Errrr... 4000 divided by 133 is 30, not 300.
Most of those "little" exchanges, especially in BDUK, aren't going to directly have exchange equipment - they'll be children to a nearby parent with the head-end.
Activating those exchanges is going to amount to converting at least one cabinet, plus the obviously longer backhaul.
Being small exchanges, there won't be many cabinets to convert on each.
The opposite way of looking at the activation count is the premise or cabinet counts, rather than the exchange count. At the moment, BT are "passing" 1.5 million premises per quarter, or about 100k per week (or around 250 cabinets per week).
There is still about 9 million premises to go, which would be 70k premises per week in your 133 week schedule. Not implausible - except lots of projects are setting later deadlines and even higher targets (so perhaps there is really 10-11 million to go).
Edited by deleted (Sat 01-Jun-13 13:52:36)