Traveller-digest     Wednesday, August 25 1999     Volume 1999 : Number 1014



(R)1996. Traveller is a registered trademark of FarFuture Enterprises.
All rights reserved.

The following topics are covered in this digest:

Re: Plankwell
Re: GT Weapons Question
Re: GT Weapons Question
Re: Plankwell
re: Streamlining
Re: Thrust effects (was HEPlar lives!)
Re: Thrust effects (was HEPlar lives!)
RE: metric units
Re: Experience System
Re: Orion Drive Modules 
Re: Experience System 
Re: Will the real Strephon..... 
Re: Thrust effects (was HEPlar lives!)
Longbow II
Re: Thrust effects (was HEPlar lives!)
Re: Help Finding Back Issues of Challenge Mag
Re Bagpipes
RE: Streamlining
Re: Long Range Scouts
re:Streamlining
GT Bridge design questions
Re Streamlining

----------------------------------------------------------------------

Date: Wed, 25 Aug 1999 18:10:42 +0100
From: SD Mooney <dom@cybergoths.u-net.com>
Subject: Re: Plankwell

 "Legate Legion" <legate@futureone.com> writes:l

>Well, Jesse, it is from High Guard, & you know what Kevin says, don't
>you?  "There is only one Traveller & High Guard is its product."

Comrade Hudson, the plot is working. Your slogan for the revolution has
been adopted by the unknowing and has permeated the consiousness of the
TML. At last we can have revenge, at last we can reveal ourselves to the
Templars.... Keven is subverted, and soon Legate will be too.


Dom

- ----------Dom Mooney---dom@cybergoths.u-net.com------------
                       MiB - Marines in Battledress
   "Protecting the Imperium from the Scum of the Galaxy"
Rob Prior's Mac software @ http://wwwbits.org.uk/ 

------------------------------

Date: Wed, 25 Aug 1999 10:15:47 -0700
From: Bruce Johnson <johnson@pharmacy.arizona.edu>
Subject: Re: GT Weapons Question

Errr, ummm, NO.

All those units predate the metric system. Their SI _definitions_ are
based on metric measurements (mks system or maybe cgs, I forget which),
as are joules,ergs, etc, but the only truly _metric_ system units are
meters (distance) or grams (mass). 

One definition of an ampere, in fact, is a _chemical_ term: one amp = 1
mole of electrons, 6.02 x 10^23 electrons.

I looked them up in my handy-dandy Microsoft Bookshelf and got:

Ampere:

A unit in the International System specified as one International
coulomb per second and equal to 0.999835 ampere.

Coulomb:

The meter-kilogram-second unit of electrical charge equal to the
quantity of charge transferred in one second by a steady current of one
ampere.


Hrmmm, I must have a Pentium Dictionary...


Anthony Jackson wrote:
> 
> Phil Kitching writes:
> 
> > Um, kW is power, kJ is energy (equivalent to kWs).
> >
> > HOLD ON!
> >
> > J = Joules. That's a metric unit!
> >
> > Shouldn't GURPS do this calculation in horsepower or therms?
> 
> Why should it?  Americans mix terms all the time.  Volts, Watts, and Amperes are all metric units, and used in this country.

- -- 
Bruce Johnson
University of Arizona
College of Pharmacy
Information Technology Group

------------------------------

Date: Wed, 25 Aug 1999 10:30:41 -0700 (PDT)
From: Anthony Jackson <ajackson@molly.iii.com>
Subject: Re: GT Weapons Question

Bruce Johnson writes:
> Errr, ummm, NO.
> 
> All those units predate the metric system. Their SI _definitions_ are
> based on metric measurements (mks system or maybe cgs, I forget which),
> as are joules,ergs, etc, but the only truly _metric_ system units are
> meters (distance) or grams (mass). 

Huh?  Ok, if you want to distinguish SI from metric I suppose.  However, those units _are_ SI units.

One joule = 1 kilogram meter/second = 1 coloumb-volt.
One watt = 1 joule/second = 1 ampere-volt.

> One definition of an ampere, in fact, is a _chemical_ term: one amp = 1
> mole of electrons, 6.02 x 10^23 electrons.

That would be mol, not mole, and is also a SI unit (1 mol is a number of grams of a material equal to its molecular weight)

------------------------------

Date: Wed, 25 Aug 1999 12:32:09 -0500
From: Black ICE <wombat@premier.net>
Subject: Re: Plankwell

SD Mooney wrote:
> 
>  "Legate Legion" <legate@futureone.com> writes:l
> 
> >Well, Jesse, it is from High Guard, & you know what Kevin says, don't
> >you?  "There is only one Traveller & High Guard is its product."
> 
> Comrade Hudson, the plot is working. Your slogan for the revolution has
> been adopted by the unknowing and has permeated the consiousness of the
> TML. At last we can have revenge, at last we can reveal ourselves to the
> Templars.... Keven is subverted, and soon Legate will be too.

I still prefer the original Arabic:

"La la'aba ila' al-musaafir, wa al-haaris al-a'ali risaalat al-la'aba."

I still recall being called to play five times daily while in the Middle
East....

- -- 
AuricTech Shipyards Journeyman Gearhead
"Gold-Plated [tm] solutions for copper-plated problems!" (r)
http://www.geocities.com/Area51/Shadowlands/9776

------------------------------

Date: Wed, 25 Aug 1999 13:23:17 -0400
From: Walter Smith <SmithW@HARTWICK.EDU>
Subject: re: Streamlining

Kurt Feltenberger wrote:
>>>>>>>>>
>or 1 (trace). Look at the ship plans in the Broadsword adventure, this ship
>has elevators in the legs and doors in the feet - this ship is made to land
>on those airless rockball moons where corporations like to have their
>armed trade disagreements.

As the illustration shows in Adv. 7.  But, Garda-Villis, IIRC, has a 
breathable atmosphere and Broadsword was mentioned to be grounded
at the starport.
>>>>>>>>>>
IMO this was either an error, or the ship was "grounded" at a highport.
Garda-Villis' starport is class B, so this should be a city-sized 
orbital installation - and if the situation on Garda-Villis was really so
bad, it should not be a problem for rebel infiltrators or sympathizers
to be present at the highport.

This gives you the questions like why the mercs were using ground
vehicles, or how the baddies got a ...never mind, I don't want to spoil
it for those who haven't played the adventure yet.

Walt Smith

------------------------------

Date: Wed, 25 Aug 1999 13:41:23 -0400
From: Juliean Galak <jg42@cornell.edu>
Subject: Re: Thrust effects (was HEPlar lives!)

oops, I accidently sent this message before I finished it... Disregard 
previous post...

At 12:44 AM 8/25/99 -0800, you wrote:
>In mail you write:
>
> > Leonard Erickson writes:
> >
> >> The problem is *wind*. USL is "unstable" in a wind. I won't go into
> >> details, just note that the wind forces act thru a point *other* than
> >> the center of mass. And where the point is depends on the angle. Thus,
> >> in the presence of even a *light* wind, the vehicle will tumble
> >> wildly.
> >
> > No, its much too heavy for that.  Your average 200-ton unstreamlined ship
> > has a terminal velocity in air of somewhere around 700 mph, a typical 
> heavy
> > wind (say, 35 mph) will accelerate it at .002 Gs or so.  Assuming the ship
> > can turn moderately quickly, this is flatly ignorable.
>
>Oh? I suggest you ask the skipper of a supertanker about how
>"ignorable" the way off center "sail" area of his superstructure is.
>Luckily, it's at the *tail* of the vessel, so it helps keep the ship
>pointed into the wind. It's a royal pain if you *don't* want the ship
>pointed into the wind. And this is with much of the ship immersed in a
>medium (water) that helps *damp* the effects.
>
>Remember that a "200 ton" ship is 200 *displacement* tons. It doesn't
>*mass* 200 tons.
>
>The force exerted by the wind is:
>
>P = 0.5 D V^2 cos^2 A,
>
>P = Pressure, N/m^2 (multiply by 0.000146 for psi)
>D = Density, kg/m^3 (=1.225 for sea-level air on Earth)
>V = Velocity, m/s (multiply by 2.24 for miles per hour)
>A = Angle from perpendicular
>
>So, let's try perpendicular impact at 35 mph, in sea-level air.
>
>P = 0.5*1.225*2.24*35
>P =  48.02
>
>That's 48 newtons per square meter. Assume the ship has 100 meters of
>cross sectional area in the plane of the wind (it likely has *more*).
>That gives 4800 newtons of thrust.
>
>Assuming the ship really *does* weigh 200 tons...

>F = m*A
>4800 = 200,000*A
>A = 0.024
>
>That's 10 *times* the thrust you guessed. And if the ship has a cross
>sectional area of 1000 m^3, the thrust is 0.24.

Err... the ship weighs a _lot_ more than a 200 tons.  so the acceleration 
is even less... but even if it did weight 200 tons, .024m/s2 is only .002G, 
nothing compared to the multi-G drives of Traveller ships.  Remember that 
the supertanker can do much, much less than a G of acceleration...

Again, it comes down to how strong the attitude jets are...



>And the important part is that the thrust is *off center*. It imparts a
>*turning* moment to the ship.
>
> >> Engine thrust is fixed with respect to the hull. And any "deflections"
> >> are figure with respect to the hull, not with respect to the outside
> >> world.
> >
> > Given that ships can turn, this simply isn't true.  Manuevering thrusters
> > are plenty to overcome wind effects.
>
>No, it *is* true. Manuevering thrusters *can* turn the ship. But the
>main drive thrust is fixed. There's no real advantage in making the
>main drive "steerable" that way, and lots of disadvantages.


Well, at least in GT, _all_ ship drives are assumed to be vectored 
thrust.  In fact, a ship built without would suffer massive penalties... 
But even disregarding GT...

>And I *wouldn't* count on thrusters intended for changing heading in
>vacuum being able to overcome any sort of significant wind forces in an
>atmosphere.
>
>As I recall, we worked out some time ago that a ship didn't need to be
>able to use even .1 g for manuevering thrusters. They'd actually whip
>the ship around so fast that it could *cause* problems.
>
>But it won't take a lot of wind to generate more force than the
>manuevering thrusters.
even .1g is still 10-100 times more than the wind effects above.


> >> Heck, look at hot air ballons. They are streamlined (really!) and move
> >> slowly. And even then, sudden updrafts and downdrafts are a danger.
> >
> > They're also 3 orders of magnitude lower density than a spaceship.
>
>Your ship on CG is *just* as light as a hot air ballon. :-)

And that's the crux of the matter, IMHO.  Just how strong are those 
maneuvering/attitude thrusters?  (I'm going to use GT as that's all I have 
handy right now...)  A 5,000 ton Young Assault Tender (GT:SM, p73) is 
approximately 101 meters long (it's about 27-7-7 proportions according to 
the book illustrations.  It's actually longer, but this should be close 
enough)   and 27 meters across.  It's loaded mass is 24,180 tons or about 
29,000 metric tons.

According to the combat rules, any ship can do a 180 turn in a single, 
20-minute combat turn.  So we can do a rotation of pi radians in 1200 
seconds.  The relevant equation is:

theta=.5 alpha*t ^2(theta is angular displacement, alpha is angular 
acceleration)

pi=.5 alpha (1200)^2
alpha=4.4e-6 rad/s2

the torque is:
tau=I*alpha (tau is torque, I is moment of inertia)

for a cylinder rotating around it's middle with the axis perpendicular to 
the axis of rotation,
I=1/4MR^2+1/12ML^2
I=.25*29e6*(27)^2+.083*29e6*(101)^2
I=30e9

tau=30e9*4.4e-6

tau=132000 Nm

to get the force back,

tau=F*x (where x is the lever arm, in this case, half the ship length)

132000=F*50.5

F=2613N

F=Ma

so,
a=9e-5m/s=9e-6G

so, assuming my math is correct, the thruster only needs to put out 
.0000009G.  That means that, in fact, wind is a huge factor, and will 
tumble the ship out of control.

Would someone double check my math please?  This doesn't look right, and I 
don't have my good calculator handy....



           -- Juliean Galak (a.k.a. Falcon)

- --
jg42@cornell.edu        "I do not agree with a word you say, but I will
                          defend to the death your right to say it."
                                              -- Francois Marie Voltaire
#include <disclaimer.h> "Imagination is more important than knowledge"
                          			     -- Albert Einstein
for PGP public-key and
more quotes, finger: jg42@gerfalcon.tzo.com
WWW Page: http://www.cadif.cornell.edu/~falcon/                

------------------------------

Date: Wed, 25 Aug 1999 10:59:12 -0700 (PDT)
From: Anthony Jackson <ajackson@molly.iii.com>
Subject: Re: Thrust effects (was HEPlar lives!)

Juliean Galak writes:
>> According to the combat rules, any ship can do a 180 turn in a single, 
> 20-minute combat turn. 

No, according to the combat rules a ship can do _at least_ a 180 degree turn
-- you just can't measure more than 180 degrees.

However, a vectored thrust ship in GT can dodge, with a bonus based on its
Gs.  According to GURPS Vehicles, dodging requires a 15 degree/second change
in direction (though the ship itself doesn't turn that fast, that's why you
have vectored thrust).  That's roughly 1/4 of the directional Gs of the ship,
and is plenty for overcoming air resistance.

Basically, any ship capable of evasion needs _substantial_ turning ability, or
substantial vectored thrust effects.  I'm not terribly familiar with all of the
starship combat rules in Traveller, but certainly in High Guard ships could
dodge.

------------------------------

Date: Wed, 25 Aug 1999 14:04:51 -0400
From: Ian Ferguson <ian@vax2.concordia.ca>
Subject: RE: metric units

Anthony Jackson writes:
>Why should it?  Americans mix terms all the time.  Volts, Watts, and
>Amperes are all metric units, and used in this country.

	Most people will look at you strangely if you ask them for
	a 0.08 horsepower lightbulb  :-)

Peez

------------------------------

Date: Tue, 24 Aug 1999 18:52:57 +0100
From: "Nick Bradbeer" <nickb@ndirect.co.uk>
Subject: Re: Experience System

>> During
>>more intensive periods though it's possible to learn at a much much higher
>>rate (usually the few weeks before an exam period...).
>
>Surely you mean *hours*, :-)


I tried that once, but decided I preferred to pass exams.

NB

------------------------------

Date: Tue, 24 Aug 1999 18:57:04 +0100
From: "Nick Bradbeer" <nickb@ndirect.co.uk>
Subject: Re: Orion Drive Modules 

>But what about the effects of the nukes going off in atmosphere? Somebody's
>going to have to clean up that mess.

<SNIP>

Oh, are you still on Orion drives? Sorry - I was thinking of the ground
plates for landing ships on at spaceports. I thought we'd moved on to
HEPlaR.

Mea Culpa.

NB

------------------------------

Date: Tue, 24 Aug 1999 18:57:49 +0100
From: "Nick Bradbeer" <nickb@ndirect.co.uk>
Subject: Re: Experience System 

>> Before you start making bad puns, remember that Gil Hamilton's in the
middle
>> of an asteroid ring right now with at least three active Zhodani ships
and
>> one that's acting decidedly funny nearby......
>
>Thing is, the 'wanker' isn't active, it's passive.


I'm sorry??  Tell me that's an obscure piece of US slang, please.....<g>

NB

------------------------------

Date: Tue, 24 Aug 1999 18:58:52 +0100
From: "Nick Bradbeer" <nickb@ndirect.co.uk>
Subject: Re: Will the real Strephon..... 

>My main complaint about Virus is, it leveled the field *too* well and
implemented a nearly undefeatable enemy in the process.


I like giving players nearly undefeatable enemies (expect to come across one
in SVL eventually). Giving them anything less doesn't stretch them enough.

NB

------------------------------

Date: Wed, 25 Aug 1999 14:00:42 -0500
From: Chris Olson <chris@pdaguy.com>
Subject: Re: Thrust effects (was HEPlar lives!)

Anthony Jackson wrote:

> Juliean Galak writes:
> >> According to the combat rules, any ship can do a 180 turn in a single,
> > 20-minute combat turn.
>
> No, according to the combat rules a ship can do _at least_ a 180 degree turn -- you just can't measure more than 180 degrees.
>
> However, a vectored thrust ship in GT can dodge, with a bonus based on its Gs.  According to GURPS Vehicles, dodging requires a 15 degree/second change in direction (though the ship itself doesn't turn that fast, that's why you have vectored thrust).  That's roughly 1/4 of the directional Gs of the ship, and is plenty for overcoming air resistance.
>
> Basically, any ship capable of evasion needs _substantial_ turning ability, or substantial vectored thrust effects.  I'm not terribly familiar with all of the starship combat rules in Traveller, but certainly in High Guard ships could dodge.

Part I:
The main problem is not being torn apart by the winds (which are faster than the 35 mph being bandied about here) aloft,  it's being torn apart by the aerodynamic forces acting on the hull once tumbling begins.  Once tumbling begins, the ship is subjected to air pressure based on its speed relative to the air around it.

Part II:
A lot less force is required to rotate an object around its center of mass than it does to start the object moving in a straight line (hint:  you are not accellerating the entire mass equally, the center is hardly being accellerated at all).  Anybody feel up to calculating torques and moments of revolution?

Part III:
It appears from all of the calculations being thrown about that landing a ship under power in an atmosphere is possible if it descends slowly enough and the winds aloft co-operate.  This would not be a casual affair attempted everyday, but it would be possible, if risky.

Chris
chris@pdaguy.com

------------------------------

Date: Wed, 25 Aug 1999 19:23:18 GMT
From: Dan.Haag@midata.com
Subject: Longbow II

What is Longbow II?

Dan Haag

------------------------------

Date: Wed, 25 Aug 1999 12:24:39 -0700 (PDT)
From: Anthony Jackson <ajackson@molly.iii.com>
Subject: Re: Thrust effects (was HEPlar lives!)

Chris Olson writes:
>> 
> Part I:
> The main problem is not being torn apart by the winds (which are faster
> than the 35 mph being bandied about here) aloft,  it's being torn apart by the aerodynamic forces acting on the hull once tumbling begins.  Once tumbling begins, the ship is subjected to air pressure based on its speed relative to the air around it. 

While the winds can be significantly faster than that, the high speed winds
are also mostly at high altitudes and thus significantly lower pressure.  In
any case, we're mostly talking about landing under contragravity, at quite low
speeds.  Given the overall structural strength of a typical traveller
starship, being torn apart is essentially a nonissue, if you can evade at 6 Gs
you're way too tough to worry about being damaged by wind.

> 
> Part II:
> A lot less force is required to rotate an object around its center of mass
> than it does to start the object moving in a straight line (hint:  you are not accellerating the entire mass equally, the center is hardly being accellerated at all).  Anybody feel up to calculating torques and moments of revolution? 

Nah, it requires a different kind of force.  It's true that a strangely shaped
ship (close or open structure) will be subject to substantial torque, but many
unstreamlined ships are basically shaped like large bricks, and aren't going to
be terribly unstable.

> 
> Part III:
> It appears from all of the calculations being thrown about that landing a
> ship under power in an atmosphere is possible if it descends slowly enough and the winds aloft co-operate.  This would not be a casual affair attempted everyday, but it would be possible, if risky. 

It depends a little bit on how contragravity works.  Landing under thrusters
is potentially quite tricky, since that's negatively stable.  Landing under
contragravity should be fairly simple, unless you're completely without power.

------------------------------

Date: Wed, 25 Aug 1999 14:48:24 -0500
From: Alex Ingram <ingram@airmail.net>
Subject: Re: Help Finding Back Issues of Challenge Mag

Peter Newman wrote:

> The game store I work for, Bosco's, has most of the
> later (50+) issues of Challenge in near mint at
> original retail.  Send an email listing which issues
> you are looking for to us at
>         mailorders@boscos.com
> and we will let you know.  We also have a fair selection
> of other Traveller products, let us know what else you are
> looking for.  We ship worldwide.

Peter,

I need the following issues of Challenge Magazine: 53, 54, 58, 60, 61, 63, 64,
65, 69, 73, 76, and 77.

I'm also looking for the following issues of Travellers Digest: 1 and 2.

And finally, MegaTraveller Journal issues: 1 and 4.

If Bosco's has any of these or if you know anyone else who might have them
please let me know. Thanks.

Alex Ingram
Dallas, Texas

------------------------------

Date: Wed, 25 Aug 1999 16:08:14 -0400 (EDT)
From: "William F. Hostman" <aramis@gci.net>
Subject: Re Bagpipes

Terry C writes
>>Robert Prior writes:
>
>>>Hm. Maybe I should add exterior speakers, so the Marines can play "Will ye
>>>no come back again" to the fleeing enemy? :-)
>>
>>How about Wagner's "Flight of the Valkyries" as in _Appocalypse Now_?
>
>Ha! Everyone knows Imperial Marines route the enemies of the 3I to the
>strains of war bagpipes.
>
Not IMTU.... Bagpipes are the Scouts weapon for chasing savages away...
(Scouts/Scots... who can tell?)

=)

William F. Hostman  |  "Smith & Wesson: THe original Point and Click
interface!"
Aramis 0602 C55A364-C S kk+ as+ hi+ dr+ va++(--) so+ zh++ vi+ da++ sy- ge-
533
Mailto:aramis@gci.net http://home.gci.net/~aramis http://www.alaska.net/~mhaa
ICQ:14640742          AIM:AKAramis	ARM 1.0: 3 R H++ P+
IMTU 1.0: tc tm++ tn- t4-- tt+ to- tg-- ru+ ge 3i+ c+ jt-() au+ st- ls
pi+() ta+ he+(-) kk+ as+ hi+ dr+ va++(--) so+ zh++ vi+ da++ sy- ge- pi+

------------------------------

Date: Wed, 25 Aug 1999 16:18:27 -0400
From: Juliean Galak <jg42@cornell.edu>
Subject: RE: Streamlining

At 10:07 AM 8/25/99 -0400, you wrote:
>Juliean Galak writes:
> >I'm having a hard time justifying that IMTU.  In fact, IMTU that's
> >precisely the system I use.  IMHO, it's really cool to watch a multi-kdton
> >freighter slowly lower itself to the pad.
> >
> >The reason I brought this up to begin with was to find reasons why this
> >_can't_ be done, since that seems to be the OTU claim...
>
>         Just because something is not done does not mean that it
>         cannot be done.  Drawing on the various posts on this subject,
>         one might assume that:
>
>         1) non-streamlined ships are unstable in atmosphere and
>            require specific software to fly
I'm still not convinced of that, although between Leonard's analysis of 
wind force and my analysis of maneuvering thrusters, it seems more an more 
likely...


>         2) even with this software, unstreamlined ships in
>            atmosphere move slowly and are unable to handle stormy
>            weather
That's ok, IMHO that's not a major factor for civilian operations (when a 
jump takes a week, a few hours on either end aren't _that_ 
significant.  I'm not talking courier work here)



>         3) landing unstreamlined ships requires special docking
>            facilities on the ground that are specific to that
>            particular class of ship (and may also require special
>            modifications to the ship).
Again, that's ok.  A given spaceline would standardize to one type of ships 
and need only one type of cradle.


>         4) using a highport with connecting shuttles is more cost-
>            effective, entails less risk to the ship, shortens the
>            turn-around time, and makes it much easier to load/
>            unload

Now that I have trouble buying.  You are talking about putting in a whole 
additional infrastructure - highports, shuttles, orbital refueling, living 
quarters, etc..

>         With this approach, the PC's could try to enter an atmosphere
>         with an unstreamlined ship in extremis, but there will be risk
>         involved and landing would tend to be a one-way affair.

If a landing is possible, the takeoff shouldn't be any difficult...

Again, I recognize the fact that in the OTU the highport/interface craft 
model is the one used.  I'm just trying to figure out why...

           -- Juliean Galak (a.k.a. Falcon)

- --
jg42@cornell.edu        "I do not agree with a word you say, but I will
                          defend to the death your right to say it."
                                              -- Francois Marie Voltaire
#include <disclaimer.h> "Imagination is more important than knowledge"
                          			     -- Albert Einstein
for PGP public-key and
more quotes, finger: jg42@gerfalcon.tzo.com
WWW Page: http://www.cadif.cornell.edu/~falcon/                

------------------------------

Date: Tue, 24 Aug 1999 21:36:26 +0100
From: "Nick Bradbeer" <nickb@ndirect.co.uk>
Subject: Re: Long Range Scouts

>>>>I haven't seen a truly LONG range scout yet.  Jump-6 with a long
endurance.
>>>>The ones in CT are Jump-4.  The Book 2 rules allow for a Jump-6 100dT
scout,
>>>>but none of the later rules make it possible.

Application of Catbert's Principle of Engineering Motivation. Simply tell
the engineers that you're convinced that what you want done is impossible,
and they'll all leap into action in an effort to prove that it in fact can.

Nick
- ---
Engineer suddenly realising the power psychologists wield.....

------------------------------

Date: Wed, 25 Aug 1999 16:34:18 -0400
From: Walter Smith <SmithW@HARTWICK.EDU>
Subject: re:Streamlining

Juliean Galak wrote:
>>>>>>>>>>
>         4) using a highport with connecting shuttles is more cost-
>            effective, entails less risk to the ship, shortens the
>            turn-around time, and makes it much easier to load/
>            unload

Now that I have trouble buying.  You are talking about putting in a whole 
additional infrastructure - highports, shuttles, orbital refueling, living 
quarters, etc...
>>>>>>>>>>>>>
A cargo shuttle built for interface work will probably be better at it
than a jump ship that isn't, even if a kludgy way can be worked
out to let an unstreamlined ship land. And don't forget, a world with
a class A or B (or even sometimes C) starport is probably supporting
a sizeable offworld population already, asteroid miners and whatnot.
They'll need these shuttlecraft even when no interstellar traders are
around.

Besides, space stations look so cool...

Walt Smith

------------------------------

Date: Wed, 25 Aug 1999 13:13:38 +0100
From: John Buston <John.Buston@tesco.net>
Subject: GT Bridge design questions

I have been trying to duplicate the bridge modules in GT using Gurps Vehicles. 
The price tags I get are significantly higher than the GT book price.

For GTL10 bridges I calculate figures around:

Cockpit   3 MCr (GT 2.5)
Basic     6 MCr (GT 4.0)
Command  11 MCr (GT 9.6)

In particular the AESA & PESA costs alone exceed the book price of the bridge.
I have allowed for the ten times range factor for non-atmosphere use and the
long range price formula but I cannot make them match. 

e.g. GTL10 Basic bridge (GT price : MCr 4.0)

Item       Range   lbs   cf     Cr        kw  comments
AESA       10000  7500  150  2,625,000  2500  ten times range in space
PESA        3000  3000   60  2,800,000     0  ten times range in space
Radscanner  2000  2500   50    525,000     0

So nearly MCr 6 for the sensors alone.

What am I missing?

------------------------------

Date: Wed, 25 Aug 1999 16:43:55 -0400 (EDT)
From: "William F. Hostman" <aramis@gci.net>
Subject: Re Streamlining

{not repeating many peoples bits on the subject, for simple brevity}
Traveller has 3 levels of Streamlining, and these three DIFFER from edition
to edition...
CT Bk5: USL PSL SL
MT, TNE T4: USL SL AF

USL - Unstreamlined
PSL Partially Streamlined
SL Streamlined
AF Airframe

I have always interpreted the MT USL as "Not designed for surviving high
winds, and incapable of withstanding reversed skin pressurizations for long
periods. Not to mention not having landing gear"

 As for landing ships, under MT, where the T-plates can generate thrust
(diminishing in ammount) in any direction, I've allowed some USL designs to
"Float down" (The Lord Baltimore is a bad ship to land this way). They
Entered in a nose up attitude, Matching the local gravity (0.9G) this left
0.05G for lateral vectors (90 deg from forward gets 50% thrust, IIRC)
without overpowering the drives. Which, BTW, MT T-plates can do... up to
400% for short times. I also required 4 Formidable piloting rolls, 4
difficult engineering rolls, and a computer roll (To lock out the computer
safety ovverrides), plus 4 determination rolls (Easy, Routine, Difficult,
formidable) for all the crew working to keep up with the stress. All but
hte determination checks were hazadous, fateful.

The problems of wind shear are also interesting... Since thrust acts on
mass in MT/TNE/T4, and TNE CG negates WEIGHT, not mass, slow wafting down
with the expected 4-12 Tons Metric mass per Td, the g levels are coverable,
provided you don't have a variety of odd structures sticking out.... that
will make you spin more surely than off-center thrust. Or, if you go too
fast, you lose them.

William F. Hostman  |  "Smith & Wesson: THe original Point and Click
interface!"
Aramis 0602 C55A364-C S kk+ as+ hi+ dr+ va++(--) so+ zh++ vi+ da++ sy- ge-
533
Mailto:aramis@gci.net http://home.gci.net/~aramis http://www.alaska.net/~mhaa
ICQ:14640742          AIM:AKAramis	ARM 1.0: 3 R H++ P+
IMTU 1.0: tc tm++ tn- t4-- tt+ to- tg-- ru+ ge 3i+ c+ jt-() au+ st- ls
pi+() ta+ he+(-) kk+ as+ hi+ dr+ va++(--) so+ zh++ vi+ da++ sy- ge- pi+

------------------------------

End of Traveller-digest V1999 #1014
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