Class A - numbers and costs?

PNK - It's the whole £600m wartime effort (dubbed "the largest construction programme in British history") that's of interest.

That would include all airfields built from scratch after the Emergency Powers (Defence) Act (1939). From that time on, these were presumably all of a 'utility' type - including Class A aerodromes; and others that were brought up to, or exceeded, that standard later in the war.

But the programme also covered upgrades to airfields that existed before 1939 - primarily with the laying of runways - such as grass-field RAF expansion period bases; and former civilian sites (e.g., St Mawgan) requisitioned for the air campaign.

I'd be interested to know where the bulk of that £600m was spent. I suspect most of it went on all the new-build Class A-types and their derivatives, given the sheer number of them constructed in the war years.

As for the "£1m average cost" of a wartime Class A airfield, I've found an interesting piece about Wimpey's involvement here. It shows some widely differing figures - but I suspect they don't account for all the 'fixtures and fittings'.

I'm now also a little closer, I think, to coming up with an approximate figure for the total number of active airfields in the UK during the war. Based purely on those allocated a two-letter ID code, it seems to be around 520, excluding Fleet Air Arm airfields. Does that concur with anyone else's figures?

PNK wrote:

I have a suspicion that St Mawgan, although a wartime build, was not actually classed as a Class A either. [mawganmad - any ideas?]

I'm inclined to concur with that, but not sure of the parameters of this debate.
I would also say that SM would be at upper end of cost of wartime airfields, size, fitted electrics and kit, and largest tower of the era.
I wouldn't mind betting that a large pre-war expansion airfield would come close though, purely because of high quality planning, buildings, and labour force (just look at the effort and workmanship in a brick C hangar).

mawganmad

Yes, given its high spec, St Mawgan must have been among the most expensive of the wartime builds.

And some of the airfields built in wwii had grass runways eg Newton and Swanton Morley.

PNK - Yes, the c. 520 figure refers to all sites given a two-letter ID code - in other words, just about every active wartime airfield (exc. FAA), and not just Class A builds.

As for the Heathrow cost, I've read that the site was originally planned as "a major transport base for the RAF", but the war ended before it was finished (and adapted for civilian use). So might that mean it had a similar 'very heavy transport' (VHT ?) specification to St Mawgan? If so, it could explain the extra costs over the standard Class A spec.

But, as you say, why was Heathrow so much more expensive than Lakenheath? Perhaps the pre-existing set-up at Lakenheath kept the development cost down, as its VHB status was an upgrade rather than a new build.

There is a bit on the St Mawgan / Heathrow link link under their relevant airfield sections and VHT section.
Yes both airfields were designed to be VHTs, from the outset it was intended that St Mawgan would be built as a 'working model' of Heathrow, hence the latest technology lighting and control, American ILS, tower etc etc. It also featured major terminal buildings and handling.
A misnomer is that Heathrow was planned as a military transport base, it was submitted and passed as such, but evidence says that it was planned as the new post-war London airport from the start.
The actual runway layout differs slightly between the two (SM got a major R/W extension before Heathrow started), and from very early on the extra runway and taxyways ware being started - which might explain the difference in £0.5 million.

BTW I only mentioned Mawgan because I know the figures involved and to give indication of upper spend limit, and not suggesting it fits in with other A class or 3 R/W stations

I was under the impression that the major spend on the VHBs was latter (the VHB towers are immediate post-war)

PNK, I'm suprised you found a final Wimpey price for Heathrow, I didn't think the place was ever finished!

On the subject of Heathrow, there was another airfield planned to the north of it with a three runway layout.