________________________________________ GURPS Vehicles 2nd Edition Additions MA Lloyd (malloy00@io.com) 9 August 1998 Modifications and Additions to Chapter 8: Surface and External Features ________________________________________ p91 Stealth. Loaded hardpoints do not negate Stealth. To compute the modifier to detect a vehicle with loaded hardpoints, find the effective size modifier of both the vehicle and each hardpoint load normally (applying any stealth either has). The net modifier is the largest of of these +1 (+2 if any two are equal, or more than one is within 1) p91 Chameleon Systems. Drop the (-x if moving) notes. The bonus for motion is covered in the general sensor rules by the sign flip on Speed. p92* Camouflage is TL0 p92* Retroreflective Coating. Laser TL is irrelevant! Should read 'any visible light, IR, UV or rainbow laser beam...' p93 Reactive Armor. Rather than destroying shaped charges, reactive armor negates the armor divisor. p93* Reactive Armor. Statistics are 8lb and $20 per sf. p93 Electrified Surface. A ground loop is necessary to produce any effect. If either the vehicle or the target are flying there is no loop. It is possible in principle to electrify the above water parts of a water vehicle, and complete the ground loop through the water, but in reality shorts and corrosion would be tremendous problems. p93 Force Screens. A force screen also completely stops radiation. Count each 10 rads as 1 point of damage. For continuous exposures, count all radiation in a single second as one 'attack' There are some excellent variant forcefield rules by Anthony Jackson at http://www.io.com/~ftp/GURPSnet/Vehicles/Construction/forcefields Official variant forcefields can be found on UT2p75. p93* Force Field Table. TL13 Deflector grid should be $62.5 p94* Top Deck. Use 'up to Surface Area/3' instead of Area/6. Some vehicles are not cubes, Area/3 is the limit for a hemisphere. p94 Drop the Angled Flight Deck. Substitute 'Aircraft with a stall speed require 20 times their surface area, or the entire deck, whichever is less, to take off or land. Vehicles without stall speeds require 4 times their area, or the entire deck. Each attempt occupies the area for 1 minute.' p95 Equipment Pods. Jettisoning a pod requires one turn, like any hardpoint discharge. Mounting a new pod takes several minutes and a Mechanic roll. p96* Solar Cell Table L7 is 7. p96 Pins. Towed vehicles - for animal drawn barges calculate performance as if the animals were pulling a skid with Lwt equal to Hdr. ________________________________________ Surface and External Features p91a Concealment and Stealth Features ________________________________________ *Biomorphics* (TL0): are features designed to make the vehicle look (or act) like a living thing. A surface sculpted to have the correct shape adds 0.1 lbs and $20 per sf; see ROp43-45 for further options. *Blackout Paint* (TL8): a cheap substitute for IR cloaking, blackout paint diffuses IR emissions enough to provide a -2 to rolls for IR detection. It is not cumulative with more sophisticated IR countermeasures. *Distortion Mesh* (TL10): generates a field that completely blocks multiscanners (including all 3 submodes) of equal or lower TL. The mesh itself is detectable, nothing within it is. Higher TL scanners are slightly affected, -2 to scan. *Noise Cancellation* (TL8): actively generates counter-vibrations to cancel or break up noise emissions. Statistics are per sf per -1 to sound detection rolls (maximum is -10). Noise cancellation works best on repetitive or fairly predictable noises, and only works against detectors in the far field region (about half a wavelength, a few meters in air, but up to hundreds in water). 8 Blackout Paint 0 $0.2 0 10 Distortion Mesh 0.2 $60 neg. 8 Noise Cancellation 0.05 $2000 0.01 ________________________________________ Surface and External Features p92a Defensive Surface Features ________________________________________ Neural Shield (TL10): completely blocks whatever energies are responsible for neural weaponry - including the effects of paralysis guns on electronics, neural detector bioscanners, and neural induction fields. A neural weapon hitting such a surface grounds out - even if it isn't part of sealed armor. Given the incredible ability of neural weapons to take down targets in unsealed armor regardless of the DR of the location hit, this is likely to be standard on unsealed armor if neural weapons are common. 10 Neural Shield 0.1 $50 ________________________________________ Surface and External Features p92a Surface Sensors ________________________________________ Touch Sensors (TL7) allow the vehicle to determine which part of the surface, if any, is in contact with something solid. Sensitivity isn't great, but it is mostly used for safety stop switches or wall detectors. Surface Sensors (TL8) are a full suite of sensors that duplicate the human skin senses - touch, temperature, pressure and pain. Interpretation will require sensory interpretation software of some type. Note that software able to feel 'pain' simply registers that a sensation would cause pain to a human, it doesn't cause stunning, penalties etc. Sensitive Touch (TL9+): the surface (usually of an arm) is equipped with hypersensitive receptors providing the Sensitive Touch advantage (CIp65). Interpreting the data requires an IQ roll (assuming the vehicle has software that provides IQ type sensory interpretation) or an appropriate Touch Analysis program. Surface Sensor Table Touch Sensors 0.001 $20 neg. Surface Sensors 0.005 $1,200 neg. Sensitive Touch 0.01 $20,000 neg. Multiply weight and cost by the surface area so equipped. ________________________________________ Surface and External Features p92a Radiation Shielding ________________________________________ Realistic radiation shielding depends on what is shielded against, but the current rules are not even close. It isn't unusual for a real spacecraft designs to be half shield. Shield effectiveness does not change with TL, it is almost purely a function of mass. *Radiation Shielding* (TL0): Protects the vehicle occupants from radiation. Radiation defenses are measured in protection factors (PF); divide the radiation intensity by the PF of any shields between the source and the victim. Since PF divisors apply separately, the PFs of multiple screens are multiplied together. Select a PF value; the weight of the shield is 40 * log(PF) lb/sf times the vehicle surface area. The weight of armor, vehicle structure, and in some designs other components such as fuel tanks, count toward the weight of a radiation shield, reducing the amount of dedicated shield material needed (this replaces the Radiation Protection sidebar on p167). Cost of dedicated shield material is $0.02/lb. ________________________________________ Surface and External Features p92a Drag Reducing Surfaces ________________________________________ Many drag reduction technologies produce small improvements - microriblets, porous or compliant surfaces and suction systems are the most promising. In principle if the flow could be kept laminar, drag around a typical vehicle would drop by more than 2/3. Drag reduction surfaces can be applied to any vehicle with mediocre or better hydrodynamics or fair or better streamlining at a cost of $300 per sf. Multiply the Hdr or Adr by 0.9 at TL7, 0.6 at TL8 or 0.3 at TL9+. ________________________________________ Surface and External Features p93a Energy Phasing Surface (TL13) ________________________________________ The vehicle is surrounded by an array of 'force lenses', which allow energy weapons mounted anywhere aboard to fire from any point on the surface. All energy weapons effectively have universal arcs of fire. Energy phasing surfaces can be installed on subassemblies as well, usually a pod, to allow weapons in the pod to fire on any arc not blocked by the rest of the vehicle. Energy phasing surface weighs .25 lbs, occupies 0.005 cf, costs $500 and consumes 0.5 kW per square foot covered. The same system can be used to allow a sensor anywhere aboard to look out in any direction. ________________________________________ Surface and External Features p94a Attachment Components - Hardpoints, Hitches and Pins ________________________________________ All attachment components perform the same function - securely linking a module to the frame of the vehicle. Design the module (hardpoint load, equipment pod, trailer, sidecar etc.) separately. To find linked performance add its Lwt, Hdr, Adr etc. to that of the vehicle and recompute statistics. Both the module and the vehicle must have attachment components. The limiting stress of the linkage is that of the weaker attachment component; if the calculated performances generate stresses above that the vehicle must be kept below its maximum performance or the link will break. The stress in a link is rarely the module weight. In a surface craft the ground or water supports the weight, so the maximum stress is the module mass times the largest of MR, accel/21.9 or decel/21.9. For an aircraft add the module weight. Links can have a variety of special features. Detachable links are hardpoints, explosive bolts or similar systems which can be cut with a Ready action. Plumbed links allow a liquid (usually fuel) to be transferred through the link, wired links allow power to flow through the link and control links allow systems to be controlled by stations on the other side of the link. Attachment Component Table Weight Cost Rigid Attachment (per lbf) 0.002 $0.002 Detachable x1 x2 Plumbed x1 x2 Wired x1 +50/kW Control x1 +500 *Soft Contacts* Often links are established at some relative speed - railway linkages, aircraft attaching to airship carriers, spacecraft with poor maneuvering control. This normally causes collision damage, DR applies, and adding a reusable impact absorber (p71a) to either side of the link reduces the impact appropriately. ________________________________________ Surface and External Features p94a Extradimensional Components ________________________________________ Extradimensional Interior (TL 15): The vehicle is larger inside than outside! Components placed in the pocket dimension do not contribute to the weight or volume of the vehicle, and usually do not interact with the world outside it; though they can be damaged by a weapon passing through the interface. Extradimensional sensors, weapons, communicators or drives are of little use, extradimensional quarters, cargo or fuel tanks are the common applications. Each pocket dimension requires a dimensional interface installed in realspace. It weighs 0.001 lb, occupies 0.00001 cf, costs $100 and draws 0.001 kW per cubic foot of pocket dimension. If damaged or powered down the contents of the pocket dimension are inaccessible, but unless the interface is totally destroyed (GM's option) they are not actually lost. Phase Anchor (TL15): A phase anchor stores a component in another dimension. On command it rotates back into normal space in a specific position relative to the anchor. Components can reappear interlocked with the vehicle as firmly as any other part, or slightly detached from it as 'extradimensional hardpoint loads'. Extradimensional components are ignored when computing performance - armor, heavy weapons, reserve fuel tanks and engines for use in an environment other than the current one are the most commonly phased systems. Missiles or spacecraft may phase the entire payload during the boost phase to improve delta-v. A phase anchor weighs 0.1 lb, occupies 0.02 cf, and costs $10,000 per pound of phased material it can recall. It consumes 20 kWs/lb on phasing out the object (none to phase it back in). *Teleportation technology* (TL16): has similar design effects, vehicles become primarily methods of transporting the gate equipment. A teleport equipped vehicle scarely needs fuel tanks, full life support is unnecessary when supplies can be gated in, quarters are optional when the crew can commute home, airlocks and corridors may go away, gigantic weapons installations can fire through tiny telegate remotes, as can powerful active sensor beams (but note the diameter of the telegate sets an upper limit on reciever surface area), and tight beam communications are as secure as the teleport effect. A telegate reciever weighs 20 lbs, costs $100,000 and consumes 100 kW to hold open a doorway sized portal. _________________________________________ Surface and External Features p94a Ram Plates _________________________________________ Ram Plates (TL8): An improved ram backed with advanced shock absorbers. Any collision with the ram plate inflicts an extra +2 per die on the object hit, and -1 per die to the ram plate equipped vehicle. Weight is 2 lb x body area and cost is $4 x body area. A ram plate must be mounted on a surface with at least DR 40. _________________________________________ Surface and External Features P96a Exo-Husk _________________________________________ A second layer of armor and surface features attached with explosive bolts. Add 0.4 lb and $10 per sf for the attachment points and bolts, and otherwise purchase it like any (combination of) surface features. The advantage of an Exo-Husk is it can be jettisoned to reduce weight - calculate two sets of statistics, with and without the husk. Surface features must be installed either on the husk or the actual vehicle surface; buy them twice if both surfaces have them. *Drop Capsules* are a special type of Exo-Husk used by Mecha for re-entry survival. In this case the husk need not conform to the vehicle; apply the streamlining multiplier to the vehicle area to find the area of fireproof ablative armor needed for the drop capsule. Some designs include stealth features, though reentry is obvious enough to make that of limited value. ________________________________________ Surface and External Features p96a Solar Cells ________________________________________ Solar cell outputs are for space based arrays perpendicular to the sunlight. On a clear day, 80-90% of the useful energy passes through the atmosphere of the Earth, but clouds can cut the output to 10% or less, and of course at night a solar cell produces no power. A solar cell array that can not tilt to track the sun also generates less power when it is not perpendicular to the sunlight, multiply output by the cosine of the angle between the incoming light and the vector normal to the surface of the cells. For a flat cell during the worst part of the year this averages to (2/pi) x cos(latitude + axial tilt).