Think phaser strip.
Multi Part.
There are 2 end pieces, together they would form the smallest version of this weapon, One end piece has a crew requirment and power is delivered to this piece. the other end piece is simply the end and has no special function.
The other pieces would be a strait peice and a 90 degree turn.
The power delivered fills up a tube running through all the pieces. once the entire tube is filled it starts to glow (visual cue) and a button appears on the HUD. It should take a lot of power to fill up even the smallest version of this weapon.
To activate the weapon, click the button and then click a square on any opponents ship. If in rangeof any part of the weapon, it fires. If not, it will fire when any part of the weapon comes in range. The range should be about that of a small cannon/ion????
The weapon discharges and a beam starting at the crewed end part connects with enemy ship directly in line with the target square. This beam travels down the length of the weapon, still targeting the same point.
The length of the beam dictates the damage, the firing time i think should always be 2 seconds ish.