At Spin Two Swords
The Life of a Pirate
Traveller gives a brief account of piracy in the Third Millenium based off assumptions which are somewhat arguable. I will use the 100-widths Jump rule to explain this. 100-widths from Earth is 1.27 million kilometers. This makes a globe of 8,580,246,646,050,961,924 cubic kilometers (19 zeroes). Radar gives a globe of 523,598,775,598,299 cubic kilometers (15 zeroes). That means it would take 16387 System Defense Boats evenly spaced to keep 100 widths in their system to cover the entirety of 100 widths. Chances are, though, that they won’t be evenly spaced. This means that to cover the system, a planet would have to have 1000s upon 1000s of system defense boats. A solid planet might have a fleet of 8 or 10. Most ships can get from 100 Earth Widths to the planet in 2 and a half hours. Assuming that the pirates are attacking where they know the system boats won’t be and assuming that they can find a ship in these areas, a pirate ship ought to be able to attack with up to an (172 minutes/half the number of System Defense Boats) window of opportunity. In a system where there are 4 patrol boats out keeping the sky safe, I have over an hour to expect a response! This assumes Thrust 5.
Now, a number of things are on a spacer’s side in this. The first is that the SDB don’t have to monitor everywhere, just where the ship is likely to end up after a jump. Unfortunately, this isn’t as easily derived as one might hope. Moons move as do planets. A system is in motion, any attempt to figure out where things are before hand, has to deal with the speed of light making it impossible to look a parsec away to see where things are. Charts and graphs are needed to determine where things might be. Chances are that one can miss any number of significant things (space is big) but as the locus of opportunity shrinks, say at 100 widths, the calculations become more and more dicey. Getting to 100 widths is not that difficult, getting to an exact spot in the 100 widths is a lot harder.
To be a pirate, then, one has to avoid detection from the SDBs while circling the 100 widths and looking for ships that come in at inopportune spots. One interesting point: arrival is random enough for pirates to attack incoming ships, but departure is likely to be guarded by SDBs.
The analysis so far has concentrated primarily on ships jumping near the main planet and flying to it at 5Gs against system boats with the electronics options from the Core book. This covers the most common set of circumstances.
When spacer traffic happens outside the 40w-100w range, things get more complicated. Basically, if a pirate knows where you are headed, you may be in danger. If, on the other hand, the path of the journey is unknown, the chance of encountering pirates is extremely slim, and the chance of a prepared ambush is negligible.
Note, that as ships move through the system, they are likely to be going very fast. A ship with M4 accelerates at 40 m/s (sq). If it’s been flying for an hour, it’s going 144 km every second. It will appear on radar for six minutes and then will be off