Tinkering with cargo units and the mining rules & enconomics

jedion357's picture
jedion357
February 24, 2010 - 11:10am
The book says a cargo unit is the amount of cargo that can be carried in one hull size point.

Under mining equipment in the ship design and build rules a ship can bring back 5 tons of ore per Hull Point

Since Each hull size equates to 5 hull points this makes one cargo unit 25 tons?

(There is also the refining process- takes 1000 tons of iron ore to make one cargo unit of the just iron that will sell for 20,000 at source)

This would mean that a Hull size 5 prospecting ship (I chose HS 5 so that it could have grapples which I think would be useful to its mission) could spend 40 days prospecting (includeing travel time to and from the belt) looking for good mines, 40 days is the period of time the typical Frontier loan compounds at 4%. plus deploy a hvy duty mining bot that would fill its hold (70 tons) in 17.5 hours. When it goes to sell the mine it would also sell the unrefined ore at the ore processors:

<!--[if gte mso 9]> Normal 0 MicrosoftInternetExplorer4 <![endif]--><!--[if gte mso 10]> <![endif]-->Selling unrefined ore: The HS5 ship can bring back 70 tons of ore but, as per the Raw Mineral Chart (Knight Hawks), it takes 1000 tons of unrefined iron ore to make 1 unit of Iron that sells for 20,000Cr. This means that the HS 5 ship will have brought back 7% of 20,000Cr which is 1,700 Cr. It’s not a lot but since one mining robot can excavate 70 tons in 17.5 hours it’s still worth the effort every trip to the asteroid belt. If the ship brought back 70 tons of unrefined plutonium ore that would be 3.5% of 100,000Cr which is 3,500Cr. (formula for determining the % is the number of tons brought back times 100 divided by ore/unit vale for the ore off the Raw Material Chart on page 89 of digitally remastered Knight Hawks) the value of the refined ore is alwasy the "at source" price

Having just priced out a HS 5 prospecting ship at 1,800,000 Cr (all prices figured for class 2 construction centers to compute price) a ship owner with a loan of say 1,600,000Cr on the ship would need to bring in 64,000 Cr every month just to cover the interest. not sure how many trips to the belt and back to the processors a ship could do in that time, 2-3? so that would be 3000 to maybe 13,500cr for unrefined ore every 40 days which would mean they'd have to make up the rest 61,000 to 50,500 in mine location sales which go for 1000 to 10000 depending on number of resources. Call it an average of 5,000Cr/ mine location that would mean finding 12 or more/per 40 day period. If all the mine locations can be sold.

prospectors would avoid over head like the plague.

This sort of ship would have a small crew pilot and engineer (maybee the pilot double as an astrogator or they never leave the system) or a family run operation with spouses and children and everyone works and no one takes a pay check and the ship is home.

There'd be other opportunities to pick up a regular freight cargo and deliver it as the ship does have a hold - it carries 70 tons of ore or 5 cargo units.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!
Comments:

TerlObar's picture
TerlObar
February 24, 2010 - 1:08pm
In the section on mining equipment, I always thought that the "hull points" it was talking about were actually hull size (HS), not the hull points (HP) lost when you get hit by a weapon.  I always assumed the OPL and MR were big things that needed a large ship to haul around.  Then you needed a 4 hull size larger ship to have a bay for a shuttle. (Now I'm not going to start in on real volume vs. hull size but that's one of the joys of KH Foot in mouth).

Of course reading it that way, only allowing 5 (or 10) tons per hull size seems a little low.  On the other hand, treating this as hull points doesn't make sense either.  In that case you should be able to put an OPR in a HS 2 ships (10 HP) but an OPR is 1000 cubic meters in size and a HS 2 ship is only 590 cubic meters in total volume, it obviously doesn't fit.

So what we have here is a nomeclature issue.  Off the top of my head, here are some thoughts.

In the mining sections, the "hull points" listed as the minimum for the OPL and MR (and additional shuttles) is acutally size of the ship Hull Size.  For ships with a OPL, it can carry 5 tons per hull size (HS).  So if you had a HS 10 ship (the minimum for an OPL), it could carry 50 tons of ore (HS 10 x 5 tons/HS = 50 tons) in addition to carrying its OPL.  This is becuase it's hold is filled with the processing center and you can't carry much more.

But since it has an OPL, why carry the unrefined ore?  What we really want is how much mass corresponds to a cargo unit.  Plus, we're now talking about a ship with effectively an empty hold, not filled up with a processing center.  Now it says that for a ship carrying an MR (which is removed from the ship and assembled on the surface), the ship can carry 10 tons per hull point.  In this case I choose to interpret hull point literally.  So my HS 12 ship that carried the MR into place can now carry back (HS 12 * 5 HP/HS * 10 tons/HP = ) 600 tons of cargo.  Since it now effectively has an empty cargo hold after removing the MR, this is essentially a HS 12 freigter.  That means that one cargo unit correposnds roughly to 50 tons of material.

So my HS 10 ship with the OPL can manage to bring back one cargo unit of refined material in a single trip (And if I made it HS 11 it could bring back 2).  While the HS 12 ship with the MR could bring back 12.  And your HS 5 prospecting ship could bring back 250 tones of unrefined ore to be sold/processed.  That actually makes it a bit more profitable for them.

Given this setup, and a known mine location you might find the following economics:
Trip to mine: ~3 days
Mining robot: 62.5 hours to fill the 250 ton hold (~3 days)
Trip to selling point: ~3 days
R & R + business : ~1 day
That means you can cycle 4 trips in a month.  For iron ore, that a full raw unit netting you 20,000 cr that month  For the plutonium, it's only half a unit but it sells for more and you'd net 50,000 cr.  It's closer to your interest payments but still doesn't cover them.

Anyway, those are some inital thoughs.
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Inigo Montoya's picture
Inigo Montoya
February 24, 2010 - 8:45pm

Lately I have struggled with the SF concept of freighters. Personally, I envision these freighters, like the Gullwind to be tramp freighters. True freighters in my opinion would be more like our modern sea going container ships. It would be a large hs ship that has recessed areas with a hatch in which cargo containers attach to it. These containers come from the manufacturer/distributer and a tug places them on the freighter and they are latched on. Reverse the procedure at the other end. This way a large freighter would sit out away from the station and it would be swarmed by a few of these tugs. Load and unload time would be much lower than suggested in the rule book.

 

I’m not a math guy like some of you. In fact, I just had to quaff half a bottle of pepto after trying to follow the posts about profits and tonnage with that new mining ship of Jedi’s. I’d rather deal with cargo capacity in dimensions rather than mass. Speaking of which, hasn’t somebody posted somewhere just how big a cargo unit is? I need to know this in order to figure out things like how many parabatteries and service robots are there in one cargo unit.


Shadow Shack's picture
Shadow Shack
February 25, 2010 - 6:05pm
As far as "how many makes a unit", I usually double the destination value and divide that by how much a single item sells for. Hence, one "unit" of air cars comes out to (45K Cr) about two air cars, one unit of type II parabatteries (70K Cr) comes out to about 117 batteries, and one unit of ship drives (80K Cr) comes out to "partial components" (about 80% worth) to assemble a class-A atomic drive, 1.5 class-A Ion drive (one complete drive plus components for half of another, or three drives for two units), or about three class-A chemical drives (which is actually pretty abstract considering all three drives are about the same size). 
I'm not overly fond of Zeb's Guide...nor do I have any qualms stating why. Tongue out

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Inigo Montoya's picture
Inigo Montoya
February 25, 2010 - 7:07pm

If I have followed your method correctly, that means that one cargo unit can contain 10 explorers or two air cars. I’m not too concerned about the volume of a cargo unit for the sake of profits as much as I am for what all can fit in it. I’m a visual oriented person. I thought though that somebody had come up with a cubic volume of a cargo unit. Is there enough information on the dimensions of the Gullwind to estimate that quantity? I’ll have to dig out my materials and … man I hate math.


Georgie's picture
Georgie
February 25, 2010 - 8:10pm
I completely scrapped the KH system of "Cargo Units" or "Hull Units" or whatever the heck its called. Like Inigo, I started with a stardard size container based on modern day cargo containers. This works out to a (rounded to even meters) measurement of 15m x 3m x 3m. Larger and smaller containers are worked to fit with this common size. I then draw my ship design and calculate how much hull volume is left over for cargo and divide by the standard container to get the max number of units it can haul. I can also make rough calculations about how much of which item can fit into a single container. Then I can make rough estimates of its value as well.

Yes, a lot of my numbers work is rough. That's because I'm not usually concerned with the money aspect of the trip. As often as not, the cargo is simply a hook into an adventure and I simply make up a number for the amount that the players earn or lose based on the outcome of the adventure.
The weak can never forgive. Forgiveness is the attribute of the strong.    * Attributed to Mahatma Gandhi

Georgie's picture
Georgie
February 25, 2010 - 8:23pm
P.S. When I was figuring all of this stuff out, I calculated the capacity of the Gullwind, it came out to 18 containter units.
The weak can never forgive. Forgiveness is the attribute of the strong.    * Attributed to Mahatma Gandhi

Inigo Montoya's picture
Inigo Montoya
February 25, 2010 - 8:25pm

I couldn’t find any real statistics on the gullwind other than it has a freight capacity of 6 hull units. But based on the 40 meter length of the bay doors (and eyeballing the image) and between the breadth of the floor plan and the 10 meter cargo arm, I guesstimate that the cargo hold is 60 meters long and 20 meters across. V= 3.14x100x60.V=18840 cubic meters. Divided that by 6 cargo units. One cargo unit equals roughly 3,140 cubic meters? So I could have a cargo container of 1 unit that would be 22 meters long, 14 meters across and 10 meters high? That sounds a bit big. That’s almost 3 times the size of my house. Somebody please check my math as well as my theory of calculating cargo unit physical size based on the gullwind. My head hurts.


TerlObar's picture
TerlObar
February 25, 2010 - 9:33pm
based on the drawing in the module I'd guess the 20m diameter is about right but only about 35m in length.  That gives a total volume of about 11000 cubic meters or about 1830 cubic meters per cargo unit.  That corresponds to a cube 12.3 meters on a side (~40 feet) still the size of a large house.  So you were a bit high but it's still large even dividing it effectively in half.

This goes back to the problems with the KH scaling things like cargo units linearly by hull size while the true volume of the ships are going up geometricly with hull size.  For example, a Hull Size 7 ship, which can only hold one more cargo unit is acutally 1.8 times bigger than a hull size 6 ship in volume.  And a hull size 6 ship is 2.3 times larger than a hull size 5 ship in volume.  So even accounting for additional space taken up by crew quarters, additional machinery, etc. a HS 7 ship should stil be able to hold 9 or 10 cargo units instead of just 7.  I'm sure the linear rule is in there for play balance and simplicity, but it makes it hard to scale things the way we want to.

And in reality, it is both the mass and the volume that matter.  The volume matters because you have to fit it in the ship.  But the more mass you have to haul, the slower your ship is going to go (or the bigger engines you're going to need).  Hauling 1000 cubic meters of gold is going to require a lot more engine power than hauling 1000 cubic meters of explorers to get the same performance.  The gold is much more dense and therefore the total mass is going to be much higher. 

Any way, there's my 0.02 cr worth.  I've always taken a cargo unit to be a certain mass of material, and ignored the volume issue since it didn't work and I didn't want to fight it.
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ArtMic's picture
ArtMic
February 26, 2010 - 9:35am
I've always thought that the hull size and diemeter/lengeth need to be looked at and updated. I've tried to make a ship with the charts and they are so small. that the cargo area is almost gone after you add in other import things.
Gold is for the mistress-silver for the maid-copper for the craftsman cunning at his trade.But Iron-Cold Iron- is master of them all

Inigo Montoya's picture
Inigo Montoya
February 26, 2010 - 5:48pm

If I read the module correctly, it said that the cargo doors are 40 meters long. That’s how I came up the 60 meters. The way I had envisioned it, the cargo pods could simply detach from the ship and be ferried to the planet by a heavy duty shuttle of some sort. From there, the cargo pod could be deposited at a warehouse or even simply set on a transport of some sort much like shipping containers are placed on semi's today. This idea of course is for professional transport companies or megacorp owned fleets for the purpose of distributing their own goods. PC's would at most have access to the traditional (tramp) freighters of KH in my game. Terl, please forgive my scientific ignorance; How much effect does mass have when a ship is not in a gravity well? Physics was low on my list of amusements when I was young....and older.


TerlObar's picture
TerlObar
February 26, 2010 - 6:33pm
Mass doesn't go away.  So it doesn't matter if you're in a gravity well or not you've still got to have the engine power to move it if you want to get it around (accelerate, decelereate or change direction). 

And you could be right on the doors.  I didn't read a description last night, just looked at the deckplans and measured the images in the cover of the Dramune run module. ... checking ... You're right, they do say they run 40m and then the illustration doesn't show them running the full length of the cargo bay.  Proportions on the cut away that shows the deck placement, however, would indicate that it is only ~35m long.  Oh well, another case of illustrations not matching descriptions.  I'd go with the 60m lenghth.


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Webmaster - The Star Frontiers Network & this site
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Georgie's picture
Georgie
February 26, 2010 - 6:44pm
Inigo, think "mass = inertia". A low mass object has low inertia and won't take as much force to move. High mass means a high inertia and will take a proportionally larger amount of force to move it. This is true regardless of gravity.
The weak can never forgive. Forgiveness is the attribute of the strong.    * Attributed to Mahatma Gandhi

jedion357's picture
jedion357
February 26, 2010 - 9:32pm
Georgie wrote:
Inigo, think "mass = inertia". A low mass object has low inertia and won't take as much force to move. High mass means a high inertia and will take a proportionally larger amount of force to move it. This is true regardless of gravity.


the reverse is true also less force to slow down small objects: basket ball sized meteor strikes the earth- no big deal; Mountian sized meteor strikes the earth and big impact.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Shadow Shack's picture
Shadow Shack
February 28, 2010 - 4:04am
Inigo Montoya wrote:

If I have followed your method correctly, that means that one cargo unit can contain 10 explorers or two air cars. I’m not too concerned about the volume of a cargo unit for the sake of profits as much as I am for what all can fit in it. I’m a visual oriented person. I thought though that somebody had come up with a cubic volume of a cargo unit.



It wasn't so much a method to determine what makes a "unit" in terms of volume, rather a simple method of letting players know "what they're hauling". As Terl mentioned, the ruling is for balance rather than realism, and you can experience a major migraine trying to make a generalized formula out of it all.
I'm not overly fond of Zeb's Guide...nor do I have any qualms stating why. Tongue out

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Inigo Montoya's picture
Inigo Montoya
February 28, 2010 - 10:36am

Yes, I am seeing (feeling) that now. I thought I'd just make cargo pods the size of train box cars (same sizish, that is) and have them attach to the freighters with docking collar/hatch that would line up with a hatch just off the elevator. I like that idea except for the fact of the vertical decks means all my cargo will be piled at one end of the pod due to the g's of acceleration/deceleration. I can't figure a cool way (totally subjective to my tastes) to orientate the pods to keep the gravity pulling toward the floor. It’s funny how we (I) can so easily have suspension of disbelief on so much crazy sci-fi stuff, but we (I) can’t overlook something as small as a cargo pod.


Gullwind's picture
Gullwind
February 28, 2010 - 1:26pm
The orientation of the cargo pods shouldn't be too much of a concern. The cargo could simply be packed in such a way that the acceleration wouldn't cause a problem.

I think one of the problems stems from the rules being written from more of a tramp freighter standpoint, where freight handling technology has moved more and more towards containers. We've been using them since the sixties, but they weren't on most people's radar in the mid-eighties (including the game designers, apparently).
"Rome didn't build an empire by having meetings. They did it by killing those who stood in their way."

Shadow Shack's picture
Shadow Shack
February 28, 2010 - 4:22pm
Inigo, check out my TT-456 Container Vessel in the current SFMan...it's also in the Deck Plans project here.
I'm not overly fond of Zeb's Guide...nor do I have any qualms stating why. Tongue out

My SF website

Shing's picture
Shing
March 8, 2010 - 6:22pm
I really should read this place more often.

I was able to calculate the size of a cargo unit using references within the books, but cannot find them (calculations) at the moment.  Somewhere in there it mentions a resource, either raw or refined that I was able to use to determine the volume of a cargo unit.  From there it was simple to create various containers that were similar in construction as those in Shadow Shack's article.

If I can find that info I will share, but if I did the math again I would probably find out that I am wrong.

*Thought about it for a few minutes, I think what I did was to take the weight of aluminium, or the volume of 1 kg of refined aluminum or something like that (maybe it was the copper) and just did the math on that. 
"I reject your reality and substitute my own."

Shing's picture
Shing
March 9, 2010 - 7:27am
So I did some online looking and I think that it was copper that I used as the info is easy to find.

Copper ore is somewhere in the 0.4%-1.6% copper range

The density of solid copper is 8.94 g/cm3

The volume on 5 kg of copper is 559.3 cm3

Pretty sure this is what I used to figure out the cargo unit.  I could be mistaken and in the end, it is really what you want to use for simplicity of game mechanics.

So using that as a basis, I calculated out the size of a cargo unit.


"I reject your reality and substitute my own."