Most Efficient Ship by TL for Cargo to X Parsecs
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Then this happens
Pretty sure those are banned by the Imperial Rules of War for their devastating kinetic impact at speed and the high probability of hitting with their cloudlike deployment.
Not to mention gumming up air intakes.
That might be too simple, though.
While I appreciate that Trav has always been designed to allow scenarios to be procedurally-generated at need, there is a problematic table from the 1977 edition of the LBBs that gives a d6 roll to determine the likelihood of there being a regular/scheduled trade route between any two starports, as a function of their respective ratings and the distance between them. Interestingly, it ignores tech levels.
The problems come in from the fact that the table gives a 1-in-3 chance of a regular J-4 route existing between any pair of A starports or any A-B starport pair that far apart, and a 1-in-6 chance of such a route bridging any two B starports similarly distant.
This is super handy for quickly filling-in the background of any situation a band of shipless Travellers might find themselves in; it is also wildly implausible given the way TLs constrain starship performance options (even in BT) and how fixed cargo/passage rates are established to work. Hence, the need for the "subsidized" handwave, I suppose. And why that table went away in the 2E.
The takeaway for BT, I venture, comes from advice on parsimony apocryphally attributed to Albert Einstein: everything should be made as simple as possible, but not simpler.
This produces a similar result, and is another argument in support of market-set rates, so yeah, I can see it.
Haven't crunched the numbers yet but it sounds close if your cargo-rate price floor is Cr1000/Td for a J-1. And it might be.
Speaking of crunching the numbers, what's the typical armament of a Type R Subsidized Merchant? I've seen deck plans on the web that seem to show it with two double turrets; one missiles, one lasers. Does that sound about right?
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Because math. Typical players back in the early 1980s were high-school/college students with calculators. Most of the starship stuff can be worked out from looking things up on the provided tables without resorting to anything more than basic mathematics. Sure, they should be able to do basic algebra. But making the ship design rules require algebra skills to interpret properly might alienate potential players.
There is no standard load-out, but this one is pretty typical.
A pair of laser-missile-sand triple turrets seems to be a fairly common setup as well (also for Far and Free Traders, by the way), since it provides a modest variety of options, yet is also not as aggressive a stance (or crewing-intensive to operate) as, for example, mounting four triple missile turrets would be.
Historically, I have found it prudent to not give PCs too many lasers, don'cha know?
AnotherDilbert
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Because regular trade goods aka "stuff" is not normally that light nor heavy. It would be a waste to build ships or trucks that had an extraordinary amount of space or mass capacity that went unused 99% of the time.
Measure the weight and size of your next house-hold appliance or grocery bag for an approximate reasonable weight-to-size relationship (density).
What is broken? The LBB2 freight system works reasonably to keep Free Traders poor, unless they take side missions.
OK, the speculative trade system can be broken, but that has nothing to do with the mass of the traded goods.
The mass limit is presumably chosen to be convenient for normal cargoes. The boxes are designed for the loads specified, we could of course build stronger or weaker containers, if that was desired.
Normal containers seems to be plenty strong... Note that the bottom containers have 5-7 other containers, potentially 100-200 tonnes, stacked on top of them.
There are more definitions of "ton" than you can shake a stick at:
https://en.wikipedia.org/wiki/Ton
Note that a "register ton" seems to be 2.832 m3, far larger than a "freight ton" of 1.133 m3, "water ton" of 1.018 m3, or "displacement ton" of 0.9911 m3. Confused yet? I am...
Traveller uses displacement tons of 13.5-14 m3 (approx. the volume of one tonne of liquid hydrogen) for volume and metric ton of 1000 kg for mass. Forget the medieval approximations vaguely based on water.
But, OK, if you don't like to measure cargo in displacement tons of hydrogen of 14 m3, call it a "small container" of 14 m3, if that makes you happier?
MT, TNE, and T4 clearly measures vehicles, spacecraft, and cargoes in m3 and tonnes.
What could be simpler or more sensible than TNE?
AnotherDilbert
SOC-14 1K
Yes, that is what I said, and meant.
Sorry, if it was unclear; I was trying to avoid the one displacement ton is about 14 m3 in CT and 13.5 m3 in MT mess, not that is matter much for this discussion.
I thought this was reasonably clear:
AnotherDilbert
SOC-14 1K
It's the same as saying "round potential down".
A drive with "2000 Dt of go" in a 1200 Dt hull has a drive potential of 2000/1200=1.667, rounded down to potential 1.
Isn't that exactly what LBB5 does? Without the clunky table of drives and hulls, of course.
The Drive and Drive Potential tables in LBB2 makes the maths very complicated, the fixed percentages in LBB5 makes the maths much simpler, hence 150 Dt or 1200 Dt ships are suddenly viable.
Yep. Aside from one spot where the table rounds up (J drives in 2000Td), that holds until TL-15 (W-Z drives).
The math underlying LBB2 is pretty simple, except for the exceptions for the TL-15 drives (W-Z) because from what I can tell the table entries that aren't math are pretty much arbitrarily chosen (to keep from needing to extend the table past Z to provide adequate ratings in higher-tonnage hulls).
Straybow
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But we know for a certainty that it isn't 14 m³/ton, and that's the point. So how big is that "ton" of cargo, or of trade goods? How many of them fit into that 14 m³?
Again, that is exactly the point. Your comment is illustrative of the problem. A barely competent GM with players who want more than a break-even trading life don't need that kind of "help." Making the trade system marginally profitable wouldn't exactly make the Free Traders so rich they aren't motivated to take a chance.
Nobody would loan money for a ship that can't make a profit at the job it is designed for. Nobody would want to buy a ship that couldn't make a profit at the job it was designed for. Nobody would design a ship that couldn't make a profit at the job it was designed for, that nobody wants, and nobody wants to finance.
The selling point for the 747, back in the day, was that it could break even on cargo capacity in excess of the passenger luggage, so that the passenger service was all gravy.
No, not convenience. It's called a freight ton, and the freight ton is used, because of safety concerns.
Not at all. The ton remains a mass-based measure. There are really only three: the short ton (20 hundredweights of 100), the long ton (20 hundredweights of 8 stone), and the metric ton (1000 kg). Anything else is trivia, and obviously the latter didn't exist until the French decided to invent a new measurement system 230 years ago.
All the volume-based standards (they are not units of measurement, per se) are based on carrying a ton of mass. They were defined precisely because they were useful. Most ships travel in salt water = 35 ft³ displacement ton, they have to be safely loaded to avoid danger of capsizing, and avoid damage to cargo and ship in rough weather = 100 ft³ register ton. The 40 ft³ freight ton is a rule of thumb average volume for what a broad range of unspecified stuff tends to take up.
If you're confused it's because you aren't using any of the numbers for practical reasons. If it were your job to load a ship you would use them and not be confused. Both mass and volume are important, but Traveller essentially ignores mass in ships and shipping.
But it isn't medieval. The metric ton is not so different from the long ton that you'd notice. The volume in a surface ship that it takes to safely load it doesn't change. The same 100 ft³/ton standard applies to land transport, again for safety reasons.
Except the trade model still calls the load that fits into the 14 m³ a "ton" and the values assigned for trade items generally don't work for that volume. It remains that the only thing that "fits" into the dT is LH2, and it is nonsensical for anything else. We don't measure the cargo capacity of a ship by the equivalent volume of marine fuel in barrels.
Except where they don't. They still predominantly use multiples of 14 m³ for stuff, often being essentially the same as LBB5 except converted to 14 m³ increments, and they still used "displacement ton" nomenclature for ship sizes. They seem to measure cargo space in dT, and it appears the "tons/tonnes" of cargo are still actually dT. I can only say by what I've read over the years here at CotI, as I've never had or played anything past CT.
AnotherDilbert
SOC-14 1K
I would say the only thing we know for certain in CT is that ships are measured in tons (displacement tons) of ~14 m3.
OK, so you mean "broken" as in "not exactly what you want". I wouldn't call that "broken" as in "does not work".
It's an engineering convenience that you design the rest of the cargo handling system around.
We could just as well design the system around, say, 10 tonnes/m3, since that would be convenient for iron and steel, and then safely design the cargo handling system around that.
It would just be inefficient to assume that containers can be up to 300 tonnes, when most containers are <30 tonnes, leading to over-dimensioned and overly expensive containers, cranes, and ships.
And good on them for bringing some order to the measurement world, and relegating the medieval avoirdupois system to the scrapheap of history. Merci beaucoup!
In Traveller (or at least most editions) only tons of 1000 kg and tons (displacement) of ~14 m3 are used.
Displacement is used for measurement, since it is often more convenient to measure mass than volume, and vice versa.
It is a convenient standard to design water-based ships around, not the other way around. Once designed to that standard, it becomes a safety concern to stick to the design parameters the ship designer choose.
As you illustrate a "ton" can be different volumes, depending on what problem you are trying to solve. Silly!
All of the above are irrelevant to aircraft and spacecraft, of course. Traveller (most editions) still only use "tons" of 1000 kg or ~14 m3, so discussing the finer point of why a "ton" is sometimes 0.9911 m3, sometimes 2.832 m3, and sometimes something else in historical Terran watercraft is entirely besides the point.
I'm an Engineer, I tend to take units of measure seriously. My natural viewpoint is to design systems to be safe, not load them when someone else has already designed them. Using a lot of different "tons" is confusing, it is of course much more convenient to use standard m3 when discussing volume.
CT simplifies away mass, at least from 1979. MT, TNE, and T4 does not.
The difference between a tonne and an Imperial ton is over 1%. It might certainly matter. Nothing I have ever done professionally would have accepted an 1% error in routine calculations.
Perhaps in your small corner of Terra but not in the rest of the world where nothing but tonnes and m3 exist except as medieval curiosities.
That is the volume ton that Traveller uses. It is just as nonsensical as "tons" of, say, 2.832 m3.
There is nothing that says that a displacement ton of cargo hold can only fit one mass tonne of cargo.
Yes, ship sizes are rated in "displacement tons" of ~14 m3, presumably to remain compatible with CT. Craft are still designed in m3 and tonnes.
Yes, they explicitly use displacement tons for cargoes. A ton of cargo is ~14 m3 and nominally ~14 tonnes.
For some reason MT thought that it was cute to call a m3 a kilolitre. It is still the exact same thing.MT RM said:
MT RM said:
T5 has gotten rid of the kilolitres and is using standard m3:
T5.10 said:
Straybow
SOC-14 1K
I like how you ignored the actual points of the argument: such a ship would not be purchased because it cannot be operated profitably, and won't by underwritten for purchase because it cannot be operated profitably, and therefore won't be built without buyers.
Of course, it might be purchased with cash, or with some collateral to offer in addition to the ship. But then the market for general production would be too small, and it would only be built on commission from the buyer.
You do use 8 t/m³ when designing equipment to handle iron and steel. You don't use that standard for general shipping.
Except 1000 kg only applies to 14 m³ for LH2. It makes absolutely no sense to use that measure for anything else.
Thank you for conceding that the units used depend on the thing being measured, and only LH2 needs to be measured in 14 m³ "tons." Any other use is nonsensical.
Except Traveller does NOT use tons of 1000 kg. The fact that tons usually are 1000 kg is mentioned, but since trade goods are sold by 14 m³ "tons" none of those trade goods are being measured in 1000 kg tons. Traveller does NOT use 0.9911 m³ tons, nor 2.832 m³ tons.
"Why are you smiling?" "I, too, am not left-handed!"
I'm a civil engineer by background. I take measurements seriously, too. I'm glad you agree that the 14 m³ "ton" is nonsense.
My point is that none of the calculations used IN TRAVELLER are "accurate" to within the difference between long tons and metric tons. I could argue that most things in ship design and trade items are not accurate to within the difference between short tons and metric tons. For certain, black-box cargos measured by 14 m³ "tons" are not measured in mass at all. Ever.
Incorrect. Every ship that goes through the Panama Canal has to be measured by 100 ft³ register tons. If the ship is loaded in excess of that, then it must reduce the volume from the nominal limit to prevent exceeding the draft limit for the locks. That's probably the majority of cargo ships in the world.
Also, the weight limit for the US standard 53' truck trailer is 32 tons. It's volume is approximately 3300 ft³. Yes, a truck load can be granted a waiver to exceed the normal limit, but then the route has to be checked for bridges that might not be rated for the oversize load.
The road weight limits in Europe are probably very close to the same standard. 1 ton, ¾ ton, and ½ ton pickup trucks are so called because it is the approximate volume of the truck bed in register tons. All the brands of trucks that are sold in the US and also sold elsewhere conform to that standard. Most people don't understand where the size rating of the pickups comes from.
So, where does it say how much in mass of any given cargo type does fit into the dT? It doesn't. The pricing is rather arbitrary and not based on working out how much of any given thing would fit. I demonstrated that their own example, shotguns, was one of the very few things that came close to matching the price listed for 1000 kg, but could easily fit two tons mass into the 13.5 m³ with generous packing. A tightly packed container could fit far more, but I didn't do that calc.
Except that many requirements are stated in 14 m³ increments, i.e., dT.
Except when you look at the pricing of items. In most cases there would be far closer to 1 ton per lot than 14 tons per lot.
Straybow
SOC-14 1K
AAAaaaandd that's my point. Why doesn't it have a drive potential of 1.67? If I want a ship with drive potential of 1, why do I have to buy an engine that could supply drive potential of 1.67?
As I said, I never played beyond LBB3, but I have seen the simple table for drive sizes in LBB5, which is an improvement. Sticking to integers is required for jump as envisioned in Traveller, but is not really required for M drive or power plant. It's an unnecessary quirk of the game system to use only integer ratings.
It isn't the math in LBB2 that is complicated, it is the design procedure of fitting an engine from a limited list into the hull and seeing where on the chart that engine size and ship size land.
Integer performance factors are necessary for LBB5 space combat, and somewhat simplify LBB2 combat (but I agree they aren't essential for the latter).
It's a chain of lookup tables. Pick your hull size, pick your performance, find the first occurrence of that performance in the hull size row and scan up to find the letter. Go to the drives and power plants table and there you go.
No math involved there, and the rest is just addition and subtraction. Ok, ok -- engineering crew size takes division, and jump fuel takes knowing percents (as does bridge size for ships larger than 1000Td).
For what it's worth, the math for the drive tables (for the TL-14 drives and below) is a bit more complex than straight percentages, but works the way they meant for it to work.
These formulae allow decimal-fraction maneuver drives and power plants. (A.5, K.5, etc.) but probably shouldn't. Jump drives will always resolve to a letter.
Jump Drive:
M=Hull tons, Jn=Jump Number
M must be between 100 and 5000 inclusive. Jn must be an integer.
If M=100, Jn must be divisible by two; if an odd Jn is desired, calculate drive size and cost using the next higher Jn divisible by 2. Drive capability and fuel consumption are based on the intended Jn.
If M < 1000 but not evenly divisible by 200, round M up to the next multiple of 200 before calculating drive tonnage.
If M > 1000 but not evenly divisible by 1000, round M up to the next multiple of 1000 before calculating drive tonnage.
This rounding up does not affect fuel consumption calculations.
Jump Drive (tons) = (0.025*M*Jn)+5
Jump Drive (percent of M) = ( (0.025*M*Jn+5)/M ) *100
Cost = MCr0.05*M*Jn
Cost per ton = MCr2*(JD tons-5)
If M=2000 and Jn=1, subtract 5Td and MCr10.
If M*Jn>4000, consult table as exceptions may be present.
Maneuver Drive:
M = Hull Tons, G = Acceleration in Gs
M must be between 100 and 5000 inclusive.
Note: values of M*G less than 100 yield negative drive tonnage!
If M=100, G must be divisible by two; if an odd G is desired, calculate drive size and cost using the next higher G divisible by 2. Drive capability and power requirements are based on the intended drive rating.
If M < 1000 but not evenly divisible by 200, round M up to the next multiple of 200 before calculating drive tonnage.
If M > 1000 but not evenly divisible by 1000, round M up to the next multiple of 1000 before calculating drive tonnage.
This rounding up does not affect fuel consumption calculations.
Maneuver Drive (tons) = (0.01*M*G)-1
Maneuver Drive (percent of M) = ((0.01*M*G)-1/M)*100
Cost = MCr0.02*M*G
Cost per ton = MCr2*(MD tons+1)
If M=2000 and G=1, subtract 2Td and MCr4.
If M*G>4000, consult table as exceptions may be present.
-----
Power Plant:
M = Hull tons, Pn = Power Plant Number
M must be between 100 and 5000 inclusive.
If M=100, Pn must be divisible by two; if an odd Pn is desired, calculate drive size and cost using the next higher Pn divisible by 2. Powerplant fuel consumption and output is based on the intended Pn.
If M < 1000 but not evenly divisible by 200, round M up to the next multiple of 200 before calculating drive tonnage.
If M > 1000 but not evenly divisible by 1000, round M up to the next multiple of 1000 before calculating drive tonnage.
This rounding up does not affect fuel consumption calculations.
Power Plant (tons) = (0.015*M*Pn)+1
Power Plant (percent of M) = ( (0.015*M*Pn+1)/M )*100
Cost = MCr0.04*M*Pn
Cost per ton = MCr2.67*(PP tons-1)
If M=2000 and Pn=1, subtract 3Td and MCr8.
If M*G>4000, consult table as exceptions may be present.
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