                 
Jump Drive          A                  1    1      10        10  
Manoeuvre D         A                  1    1       1         4  
Power Plant         A                  1    1       4         8  
Fuel, #J, #weeks    J-1, 4 weeks            1      29            
                                                                 
Bridge                                      1      20         1,0
Computer            m/1                1    1       1         2  
                                                                 
Staterooms                                  1       4         0,5
                                                                 
Cargo                                             120            
                                                                 
Empty hardpoint                             1       1         0,1
                                                                 
Nominal Cost        MCr 47,45            Sum:     120        47,5
Class Cost          MCr  5,22           Valid      ≥0          ≥0
Ship Cost           MCr 42,71                                    
                                                                 
                                                                 
Crew &               High     0        Crew          Bridge     1
Passengers            Mid     0           1       Engineers     0
                      Low     0                     Gunners     0
                 Extra SR     0      Frozen         Service     0
               # Frozen W     0           0          Flight     0
                  Marines     0                     Marines     0

Why would this slightly under-tonnage Free Trader only need 1 crew?

 

[Grav_Moped]

Because the rules say so.
I'm not disputing that it's arbitrary.
I'm just coming to believe that it's an arbitrary exception rather than an arbitrary imposition.

...and I'm out for the morning. (0530 pacific standard time).

Have a great day (or night)!

 

[AnotherDilbert]

Which gives a really good in-universe explanation:

...

You are just inventing an explanation without any base in the rules or the setting.

Crew requirements are tied to ship size, not whether it is built for the Scouts or not.

 

[Condottiere]

The writers of High Guard assume that drop tanks are eggshelly fragile.

Drop tanks are essentially subhulls, and you can build with any number of amenities.

 

[Grav_Moped]

You are just inventing an explanation without any base in the rules or the setting.

Crew requirements are tied to ship size, not whether it is built for the Scouts or not.

It's based on the rules. All ships except small ones need navigators and engineers. Why don't the small ones need them? I'm arguing that they do need them, but for some reason they're not required to have them (typically, this gets resolved by having the pilot multitask).

Larger ships have more need of those crew positions, for tonnage-based reasons. Ships big enough for command crew and maintenance staff end up (effectively) short-handed when carrying drop tanks, and have (effectively) too little bridge space. This is acceptable as an exception necessary for particular missions, but not acceptable as a standard practice. Ship designs reliant on drop tanks being carried through jump for normal operation would require crew and bridge appropriate to their all-up displacement.

Examples of invalid and valid designs:

Spoiler:

331 Td Jump-4/1G freighter (TL 13)
199 Td main hull with drives, cargo, and power plant fuel.
132 Td drop tank containing all Jump fuel. (Legal via TCS, p.13)
This gives two advantages: saves almost 40% of the hull cost (drop tanks are far cheaper than hull), and saves 4 crew positions -- navigator, medic, and two engineers -- because it can be flown single-handed.

The tradeoff is that taking a single fuel hit kills Jump capability.

The clues that it's wrong are that it probably wouldn't have a Mod/6 computer (if TL allowed, the main hull could do J6 and then some on the drives), and the drop tank capacity doesn't work out for any reasonable combination of jumps). Frankly, the rules may allow it, but that's ok because the rules provide opportunities for referees to penalize this kind of min-maxing.

It'd be valid if done like this:
279 Td Jump-2/1G freighter (TL 13)
199 Td main hull with drives, cargo, and power plant fuel
80 Td drop tanks with all jump fuel
Crew=1

199 Td main hull is J4/1G*, drop tanks are expended every Jump.

*even shedding 80 Td doesn't bring the M-drive up to 5% of 199Td...

The thing about the Scouts is just an in-universe explanation for why the rules are the way they are.

I'm ok with my 199-ton ship with 801 tons of drop tanks as a one-off stunt, like the Spirit of St. Louis or the Rutan Voyager round-the-world airplane. I wouldn't expect it to be allowed to be built as a class of cost-saving 1000-ton refueling tankers.

And at this point we're talking in circles. I'm done.

 

[Grav_Moped]

The writers of High Guard assume that drop tanks are eggshelly fragile.

Drop tanks are essentially subhulls, and you can build with any number of amenities.

Subhulls don't have explicit rules in Classic Traveller. It is a trivial step from those rules though.

The Jump Ship (Supp. 9, pp.22-3) shows that it can be done, and reverse-engineering the described payload pods suggests that they're standard hull material and "waste" 5% of volume, all of that "waste" being inside the payload pod. (It's also interesting that the ship can't maneuver if it's carrying cargo externally, since the core hull only has 1G capability.)

 

[AnotherDilbert]

The Jump Ship (Supp. 9, pp.22-3) shows that it can be done, and reverse-engineering the described payload pods suggests that they're standard hull material and "waste" 5% of volume, all of that "waste" being inside the payload pod.

There is also ~500 Dt and MCr ~200 waste in the jump ship, presumably for the "jump mesh" that holds the external cargo, and, I assume, extends the jump field over it.


We have no rules for how that works, and I guess the authors did not consider that necessary for us to build such ships, cf. Modular Cutter.

 

[AnotherDilbert]

The thing about the Scouts is just an in-universe explanation for why the rules are the way they are.

If you want to add extra rules or extra chrome to YTU, great! But don't blame it on LBB2...

All ships except small ones need navigators and engineers. Why don't the small ones need them?

Read the skill description, and the Generate software description. A single Pilot can fly an interstellar ship. The Navigator is there to offload some tasks from the Pilot, and make the ship more efficient.

Larger ships have more need of those crew positions, for tonnage-based reasons.

I can't see any tasks that a 201 Dt ship's crew has to perform, that a 200 Dt ship's crew doesn't also have to perform.

It's just a smaller relative extra cost for the same benefit for the larger ship.

One extra crew stateroom in a ship with 200 Dt payload (say Subbie), small extra cost relatively.
One extra crew stateroom in a ship with 20 Dt payload (say Scout), large extra cost relatively.

But that is just my opinion, of course.

Ships big enough for command crew and maintenance staff end up (effectively) short-handed when carrying drop tanks, and have (effectively) too little bridge space. This is acceptable as an exception necessary for particular missions, but not acceptable as a standard practice. Ship designs reliant on drop tanks being carried through jump for normal operation would require crew and bridge appropriate to their all-up displacement.

But the rules don't say that, they say that drop tanks can be added to any design, and when you do you have to recalculate drive performance and nothing else.

See the published design I quoted before.

199 Td main hull with drives, cargo, and power plant fuel.
132 Td drop tank containing all Jump fuel. (Legal via TCS, p.13)
The clues that it's wrong are that it probably wouldn't have a Mod/6 computer (if TL allowed, the main hull could do J6 and then some on the drives), and the drop tank capacity doesn't work out for any reasonable combination of jumps).

The rules don't require any specific computer to be installed, you just can't perform some jumps without it. Perfectly legal.

The fuel capacity does not have to "work out" for some combination of jumps. As long as you have enough fuel for 4 weeks and a full jump you can have as much extra fuel as you feel like, cf Mercenary Cruiser.

Note that the ship can't make J-4 with the drop tank since it would require 331 × 40% = 132.4 Dt jump fuel. Still legal since it can make J-4 by dropping the tank.

It'd be valid if done like this:
279 Td Jump-2/1G freighter (TL 13)
199 Td main hull with drives, cargo, and power plant fuel
80 Td drop tanks with all jump fuel
Crew=1
... drop tanks are expended every Jump.

Yes, I agree that is perfectly legal, if a bit wasteful, since the ship without drop tanks only needs 39.8 Dt jump fuel.

I see you now say a crew of one, so based on crew requirements for 199 Dt, is enough. I thought you maintained that crew requirements had to be based on total tonnage including the drop tank?

 

[Grav_Moped]

If you want to add extra rules or extra chrome to YTU, great! But don't blame it on LBB2...

It's chrome, but its consistent with the rule.

Read the skill description, and the Generate software description. A single Pilot can fly an interstellar ship. The Navigator is there to offload some tasks from the Pilot, and make the ship more efficient.

Read the Navigation skill, and the Pilot skill. Pilot does not include interstellar course plotting.

If Generate replaces a navigator (because a pilot can provide the input) then there should be no need for a navigator on any starship, and the description of the Generate program should explicitly state that it replaces the navigator. And yet, navigators are required except on the smallest ships.

This strongly suggests that the only pilots who can provide the necessary input are those with Navigation skill. J-o-T skill should suffice, since it provides all skills at level 0.

I can't see any tasks that a 201 Dt ship's crew has to perform, that a 200 Dt ship's crew doesn't also have to perform.

It's just a smaller relative extra cost for the same benefit for the larger ship.

One extra crew stateroom in a ship with 200 Dt payload (say Subbie), small extra cost relatively.

One extra crew stateroom in a ship with 20 Dt payload (say Scout), large extra cost relatively.

But that is just my opinion, of course.

That's my point. It's a carve-out for smaller ships that can't spare the room for additional crew. The Navigation skill is always required, but it isn't mandated to be a designated crew position on small ships -- it can be done by a Pilot-2/Nav-2 individual, performing as Pilot-1/Nav-1, or perhaps even Pilot-2 plus Nav-1 or J-o-T if the Generate program is in use. But once the ship is big enough to spare space for a separate navigator, it's a required crew position.

On the other hand, engineering is kind of weird. Size A Drives in a Type S don't need an engineer to avoid the misjump DM, but do in a Type A. On the other hand, those drives need 40 tons of fuel in a Type S, but only 30 in a Type A. Perhaps there's a connection?

But the rules don't say that, they say that drop tanks can be added to any design, and when you do you have to recalculate drive performance and nothing else.

See the published design I quoted before.

That design was specifically designed to min-max its capabilities in the context of a tournament scenario. Specifically, it met the scenario's minimum Jump capability requirement in a way that would not be acceptable for "real"-world operation.

The rules don't require any specific computer to be installed, you just can't perform some jumps without it. Perfectly legal.

The fuel capacity does not have to "work out" for some combination of jumps. As long as you have enough fuel for 4 weeks and a full jump you can have as much extra fuel as you feel like, cf Mercenary Cruiser.

These are indications that the design is being presented in bad faith. While perhaps technically allowed, they're absolutely an invitation for a referee to exploit its weak points.
"You've encountered space debris on a collision course with your ship. Roll to notice it... and take a fuel hit if you don't."
"What debris?"
"The debris your navigator would have known was there from the charts... if you had a navigator"
"But that'd destroy my fuel tanks!"
"It'd have bounced off ordinary hull material, but that's not my problem. Roll."

Note that the ship can't make J-4 with the drop tank since it would require 331 × 40% = 132.4 Dt jump fuel. Still legal since it can make J-4 by dropping the tank.

or having 1.4Td extra fuel in the 199Td portion, or having slightly larger drives and tanks. I didn't work it up other than "drop tanks = 40% of (199Td + drop tanks)" and "M-Drive is 2% of (199Td + drop tanks)".

Yes, I agree that is perfectly legal, if a bit wasteful, since the ship without drop tanks only needs 39.8 Dt jump fuel.

I see you now say a crew of one, so based on crew requirements for 199 Dt, is enough. I thought you maintained that crew requirements had to be based on total tonnage including the drop tank?

If the tank is going to be dropped, I'm ok with basing crew requirements on the basic hull. If it's just being used to cut hull costs and save on crew (that is, it's intended to be carried constantly) I'm not.

Intent matters.

 

[mike wightman]

Nowhere does it say in CT that you need a navigator to do anything in order to plot a jump.

The course cassette or the generate program are needed - you are inferring from the need for a navigator on ships larger than 200t that you need at least one level of skill in navigation or JoT - you don't.

A 200t or smaller ship does not require a navigator or anyone with navigation skill, it says so in the rules as written.

Navigator: Each starship displacing greater than 200 tons must have a navigator.
The pilot of a small craft or non-starship can handle its navigation requirements.

Generate creates a flight plan which will govern the use of the jump program.
The navigator or pilot can input specific co-ordinates into the computer concerning
a destination, and the generate program will create a flight plan to take the ship
there. In cases where a generate program is not available, starports have single-use
flight plans (in self-erasing cassettes) available for all worlds within jump range for
Cr10,OOO per jump number. The generate program may be used independently and
produces the required flight plan, which is then used by the computer when jump is
performed.
Navigation controls the jump process after a flight plan has been produced.
Flight plans must be fed into the navigation program, which then interfaces with
the jump program to actually take a ship to i t s destination. To actually make a
jump, both the jump and navigation programs must be functioning in the computer
(the generate program need only run long enough to actually create the flight plan).

Navigation: The individual has training and expertise in
the art and science of interplanetary and interstellar navigation.
Travel between worlds depends on the starships and
their crews; the navigator is relied upon to plot the course
and to insure that correct information is made available to
the pilot and crew as they need it. The navigator interprets
the long-range data provided by the ship's scanners and
detectors.
Navigation expertise qualifies a character for the job
position of navigator on a starship or interplanetary vessel.
Referee: In general, navigation skill allows a character to
perform in a starship crew position which requires this type
of skill. On exploratory missions, or when venturing into
unexplored territory, navigation skill may be used to assist
in the speedy computation of courses, in the accurate
determination of courses, and in the determination of
position when lost or strayed.
Navigation expertise can assist an individual in land or
sea navigation as well. In any situation where directions
need to be known or location must be determined, navigation
expertise can be used as a DM of +I per level on a
throw to determine the needed information. The only
requirement is that the night sky must be visible from the
planetary surface.

 

[Grav_Moped]

Nowhere does it say in CT that you need a navigator to do anything in order to plot a jump.

The course cassette or the generate program are needed - you are inferring from the need for a navigator on ships larger than 200t that you need at least one level of skill in navigation or JoT - you don't.

A 200t or smaller ship does not require a navigator or anyone with navigation skill, it says so in the rules as written.

Quote:

Navigator: Each starship displacing greater than 200 tons must have a navigator.
The pilot of a small craft or non-starship can handle its navigation requirements.

Quote:

Pilot: The individual has training and and experience in the operation of starships and large interplanetary ships. This skill encompasses both the interplanetary and the interstellar aspects of large ship operation.

In other words, pilot skill covers normal-space flight, and for ships 200 tons and below it also covers Jump. But the skill's capsule description literally states that it covers the interstellar aspects of large ship operation as well. If this is correct, no ship should ever be required to have a crew member with navigation skill. And yet, it's required.

Quote:

Generate creates a flight plan which will govern the use of the jump program.
The navigator or pilot can input specific co-ordinates into the computer concerning a destination, and the generate program will create a flight plan to take the ship there. In cases where a generate program is not available, starports have single-use flight plans (in self-erasing cassettes) available for all worlds within jump range for Cr10,OOO per jump number. The generate program may be used independently and produces the required flight plan, which is then used by the computer when jump is performed.
Navigation controls the jump process after a flight plan has been produced.
Flight plans must be fed into the navigation program, which then interfaces with the jump program to actually take a ship to its destination. To actually make a jump, both the jump and navigation programs must be functioning in the computer (the generate program need only run long enough to actually create the flight plan).

This lists the crew members who know how to input the coordinates. It does not state that both are capable of determining what those coordinates should be.

Navigation: The individual has training and expertise in
the art and science of interplanetary and interstellar navigation.
Travel between worlds depends on the starships and
their crews; the navigator is relied upon to plot the course
and to insure that correct information is made available to
the pilot and crew as they need it. The navigator interprets
the long-range data provided by the ship's scanners and
detectors.
Navigation expertise qualifies a character for the job
position of navigator on a starship or interplanetary vessel.
Referee: In general, navigation skill allows a character to
perform in a starship crew position which requires this type
of skill. ...

This indicates that the pilot does not necessarily know the course or the "correct information". Why would a pilot not know these things on a ship larger than 200 tons, but understand them for a smaller ship? The pilot probably does, but...

Pilot: The individual has training and and experience in the operation of starships and large interplanetary ships. This skill encompasses both the interplanetary and the interstellar aspects of large ship operation.

Interstellar travel depends on starships and their crews; the single most important crew position is that of the pilot, responsible for control of the starship's lift-offs, landings, and routine flight.

Pilot expertise qualifies a character for the
job of pilot on a starship or interplanetary vessel over 100 tons.
Referee: Pilot expertise is usable as a DM in handling of starships...

"...routine flight". And that's the last piece of the puzzle.

Navigation skill is only necessary when the flight is not routine.

Chances are that any given flight will be routine. There's always a risk that it won't be, though. For ships of 200Td or less, it's considered an acceptable risk -- at least, enough so that there's an exception from the requirement for a dedicated crew slot.

And I'd argue that flying a starship with drop tanks attached is not routine. Or, if the ship is routinely flown with drop tanks, then the crew should be based on the size of the ship+drop tanks because that's the normal configuration.


From a game-play perspective, if the rules don't require a skill or position the referee shouldn't penalize players for their absence.

If the players are rules-lawyering (for example, removing one turret from a Type A Free Trader to get away without a engineer because the ship is then technically just under 200Td), the referee should feel free to penalize that*.


(*unless the referee specifically allows it, perhaps because there aren't enough players in the group for a full crew. But it's up to the referee, not the players, to make that call.)

 

[whartung]

If this is correct, no ship should ever be required to have a crew member with navigation skill. And yet, it's required.

Chances are that any given flight will be routine. There's always a risk that it won't be, though. For ships of 200Td or less, it's considered an acceptable risk -- at least, enough so that there's an exception from the requirement for a dedicated crew slot.

Or, simply, that as the ship gets bigger, there's more stuff going on, more distractions, so it's better to have dedicated slot to this task than to put the entire burden on the pilot.

Plotting a course from Los Angeles to Hawaii is the same whether you're plotting for a sail boat, a pleasure yacht, a cruise ship, or a container ship.

Yet I bet that the large ships, which have scale of operations to afford one, and space on board to accommodate one, have more specialized people available to do the work simply so others don't have to. The large the vessel, the more complicated everything is.

I have no doubt the captain of a Carnival Cruise ship can plot a course anywhere in the world. But he doesn't have too, he's the Captain, it's not his job.

Large jet liners used to have Navigators.

From Wikipedia:

Navigator (archaic), also called 'Air Navigators' or 'Flight Navigators'. A position on older aircraft, typically between the late-1910s and the 1970s, where separate crew members (sometimes two navigation crew members) were often responsible for the flight navigation, including its dead reckoning and celestial navigation, especially when flown over oceans or other featureless areas where radio navigation aids were not originally available. As sophisticated electronic air navigation aids and universal space-based GPS navigation systems came online, the dedicated Navigator's position was discontinued and its function was assumed by dual-licensed Pilot-Navigators, and still later by the aircraft's primary pilots (Captain and FO), resulting in a continued downsizing in the number of aircrew positions on commercial flights. Modern electronic navigation systems made the navigator redundant by the early 1980s.

I'm pretty confident all pilots are navigators, for large aircraft, longer flights, it was better to have a dedicated person. Larger craft is more responsibility, one less thing to distract the pilots.

 

[Grav_Moped]

So in the real world, navigators are obsolete.
So are Flight Engineers in airplanes.
Also, computers are small.
Furthermore, ship crews in general are much smaller than in Traveller. The container ship Ever Given that was in the news recently has a 25-man crew, and at 220,000 gross tons works out to about 50,000Td if my math is right.

An unarmed 50KTd J1/1G ship at TL 13 needs 30 engineers under LBB5 rules (just engineers, excluding engineering-related officers). 20 more for the command section (dropping those who would have overseen gunnery), and 100 service crew (skipping the issue of ship's troops), for a total crew of 120.
Under LBB2 rules -- 10 per 1000Td -- it'd be 500! (... but those rules don't scale up that far.)

Traveller isn't a future technology simulation, it's a simulation of mostly-pre-1980s science fiction as a role-playing game. There are limits to what parallels can be drawn from the contemporary real world.

The rules say navigators and the navigation skill are necessary. The reason why they're necessary only has to make sense in the context of the game universe. And that reason should be internally consistent as well as consistent with the rules as written.