Thanks Mike, much appreciated.
Nice website, too.
Here's ours (unofficial).
Edited to add:
In a tower environment, we too are allowed to anticipate separation, but not to the extent you do.
That is, we can anticipate if we need to when we issue the clearance, but we don't issue the clearance until the aircraft is #1 to use the runway.
eg, if an arrival is tight behind a departure, a controller can issue the landing clearance before the standard is met, providing he is satisfied, in his judgement, that the standard WILL be met.
As a matter of interest, how far out (generally) are aircraft when they are transferred by approach to TWR? I'm trying to get an idea of the extent of your anticipation, such as how many movements might occur on the runway in the time between an aircraft getting its landing clearance and actually landing. Could there be, say 3 arrivals and you fire off a departure in each arrival gap, for a total of maybe 6 movements before the aircraft lands? (I don't mean pattern traffic here, you already answered that. I'm thinking IFR departures.)
Cheers
AA