33k in the air
Staff Sergeant
- 1,266
- Jan 31, 2021
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No, I'm just someone who gets too deep into details sometimes.
To obtain 1,388 mark II series I requires all mark II production until sometime in July 1943, for 388 mark V series I requires all mark V production to sometime in August 1943. Assuming the lines all changed over in the same month. If Handley page built 299 mark II series Ia that requires all production from sometime in December 1942.
Assuming for the sake of argument all Mark II and V were series I to end February 1943 and Series Ia thereafter, the split is 994 to 976 mark I, 149 to 755 mark V. Since the mark II was in production until May 1944 and the mark V until July 1944.
A good chance all the Series I special were converted. Unless the form 78 cards say something it is contact the authors and ask where their series information came from time. Or do photograph searches to see if anything can be pinned down. From a quick check of the aircraft cards,
HP II serials, HR660 in December 1942, seems to be the first Merlin 22, some later serials with Merlin XX. The first serial with Ia marked on its card is HR841 in May 1943, then HR845, HR847, HR855, as time goes on more cards are marked Ia
LAP II looks like they begin fitting Merlin 22 with BB329 in March 1943, JN882 the first Ia in July 1943, JN884 no series information, JN885 on seem to be series Ia.
English Electric II were still fitting Merlin XX to end production in October 1943, none of the cards checked were marked Ia.
Fairey V began fitting Merlin 22 with DK235 in June 1943 and it appears to be a clean change over, with DK244 in July the first card marked Ia, but some later cards have no series information.
Rootes V first series Ia LK890 in July 1943, again not all cards marked.
Of the 5 production lines the switch to series Ia was 1 in May 1943, 3 in July, 1 unknown assuming the early series Ia cards are properly annotated. Rather later than the biography states.
Aircraft equipped with this modification [clear perspex nose and four-gun dorsal turret] were designated HP.59 B.Mk II Series Ia, or HP.63 Mk V Series Ia. These also featured low drag nacelles derived from the Bristol Beaufighter Mk IIF which had rectangular Morris block radiators in place of the Galley twin drum radiators as installed in the HP.57 Halifax B.Mk I. The fully modified prototype HP.59 Halifax B.Mk II Series Ia, HR679, first flew at Radlett on 24 December 1942. The aircraft was 10 mph faster than Halifax B.Mk II W7922, even when the latter had its Boulton Paul Type C1 upper turret removed . . .
. . . The first GR.Mk II Series Ia was JP258 and the first B.Met Mk II Series Ia was DG344.
. . . A total of 299 HP.59 Halifax Mk II Series Ia variants were built at Cricklewood, nearly all equipped with Boulton Paul Type A Mk VIII four-gun upper turrets.
The prototype Halifax Mk II Series Ia (HR679) flew from Radlett for the first time on 14 December 1942. 299 were built, all by Handley Page.
Month | I | Ia | II/V production x4 |
Jul-42 | 1194 | 0 | 248 |
Aug-42 | 1377 | 0 | 292 |
Sep-42 | 1627 | 0 | 316 |
Oct-42 | 1632 | 0 | 436 |
Nov-42 | 1367 | 0 | 396 |
Dec-42 | 1397 | 16 | 408 |
Jan-43 | 1046 | 32 | 484 |
Feb-43 | 945 | 98 | 548 |
Mar-43 | 1022 | 100 | 612 |
Apr-43 | 964 | 96 | 620 |
May-43 | 803 | 222 | 720 |
Jun-43 | 640 | 284 | 636 |
Jul-43 | 710 | 365 | 624 |
Aug-43 | 623 | 486 | 524 |
Sep-43 | 462 | 481 | 604 |
Oct-43 | 240 | 536 | 480 |
Nov-43 | 335 | 355 | 340 |
Dec-43 | 327 | 393 | 324 |
Jan-44 | 293 | 366 | 260 |
Feb-44 | 438 | 336 | 252 |
Mar-44 | 277 | 359 | 236 |
Apr-44 | 100 | 284 | 268 |
May-44 | 348 | 258 | 204 |
Jun-44 | n/a | 158 | 144 |
Jul-44 | n/a | 166 | 76 |
Aug-44 | n/a | 154 | 0 |
Although I do not know if this applies to the particular aircraft you are referring to, there were often different Modifications for different Sqns/Groups - sometimes depending on environment and/or the mission types being flown, and some would be requested by the Unit Commanders due to operational preferences or testing.
As I understand it Cunliffe-Owen did the MET conversions, so look where the aircraft went afterwards, 58/502 or 517/518.
I'm unclear if the Series I (Special) was only from conversions of Series I aircraft, or if some came out of the factory that way. Photos and illustrations of Series I (Special) aircraft show some with no dorsal turret, some with the two-gun dorsal turret, and some with the four-gun dorsal turret. So alterations and variations for this subvariant seem not uncommon.
I'm not sure if you're still unresolved about production of Series 1A's vs modifications, but a Bomber Command operational Research report I have from November 1943 suggests that the Series 1A were made up of both aircraft produced in factory, and also older Halifax models modified to the Series 1A standard. I would guess the ones without dorsal turrets or the 2 gun ones were the older Halifax models brought up to Series 1A standard (as far as possible), especially those lacking a dorsal turret as that was a very common modification in early 1943 when the Halifaxes had the "Z-fairing" instead of the glazed nose.
View attachment 718766
This image is from "ORS BC #90 - Monthly Review of Losses and Interceptions of Bomber Command Aircraft in Night Operations – November 1943" which can be seen on my website.
Ah well, one can only work with what one has.