Mesons and the ground combat picture

[HG_B]

Not quite

In CT you have the super tough material hulls too;

Not ANYWHERE near the degree that MT & MgT hulls are tough. MANY orders of magnitude less in fact. Otherwise, there would be no need for deflector shields in CT. Axiomatic. It is relative. Compared to MGT hulls, CT ones are melted butter.

How does T5 handle? Maybe that is what Marc has settled on...

 

[mike wightman]

Actually Striker makes hulls tougher than MT.

Bonded superdense has a higher toughness factor in Striker than in MT, and yet the same armour value is required for a spaceship hull.

So if you compare a Striker designed hull with a MT designed hull the Striker hull is half the thickness for the same armour value.

 

[HG_B]

Actually Striker makes hulls tougher than MT.

A Striker (CT?) hull can't survive space travel without a force field. MT hull can... Two different aspects I guess. Which goes back to MT miscalculating (pen) vs. ship hulls.

 

[mike wightman]

Striker doesn't mention the magic force field, the only place it comes up as a plot point is that one adventure

Don't forget that CT says the m-drive is a fusion rocket in the only place it is defined (HG1) and it isn't redefined until MT.

Basically the authors invented stuff as and when needed.

 

[Carlobrand]

According to the CT boxed module the manoeuvre drive generates a field that protects a ship from intense radiation and micro meteorite impact:

Ships under power are not affected - part of the M-drive generates a low-power screen against radiation and meteorite impact -

Do what now? What boxed module? I don't find that in Book 2 or TTB.

Actually Striker makes hulls tougher than MT.

Bonded superdense has a higher toughness factor in Striker than in MT, and yet the same armour value is required for a spaceship hull.

So if you compare a Striker designed hull with a MT designed hull the Striker hull is half the thickness for the same armour value.

A Striker (CT?) hull can't survive space travel without a force field. MT hull can... Two different aspects I guess. Which goes back to MT miscalculating (pen) vs. ship hulls.

Where is all this coming from??

Per errata, a ship hull has a Striker rating of 40. A Striker rating of 40 requires 33.6 cm of hard steel. Bonded superdense has a toughness of 14: you need only 1/14th as much bonded superdense to achieve the same rating as 33.6 cm thickness of hard steel. Unfortunately, it's also denser than steel: 1 7/8 times as dense. When all is figured, you need 13.4% (1/14 * 15/8) the weight of bonded superdense to achieve the same rating as a ton of hard steel armor.

Per MT Referee Manual, minimum value for a ship hull is 40. A rating of 40 is equivalent to 33.0 cm of hard steel. Bonded superdense armor is 0.14% the weight of an equivalent rating of steel. MT does not provide volume information; armor is not subtracted from the ship's volume.

I'm seeing a little under a 4.5% difference in mass, most likely the result of rounding up to bring it to two decimal places. I'm seeing no data from which to draw comparisons about hull thickness. If I had a need to determine hull thickness, I would conclude from the similarities between the two tables that the MT bonded superdense was probably the same density as the Striker bonded superdense. What am I missing here?

 

[HG_B]

Where is all this coming from??

They are saying that the CT ships use force fields. None of my books (LBB's 1-5) said that so don't ask me.

 

[Carlobrand]

And the free electrons (beta) accrue a charge on your ship and erode the surface as well. Plus, the alpha triggers beta on impact.

Once you get to a week at 1G, you're talking earth-saturn or further, mind, you're going fast enough that the basic equations no longer suffice, and dilation has to start being accounted for. 1 week at 3G, and you're getting standard energy alpha in significant doses.

It makes the metal brittle.

Plus, at those speeds, the miligram grain of dust at 5,900,000m/s, is dumping 1.7e10 joules... a 20mm APDS round carries 1.23e5 J... so about 1.5e5 * the energy... that grain of silica has enough oomph to go in one side and out the other of a wwII era battleship... sufficiently high energy to not even deform the armor a lot; the armor does not have time to bend. a 1 milligram chunk of rock is half a millimeter, by the way. A tiny spec of dust will hit with as much energy a 20mm cannon... but a small enough area that it penetrates 50m+...

That much energy density, you get near instant liberation of molecular bonds.

Okay, now this kicks back to a discussion I was having elsewhere about why I wasn't buying Trav ships sailing between the stars at 0.8c. Energy calculations I can do. How are you calculating penetration depth? And, assuming the hull is equivalent to 33 cm of steel and that 1 mg of rock represents the lower limit for safely detecting and avoiding masses in your path, what exactly is the top safe speed of the typical ship?

Also, let's look at the reverse. Assuming the sensors described in CT or MT, what is the smallest mass that can safely be detected and avoided at a speed of, say, 6 million meters per second (or 0.02c), assuming a 1G drive on a typical free trader?

 

[HG_B]

what exactly is the top safe speed of the typical ship?

See the Trav interplanetary travel examples. Particularly the planet to GG examples. That (~6,000km/sec) would be the lower end of the top safe speed.

 

[whulorigan]

CT: Beltstrike - Radiation/Meteorite Screen

Striker doesn't mention the magic force field, the only place it comes up as a plot point is that one adventure

Do what now? What boxed module? I don't find that in Book 2 or TTB.

Where is all this coming from??

They are saying that the CT ships use force fields. None of my books (LBB's 1-5) said that so don't ask me.

It is an obscure reference in CT: Beltstrike.

CT: Beltstrike: Folder 1 - Lodes of Adventure (p.2):
Alpha is held in a tidal lock by Bowman Prime, with one side always facing the gas giant; the inhabited section of Alpha is on the opposite side from the primary. This gives extensive natural shielding against the dangerous radiation which is found this close to Bowman Prime. (Ships under power are not affected - part of the M-drive generates a low-power screen against radiation and meteorite impact - but a power faiiure during approach within about a million kilometers of the gas giant would be fatal.)

 

[HG_B]

It is an obscure reference in CT: Beltstrike.

Thank you for the reference.

 

[aramis]

How so?

Amortization of the time-fixed costs.

Using MGT
Taking a 200Td Budget Box... for the 10Td bridge.

__ 0	__ 8.0	Hull
_ 10	__ 1.0	Bridge
__ 4	__ 8.0	PP-A=1
__ 2	__ 4.0	MD-A=1
_ 10	_ 10.0	JD-A=1
_ 20	__ 0.0	Fuel-Jump
__ 2	__ 0.0	Fuel-Power
__ 8	__ 0.5	2xSR
-144	_ 30.5	Subtotal
-144	_ 27.45	SDD

And the system ship version:

__ 0	__ 8.0	Hull
_ 10	__ 1.0	Bridge
__ 4	__ 8.0	PP-A=1
__ 2	__ 4.0	MD-A=1
__ 2	__ 0.0	Fuel-Power
__ 8	__ 0.5	2xSR
-174	_ 23.5	Subtotal
-174	_ 21.15	SDD

Each higher G costs MCr+10 and -5Td for the drives and -2Td for PP fuel per 2 weeks, before SDD, and +MCr9 after SDD.
(Note: the extra KCr30 for the computer model 1 is 125Cr a month per ship. Less than Cr1 per cargo ton. I forgot it in the above, but it's amortization is literally trivial - lost in the rounding!)

Crew for either is pilot and engineer. That's KCr10 per month.
note that the distance a 1G can hit in a week is about 7.3e12m or about 49 AU (Using the Traveller 10m/s^2 G.). You can just flat multiply that distance by the G-Rating... but increasing G's has some interesting costs.


I'm using a small ship because it magnifies the differences.

Rounding up to the next whole credit.

Item, per cargo ton:	Cost, J1 M1	Cost M1	M2	M3
Hull, Monthly	_ 795	_ 507	_ 748	_ 1020
Salaries	__ 70	__ 58	__ 60	___ 63
Life Support	__ 28	__ 23	__ 24	___ 25
Fuel, PP	__ 14	__ 12	__ 24	___ 38
Fuel, per jump	__ 70	——	——	——
Monthly	2J 1019 3J 1089	_ 600	_ 856	_ 1146
Range, AU	206264	49	98	147
Cargo Td	144	174	167	160

Now, a 13 day trip is half the month (14 days), allowing half a day to land, refuel, unload/reload, and take off again, at either 300 or 428 credits per Td of cargo. The jump is Cr363 per Td... and not rolling for in-system events, not subject to piracy, etc. The lack of random bad-stuff happening, plus the faster time, only J1 is still profitable, and it's not for anything time-sensitive.

Note that a 2 jumps per month is Cr510 per cargo ton per trip.

A 3 jump per month schedule also allows the day down each jump, plus an extra day a month, and will result in crew usually having 1 day liberty, and sometimes 2 days liberty.

The 8 day travel cost at 1G (12.25 AU or so) is only about 193 per Td. So, vs a 3 jump schedule, you are 40% of the cost of jumping, and probably worth the risks of hitting stuff at 0.005C...

Also, if one's being realistic, one needs armor to survive the 2-weeks, because at peak, you're doing 5.9e6 m/s, 5.9e3 km/s, or about 0.02C. (1G-week is 0.02C peak.)

And, in these budget boxes, I wouldn't want to be going that fast. The risks of a loose 1mm rock are horrendous. A 10cm rock on a closing vector will be catastrophic... a 1m hole through at least the hull...

Oh, and for comparison: Jupiter is 5.2 AU, Pluto's 29.7-49.3 AU...

 

[HG_B]

Amortization of the time-fixed costs.

Wow, nice break down. I think that systems with significant intra-planetary traffic it would be handled by spacecraft rather than starships. Your data just cements that feeling.

 

[aramis]

Wow, nice break down. I think that systems with significant intra-planetary traffic it would be handled by spacecraft rather than starships. Your data just cements that feeling.

Note that some systems have habitable planets out in the 10-40 AU range, and two that are more than 90° apart can exceed the week.

Anything within 12 AU is easily safe under accel, but once you cross a 7 G-Day burn, you're at the point where you're triggering secondary radiation from the low-energy alpha. That isn't figured into the above, but the banks will amortize the cost of losses for system ships, quite possibly limiting ships to one or two G-days burn (local stellar relative) then coasting for safety reasons.

Note that one G-Day is 864km/s, or just shy of 0.3%C... 335.65 seconds per LS, or an AU in about 46.6 hours. So, 2 days per AU. 2 G-Days would cross 1AU, and be doing about 1 AU per day coasting...

G-Days	Time	Distance D meters	Dlstance Dls lightseconds	Distance Dau Astronomical Units	Velocity V m/s	Velocity Vc In fraction of C
2 G*Days	48 hours * 3600 seconds per hour =172800 seconds	D=0.5AT² D=0.5*10*172800² D=5*29859840000 D=149299200000	Dls=D/C Dls=149299200000/3e8 Dls=497.664	Dau=Dls/499 Dau=497.664 Dau=0.997 AU	V=AT =1728000 m per s	Vc=1728000/3e8 Vc=0.00576 PSL=%C=0.576
1 G*Days	24 hours * 3600 seconds per hour =86400 seconds	D=0.5AT² D=0.5*10*86400² D=5*7464960000 D=37324800000	Dls=D/C Dls=37324800000/3e8 Dls=124.416	Dau=Dls/499 Dau=124.416/499 Dau=0.249 AU	V=AT V=10*86400 V=864000 m per s	Vc=864000/3e8 Vc=0.00288 PSL=%C=0.288

[tc=6]Using Traveller G=10m/s² and
LS = 3e8m/s, C=3e8 m/s and AU = 499 LS[/tc]

 

[Ulsyus]

This problem could be neatly explained away by Alan Dean Foster's interstellar drive, which had a singularity projected in front of the vessel (there's a few problems there) but which could have cleared a path for the ship.

 

[aramis]

This problem could be neatly explained away by Alan Dean Foster's interstellar drive, which had a singularity projected in front of the vessel (there's a few problems there) but which could have cleared a path for the ship.

The Drive used in the Commonwealth series won't actually clear the path. And, further, it will have more hit you; it will function largely as a scoop.