Swordfish and it armor.

[Mac Eyka]

Hi.

I have small question

Swordfish Mk.III ASV XI radar equipment have a fusulages machine gun?

 

 

[Ex-FAAWAFU]

Assuming you mean the forward-facing gun alongside the pilot, no.  Indeed, many Swordfish had it removed quite early in the war; it was thought to be pretty much useless and a waste of weight / space.

[Ed Russell]

It's not the easiest area to see in pictures but the bulge seems to be present on all Mk I and Mk II Swordfishes and maybe on some Mk III but is not there on most Mk III models. I suspect the above is correct and even if the bulge is there the gun is not. A caveat to this is that it is based on not that many pictures - a few dozen.

[Ex-FAAWAFU]

The bulge was never removed, as far as I know; just the weapon itself

[Mac Eyka]

On 2/10/2022 at 9:43 PM, Ex-FAAWAFU said:

The bulge was never removed, as far as I know; just the weapon itself

 

This is the last Fairey Swortfish, NS204. I don't think he had the bulge

 

[Ed Russell]

On 2/11/2022 at 7:43 AM, Ex-FAAWAFU said:

bulge was never removed, as far as I know; just the weapon itself

I think that is correct but there are quite a few pictures of later Swordfish showing no bulge, like @Mac Eyka 's picture above. That's what my post above meant.

[Ex-FAAWAFU]

I wonder if that was a Mk.III thing?  After all, they needed to save every ounce of weight they could get, and it makes perfect sense not to persist with a bump on the airframe once the front line had clearly decided that the gun was useless.

 

Ray Sturtivant's "The Swordfish Story" isn't completely clear on this; "Both versions (Mk.I & Mk.II) had a foxed forward-firing Vickers gun operated by the pilot....  The final Blackburn production version was the Mk.III, which had an additional 'guppy'-type ASV radome mounted between the undercarriage legs, the TAG position being deleted."  He goes on to talk about RATOG and an up-rated Peggy 30, but nothing specific about the pilot's Vickers.  I also cannot find anything definitive in any of my other Stringbag references (Haynes, Harrison and others).  

 

However, there is a phots in the Haynes manual of NF389, the Navy Wings Mk.III (currently not airworthy, as they concentrate their resources on their Mk.I & Mk.II).  NF389 is a Blackburn-built Mk.III and the photo definitely seems to show that she has no Vickers bulge.  

 

My guess, therefore - and it is definitely a guess! - is that the Mk.III new builds probably didn't have the bulge (i.e. Ed is right).  I'd certainly never spotted that before.

[iang]

 It appears that some Mk II retained both bulge and gun.

 

 

 

When looking at photographs of Swordfish, it is worth noting that Sturtivant's classification of Swordfish marks is incorrect. The Swordfish Mark II was a designation change in relation to an operational requirement for rocket projectile equipped submarine hunters in the Battle of the Atlantic in the spring of 1943. Sturtivant misclassifies many Mk I Swordfish incorrectly  as Mk II (both in the Swordfish Story and FAA Aircraft 1939-45). These errors are carried over to photo captions too.

 

According to Blackburn Aircraft Co. records, a total of 1,699 Swordfish were produced by Blackburn.  Of these, 834 were Mark I, 545 Mark II and 320 Mark III. The number of Mark IV is not recorded in the Blackburn records, though we know from other sources that the numbers were quite small. It is unlikely that the 545 Mark II Swordfish would have been produced sequentially at first. The Mark I/II break is somewhere in the serial block HS579 to HS625, as both were likely to be found on the production line side by side for a short while.

 

Mk III don't appear to have the bulge (or gun obviously). I'm not sure when the bulge was deleted in the Mk II/III run.

 

 

 

[Graham Boak]

Not just Sturtivant, but HA Taylor identifies HS227 as a Mk.II in Putnam's Fairey Aircraft since 1915  I must admit to thinking "Aha! I've found a Mk.II with a gun" before checking your serials. 

[iang]

Yes - rule-of-thumb- unless it's got rockets it's a Mk.1

[Geoffrey Sinclair]

Swordfish production, Ministry of Aircraft Production figures are 693 from Fairey and 1,699 from Blackburn, no mark information provided.

 

However the RAF contract cards for the Fairey orders are complete, which give a total of 692 built

Contract 402278/35 Requisition 33/35 for 89, K5660 to 5662 and K5926 to 6011

Contract 466845/35 Requisition 5/36 and 111/36 for 131, K8346 to 8449 and 8860 to 8886

Contract 534297/36 Requisition 51/36 for 150, L2717 to 2866

Contract 672134/37 Requisition 51/36 for 62, L7632 to 7701 (including blackout blocks from now on)

Contract 743308/38 Requisition 167/37 for 60, L9714 to 9785

Contract 968679/38 Requisition 198/38 for 200, P3991 to 4279

 

Add one to Blackburn total to account for V4690 which crashed before delivery, it was not replaced and not counted as produced, so total Blackburn production 1,700

 

The incomplete RAF contract cards for Blackburn production also do not mention marks, the serials used were 300 V, 100 W, 100 DK, 400 HS, 250 LS, 350 NE/NF, 200 NR/NS. (Cumulative totals 300, 400, 500, 900, 1,150, 1,500, 1,700).  The first order from Blackburn is given as either 300 or 400 (probably the latter), if 300 then total order to 400, then to 500, then to 1,150, then to 1,500, no mention of the final 200 serials.  Order B31192/39 initial requisition 1/E1/39, additional requisitions 28 April 1941, 13 December 1941 and 9 June 1942 with possibly a final one on an illegible date 25? May? 194?  Interestingly after building 500 Swordfish to end April 1942 Blackburn produced none in May 1942 before resuming in June. 

 

The British Bomber by Mason, British Military Aircraft Serials by Robertson report
The V serials were mark I = 300
The W, DK, HS, LS, NE and NF serials to NF250 were mark II  = 1,080
NF251 on and NR/NS serials were mark III = 320.

No mentions of mark IV.

[British Naval Aircraft by Thetford, was originally in the above list but in fact it correctly states the mark II began production in 1943]

 

The above puts the change over mark I to II in October 1941 and mark II to III in February 1944, assuming aircraft built in serial order.  Canadian Military Aircraft by J.A. Griffin has W, DK and early HS serial Swordfish serving with the RCAF as mark II, a total of 99 served between 5 January 1943 and 12 July 1947, along with 6 mark III, retaining their British serials.  https://www.silverhawkauthor.com/post/canadian-warplanes-1-fairey-swordfish lists HS268 as a mark IV, local conversion?

 

If Blackburn produced 834 mark I then the mark I to II change over was in April 1943, again assuming aircraft built in serial order, Blackburn Swordfish production to end March 818, to end April 863.  First successful Swordfish rocket attack on 23 May 1943.  ASV radars were carried from around October 1941.  A change of mark for ASV carriage in 1941 matches 300 mark I built, but not for rocket carriage, a mark number change in April 1943 for rockets seems too late to enable the aircraft and trained crews to be in the Atlantic in May, Paul Kemp in U-Boats destroyed reports the rockets had been issued for front line service three weeks previous to the first successful attack.

 

Edited March 3, 2022 by Geoffrey Sinclair
reference correction.

[Lee Howard]

4 hours ago, iang said:

 

When looking at photographs of Swordfish, it is worth noting that Sturtivant's classification of Swordfish marks is incorrect. The Swordfish Mark II was a designation change in relation to an operational requirement for rocket projectile equipped submarine hunters in the Battle of the Atlantic in the spring of 1943. Sturtivant misclassifies many Mk I Swordfish incorrectly  as Mk II (both in the Swordfish Story and FAA Aircraft 1939-45). These errors are carried over to photo captions too.

 

Any particular instances (in case we've overlooked it - which I would like to think we haven't)? Not in photo captions, as these will all be different (and checked), but if there's something specific in the text, I can double check. I wouldn't want anyone picking this up once we've gone to press...

 

 

[EwenS]

16 minutes ago, Geoffrey Sinclair said:

 

..... ASV radars were carried from around October 1941.  A change of mark for ASV carriage in 1941 matches 300 mark I built, but not for rocket carriage, a mark number change in April 1943 for rockets seems too late to enable the aircraft and trained crews to be in the Atlantic in May, Paul Kemp in U-Boats destroyed reports the rockets had been issued for front line service three weeks previous to the first successful attack.

ASV II radar was being carried by Swordfish prior to Oct 1941 (from spring that year IIRC). Not all but some. Some of the Swordfish on Ark Royal that attacked Bismarck in May 1941 were radar equipped.

 

The question is where the radar was being added. On the production line or the MU or elsewhere. ISTR reading that when Illustrious was sailing to the Indian Ocean in March/April 1942 the squadron personnel fitted ASV.II sets to the Swordfish, or at least some of them, of 810 & 829 squadrons will en route.

[iang]

1 hour ago, Geoffrey Sinclair said:

 

 

British Naval Aircraft by Thetford, The British Bomber by Mason, British Military Aircraft Serials by Robertson all report
The V serials were mark I = 300
The W, DK, HS, LS, NE and NF serials to NF250 were mark II  = 1,080
NF251 on and NR/NS serials were mark III = 320.

No mentions of mark IV.

 

The above puts the change over mark I to II in October 1941 and mark II to III in February 1944, assuming aircraft built in serial order.  Canadian Military Aircraft by J.A. Griffin has W, DK and early HS serial Swordfish serving with the RCAF as mark II, a total of 99 served between 5 January 1943 and 12 July 1947, along with 6 mark III, retaining their British serials.  https://www.silverhawkauthor.com/post/canadian-warplanes-1-fairey-swordfish lists HS268 as a mark IV, local conversion?

 

 

 

Sadly, that is all incorrect. My research is based upon the extant Blackburn production records held at TNA. I've published an article on this in Aeromilitaria (Air Britain), which laid out all of the details concerning marks and the change over to the more powerful Pegasus XXX engine (which Sturtivant also has wrong).  This one:

Ray commented on the contents and accepted the conclusions before he died.

 

 

[iang]

1 hour ago, Lee Howard said:

Any particular instances (in case we've overlooked it - which I would like to think we haven't)? Not in photo captions, as these will all be different (and checked), but if there's something specific in the text, I can double check. I wouldn't want anyone picking this up once we've gone to press...

 

 

Lee,

 

All of the mark descriptions in FAA 1939-45 for Blackburn Swordfish before MK III are wrong. I thought you had amended this years ago in your digital files?

 

1anG

[Graham Boak]

Further, October 1941 would seem to be a very early change-over for rocket-firing aircraft.  I don't believe that these were service ready at this date on any type, judging from the evidence of Hurricanes, Typhoons, Beaufighters and Mosquitos.  (Perhaps including the last one is unfair.).  I did say more but Ian has got in first with the most.  Sturtivant does have the W serials as Mk.Is, but that only goes partway.

 

Edit: Taylor has Fairey records for 1699 deliveries from Blackburn whereas the serials allocated were 1700.  I was going to ask Lee if his work had solved this discrepancy, but perhaps I should dig out Ian's article first.  Sorry, but there have been a lot of aircraft magazines and books past my eyes since that one!

[iang]

I still have a copy of the text of the Aeromilitaria article. This may not have been the final version that was printed, but it is pretty close, For PRO references read TNA:

 

Blackburn Built Swordfish, 1940-44.

 

 

Fairey Aviation produced a total of 692 Swordfish Mk I between the end of 1935 and the beginning of 1940, before production was transferred to the Blackburn Aircraft Co. Ltd. Blackburn built 1,699 Swordfish (of various types), or ‘Blackfish’ as they were colloquially known, between November 1940 and August 1944. This article is based upon an examination of the surviving Fairey and Blackburn records held at the Public Records Office. Information that survives in the Ministry of Aircraft Production file relating to the Blackburn Aircraft Co. Ltd provides an unequivocal answer to the question of when and why the Swordfish Mk II came into existence. [1]  It also provides details of the number of each mark of Swordfish produced that are at variance with figures given in secondary accounts. From the Air Ministry and Admiralty records, it is also possible to draw tentative conclusions about the number of Swordfish equipped with the more powerful Pegasus 30 engine and to the nature of modifications carried out to Swordfish lower main planes to enable them to operate rocket projectiles.

 

The move to Blackburn

In September 1938, it was expected that the entire Fairey Swordfish programme of 492 aircraft would be complete by March 1940, at which point Fairey’s would switch production to the new Albacore. According to the official history, the Albacore was ‘greatly delayed’ because of the ‘tardy progress of its engine (the Taurus)’.[2] Because of these delays, in September 1938, the Admiralty accepted an additional 200 Swordfish in place of the equivalent number of Albacores. Fairey’s contract for Swordfish production was increased accordingly. The Admiralty agreed to accept further 100 Swordfish as a stopgap in November 1938, but Fairey never built these Swordfish, however. In an effort to expiate the production of Albacores by Fairey the Air Ministry took the decision in September 1939 to move Swordfish production from Fairey to Blackburn under the Air Ministry extension scheme.

The original intention of the Ministry of Aircraft Production was for Blackburn Aircraft Company to act as assemblers at their Sherburn-in-Elmet site for component parts sub-contracted to other firms in the Leeds area. This reorganisation of aircraft production was expensive.  The Sherburn site required an initial capital expenditure of £227,000 for the construction of assembly shops and railway sidings. Blackburn (Leeds) was to produce all drawn or rolled form sections and spars for the main planes. Appleyards were to produce main planes and slats and Hudswell Clarke and Co Ltd. the fin, rudder, tail plane, elevators and ailerons. Thomas Green and Sons Ltd were to produce the undercarriage and tail wheel units and London and North Eastern Railway Co Ltd (York) the fuselage.

In all, about 120 firms were sub-contracted to produce parts for Blackburn’s Swordfish. These were completely new sub-contractors for the production of the Swordfish. Fairey’s sub-contractors were to be fully engaged on Albacore production. Fairey retained most of the original Swordfish jigs because Fairey were initially required to maintain the production of spare parts, but it was stipulated that Blackburn produced Swordfish were to be fully compatible with Fairey produced aircraft with respect to the manufacture and assembly of all component parts. The Air Ministry Directorate of Technical Development wrote to Blackburn with a detailed specification for the original contract on 21/3/40. Blackburn was instructed to construct the aircraft in ‘strict accordance’ with the Swordfish specification of 15/7/39.

The Ministry of Aircraft Production carefully supervised the move to Blackburn. An Aeroplane Production Officer was appointed by the Ministry of Aircraft Production to act as overseer for Blackburn Swordfish production. In June 1940, the Ministry was sufficiently nervous of the capability of London and North Eastern Railway Co. Ltd to deliver fuselages to the production timetable that they instructed Blackburn to produce them instead. This new requirement for Blackburn (Leeds) to produce the fuselage delayed the production schedule. The first Blackburn Swordfish was completed in November 1940, one year after the switch to Blackburn was finalised.  Blackburn’s also protested at the shortage of light alloy steel stampings in the spring of 1940 and this was subsequently accepted by the Ministry of Aircraft Production as one of the reasons for delay.  Efficacy in the speed of production of complete airframes was undoubtedly also hindered initially by the large quantity of spares required as part of the original contract with Blackburn’s. Indeed, in order to expiate production, a temporary reduction in the stock of spares was sanctioned in January 1940.

There is also a suggestion in the extant MAP internal memoranda that delay was exacerbated by a lack of full co-operation between the parent and daughter companies.[3] In an interview with Prof. Postan, in June 1943, the then CNR (Commodore Slattery)[4], contrasted the lamentable war production performance of Fairey’s with Blackburn’s, which ‘always did better.’[5] Indeed, Blackburn production performance, which peaked at about 55 Swordfish per month plus 40% spares, was regarded as ‘a remarkable example of how capacity [could] be organised’.[6]

 

Contracts.

The first Blackburn contract was for 300 Swordfish under B31192/39/C20 (b). These Swordfish carried serials V4288 to V4337, V4360 to V4399, V4411 to V4455, V4481 to V4525, V4551 to V4600, V4621 to V4655 and V4685 to V4719. In February 1940, this contract was increased to 400 aircraft as the Admiralty accepted a further 100 Blackburn Swordfish in lieu of Fairey Albacores. These carried serials in the ranges W5836 to W5865, W5886 to W5925 and W5966 to W5995. The 400th Blackburn Swordfish (W5985) was delivered in November 1941, exactly one year after the first aircraft. The original contact was further extended in April 1941 to 500 aircraft, with serials in the ranges DK679 to DK719 and DK743 to DK792. It was envisaged that the total production programme would be completed in April 1942, after which it was planned that Blackburn would produce the Sea Otter.

In November 1941, however, the Ministry of Aircraft Production further revised contract B31192/39/C20 (b) and ordered an additional 400 aircraft, with serials in the range HS154 to HS196, HS208 to HS231, HS254 to HS299, HS312 to HS346, HS361 to HS410, HS424 to HS471, HS484 to HS519, HS533 to HS561, HS579 to HS625 and HS637 to HS678. Hitherto, the beginning of the HSxxxx range Swordfish has often been regarded as the beginning of the Swordfish Mark II, but this is not the case, as we shall shortly see. Plans for Sea Otter production by Blackburn were shelved (and subsequently transferred to Saunders Roe). It was realised these inter-manufacturer changes in aircraft production would cause some short-term disruption to production. In the case of the Swordfish, it was understood that Blackburn would not be able to continue production smoothly and there would be a break in production in May 1942.

Because the Admiralty were so short of Swordfish for anti-submarine work in the Atlantic, a further 250 Swordfish were ordered in March 1942 (with serials in the range LS151 to LS193, LS214 to LS248, LS261 to LS299, LS315 to LS358, LS362 to LS403 and LS415 to LS461), another 350 in May 1942 (with serials in the range NE858 to NE906, NE920 to NE957, NE970 to NE999, NF113 to NF161, NF157 to NF217, NF230 to NF274, NF288 to NF347 and NF369 to NF414) and an additional 400 in March 1943, of which the last 200 were cancelled. Those produced had serials in the range NR857 to NR898, NR913 to NR958, NR970 to NR999, NS112 to NS156, NS168 to NS204 (the 200 cancelled Swordfish were to have had discontinuous serials in the range NS205 to NS484).  In addition, a further 400 Swordfish were ordered in October 1943 (with discontinuous serials in the range RL435 to RL333) and subsequently cancelled in February 1944

Pegasus Engines.

The contracts for the first 500 Blackburn Swordfish refer to Pegasus IIIM.3 machines (Pegasus 3). The subsequent contract for an additional 400 aircraft placed in November 1941 (with serials in the range HSxxxx) specifies the more powerful Swordfish Pegasus XXX (Pegasus 30). This is the first mention of the new engine in any Air Ministry contract. Thereafter, it is used consistently in all contracts. In fact, despite the contract specification, possibly as few as 120 of the first 500 Blackburn built Swordfish were equipped with the Pegasus III engine, all the rest were equipped with the Pegasus XXX.

There are several additional sources of information which suggest this interpretation: the notes and annotations pertaining to Bristol engines in a file relating to engine modifications for naval types, the contents of a Confidential Admiralty Fleet Order for July 1941 and published photographs.

Taking the published photographs first, there are surprisingly few published photographs available of Swordfish in the Blackburn production blocks with serial Vxxxx or Wxxxx, taken from the starboard side (with the enlarged oil cooler visible) and that also have the serial number visible. There are photographs of the following aircraft: V4387 (Pegasus III), V4388 (Pegasus III), V4417 (Pegasus III), V4438 (Pegasus 30), V4517 (Pegasus 30), V4631 (Pegasus 30), V4638 (Pegasus 30), V4689 (Pegasus 30), V4719 (Pegasus 30), W5848 (Pegasus 30) and W5889 (Pegasus 30). In addition, there are other  Wxxxx (Pegasus 30) aircraft where the exact serial is not clear, but there appear to be no Wxxxx fitted with the earlier engine. This is also true of published photographs of DKxxx serial Swordfish.

It seems extremely unlikely that maintenance departments would have upgraded all of these aircraft. One check as to how likely this is, would be is to find photographic evidence of Fairey built Swordfish retrofitted with later Pegasus 30 engines. These seem to be non-existent, despite the fact that from fatality records, it is known that some Fairey produced Mk I Swordfish were upgraded with the more powerful engine (for example, K5953, P4017 and K8444 are noted as having the later engine fitted).[7]

The second piece of evidence is data relating to the modification schedule for Bristol engines.  There is a file entry for Swordfish engine modification 317 that is described as a ‘change in nomenclature of engine to Pegasus XXX’. There is also an annotation to this, which reads ‘Blackburn’s responsibility - c.280 engines’.  Unfortunately, this note is not dated, but the last item on file is dated 26/11/41.[8]

The third source is Confidential Admiralty Fleet Order 1549 of 31/7/41. This advises of the change in engine type and outlines changes in the maintenance specification for the later Pegasus XXX engine.[9] In terms of the delivery of Blackburn Swordfish to units, according to the information in Sturtivant’s Swordfish Story (1993), Vxxxx serial aircraft in the range V4438 to V4505 were first delivered in June 1941, but there would then have been some delay in delivering these aircraft to front line units.

What should we conclude from this?  After the end of July 1941 (but probably a little before), all Blackburn built Swordfish Mark I were fitted with Pegasus XXX engines.  As to the timing of the switch, the fact that the Bristol engine notes on engine modifications to Swordfish are undated is a problem. If these notes on modification were written prior to April 1941, when the DKxxx serial Swordfish were ordered, it may be that as few as 120 Swordfish were equipped with the earlier engine. If the notes post date the DKxxx contract, maybe as many as 220 Swordfish were equipped with the Pegasus III. We will probably never know the exact number, and both these estimates assume that the 280 engines to be modified do not include spares.

If this we take the lower estimate of 120 Pegasus III aircraft, it would imply that all Vxxxx serial Swordfish up to about V4440 were Pegasus III. This would roughly fit with the photographic evidence and the timing of CAFO 1549 cited above, as V4440 was delivered in June 1941. The last Swordfish Mk I Pegasus III serial I have been able to confirm is V4417, which was delivered in May 1941.[10]  V4438 would appear to be one of the first examples produced of a Blackburn Swordfish Mk I Pegasus 30. It is probable, however, that even if this estimate is broadly correct, Swordfish with serials in the V4411 to V4455 block could have been fitted with either Pegasus III or Pegasus 30 engines as the change in engine appears likely to have occurred on the production line in May or June 1941.

 

Swordfish Mark II

There is a brief note in the file headed ‘Nomenclature of Aircraft Swordfish Mk II’, dated 29/5/43, which simply states “The designation Swordfish Mark II has been allotted for Swordfish aircraft modified for the installation of R.P. The Swordfish Mark II is on the secret list.”  The Swordfish Mark II was a mark designation change in relation to an operational requirement for rocket projectile equipped submarine hunters in the Battle of the Atlantic in the spring of 1943.  This designation is confirmed by a later Confidential Admiralty Fleet order, CAFO 173 of 27/1/1944. [11] This sets out the particulars of the different marks as follows:

Mark I             The original type, fitted with ASV Mark IIN, front gun, facilities for high-level bombing and F.24 camera. Either internal or external overload fuel tank could be carried.

Mark II            As Mark I, but fitted with R.P. installation. No provision for front gun, high level bombing or F.24 camera in later production aircraft. A number were fitted with a special version of ASV Mark XI that permitted a crew of three to be carried.  Referred to as Mark II ASV Mark XI.

Mark III           As Mark II, but with accommodation for two crew only. ASV Mark XI with equipment in rear cockpit. RATO gear installed. Internal fuel tank could not be carried, and external tank only if ASV removed.

Mark IV         Mark I type modified for training duties in Canada in winter. The main modifications included a Perspex hood, windscreen and propeller de-icing. No front gun, high-level bombing facilities or F.24 camera. Only a few of this type were produced.

The modifications for the Mark II are described in a separate letter from the Aircraft Maintenance and Repair Department to the Director of Aircraft Production, dated 14/3/43. Two Swordfish (HS 544 and HS 545) were modified by Fairey (Reddish) in April 1943. There were three modifications carried out: Modification 414 (parts A and covered the rocket projectile installation, moveable adaptor frame, modification to the blast plate to fit the adaptor frame and the installation of a master selector switch; Modification 376 specified a requirement for 24 volt electrics and Modification 431 was a sight for the rocket projectiles.

The first installation trials for rocket projectile equipped Swordfish had been carried out between 8/10/42 and 8/1/43 at the Aircraft and Armament Experimental Establishment, Boscombe Down. These tests were carried out using Blackburn built Swordfish DK747.  The initial test firing of eight 60lb rocket projectiles involved DK747, stationary, and on trestles. Flight tests were carried out on 17/12/42 and were considered successful, but a triple bead foresight was recommended for service use.[12]

 

On the 23 May 1943, a Swordfish of 819 Squadron from H.M.S. Archer sank U-752 using rocket projectiles.  H.M.S. Archer sailed on the 19/5/43, and its nine 819 Swordfish would have been embarked shortly after, so it is clear that the highest priority was accorded Mark II production once the modifications had been installed by Fairey Aviation in April 1943. Even so, only 5 additional sets were produced in May. The weapon was brought into volume production in just 14 weeks by ‘turning somersaults’ according to one Ministry official.

 

According to figures provided by the RTO at the Sherburn site, 1,699 Swordfish were produced by Blackburn.[13]  Of these, 834 were Mark I, 545 Mark II and 320 Mark III. The number of Mark IV is not recorded in the Blackburn records, though we know from other sources that the numbers were quite small. It is unlikely that the 545 Mark II Swordfish would have been produced sequentially at first. According to Ministry estimates, sufficient Modification 414 sets were only available for 50% of Blackburn’s production in June 1943. It seems likely, therefore, that the Mark I/II break is somewhere in the serial block HS579 to HS625, as both were likely to be found on the production line side by side for a short while.[14]

 

 

‘Strengthened’ Lower Main plane.

 

There is only one reference to a ‘new wing’ in the Blackburn file. On the 16/4/1940, there is a letter from the Air Council Committee on Supply (172nd meeting), which refers to the extension of the contract from 400 to 500 aircraft  (in the DKxxx serial block). These were to be produced with the ‘existing type of wing’, but that ‘an option should be obtained to have incorporated in these aircraft before delivery the new type of wing and other modifications.’ It seems reasonable to assume that this refers to the partial, non-structural, metal skinning of the under surface of the lower wing and that this change just pre-dates the introduction of the Mark II.

 

It is clear, however, from restoration work on Swordfish carried out by BAe that there are no structural differences between the Mark I and II lower wing.[15]  It is likely, however, that the spars were subject to tempering treatment in order to strengthen Blackburn built Swordfish main planes, probably from early 1943 onwards. In the summer of 1942, there were several structural failures involving Blackburn built Swordfish. One machine, V4646, crashed on land and parts of the airframe were extensively analysed by the Royal Aircraft Establishment in November 1942.[16] The structural strength of the main spars was compared with those built by Fairey and the parent firm's spars were found to have a tensile proof stress 11% greater than the failed Blackburn spar. Moreover, new Blackburn spars were found to have tensile proof stress values significantly below the design specification. Although there is no direct evidence in the extant Blackburn production file to suggest that the RAE recommendation for tempering all wing spars was followed, it seems unlikely to have been ignored as the treatment provided a relatively simple means of ensuring Blackburn's spars met the design specification.

 

 

On a broader canvas, there is some interesting correspondence in the MAP records regarding the divergence between the view of Admiralty and public perception of continued Swordfish production in 1943. As far as the Ministry of Aircraft Production was concerned at least, the public perception of the Swordfish was of a deeply antiquated aircraft, which had had its day. In the interview with Postan, the CNR defended vigorously the performance of the Swordfish, ‘The Swordfish is called a slow and obsolete aircraft, but…for the first three years of the war, it did its job superlatively well.’  The Admiralty clearly regarded the Swordfish II as a crucial weapon in the U-Boat war. The CNR described the Swordfish as ‘the most successful aircraft they now have’ (in June 1943) for the Battle of the Atlantic.[17] The use of rocket projectiles was classified ‘secret’, and, therefore, the success of the Swordfish II was not widely appreciated. In contrast, the spectacular failure of torpedo equipped Swordfish during the ‘Channel Dash’ debacle, in February 1942, was reported and this information asymmetry almost certainly explains the poor perception of the aircraft. 

 

The metamorphosis of the Swordfish from a pre-war designed and produced fabric covered TSR/B biplane, which was obsolete in this role prior to hostilities, to a mid-war submarine hunter-killer par-excellence, is an example of how the piecemeal improvement of old types helped maintain the quality of British naval aircraft in the face of the slow (and generally disappointing) development of replacement types during the early and middle phase of the war. The mass-production of Swordfish, and the speed with which transfer to the rocket equipped Mark II was achieved, is also a testimony to the efficiency with which the Blackburn Aircraft Company organised production at their Sherburn plant.

 

 

[1] PRO file reference AVIA15/237

[2] Postan, MM, Hay, D and Scott, JD Design and Developments of Weapons (HSWW, HMSO 1964) p.134

[3] PRO file reference AVIA46/143

[4] The Chief Naval Representative was a naval officer of Flag rank who represented Admiralty views in the Ministry of Aircraft Production. See  Scott, JD and Hughes, R The Administration of War Production (HSWW, HMSO 1955) pp.153-5

[5] PRO file AVIA 46/136, Interview with Commodore Slattery, 25/vi/43 p.12

[6] PRO file AVIA 46/136, Interview with Commodore Slattery, 25/vi/43 p.13

[7] Correspondence with Ray Sturtivant.

[8] PRO file reference AVIA15/2866

[9] PRO file reference ADM182/131. CAFO 2131 of 30/10/41 amends the previous order and includes a description of the larger oil cooler (modification 344).  

[10] The fatality records indicate that V4380 was fitted with the later engine (information provided by Ray Sturtivant in correspondence). V4646 was also so equipped. Accident report, PRO file reference AVIA5/21.

[11] PRO file reference ADM182/137. I am grateful to Ray Sturtivant for providing the reference to this file.

[12] PRO file reference AVIA18/1022

[13] In addition, V4690 was written-off by Blackburn in September 1941

[14] The fatality records give HS657 as Mark I and HS615 and HS638 as Mark II. Rather oddly, HS439 is also listed as Mark II.  Data provided by Ray Sturtivant in correspondence.

[15] Information supplied by Paul Fontenoy in correspondence.

[16] PRO file reference AVIA6/8107

[17] PRO file AVIA 46/136, Interview with Commodore Slattery, 25/vi/43 p.4 Indeed, Slattery implies that the Admiralty preferred Swordfish to Avengers.

[iang]

1 hour ago, EwenS said:

 Some of the Swordfish on Ark Royal that attacked Bismarck in May 1941 were radar equipped.

 

Only two of them, and of these one was definitely Fairey built.

[iang]

1 hour ago, Graham Boak said:

 

 

Edit: Taylor has Fairey records for 1699 deliveries from Blackburn whereas the serials allocated were 1700.  

V4690 was written-off by Blackburn in September 1941, and not included in the 1,699 total

[Carl V]

1.            While I fear that I cannot contribute anything worthwhile to the subject of the fixed gun on the Swordfish, the excellent production summaries etc. that have recently appeared on this thread have prompted me to contribute a little on the ofttimes vexed (at least to me) subject of the Swordfish IV.

2.            Quite some time ago I became annoyed at the frequent querying of the legitimacy of the Mark IV designation and checked it out. To my mind, there is absolutely no doubt that it was a very official designation. For one thing, an examination of the RCAF general and technical files on this aircraft indicate that it regularly appeared in official documentation, e.g. correspondence, originating both with the RN and RCAF.

3.            Another official source was the monthly diary and record book of 1 NAGS, the prime Canadian user of the type. Below are a few, hopefully relevant, quotes and extracts.

                31 January 1944.               68 Swordfish I on strength.

                29 February 1944.            3 Swordfish IV, 2 Swordfish II and 63 Swordfish I on strength.

                Note:    As 1944 progresses, the Swordfish II have disappeared by April and the ratio of Swordfish IV to Swordfish I increases rapidly.

                31 December 1944.  The notations below are direct quotes.

                Swordfish HS555, transferred to 3 TC for T & D flight for installation and tests of cine gyro gunsight, is now ready for return to the school. [I have no idea whether this has anything to do with a fixed gun.]

                59 Swordfish have now been converted to Mark IV’s, two of which have been written off and one transferred as above. On return of this latter aircraft the establishment of Mark IV’s will stand at 57 as proposed in last month’s report.

                In addition to the fully converted aircraft, eight have been completed to enclosed cockpit form for use as sleeve towers. These cannot be classified as Mark IV’s as they have not been fully converted and, as until Admiralty permission is received to classify these as the suggested Mark IVA’s, they are still held on strength as Mark I’s.

4.            It is an extremely nearfetched assumption that, somewhere along the line, there was an official order authorizing the adoption of the designation Mark IV. Unfortunately, this has not yet come to light and this has led to the occasional doubt expressed as to the legitimacy of the Mark IV designation.

5.            Unfortunately, there is no documentation that I have discovered listing those aircraft converted to Mark IV. This applies to the RCAF aircraft record cards which have formed the basis of the comprehensive listings created by Griffin, Walker et al. These particular documents are riddled with errors, inclusive and exclusive. There have been times over the last half-century that I have been tempted to nominate them for some sort of literary award in the category of Canadian humorous fiction!

Carl

 

[Geoffrey Sinclair]

On 01/03/2022 at 02:20, iang said:

Sadly, that is all incorrect. My research is based upon the extant Blackburn production records held at TNA.

No problems, I reported the information and add to it here, to see how accurate the information is and whether it can help sort out the Swordfish mark I/II split.  That article is an impressive piece of research, it took a while to absorb.

 

I believe non members can now download copies of Aeromilitaria back issues from the Air Britain site, see if this works https://air-britain.com/web/da-aeromilitaria/ as given the Swordfish article is in Spring 2001.

 

Swordfish ASV, agreed some of the Ark Royal Swordfish had it in May 1941, what I should have written was the idea the aircraft were coming off the line either equipped or able to be equipped with ASV could have prompted a mark number change, October 1941 is definitely too early for RAF rocket capable aircraft production.

 

Agreement Blackburn built 1,700 Swordfish, but V4690 crashed before delivery and was not officially counted, but no primary source I have gives the numbers of mark I and II.  It is only in May 1944 the Ministry of Aircraft Production monthly reports start to use a mark number, III.  Cumulative totals simply say Swordfish.  Is it agreed no Swordfish were built as mark IV, they were all Canadian modifications?  The Canadians say the Swordfish that arrived in Canada, mark II and III, used the Pegasus 30.

 

The Blackburn RTO would give 835 mark I when V4760 is counted.

 

ADM 1/16407 Aircraft Stocks and Movements October 1943 to December 1943 {not 1944 in original text) (actually includes September 1943 and January 1944).  As of 25 September 1943, 874 Swordfish I and II on strength, 30 October 1943, 921 Swordfish I, II, II ASVX on strength, 27 November 1943, 950 Swordfish I, II, II ASVX on strength, 25 December 1943, 981 Swordfish I, II, II ASVX on strength, 29 January 1944, 1,016 Swordfish I, II, II ASVX, III, IV on strength.  This does not help the mark I/II split, while if the aircraft were built in serial order the first mark III appeared in February 1944, it does further show the mark IV designation was in official documents and in early 1944.

 

Contract Cards exist for the V, W, DK and HS154 to HS400 serials (first 188 HS serials).  The engine for the first 165 V serials (to V4510) is given as Pegasus III, it then becomes Pegasus II for the remaining V, the W and DK serials.  The HS serials production began in June 1942, have a Pegasus 30.  The entry for V4690 notes crashed before delivery, not being replaced 1 October 1942, decisions on what to do with aircraft that crashed under test could take a while.  V4689 and V4691 were both delivered on 13 September 1941.  DK789, delivered 23 November 1941 was sent to an illegible destination to replace V4690.

 

The first Blackburn built Swordfish V4288 was loaned to the Air Member for Development and Production, which meant it was officially delivered on 13 March 1941, V4289 was delivered on 29 December 1941 to RNAS Donibristle, the last V serial, V4799, was delivered on 4 October 1941, W5836, the first W serial, on 5 October 1941, the last 3 W serials, W5993 to 5, were delivered in 27 December 1941, the same date as DK670, the first DK serial, however the DK serials deliveries are not all in serial order, the final 10 serials DK783 to 792 were delivered first, in November 1941, those between DK670 to DK749 start delivery in December then have blocks of January, then February, then back to January deliveries, then February then throw in some March, it is not until DK772 that serials again normally align with delivery dates.  DK781 and 782, the last DK serials, were delivered on 25 April 1942, HS154, the first HS serial, was delivered on 9 June 1942.

 

Where possible the British system tried to have the engine in production before the relevant airframe, building stocks at manufacturer’s and maintenance units, which also often meant the engine went out of production before the airframe, so Swordfish production in 1944 was 419, ending in August, while Pegasus 30 production was 220, ending in May (and only 19 in April and 1 in May).  Unfortunately none of the figures I have give a breakdown of Pegasus production by version before March 1942, there were 5,061 Pegasus produced in 1941, and another 772 January and February 1942, as of March 1942 the Pegasus VI, XVIII and 30 were in production, the VI ended in May 1942, the XVIII in September 1943.  In a similar arrangement to the Blackburn production pause in May 1942 no Pegasus 30 were officially built in April 1942.   Pegasus production cut backs began around mid 1942, and in early 1943 it was down to 100 to 110 engines per month. 

 

There were 1,719 Pegasus 30 built March 1942 to May 1944, out of an official total of 2,200 leaving 481 built to end February 1942.  The Ministry of Aircraft Production monthly reports starting in March 1942 have 3 relevant tables, Repaired Engines, Engine Stocks in the United Kingdom, Stocks of Engines and Power Plants, with figures to the end of the previous month.  In addition there is an engines allocated for export by the Air Ministry report but it means it excludes Admiralty shipments.  In April 1942 the explanatory notes state the two engine stocks report now includes Admiralty stocks but the repair report does not, but the stocks report only has Pegasus XVIII, while the stocks and power plants report has 178 Pegasus 30, most of which were at maintenance units or naval air stations as of 28 March 1942, another 8 under repair are probably included in the stocks report.  In May 1942 repaired engines report includes Pegasus 32.

 

So out of 501 Pegasus 30 production to end March 1942, 178 can be accounted for leaving 323 versus 490 Blackburn Swordfish production (V, W, DK serials).  Certainly some of the “missing” engines would have been lost without the loss of the associated aircraft, but then some aircraft could be lost and the engine saved, other engines exported, others fitted as upgrades to earlier aircraft and it was practice to build anything up to 35% spare engines early in the war (USAAF), the RCAF Merlin order for its Hurricanes had 20% spares, which provide rules of thumb for an idea of how many Pegasus 30 would be held overseas, including under repair once you have an idea of the (planned) local Swordfish strengths and shipping times to the relevant area.  Over and above movements overseas of Swordfish as part of naval units, 30 were exported in 1940, 194 in 1941 and 120 in 1942.  A 20% spare engine allowance for 1941 would be around another 40 engines but early year exports would be Pegasus III equipped.

 

In January 1943 there were Pegasus 30 and 32 engines under repair, the stocks report including those with the Admiralty still only has Pegasus XVIII, while the Stocks of Engines and Power Plants as of 26 December 1942 has 564 Pegasus 30, most of which were at maintenance units or naval air stations. That is out of 1,110 Pegasus 30 built, Blackburn had built 689 Swordfish to end 1942.

 

While 490 Blackburn Swordfish production to end March 1942 minus 165 definite Pegasus III V serial aircraft = 325 or about the number of unaccounted for Pegasus 30 at the time, this is not sustainable given the need for spare engines overseas and losses.  The remarks section for each contract card serial have no entries about engine changes, only whether the aircraft was being sent packed for export.  The evidence above can only say the change over of engines was in 1941 and at most under 300 Pegasus 30 were available for the early Blackburn Swordfish.  This does align with the 280 engines noted as being a Blackburn responsibility, it is unlikely Blackburn were given spare engines, that would be handled by deliveries direct to maintenance units.  Having 280 engines and assuming it was straight change over would place it in August 1941 (see below), serial number 221 of the order would be V4591 delivered 11 August 1941, V4440, delivered 31 May 1941 (two weeks earlier than the serials around it) is noted as being on loan to Controller of Research and Development at Fairey, so there was some sort of testing going on, which seems to have ended in mid August. 

 

If Blackburn had to do some work on the engines then a mixed batch of Pegasus III and 30 could have been built.  The earliest photographed confirmed Pegasus 30 installations given above V4438 (delivered 13 June 1941), then V4517 (30 June 1941) then V4631 (23 August 1941).  The contract cards say all these serials were delivered to the usual locations, no different to the serials around them.  As noted before V4511 is where the contract cards switch from Pegasus III to II.

 

Cumulative Blackburn Swordfish production to end of month,

Dec-40  1, start V serials

Jan-41   9

Feb-41  19

Mar-41 46

Apr-41  79

May-41 116

Jun-41   162

Jul-41    203

Aug-41  247

Sep-41  292

Oct-41   333, end V, start W serials

Nov-41 379, start DK serials

Dec-41  419, end W serials.

Jan-42   449

Feb-42  469

Mar-42 490

Apr-42  500, end DK serials.

 

When it comes to the mark I/II change over, with 835 mark I, Blackburn cumulative totals and monthly production for the relevant period are,

Jan-43   731         42

Feb-43  773         42

Mar-43 818         45

Apr-43  863         45

May-43 909         46

Jun-43   949         40

Jul-43    1,000     51

 

If you assume mark II first came off the line in April then there are 818 out of the 835 mark I already produced by end March and it means almost all Swordfish from April onwards were mark II.  Assume half of production was mark II from January and mark I production ends in July, half from February, mark I ends in June, half from March, mark I production ends in May.

 

Sorry I cannot be more helpful. 

Edited March 3, 2022 by Geoffrey Sinclair
fix date typo