Harris started to campaign in earnest to switch production from the Halifax to Lancaster in late 1942. He met immediate resistance from the MAP. On 11th September '42 John Llewellin (the then Minister) wrote:
"If we gave the order to change over now, English Electric would produce the first Lancaster about November 1943 [more than a year later!] and would not reach peak production until December 1944. Between August 1943 and December 1944 you would lose some 220 bombers. This would probably be the firm that would give the best result. In my view, the changeover is not the remedy. The remedy is to modify the Halifax so as to bring its performance more like the Lancaster's"
Harris didn't believe him and nor incidentally did the more dynamic Stafford Cripps who would take over his job shortly. Llewellin's remedy took nearly as long to implement as the changeover, and in the meantime men continued to die in an inferior aeroplane.
Llewellin had the support of Sinclair, but Freeman was more sympathetic to Harris and Bomber Command. His compromise solution was that English Electric should, over the next twelve months, erect additional capacity with jigs and tools to build the Lancaster at its Preston plant. He would write:
"In this way the time lag should be cut down and the Halifax can go at almost peak rate until the Lancaster is in reasonable production. The shops that are now producing the Halifax would eventually turn on to the Lancaster and we should get the combined output of both."
This was rejected by the MAP for no good reason. Handley Page were an old client and whereas the suggestion that Avro, the new kids on the block, should produce the Halifax (made in 1940) was acceptable, the idea that Handley Page produce the Lancaster was not. I believe this was a political decision which has a whiff of the sort of cronyism that so bedevilled German aircraft production about it.
Rootes and LPTB production is irrelevant at this time. Between them they manufactured just 20 Halifax BIIs. Fairey hadn't even started (LK747 a BIII was the first to come from Fairey Aviation).
Cherwell liked his statistics and was also a supporter of the changeover on grounds of efficiency. His department calculated that due to the ease of construction of the Lancaster, and its heavy bomb load, 3.6lbs of bombs were dropped for every factory man hour compared with just 0.95lbs for the Halifax.
Ease of construction is reflected in production figures for 1942 of 516 from Avro with a further 172 from Metropolitan Vickers and Armstrong Whitworth.
Edgar raised a very valid point about engines. The Lancaster II was forced to use Hercules engines whilst the inferior Halifax got the limited allocation of Merlins. As you can imagine this got Harris going again. He wrote to Portal:
"The Lancaster II has a marked falling off of performance which is not acceptable now and will be still less acceptable in 1943. It has over 200 miles less range in theory and in practice we are already finding that it has some seven hours endurance compared with the ten hours of the Lancaster I. It is slightly slower. It's maximum speed is achieved at 15,000 feet [which Harris considered lethal] as compared with the 19,500 of the Lancaster I. The Hercules engine is notoriously unreliable, though this may be got over. The raison d'etre of the Lancaster II is that insufficient Merlin engines are now available to put Merlins in the total production of Lancaster fuselages. But Merlin engines are being used in large quantities in the deplorable Halifax. Therefore in order to overproduce one deplorable type we are virtually wrecking a large proportion of the output of a first class type, the Lancaster I."
Cheers
Steve