ITOM -- Interface Travel Operations Manual A 2300ad ship rules enhancement
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1. INTRODUCTION
In the standard rules of 2300ad all worlds and all ships are created equal.
The time for interface operations and fuel use are stated as constant for all
worlds and ships, for ease and speed of play. However, with the current war
situation along the French arm, the lack of detail precludes many adventure
possibilities and denies the referee certain facets of play.
This document, using the basic 2300ad rules, Star Cruiser, and various
Challenge articles, is an attempt to bring greater flavor to interface
operations.
2. ALL WORLDS ARE NOT CREATED EQUAL
On page 102 of the Director's Guide, interface travel times are given for
the various types of interface craft, and it is presumed that these times are
valid for every world a PC might wish to land on or take off from. However,
not every world has the same mass and size as Earth. Why treat Crater the
same as King, if they are truely different?
Using Earth as the standard, a reasonable assumption given the common use of
Earth masses, Earth years and Earth gravities, each world has an "Interface
Travel Time" (ITT) modifier based on it's diameter and mass. This modifier
is multiplied by the base travel time for the type of craft to find the true
travel time (rounding to the nearest 5 minutes). This formula is:
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| SQRT(mass x 2.1395) - (diameter/27582) |
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If mass is not available, the folling formula will determine it:
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| ((diameter x 5000)^2 x 980 x gravity) / (3.98653 E+20) |
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Plugging Earth into the formula produces an ITT of 1.0, as expected. Other
worlds have different values. Using the given travel times as multipliers, the
per-hour rate is the time in minutes per "hour" of trip time.
Name Per/Hour Rate Name Per/Hour Rate
Adlerhorst 75 minutes Aurore 35 minutes
Austin's World 75 minutes Beowulf 65 minutes
Beta Canum 4 55 minutes Cold Mountain 42 minutes
Crater 36 minutes Daikoku 72 minutes
Doris 54 minutes Dukou 109 minutes
Dunkelheim 20 minutes Earth 60 minutes
Ellis 57 minutes Heidelsheimat 33 minutes
Hermes 41 minutes Joi 82 minutes
Kie-Yuma 119 minutes Kimanjano 81 minutes
King 296 minutes Kingsland 57 minutes
Kormoran 32 minutes Kwantung 45 minutes
Montana 53 minutes Nibelungen 26 minutes
Nous Voila 71 minutes Tirane 64 minutes
As you can see, it takes a spaceplane nearly 10 hours to reach the 0.1 gee
discharge gradient when launching from King, but only 72 minutes when taking
off from Crater. The orbital facilities of most worlds will be at this point
since it is the inside limit of stutterwarp operation. This time will also
limit the response time of ground-based system defense craft. The above list
is not complete -- I have only included those worlds whose mass and diameter
statistics were either provided by the Colonial Atlas or calculated on my own
with my s2300 program.
Note: the above times are for reaching orbital docking. A ship that is
"scrambling" (racing for stutterwarp) will reach stutterwarp capacity in half
the given time.
3. BATTLESHIPS WITH OUTBOARD MOTORS
In Star Cruiser, "multiply the given travel time by the power output of the
MHD turbine to find the actual travel time" is stated as the means to determine
travel time for steamlined ships. Taken at straight value, this statement says
that if you want rapid ascent, use a smaller drive. This provokes images of
ships the size of Alpha-Class battlecruisers using Estes rocket engines for
interface travel.
Even assuming the intent was "smaller drives equals smaller ships", we still
have problems with large ships adding a small MHD turbine for interface travel.
Given that energy is related to mass by the square of the velocity, we can
assume that "Thruster Efficiency" is calculated similar to "Warp Efficiency"
but using the square root instead of the cube root. Using a "generic" lander
given in Ships of the French Arm, this formula is taken to be:
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| SQRT(output/mass) x 18.5 |
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With this formula, the TE of any interface capable craft can be found. I
have calculated several ship's values, as taken from Ships of the French Arm:
Name Origin Thrust Lift Notes
Udet German 3.17 Full
Wespe German 2.89 Part
Mistral-IIIbis French 2.31 Full unloaded
Wellington British 2.16 Full
Mistral-IIIbis French 2.15 Full w/Ritage-2 missile
Bonapart French 1.98 Part
Riche French 1.88 Full
Faidi Azanian 1.43 Full
Merkur German 1.36 Part
Bufer French 1.33 Full
Exeter British 1.10 Part
Yinma Manchurian 0.99 Part
Hayabusa Japanese 0.96 Full
Thorez Brazilian 0.94 Part empty
Cambaceres French 0.84 Part
Marseilles French 0.77 Full
Krupp 821 German 0.63 None empty
Thorez Brazilian 0.34 None fully loaded
Krupp 821 German 0.16 None fully loaded
"Full" lift indicates full streamlining -- the ship is designed to operate
like a spaceplane. "Part" indicates partial streamlining, meaning it operates
like a shuttle (rocket plane/dead glider). The Krupp 821 is designed to be
able to land on worlds with no atmospheres, and operates like a rocket. I have
determined streamlining type from the picture in Ships of the French Arm.
As for interstellar travel, divide the average travel time by the thruster
efficiency to find the actual time. While it takes a Marseilles 156 minutes to
make a run to the discharge orbit, an Udet needs only 38 minutes (and only 19
minutes if scrambling for stutterwarp capability).
It should be noted that while ships with Partial streamlining take half the
amount of time to get to orbit, they also use twice as much fuel. As a rule of
thumb, with partial streamlining being the default lander configuration, assume
that no streamling takes 50% more fuel for interface operations while full
streamlining uses 50% less fuel.
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| NOTE: |
| At the present time, my Star Cruiser rules are not available to me. |
| If some kind soul could let me know how much fuel an interface operation |
| uses (both ways), so that I can formulate a reasonable per-MW/hour fuel |
| consumption, I would be most appreciative. |
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4. CONCLUSION
Well, that ends this document. I hope that the information given within is
useful to your running of 2300ad. If you have any comments, additions or other
notes, please drop a line to [email removed] and let me know.
-- Burton Choinski