ah, well, the numbering convention is a bit confused.
To start with, Cam is wrong and the numbering was originally done on the bridges over the tidal section, so first was the old Stirling Bridge, where they had the battle, second was the new one just downstream, built by the Victorians, third was the railway bridge at South Alloa (across to Alloa, oddly enough) and then you had the big, iconic iron one (hence Forth).
They should have renumbered it to Fifth Bridge when they opened the one at Kincardine back in the 1930s, but the prohibitive cost of redesigning the souvenir tea towels and ashtrays precluded any change. As a result of this they completely screwed up the numbering scheme by counting back upstream as well...
so we now have heading downriver:
First bridge: the medieval Stirling Bridge, now pedestrianised
Second bridge: the Victorian Stirling Bridge (which is an interesting split number, doing rail & road on completely separate structures, don't ask)
Third Bridge - Kincardine (renumbered when the railway bridge at Alloa was removed after Beeching)
Forth Bridge - the big red one
then turning back up river we have:
Fifth Bridge - suspension, next the big red one
Bridge 3A - AKA Clackmannanshire Bridge, built to ease traffic pressure on Third Bridge
Sixth Bridge - carries the Stirling ring road, acts as bypass for Second Bridge
Bridge Zero - upstream from First bridge, carries the M9
With the new one currently under construction there is a controversy - should it be the Seventh bridge? Bridge 5A? Or should they renumber the existing Sixth Bridge as 2A to allow the new one to be Sixth for the benefit of the tea towel makers
In international understanding
Bob
PS this "Coffee plus" with added caffeine & gurana is good shit
PPS didn't do much rummaging in the shed for engine protectors, the subzero temperatures and gusting hangover put paid to spending much time out there