Try yet again, 637 Hurricane mark I in 1941.
The following is from the US Study into industry efficiency, Republic Farmingdale, measured worker hours required to make 1 pound of airframe, actual acceptances, output if the factory started at December 1943 efficiency, output if the factory started at peak efficiency of 0.57 hours per pound.
| month | hrs/lb | actual | better | best |
Oct-42 | 8.85 | 2 | 8.81 | 31.05 |
Nov-42 | 8.85 | 2 | 8.81 | 31.05 |
Dec-42 | 8.85 | 6 | 26.42 | 93.16 |
Jan-43 | 6.45 | 12 | 38.51 | 135.79 |
Feb-43 | 6.45 | 21 | 67.39 | 237.63 |
Mar-43 | 7.26 | 50 | 180.60 | 636.84 |
Apr-43 | 4.6 | 52 | 119.00 | 419.65 |
May-43 | 3.79 | 80 | 150.85 | 531.93 |
Jun-43 | 3.62 | 82 | 147.68 | 520.77 |
Jul-43 | 3.62 | 65 | 117.06 | 412.81 |
Aug-43 | 3.59 | 90 | 160.75 | 566.84 |
Sep-43 | 2.78 | 133 | 183.95 | 648.67 |
Oct-43 | 2.46 | 136 | 166.45 | 586.95 |
Nov-43 | 2.23 | 190 | 210.80 | 743.33 |
Dec-43 | 2.01 | 220 | 220.00 | 775.79 |
| Total | | 1,141 | 1,807 | 6,372 |
You want lots have long undisturbed production runs. When the British did their analysis they concluded it was about 18 months from first production to hitting the planned peak output.
Ford made a big effort to introduce true mass production methods to the B-24 but kept running into the reality steel was a very different material to the light alloys used by aircraft, it was not a simple transfer of knowledge, lots had to be learnt and successes were compromised by the frequent changes being ordered for the airframe.
Aircraft factories ranged from places that mainly assembled supplied components through to doing significant manufacturing from raw materials. It helps explain bombing the "factories" often did little to aircraft production numbers.
The western allies went from not enough aircraft to too many in a matter of weeks in 1944, with some exceptions like Mustangs. "Suddenly, Overnight" loss rates were falling, allied advances were accelerating, maximum force sizes had been met, the cuts already being done to trainers could be extended to combat types
In 1939 and 1940 the British economy went through major shocks, the cutting of trade with the continent, loss of Mediterranean routes, the U-boat blockade, before adding the direct attacks. The mid 1940 crisis drove fighter production to unsustainable levels, falling back over winter, air attack or its threat cut production from around September 1940 to May 1941 while the system adapted. There had to be more than one source of anything important, factories could only grow so big given they were subject to attack. All while weeding out the weapons that did not work for those that did. While ensuring enough weapons were ready for Battle of Britain second round.
The Spitfire arrived with a 1,375 pound engine, would it still be a viable flying machine with a 1,640 pound Merlin 61, how about a 1,980 pound Griffon? Would required changes mean a new design would be better?
Three Beaufighter lines, Bristol Filton, Bristol Weston, Fairey, the latter two in early 1941. Production 0 in 1939, 803 in 1940, 1,582 in 1941.
Three Hurricane lines, Hawker Brooklands, Hawker Langley and Gloster. (Ignoring the Austin Cameo) The Brooklands site was being absorbed into greater London, limiting its expansion ability. Langley and Gloster arrived in Q4/39 and did well, in 1940 the production split was roughly 1/4 Brooklands, 1/4 Langley, 1/2 Gloster. It was Langley that received most of the increases in capacity post 1940, with Brooklands ceasing production around September 1942, Gloster in March 1942. Hurricane production 1939 to 1941, 586, 2,521, 3,169, which was peak production year by a small amount, 1942 production 3,067.
Gloster built up to 140 to 150 Hurricanes a month in mid 1940 and largely held that output until a dip during the mark I to II change over, rebuilt to 144 in September 1941, then the wind down 119, 100, 71, 89, 41, 18, production ending in March 1942. Typhoon production had started in June 1941, slowly, it took until Q3/42 for output to reach around 100 a month, in airframe weight terms around that of 150 Hurricanes. By that stage the Sabre engine problems meant there was no point increasing airframe production. Gloster built 677 Typhoon in 1942, 150 Hurricane x 12 = 1,800 aircraft, in round terms the change over cost several hundred aircraft. IF you look at the production list, 1,874 Typhoon lost to end April 1945. Rapidly retired from RAF service in 1945.
Hawker had its patented construction methods, which needed to be changed for the next generation of aircraft, the Typhoon and later. Hurricane orders were increased as Typhoon problems continued, leading to the Hurricane V as the substitute for the Typhoon for Overlord, engine production had started before the order was cancelled. Note while the Hurricane was cleared for under wing 500 pound bombs or fuel tanks the Spitfire stayed at 250 pounds and no fuel tanks.
One irony in altitude terms the Typhoon was the best adapted to the war the 2nd TAF and 9th AF fought, all their other fighters were carrying around supercharging designed for best performance at 20,000 feet or higher when the missions meant 10 to 12,000 feet was considered high altitude.
The Supermarine works were judged too vulnerable to invest much into until 1942, dispersal was done instead, the division of work being Supermarine would do the small runs and initial versions, Castle Bromwich would do series production of preferred versions, the result it had about twice the worker efficiency of Supermarine. Spitfire output, Supermarine, 895, 1,079, 1,174, 1939 to 1942 (plus 168 Seafire in 1942). Castle Bromwich 345, 1,384, 2,550. Westland provided a cameo before switching to Seafires. Ignoring some prototypes, Spitfire production 1939 to 1942 was 435, 1,249, 2,519, 4,134.
Britain is not able to do much to its fighter production mix in 1941, which in turn locks in 1942 production. The US need for aircraft in 1942 meant promised aircraft were not delivered, increasing reliance on local output, further locking things in.
The USAAF was not very interested in the P-39 but it kept being ordered for similar reasons to the Hurricane, it could arrive soon, better safe than sorry, plus the commitments to and interest of the USSR. The P-47 was running late and reserved for the USAAF though 1943.
Austin at Longbridge managed to build around 50 or Fairey Battle a month in 1940, winding down to 11 in October and a final 1 in December, next came the 300 Hurricane, first one in February 1941, a total of 15 by end August 1941, production ending in October 1942, best monthly output 30. Short Stirling from March 1941 with 40 built in 1941, monthly output in the teens in 1942, peaking in the upper 20's in 1943 production ending in October 1944. Lancaster production began in March 1944, six by end June, to upper 20's per month in February 1945. By the looks of things the Stirling to Lancaster change cost around 100 aircraft, or about 4 months production, changing from the lancaster I to VII about a month's output.
When it comes to weapons costs, yes, they cost, actually how much is another question. Mass production was driving prices down, complexity driving them up. This is the money paid to Hawker per airframe, not the full amount for a complete aircraft. £4,750 for the first order, £4,275 from final order. Supermarine £5,782 for most of the first order, £6,208 for a Vb, £6,088 for a Vc as of mid 1942. With lots of variations with production time, version and factory.
, the question re the Spitfire fuel load and range is what would have been practical in the time period currently under discussion.
