Air Commodore Les O'Dea, Commanding Officer of UK Joint Force Support, said:
"The US operation is already huge. To make sure that everything will be ready and waiting, cargoes of freight are already arriving on a US scale."
In January, nearly 30 C17 cargo planes full of supplies and equipment were flown in. By May that will rise to 675 flights a month, and by late summer to a remarkable 860 a month:
"That is about the same amount of freight that Gatwick airport has to cope with," said Air Commodore O'Dea.
The forthcoming handover from 3 Commando Brigade to 19 Light Brigade will take place while the pace of the US expansion is accelerating, squeezing the number of air transport slots available for roulement.
Bastion's increasing size will mean that the area to be protected will also grow.
On the other hand, force protection for those making the 10-minute journey from Bastion to Camp Tombstone, where the Operational Mentoring and Liaison Team are based alongside members of the Afghan National Army, will no longer be necessary. When Bastion expands, Tombstone will find itself well within the wire.
As well as extra accommodation, cafes and gyms, there are plans to upgrade the UK-led role three hospital, making it a larger, joint US/UK facility. A problem of growing waste disposal will have to be addressed:
"The burn pit at Bastion needs sorting out anyway," said Air Cdre O'Dea. "And plans to do that are already underway."
At the moment the pit burns about 30 tonnes of rubbish a week. That will soon become 90 tonnes.
Fortunately, Bastion enjoys plentiful water supplies. Below the base is a massive aquifer from which the camp bottles its own water. Tests have shown that the aquifer will be able to quench thousands of extra thirsts. If the rate of C17s landing at the base is maintained, those extra troops can expect to be comfortably accommodated and fed as well.