05-19-2015, 11:58 AM | #11 | |
Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
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Re: [Spaceships] Homebrew - Alternate Contragrav
Quote:
Commercial G-Screen: As above, but provides 1/10th the gravity shielding at 10% the cost for 1/3rd the power (use small energy points). Commercial vessels use this system in conjunction with underpowered reaction(less) drives (which would otherwise be unable to liftoff against local gravity) to save money. Provides no protection against Tractor Beams or Graviton Guns. Can be jammed by a G-Screen Damper (see below). Code:
System Size SM+4 SM+5 SM+6 SM+7 SM+8 SM+9 SM+10 SM+11 SM+12 SM+13 SM+14 SM+15 Gravity Divisor TL11^ 1.5 2 3 5 7 10 15 20 30 50 70 100 TL12^ 2 3 5 7 10 15 20 30 50 70 100 150 Cost ($) Light screen 15k 50k 150k 500k 1.5M 5M 15M 50M 150M 500M 1.5B 5B Heavy screen 50k 150k 500k 1.5M 5M 15M 50M 150M 500M 1.5B 5B 15B Also known as a Landlock, this system is used by spaceports to prevent vessels using a commercial G-Screen and underpowered drives from leaving without paying their docking (and other) fees. It has no effect on standard (military) grade gravity screens. This system works by disrupting the G-Screen’s integrity and is typically located beneath the surface of the landing pad (or deck). Each system has a base radius of effect equal to range distance for its SM (see the table below) within which it can jam any number of G-Screens of equal or smaller size. Code:
System Size SM+4 SM+5 SM+6 SM+7 SM+8 SM+9 SM+10 SM+11 SM+12 SM+13 SM+14 SM+15 Range (yds) 10 15 20 30 50 70 100 150 200 300 500 700 Cost ($) 100k 300k 1M 3M 10M 30M 100M 300M 1B 3B 10B 30B Armor, Structural Field Variant Gravity Armor: For double the price, the “unstable exotic matter” of Structural Field Armor (S7:p7) can also act as a commercial grade gravity screen. Use 1/10th the armor’s "dDR" as the divisor applied to a planet’s gravity to determine its effect on the ship. The ship’s mass remains the same however, so the rate of ascent in a vertical take-off would be A-10*G/dDR where A is the spacecraft’s drive acceleration in G, G is the world’s gravity and dDR is the armor’s dDR. To find the effective escape velocity of planet while using the armor, divide its natural escape velocity by the square root of 1/10th the dDR. Example: An SM+10 (10,000 ton) streamlined ship with gravity armor installed has an effective weight of 666 2/3 tons on a 1G planet. If that planet is Earth, its effective Ve would be 6.96/sqrt(15)=1.797 mps or 6,469 mph. Note: this assumes that one Grav Armor system is applied to each of the three hull sections. Dalton “still looking for my Serenity” Spence
Last edited by DaltonS; 05-19-2015 at 12:08 PM. |
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07-30-2015, 08:48 AM | #12 | ||
Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
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Re: [Spaceships] Homebrew - Alternate Contragrav
Gravity Screen System (TL11^) [Hull!]
I decided to go back to first principles (AKA GURPS Vehicles Expansion 2); by analyzing the “Gravity Screen Table” on page 13, a weight reduction of n% requires n/(100-n) kW per square foot of vehicle surface area, with a cost of $100 per kw used. This makes the “Weight Multiplier” equal to 1/(E+1) where “E” is the number of kw/sf used. Using a standard energy point* (and vehicle density) of 100 kW (and cubic feet) per vehicle ton, and the old standard surface area equation Area(sf) = Volume(cf)^(2/3)×6 from GURPS Vehicles, Second Edition, I used a spreadsheet to calculate the table below. Use the “Weight Multiplier” to find the effective weight of the ship. When using a smaller SM system, use three times the “Weight Multiplier” of the larger system to reflect the reduced power of the screen. If multiple systems are used, consider the screens to be layered (ie. use M^n where “M” is the multiplier as a fraction and “n” is the number of systems). Note that this is NOT a force screen variant, and provides no protection against gravitic weapons. The G-Screen Damper described above may still be used against it. Code:
Size Cost Weight | Size Cost Weight | Size Cost Weight Modifier Multiplier|Modifier Multiplier|Modifier Multiplier SM+4 $1 k 37.50% | SM+9.5 $600 k 6.64% | SM+15 $300 M 0.89% SM+4.5 $2 k 32.26% | SM+10 $1 M 5.66% | SM+15.5 $600 M 0.71% SM+5 $3 k 29.38% | SM+10.5 $2 M 4.55% | SM+16 $1 B 0.60% SM+5.5 $6 k 24.82% | SM+11 $3 M 3.99% | SM+16.5 $2 B 0.47% SM+6 $10 k 21.78% | SM+11.5 $6 M 3.20% | SM+17 $3 B 0.41% SM+6.5 $20 k 18.10% | SM+12 $10 M 2.71% | SM+17.5 $6 B 0.33% SM+7 $30 k 16.18% | SM+12.5 $20 M 2.16% | SM+18 $10 B 0.28% SM+7.5 $60 k 13.29% | SM+13 $30 M 1.89% | SM+18.5 $20 B 0.22% SM+8 $100 k 11.45% | SM+13.5 $60 M 1.51% | SM+19 $30 B 0.19% SM+8.5 $200 k 9.31% | SM+14 $100 M 1.28% | SM+19.5 $60 B 0.15% SM+9 $300 k 8.23% | SM+14.5 $200 M 1.02% | SM+20 $100 B 0.13% Quote:
Dalton “feeling nostalgic about GURPS 3rd Edition” Spence
Last edited by DaltonS; 08-01-2015 at 10:44 AM. Reason: Added links to GURPS Vehicles books. |
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02-16-2017, 11:48 AM | #13 |
Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
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Re: [Spaceships] Homebrew - Alternate Contragrav
Design Feature: Gravity Proof Paint (TL^)
This esoteric hull coating blocks any external gravity fields, and may be magical, alchemical or super-science in nature. It has much the same lifting ability as etherwood or skystone (1/3 per hull section) but has no effective mass and requires no power. Any hull section covered will be weightless inside without a form of artificial gravity. This does not cancel the effects of other forms of acceleration or the vessel's inertia. I have no idea what it should cost, except it should follow the standard 1-2-5-10 SM price progression. Dalton “this may be a dead horse, but it's my dead horse” Spence
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02-16-2017, 12:28 PM | #14 |
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Join Date: Oct 2004
Location: Forest Grove, Beaverton, Oregon
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Re: [Spaceships] Homebrew - Alternate Contragrav
Thus making turpentine a terrorist weapon?
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02-16-2017, 01:33 PM | #15 |
Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
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Re: [Spaceships] Homebrew - Alternate Contragrav
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02-16-2017, 01:45 PM | #16 |
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Join Date: Oct 2004
Location: Forest Grove, Beaverton, Oregon
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Re: [Spaceships] Homebrew - Alternate Contragrav
I would think simple contact of anything capable of scuffing paint would count. It wouldn't have to be vehicle damage by any Gurps or even common language definition.
But defining what percentage is lost over time scuffed, as that would likely matter greatly for anti-gravity purposes, I have no clue. On a more serious note, I'd imagine anyone above TL 5 or so would try to laminate or cover up the active paint with some kind of ablative material even if it acts as dead weight.
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02-17-2017, 10:08 AM | #17 | ||
Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
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Re: [Spaceships] Homebrew - Alternate Contragrav
Quote:
Quote:
Dalton “isn't re-painting the ship a crew function?” Spence
Last edited by DaltonS; 02-17-2017 at 10:33 AM. Reason: Found "magnetic tractor beam" reference. |
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