Archive for August, 2020

System travel maps

Posted in Intercept, Traveller on August 31, 2020 by Anders Backman

Traveller in system travel times

In Traveller system travel (ie planet to planet) usually consist of the referee deciding the distance between the planets and then use the formulae or tables to calculate the travel time – boring!

What if one could actually Travel the distance using vector movement, possibly taking detours as to not get too close to the sun, perhaps detecting an emergency broadcast and having to change course to reach the vessel in distress, or maybe that old clunker of a maneuver drive gives out midway and you will have to repair during a couple of days and thus you miss the estimated arrival time pissing certain people off etc etc? I’m not saying this should be done all the time, just that whenever the referee wishes to spice things up with actually travelling the distance you could do it.

System maps

I have created three maps for you to download and print. At the top of each map there’s a line telling what the scale is and there are grey orbit lines for each Traveller planetary orbit. The referee has to decide where along these orbits the planets currently are. Your ship will move on the map using vector movement, each square is 1 G of thrust, diagonals count as 1.5 but any fractions are dropped when the total thrust for the turn has been counted (a ship thrusting 3 squares diagonally is 4.5 squares but the fraction is dropped so only 4G is required), freshen up on vector movement here if you are unsure. You do not need to worry about facing and turning of course when using the system travel maps, 4 hours, 12 hours or 2 days per turn is ample time for even the largest ships to turn however they like, landings are simply the process of moving your ship unto a planet square (drawn there by the referee) and in the next turn brake off the speed to zero. On these scales there are no real gravity effects, not even from the sun as getting so close to the sun would melt your ship anyway.

There are three system travel mas that can be used to move ships between planets, the reason for three maps is that star systems vary enormously in scale so the maps show the inner system orbits out to 1.6 AU (Mars orbit in our solar system) and the outer system map cover out to 20 AU.

Outer system map has 150 million km squares (1 AU) with 2 day turns and 1 G of thrust equals 1 G, ships can turn and roll however they like.

Inner system map has 15 million km squares (0.1 AU) with 12 hour turns and 1 G of thrust equals 1 G, ships can turn and roll however they like.

M system map has 1 million km squares with 4 hour turns and 1 G of thrust equals 1 G, ships roll Pilot tasks or use Pilot Default but with a +4 DM. These maps are used for M class stars where the lifezone is ~0.1 AU.

I might make a fourth map with even larger distances, 10 AU per square and turns of a weeks each but that will have to wait until I see a need for it.

Flying too close to the sun, Icarus or Sunshine style, is a real danger but rules for that will have to wait until the next post. There I will add rules for heat damage both during Intercept combat and the system travel maps. That post will also cover the annoying tendency of jury-rig repairs breaking down, how to do real repairs and what can be made within the ship and what need a starport visit.

Well, that is all folks, until next time, don’t fly too close to the sun or learn why so many space crew get the nickname Fry…