The Transhuman Files are an irregular posting of material for the Transhuman Space setting.

CYBERSHELL DESIGN

by David Pulver

This was an old draft that wasn't fit for prime time, back when I was still thinking of using GURPS Robots as the basis for Cybershell design. It's not really complete, but some folks might find it of interest.

Cybershell Design
A cybershell is a suit of cybernetic armor that an infomorph can wear, just like a human can wear clothes or step into a vehicle. A cybershell does not cost an infomorph points any more than a battlesuit costs a human character points. Infomorphs can move freely between cybershells; many possess dozens of them.

This design system is a simplified version of GURPS Robots.

Chassis Subassemblies
Select one of five body sizes: tiny (about rat-size, 0.1 cf), small (about dog-size, 0.4 cf), medium (about man-size, 2 cf), large (about horse-sized, 10 cf) or huge (elephant-sized, 50 cf).

Motive Subassemblies: Select"2 legs", "4 legs", "6 legs," "tracked," "wheeled," "winged" or "polybot," or none (typical for serpentine or submarine cybershells). It may combine systems.

Arms: Decide how many arms the cybershell has, and what size (tiny to huge). Arms may not be larger size than the body size.

Head: This is optional. It may be the same size as the body or smaller.

Any cybershell may be submersible, able to operate underwater, or flexible (moving like a snake; also able to operate underwater).

Chassis Table
Size	Body	Head	2 Legs	4+ Legs	Tracks	Wheels	Wings	Poly	per Arm
Tiny	1.5	0.5	1	1.5	1	0.5	2	1.5	0.5
Small	4	1.5	3	4	2.5	1.5	4	4	1
Medium	10	4	8	10	7	4	10	10	2.5
Large	30	11	20	24	20	10	24	24	6
Huge	100	40	60	72	60	30	72	72	18

The table shows the structural area of individual parts. Add them together to get the cybershell's Total Area (TA). Multiply body structural area by 1.25 if very good streamlining or submersible.

The chassis weighs TA x 3 lbs. Multiply by 2 if submersible or flexible (but not x 4 if both).

The chassis costs TA x $500. Multiply by 2 if submersible or flexible, 10 if poly or winged. All modifiers are cumulative.

Example: RATS has a tiny body with two arms and six legs. Its total area is 1.5 + 0.5 +0.5 +3 = 5 sf. Chassis weight is TA 5 x 3 lbs. = 15 lbs. Chassis cost is TA 5 x $500 = $2,500.

Armor
Select an armor material: steel (wt. 0.5, cost $0.25), aluminum (wt. 0.4, cost $0.5), titanium alloy (wt. 0.3, cost $1), foamed alloy (wt. 0.15, cost $6), metal matrix composite (wt. 0.1, cost $20), nano-composite (wt. 0.06, cost $100) or diamondoid (wt.. 0.04, cost $500).

Find the weight, cost and PD. Armor weight is the wt. value of the material x TA x desired DR. Armor cost is the armor's weight times the cost value.Armor PD depends on DR: DR 1 is PD 1, DR 2-4 is PD 2, DR 5-15 is PD 3, DR 16+ is PD 4.

Example: RATS has a DR 10 nano-composite. This weighs wt. 0.06 x TA 5 x DR 10 = 3 lbs. It costs $3 x $100 (nano-composite) =$300.

Other Surface Features
Sealed: A cybershell can be sealed to protect it from contaminants, water, etc. for $10 times TA. It must be sealed if submersible. There is no weight.
Living Flesh: Cybershell looks, smells, feels and sounds like a living being. Of course, if the cybershell has tracks or wheels, it won't fool anyone. If the cybershell is of exotic size or shape (e.g., six legs and man size), it might pass as a gene-altered animal. TA x 0.5 lbs., TA x $250.
Living Fur: As above, but with fur. Weights 0.75 lbs. x TA, costs $225 x TA. Also gives bot PD 0, DR 1.
Sex Implant: Gives the cybershell functional genitalia. $2,000.

Example: RATS is sealed at a cost of TA 5 x $10 = $50.

Electric Motors
Determine the weight, cost and motive power of the propulsion system by cross-indexing the size of the cybershell with the type of propulsion system. (Winged cybershells use ducted fans, submersible use aquajet). A cybershell can install a low or high power propulsion system: halve or double all values.

Propulsion Weight Table
Type	Tiny	Small	Medium	Large	Huge
2 Legs	0.4/80	2/400	8/1,600	40/8,000	110/22,000
4-6 Legs	0.4/20	2/100	8/400	40/2,000	110/5,500
Tracks	0.3/6	1.5/30	6/120	30/600	90/1,800
Aquajet	0.1/4	0.5/20	2/80	10/400	30/1,200
Wheels	0.15/3	0.75/15	3/60	15/300	45/900
Flexibody	1.2/240	6/1,200	24/4,800	120/24,000	330/66,000
Polybody	1.8/360	9/1,800	36/7,200	180/36,000	46/99,000
Ducted Fans	0.3/12	3/120	30/1,200	57/2,280	327/13,080
Motive Power
if fans	0.05	0.5	5	50	500
if others	0.02	0.1	0.4	2	10

Example: RATS has a tiny body and six legs. They weigh 0.4 lbs. and cost $20 and require 0.02 kW.

Arm Motors
Find the ST, weight, cost and power of all the cybershell's arms using this table:

Arms
Cybershell	Tiny	Small	Medium	Large	Huge
ST	1	4	10	50	200
Wt.	0.15	0.6	1.5	7.5	30
Cost	$300	$1,200	$3,000	$15,000	$60,000
Pow.	0.005	0.02	0.05	0.25	1

An arm may have a micromanipulator for five times cost. It may be an extra-flexible tentacle for twice weight and cost. A cybershell can install low ST arms (halve all values) or high ST arms (double values).

Example: RATS has a tiny body. Its two arms are ST 1. The weight is 0.15 x 2 arms = 0.3 lbs. The cost is $300 x 2 arms = $600. The power is 0.005 x 2 arms = 0.01 kW.

Component Plug-Ins
The cybershell's body, head and each arm contain as many pounds of components as shown on the table below. (If cybershell uses tracks, wheels, flexibody or aquajet, count drivetrain weight against body's capacity.)

Internal Capacity Table
Size	Tiny	Small	Medium	Large	Huge
Body	2	8	40	200	1,000
Head	0.5	2	10	50	250
Arm	0.14	0.56	3.4	17	68
if low ST	0.17	0.68	3.7	18.5	74
if high ST	0.08	0.32	2.8	14	56

Brain: A cybershell must have a computer brain. Select one from the Computers table (p. TS141). This will govern the software that can inhabit it. The brain also includes voice input/output systems.
Power: A cybershell must have a power system. Select one or more energy cells (pp. TS140-141).

Example: RATS can put 2 lbs. in its body, 0.5 lbs. in its head, and 0.2 lbs. in each arm. In RATS body goes a tiny brain ($100, 0.25 lbs.) with Complexity 4 and a short-range radio (0.5. In its head goes minimal sensors ($500, 1 lb.). We add infrared cloaking ($75 and 0.5 x TA 5 = $375 and 2.5 lbs.

Weaponry: Any ranged weapons (pp. TS155-159) can be installed. Weapons should normally go in arms or head.
Equipment: A cybershell usually installs a Basic Sensor package giving human-level senses. This is $5,000, 1 lb. An alternative is Minimal Sensors ($500, 0.1 lbs.) giving Bad Sight (short sighted) and Hard of Hearing. A cybershell lacking either suffers Blindness, Deafness and No Sense of Taste or Smell.
Sensors should go in arms or head to avoid poor peripheral vision and hearing (-2 penalty to notice anything not in front of it).

A head may have jaws. $200 and 0.1 lbs. x desired jaw ST. Multiply cost by 1.5 if it does cutting damage; multiply weight by 1.5 and cost by 2 if it does impaling damage

Statistics
Calculate these statistics for the cybershell.

Total Weight: Add together the weight of everything to get the cybershell's total weight. Divide by 2,000 to get mass in tons.
Total Cost: Add together the cost of everything to get the cybershell's total cost.
Endurance: Add together the motive power of the drivetrain and arms. This is the power usage. A cybershell will drain that many kWs power every second it is operating. Divide the energy in its batteries the power usage to get endurance.
Strength (ST): This is based on the arm's size. Tiny has ST 2, small has ST 5, medium has ST 15, large has ST 40, huge has ST 150.
Dexterity (DX): This is its based on the infomorph.
Intelligence (IQ): This is based on the informorph.
Health (HT): The cybershell has a split HT. Its body hit points are body area x 6. If it has legs, their hit points are leg area x 6 divided by number of legs. If it has tracks, each of the two track's hit points are track area x 3. Head's HPs are head area x 6. Each arm's HPs are arm area X 12. Its HT is [(200 x body hit points)/weight] + 5, rounded up, to maximum HT 12.

Other Statistics
Ground Speed: If the cybershell has tracks or legs, its ground speed (in yards/second) is M times the square root of (weight in tons/motive power), where M is 2 if flexibody, 4 if it has 2 legs, or 6 if 4+ legs or tracks, or 8 if wheels. (Double this to get speed in MPH). A cybershell with flexibody or two legs is treated as human for Move and Dodge. Otherwise, it is treated as an animal with Dodge equal to half Speed or 10, whichever is lower.
Water Speed: If the cybershell is sealed and has an aquajet or flexibody, its water Speed (in yards/second) is 4 times [cube root of (motive power/weight in tons)], rounded off. (Double this for MPH.) A cybershell with legs and arms can also swim like a human.
Stall Speed: If the cybershell has wings, calculate stall speed. In order to take off and stay in the air, the cybershell must be moving faster than its stall speed. Divide the cybershell's weight (lbs.) by lift area. The lift area is 10% of the body structural area + the wing's structural area (see Chassis Table). This gives the stall speed in yards per second. Double to get MPH.
Air Speed: If the cybershell can take off, its air speed is equal to [square root of (4 x ducted fan motive power/cybershell area)].
sAccel: If cybershells have built-in hand thrusters or thruster packs, each hand thruster gives 20 lbs. thrust (for 30 seconds) and each pack gives 60 lbs. thrust (for 100 seconds). Divide total thrust by weight (under normal gravity) to get sAccel in G. Multiply by 20 get sAccel in yards/second/second.