Friday, April 09, 2010

AT-43 - Megatraveller conversion, pt.1

I'm quite interested in utilizing my growing collection of AT-43 miniatures in a role-playing game system. One major stumbling block is statting out the units. To this end, I found myself digging out my old Megatraveller books, since this game has detailed rules for creating vehicles. For my first effort, I have turned my attention to the backbone of the UNA force, the Fire Toad.

I've estimated the overall tech level of the UNA to be TL10. This is significantly below the default TL in the Megatraveller campaign setting, but I think given the absence of grav vehicles, it is appropriate. For the hull, I have the following:

6/14, Disp = 6, Config = 4USL, Armor = 20E

The volume is 81 kl and the weight of the hull is 4.8 tonnes.

So far, so good. Next is power supply, but I have to jump ahead a bit because the Fire Toad is armed with two laser cannons, so I have to know what kind of power requirements are going to be needed. I choose 2 5Mw TL8 beam laser guns to give me the kind of firepower I envision for the Fire Toad. So, getting back to power supply, I add a 6kl TL10 fusion reactor, which provides a total power output of 12Mw, sufficient to fire the guns and run all the other systems the vehicle will require. Locomotion is, of course, two legs and the required suspension and transmission. The power supply and locomotion systems weigh in at a hefty 36.9 tonnes.

For sensors and communications, I include Passive EMS V.Distant (50km) and MaserComm and Radio Regional (500km), respectively. I also install Basic Env, Basic LS and Extended LS.

The Fire Toad seems to be limited to a single crewman, so an onboard computer is clearly required. Without it, one would need a driver/operator, two gunners and a commander. I select a 1/bis system with 13 dynamic-linked control panel units and a heads-up display. I also include electronic circuit protection since it is a military vehicle.

The entire vehicle weighs 51.7 tonnes.

At this point, everything is pretty straightforward, but I'm guessing any of you who are veterans of the Traveller vehicle design procedure may have already noticed where I am about to hit a speed bump (and I mean that literally). When I proceeded to calculate my power-to-weight ratio (P/W), I got:

(12.0 Mw / 51.7 tonnes) x 1000 = 232

A quick look at the speed table will tell you a P/W of 232 results in a top road speed of 276 kph, which seems about an order of magnitude too high for the lumbering Fire Toad. Now, I'm stuck. I can't reduce the power output without greatly reducing the firepower and I can't increase the weight very much since most of the weight is power supply. If I increase its size, I also increase its power output. One possibility is to switch from a fusion to a fission reactor, which has a significantly lower P/W. It is also a much lower TL and takes up a lot more space, so I will have to recalculate everything and watch my hull volume closely. I will post my revised build soon.


A further thought, perhaps what I have to do is houserule a power management system. After all, the current build assumes the vehicle has all the power it needs to fire all weapons, move at full speed and run all other systems simultaneously. I used to play BattleTech quite a bit. Maybe I will borrow some of that system's ideas on power distribution and management. Perhaps the weapons could be powered by capacitors that have a delayed period of charging before they can be fired.

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