Ok sussed it.
Now, a possible bug report. Whilst playing it tonight, one of the parts to the power appeared to be missing..I found the panel & fuse but the switch was no where to be found. I spent around 50 mins looking for it, it wasn't there.. and I mean I looked everywhere, it wasn't there. I restarted the map and I found all three pieces with around 6 minuets.
Along with Project Viking , this is just about the best map I've ever played.