Nigel.. Just for info, runway 23 is "closed" for about 90% of the time and forms one of the major taxy routes on the airfield. When the weather forecast suggests we may need to use it, it can take 3 hours to clear it ready for use.
When 27R is closed to landing a/c with the crane up we are not permitted to vector traffic to it.
I guess in the event of a truly catastrophic emergency we'd have to do what we could but I don't think fuel shortage comes anywhere close and I have never experienced such a situation whilst I've been there.