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Vehicle Design for Beginners

kuros

SOC-8
Just took my first look at MegaTraveller vehicle design, and am pretty darn stumped. Perhaps the problem that I'm having is that I'm looking at the entire thing backwards.

The reason that I'm looking at it is that I have this idea for a PC who is attempting to build his own grav'cycle out of scrap parts, much like the modern trope about kids building scooters or motorcycles out of junkyard pieces.

So, what I'm trying to figure out is how to build the smallest possible 2-seater grav vehicle.

Are there any step-by-step examples online, or better yet, a spreadsheet or other software solution?
 
That's just the layout you need for writing out the numbers. It doesn't help me determine the numbers, sadly.
 
Here I give you a grav vehicle I designed some years ago. I tried to detail you the design process so that it can help you to understand it:

HTML:
The APC201 series was designed by an Efate firm as a police riot control vehicle (using tear gas grenades). It has been adopted by some mercenary units to give them some light grav mobility and (using more lethal grenades for its RAM launcher) light fire support and armor protection (enough for shrapnel and small weapons, including laser TL 12-rifles).
This is the model  A (APC). Variants exist (by forfeiting the roomy seats) for command (better sensors/communications), medevac (bunks), APG (12 cm mortar), MRL and cargo (1.3 tons). Other variants are possible as needed.
Note: think of this vehicles series as the WWII SdKfz251 series.
CraftId		Grav APC201A, TL 13, Cr 87550 (70040 in quantity)
Hull		4/9, Disp=4, Config=4USL, Armor=10F, Unloaded=4.73 ton, 
		Loaded=6.035 ton
Power		1/2, Fuel Cell x 7= 0.945 Mw, Dur=24 hours
Loco		1/2, StdGrav, Thrust =7 ton, NOE= 40 kph, Cruise=130 kph, Top=180kph
Commo	Radio=continental (5000 km), Maser=VDistant (50 km)
Sensors		Radar=VDistant (50 km), headlights (x2), Passive IR, Light amplifier
Off/Def		Hardpoints=1. Auto RAM Grenade Launcher (1000 rounds)
Control		Electronic x 23
Accom		Crew=2 (Operator, gunner/comander), Seats= Roomy x 12
		Passengers =10
Other		Fuel= 0.0672 kl, Cargo=none
		ObjSize=Small, EmLevel=Moderate

DESIGN
We begin with a 4 dton hull. Configuration is unstreamlined close structure. Armor is factor 10 with superdense materials:
-	This gives us 54 kl of internal layout
-	 cost is Cr 5800 (base) multiplied by 2.5 (as AF 10 table) and by 1 (armor type), so Cr 14500
-	Weight is 3.5 tons (base) multiplied by 2.5 (AF10) and by 0.26 (armor type), so 2.275 ton.
We leave power for now until the main power users has been determined.
For locomotion, we use standard grav plates. We target for 7 tons trust:
-	Power needed is 0.1 Mw per ton of trust, so 0.7 Mw
-	Volume is 0.02 kl per ton of trust, so 0.14 kl (well over the minimum volume of 0.02 kl)
-	Weight is 0.04 ton per ton of trust, so 0.28
-	Cost is Cr 2000 per ton of trust, so Cr 14000
As it is a grav vehicle, there’s no need for transmission nor suspension.
We give it no avionics, limiting our NOE speed to 40 kph.
For communications, just a radio and a maser communications will be enough:
	Power (Mw)	Volume (kl)	Weight (ton)	Cost (Cr)
Radio (continental, TL12)	0.001	0.002	0.001	5000
Maser (VDistant, TL12)	0.004	0.008	0.004	10000

For sensors, we’ll give a vdistant radar, 2 headlights,  passive IR and light amplification:
	Power (Mw)	Volume (kl)	Weight (ton)	Cost (Cr)
VDistant radar (TL9+)	0.008	0.016	0.008	8000
Headlights (x2)	0.001	0.004	0.002	100
Passive IR	0.001	0.002	0.001	500
Light amplifier	0.001	0.002	0.001	500

For weaponry we’ll give it an automatic 4 cm RAM GL.
As it is not in the books (and I have no access to Striker), I extrapolate it from a 20 mm LAG (in Imperial Enciclopedia), doubling all the factors (weight, volume and price) and adding a 0.5 kl volume for ammo.
So,  weight will be 0.008 ton, volume 0.508 kl and price will be Cr 1200.
For environ, being just an APC, we just target for intake compressor (to allow it to work under thin atmospheres), basic environ and basic life support (see Consolidated Errata, page 35 for basic life support volume and weight) .
	Power (Mw)	Volume (kl)	Weight (ton)	Cost (Cr)
Intake compressor	0.005	0.1	0.1	200
Basic Environ (54 kl)	0.054	0.27	0.27	540
Passive IR	0.054	0.27	0.27	16200

Now we can go to power. We need 0.4 Mw for locomotion, 0.005 for communications, 0.011 for sensors and 0.113 for environ, for a total of 0.529 MW.
We want to obtain this power from TL13 fuel cells. At TL13 fuel cells raise its output by 1.5, so a 0.1 kl fuel cell will have an output of 0.09 x 1.5 = 0.135 Mw.  Seven such cells will give us 0.945 MW (more than enough). Volume will be 0.7 kl, weight will be 1.155 ton and cost Cr 14000. Fuel needs will be 2.8 liter/hour (0.0028 kl/hour).
To now:
	Power (Mw)	Volume (kl)	Weight (ton)	Cost (Cr)
Hull	-	54	2.275	14500
Power	0.945	0.7	1.155	14000
Locomotion (6 TT)	0.7	0.14	0.28	14000
Sensors and commo	0.016	0.034	0.017	24100
Weaponry	-	0.508	0.008	1200
Environ	0.113	0.64	0.64	16940
TOTALS	0.116	51.978	4.375	84740

For controls, we’ll need 84740/100000 x 13 control points, so 11.016. 
We take them in form of electronic controls, needing (at 0.5 CPs each) 23 such controls:
	Power (Mw)	Volume (kl)	Weight (ton)	Cost (Cr)
23 x electronic controls	0.0115	2.3	0.115	1610

As those are not linked controls, we don’t need computer. Also the volume is under the 12 kl a single person can operate according to Consolidated Errata page 35.
For Crew, a vehicle needs an operator and a gunner/commander. We give them roomy seats.
We also give the vehicle 10 adequate seats for passengers, as its mission is to transport them.
	Power (Mw)	Volume (kl)	Weight (ton)	Cost (Cr)
2 roomy seats	-	8	0.04	200
10 roomy seats	-	40	0.2	1000

Thus, so far:
	Power (Mw)	Volume (kl)	Weight (ton)	Cost (Cr)
Hull	-	54	2.275	14500
Power	0.945	0.7	1.155	14000
Locomotion (6 TT)	0.7	0.14	0.28	14000
Sensors and commo	0.016	0.034	0.017	24100
Weaponry	-	0.508	0.008	1200
Environ	0.113	0.64	0.64	16940
23 Electronic controls	0.0115	2.3	0.115	1610
12 adequate seats	-	48	0.24	1200
TOTALS	0.1045	1.678	4.73	87550

We give it 24 hour endurance (at 0.0028 kl of fuel per hour, as seen in power section), so 0.0672 kl of fuel and 1000 RAM grenades as ammo (not specified in books AFAIK, I make them 0.1 kg each)
Loaded weight will add 1200 kg for passengers (house rule, but I’ve always added 100 kg/person in vehicles, as people does weight), 0.005 ton per fuel and 100 kg for ammo, giving a total loaded weight of 6.035 tons.
As it has 7 tons trust, loaded acceleration would be 0.15 G, giving it a top speed of 180 kph ( well under the 300 kph maximum for a unstreamlined craft) and a cruiser speed of 135 kph. NOE is 40 kph, as it lacks avionics.
As I see the tables are quite a chaos (and I'm not able to fix them), I also give it to you as attachement for easiness to read:

View attachment APC.docx

Hope this helps
 
Last edited:
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