Canadian Hurricanes

[Geoffrey Sinclair]

Compendium third

19 hours ago, Graham Boak said:

Be careful with nomenclature: at this period most aircraft parts were not interchangeable, which has a very specific engineering meaning.  Most parts would be require some work before being used as replacements - for example the holes would not have been predrilled for rivets.  It was common for parts such as engine cowlings and  Spitfire wing/fuselage fairings to be marked in some manner - which could be chalk - with the aircraft serial.  All parts would have been etched/stamped with their own part number, ..... the Hawker system worked differently, being a block of numbers in the A100,000 series.  Lower numbers were included if the part had been used on an earlier design or was a standard Hawker part.

 

The RAF position was that the aircraft identity was that of the major fuselage assembly and this would carry a data plate with the aircraft serial and construction number.  It was perfectly normal that outer wing panels would be replaced with spare ones which may well have come from a different individual aircraft.

Noted about using interchangeable, should I have said meant to be the same within the contracted tolerances?  For aircraft the wing/fuselage joint are would be a logical place for the construction number marking as it was usually amongst the strongest part of the airframe.

Agreed we need to make clear part number versus serial/construction number.  Everything would have a part number but only selected items or assemblies would have a serial number.  Think of say the radio, the fully assembled radio had a serial number, its components had parts numbers and some components could have had serial numbers as well.  Similar for the aircraft.  Or perhaps all those parts and serial numbers in the airframe and engine and the air force has only 1 serial number, like say AG665, similar for construction number.  I would also expect CCF to follow Hawker parts numbers leaving open the possibility of an additional field identifying the parts maker.

 

19 hours ago, ClaudioN said:

Gloster finished Mark I production in June 1941, CCF in July. BSB598 was around in June 1941 at least and was always 50 I and 150 II. Agreed the Sea Hurricanes were given elevated priority.   I'm just conjecturing, but if I place your opening sentence: "I do not think BSB598 comes into play" after those three, I can think you have some hard feeling that it can't be that way...?

 

Another point:

1)   "the stopping of exports to Britain was done before the line shut down,"

Comparing AIR 19/524 data provided by gingerbob with data from the US War Production report you posted, it seems the break in UK imports was from September to November 1941. Allowing one month for the sea voyage, I'd assume the stopping of exports from Canada was between August and October 1941. The production break was in September, but final production was retained in Canada and into storage. 

 

2)  "based on the plan to store 100 but only 59 were available until October."

If I'm not mistaken, you mentioned that by mid-1941 the plan was to retain 100 Mk. IIs in Canada and place 44 Mk. Is into storage for the Empire Air Training Scheme.

The production numbers.  The plan was to store 100 airframes in Canada for use in the training system, *of these* 59 were built before the August 1941 shut down, *of these* I found 44 entries in the delivery logs that were marked as being stored, a contract card added another 5.  So 44/49 out of 59 out of 100, not 100+44. 

The Canadian documentation mention BSB598 as a known order as of 30 June 1941.   In the March to July 1941 period the CCF production line was turning out an average of over 63 aircraft per month, in August that drops to 11 which is 5 to 6 days worth at the monthly rate.  Why then decide production ended in September?  More so when we know AG665, nearly the last built, must have been flying early in the month to be ready for the exhibition starting mid month?  To finish mark I production CCF needs to build 14 in July 1941 and given production was being done in serial number order that means about the first week’s production.  Then look at British imports for August, total 8, which shows how early the mark I must have been built in July.  While ships could be delayed etc. it is more reasonable to assume the final mark I imports were in early/mid August, not end August.

Looking at the RAF taken on charge dates they are mostly blank for the AG2xx and AG3xx airframes retained in Canada, the *earliest* taken on charge dates for AG6xx and AM2xx is 17 December 1941 for AM299.  There were 426 mark I shipped before the decision to store airframes, AM299 is the 530th serial ordered, 530-426 = 104 versus the plan to have 100 stored.  Circumstantial evidence when production restarted in October 1941 initial non Sea Hurricane production was stored, note AM275 and 3 AG6xx dates are 26 or 28 February, then comes early March dates and so on.  By no means a perfect fit but too close to 100 stored and 120 Merlin 28 (plus 24 spares) on order to be simply a coincidence.

We are still left with the production reports saying they were all mark II and the photographs of AG665 and RCAF1851-80 saying they were mark I.  Next item to tick off is whether fitting the mark II wing centre section was independent of the extra fuselage length the Merlin XX and later required, so this would mean it also did not require the more extended fuselage to wing fairing.  In other words can we rule out RCAF 1851-80 were mark II airframes *except* for the extra fuselage length and associated visible changes?

[ClaudioN]

16 hours ago, Geoffrey Sinclair said:

when production restarted in October 1941

There's not nothing I can argue about the calculations you make, but why do you say "production restarted"?

I understand from the information you provided that report numbers referred to production deliveries, and we have a photo dated 18 September 1941 that shows about 50 Hurricanes (at least the closer ones being Sea Hurricanes) on the final assembly line. To me, this suggests that it was deliveries that were slowed down, and even stopped for one month, not production. Of course, this up to interpretation and we may agree to disagree.

 

The "taken on charge date" for AM299 is interesting: does it refer to delivery to 13 MU, as in the case of AP138 you mentioned, or to acceptance at Fort William before reaching Halifax, as in some other cases?

Edited July 16, 2019 by ClaudioN

[ClaudioN]

16 hours ago, Geoffrey Sinclair said:

We are still left with the production reports saying they were all mark II and the photographs of AG665 and RCAF1851-80 saying they were mark I.

Which proves they were Mark Is at the time the photographs were taken.

 

16 hours ago, Geoffrey Sinclair said:

Next item to tick off is whether fitting the mark II wing centre section was independent of the extra fuselage length the Merlin XX and later required, so this would mean it also did not require the more extended fuselage to wing fairing.  In other words can we rule out RCAF 1351-80 were mark II airframes *except* for the extra fuselage length and associated visible changes?

Of course we can't rule it out, as you can't see that from a picture. Personally, I try to look for the simplest possible interpretation and creating 30 hybrids does not sound like a simple one to me.

 

1351-80 also had the eight-gun wings (and the Mark I tailwheel, but this is also found on a few RCAF Mk. XIIs). By the way, after the conversion programme at CCF these machines were redesignated Mark XIIA. Fitting the lengthened engine mount and a Merlin 29 on a Mark I airframe is almost the same conversion that produced the Hurricane Mark IIA Series 1 (dimensionally the Merlin 29 is a Merlin XX). Not a proof, but possibly a hint that 1351-80 were Mark I airframes throughout their life.

Edited July 16, 2019 by ClaudioN

[Troy Smith]

4 hours ago, ClaudioN said:

and the Mark I tailwheel, but this is also found on a few RCAF Mk. XIIs

it's not a 'Mk.I tailwheel'  

Straight leg tailwheel maybe a better term.  

Usually seen on the Mk.I,  but plenty of early Mk.II's as well,  but the 'knuckle leg' type was retrofitted to Mk.I's, P2617 at Hendon has one of these from Training Command days still.

I suspect the 'knuckle leg' tailwheel was introduced when greater loads (bombs, drop tanks)  became more common?  @Graham Boak  may know more.

[Geoffrey Sinclair]

9 hours ago, ClaudioN said:

but why do you say "production restarted"?

I understand from the information you provided that report numbers referred to production deliveries, and we have a photo dated 18 September 1941 that shows about 50 Hurricanes (at least the closer ones being Sea Hurricanes) on the final assembly line. To me, this suggests that it was deliveries that were slowed down, and even stopped for one month, not production. Of course, this up to interpretation and we may agree to disagree.

 

The "taken on charge date" for AM299 is interesting: does it refer to delivery to 13 MU, as in the case of AP138 you mentioned, or to acceptance at Fort William before reaching Halifax, as in some other cases?

Production restarted is the usual term, as production is measured by output.  Certainly work could and usually was done during the pause, even something simple like a clean up of the working areas.   Also it was more than a 1 month production pause, more like early August to late October, based on what the line could produce versus what was produced in those three months.  We have a still photograph of the Hurricanes, and I expect assembly work was being done though probably not at full pace given Sea Hurricane production dates, at the same the line could be frozen, no work being done, proof of course would be a sequence of photographs showing change.  Anyway given the time required to build airframe assembly work would have started before production officially did.

 

AM299 and AM300 Taken on Charge Dates are arrival at 20 MU.  However AM295 ToC is 11 March 1942, at 13 MU 3 May.  When the ToC date was measured clearly varies.

 

Now to throw in yet another anomaly, if built in serial number order AM299 and 300 are numbers 530 and 531, but only 517 were built to end November 1941, and at regular production rate AM299 and 300 would appear around 7 December, and yet are reported at 20 MU under two weeks later and I really doubt they flew.  So we may have a "Sea Hurricane" effect of serials being built out of order, or airframes set aside awaiting engines or earlier airframes needed to be reworked to mark II standard or a highly unlikely really fast delivery or something else.

 

7 hours ago, ClaudioN said:

Which proves they were Mark Is at the time the photographs were taken.

 

Of course we can't rule it out, as you can't see that from a picture. Personally, I try to look for the simplest possible interpretation and creating 30 hybrids does not sound like a simple one to me.

 

1351-80 also had the eight-gun wings (and the Mark I tailwheel, but this is also found on a few RCAF Mk. XIIs). By the way, after the conversion programme at CCF these machines were redesignated Mark XIIA. Fitting the lengthened engine mount and a Merlin 29 on a Mark I airframe is almost the same conversion that produced the Hurricane Mark IIA Series 1 (dimensionally the Merlin 29 is a Merlin XX). Not a proof, but possibly a hint that 1351-80 were Mark I airframes throughout their life.

 

Given Hurricane marks were defined by the engine fitted it is quite correct RCAF1351-80 were mark I as initially flown, later mark XII, and agreed the mark XII conversion could have been done to mark I airframes.  What I am trying to do is figure out why the airframes should be reported as mark II by the production system, it could be a mistake or it could be the RCAF took mark II airframes and made them mark I.  Removing the wing centre section is work, removing the mark II wing fairings and extra length less so.  Essentially were the RCAF forced to work with mark II airframes (and possibly constrained by RAF standards requirements when doing modifications), or were they mark I and the ones sent to Britain reworked to mark II.  So far no evidence seems to exist to prove either case conclusively as not all the mark I to II airframe changes are visible.  With the extra airframe strength, slightly longer fuselage and ability to take a heavier engine a standard mark II airframe would be slightly more expensive than a mark I.

 

How many mark XII had the A wing, or ended up with A wing armament?  When I went looking almost all photographs of RCAF Hurricanes I found had the A wing.  From the very start the value of the extra machine guns and the problems they caused meant the B wing armament was being questioned.  As far as I am aware mark I wings could be fitted to mark II and vice versa.  So agreed A wing armament along with the tail wheel are good pointers but not proof.

[Graham Boak]

Sorry but no.  Deliveries/acceptances are not the same as production.  Production could have continued at the same or planned rate whilst the finished airframes crowded togefher in the outside yard without being accepted (for whatever reason).  Stopping production in the middle of wartime was seen as a heinous crime, not just for the loss to the war effort but because specialist workers were in short supply and if production was not maintained they would move to other companies and CCF (in this case) would then be unable to carry out its contractual obligations.

 

There is the possibility that workers were simply transferred from one line to the other because the priority was for SH rather than H Mk.Is.  In which case the total delivery of H and SH variants has to be considered, and it may be that there was no shortfall at all in this period?  The question then arises as to why there  were two lines in the first place or was it just chance that the factory was so badly organised as to leave so precisely half the factory floor empty.

Edited July 16, 2019 by Graham Boak

[ClaudioN]

4 hours ago, Graham Boak said:

Stopping production in the middle of wartime was seen as a heinous crime, not just for the loss to the war effort but because specialist workers were in short supply and if production was not maintained they would move to other companies and CCF (in this case) would then be unable to carry out its contractual obligations.

 

6 hours ago, Geoffrey Sinclair said:

AM299 and AM300 Taken on Charge Dates are arrival at 20 MU.  However AM295 ToC is 11 March 1942, at 13 MU 3 May.  When the ToC date was measured clearly varies.

 

Now to throw in yet another anomaly, if built in serial number order AM299 and 300 are numbers 530 and 531, but only 517 were built to end November 1941, and at regular production rate AM299 and 300 would appear around 7 December, and yet are reported at 20 MU under two weeks later and I really doubt they flew.  So we may have a "Sea Hurricane" effect of serials being built out of order, or airframes set aside awaiting engines or earlier airframes needed to be reworked to mark II standard or a highly unlikely really fast delivery or something else.

Considering one-two weeks by rail from Fort William to Halifax and then loading aboard a ship, and about one month by sea, the Taken on Charge date of 17 December 1941 at 20 MU Aston Down may well mean that delivery of AM299 and AM300 at CCF took place in late-October to early November, that is, as soon as production "restarted".

 

Other dates Geoffrey provided:

AM275 and three AGxxx Taken on Charge 26 and 28 February

AP138 at 13 MU Henlow 28 February

AM295 at 13 MU Henlow on 3 May 1942 but Taken on Charge 11 March.  In this case the latter is likely to be the production delivery date, which gives a reasonable CCF-to-UK travel time of little less than two months.

AG665 Taken on Charge 29 April 1942

AM274 arrived at Liverpool 6 June 1942, to 13 MU Henlow 3 July 1942

Even though some dates are not prefectly aligned, I think there's enough evidence to suggest that, at least from AG665 to AM275, that is 36 airframes, production was indeed "not in serial order".

 

Assuming that AM299 (530th airframe) and AM300 531st airframe) were instead delivered at the earliest possible date, after a production "stop" at the 485th machine, then 529-485 = 44 airframes might have been involved in a possible disruption of schedules caused by priority production of Sea Hurricanes. These might have been delayed, then delivered out of sequence when possible.

4 hours ago, Graham Boak said:

The question then arises as to why there  were two lines in the first place or was it just chance that the factory was so badly organised as to leave so precisely half the factory floor empty.

Actually, Hurricane production at CCF was managed by an outstanding Canadian woman engineer named Elsie MacGill.

 

Hardly any chance the factory was badly organized:

MacGill's paper, Factors Affecting the Mass Production of Aeroplanes, won the Gzowski Medal from the Engineering Institute of Canada in 1941.

 

Edited July 16, 2019 by ClaudioN
reference to MacGill's paper

[Graham Boak]

I didn't think it was: my somewhat elliptical phrasing was meant to convey that I was not impressed by the suggestion of a complete standstill.  Apologies for being unclear. 

[ClaudioN]

On 7/6/2019 at 8:09 PM, Geoffrey Sinclair said:

Great, a chance to compare notes with someone who has really studied the subject.  Yes the RN received plenty of non carrier capable Hurricanes, and I presume the 400 number comes from Sturtivant, and not things like the Air Britain Serials books.  Any comments on AE963/5, AG332/22,  NF702 and NF735? Or the version breakdown?

I did not do a proper breakdown by version, but here's what I have:

Sturtuvant lists 406 serials as Mark I of all variants. Of these, 50 are Mk. I /Trop that served with the RN Fighter Squadron (803/806 Sqn.) in the Western Desert.

This leaves 356 serials, that can be unmodified Hurricane Mark Is, Sea Hurricane Mark IAs or Sea Hurricane Mark IBs.

 

Sea Hurricane Mark IAs are harder to track, as movements to and from No. 804 Sqn. FAA and MSFU RAF did occur and are not always clear. In addition, a number of conversions appear to have been issued directly to MSFU and were not on FAA records. Adding serials recorded as Sea Hurricane conversions by Bruce Robertson to those listed by Sturtivant, I have built a spreadsheet that includes at the moment 401 serials (excluding the 50 desert Hurricanes), a number of which are not in Sturtivant.

 

The breakdown by constructor I get in this spreadsheet is interesting:

Hawker:   111

Gloster:   201

CCF:        89

which refers to Mark Is of all variants that have either "Sea" in their records or allocation to the FAA. I'd think nearly half of them are likely to be plain Hurricane Mark Is, either used by FAA training units or in the training phase by first-line FAA fighter squadrons.

 

Then, there's the two CCF-built Sea Hurricanes, BW841 (obtained in exchange for V7402) and BW855 (seemingly "bought" by the Admiralty). BW856 is, I believe, a misread for BW855.

 

As for the Mark IIs, again I tend to disregard land-based second-line machines and focus on carrier-based ones.

What I have is:

• CCF-built Hurricane Mark IIs converted to Sea Hurricane Mark IIs: 65 serials with some apparent confusion. I assume 61 aircraft were actually involved.
• Hawker-built Sea Hurricane Mark IICs: of course, 60
• then, I have 107 land based Mark IIB/C (mostly C) and a single trials Mk. IV.

Edited July 17, 2019 by ClaudioN

[Geoffrey Sinclair]

23 hours ago, Graham Boak said:

Sorry but no.  Deliveries/acceptances are not the same as production.  Production could have continued at the same or planned rate whilst the finished airframes crowded togefher in the outside yard without being accepted (for whatever reason).  Stopping production in the middle of wartime was seen as a heinous crime, not just for the loss to the war effort but because specialist workers were in short supply and if production was not maintained they would move to other companies and CCF (in this case) would then be unable to carry out its contractual obligations.

 

There is the possibility that workers were simply transferred from one line to the other because the priority was for SH rather than H Mk.Is.  In which case the total delivery of H and SH variants has to be considered, and it may be that there was no shortfall at all in this period?  The question then arises as to why there  were two lines in the first place or was it just chance that the factory was so badly organised as to leave so precisely half the factory floor empty.

I know the above text did not come out as intended.  Everything I have seen refers to production as the finished product, but then I am dealing with the production reports, work could certainly continue without completing airframes.

 

At the same time there were storage limits, aircraft rapidly take over a lot of area.  More so if you want to keep them indoors, safe from a Canadian winter.  As noted the British would install dedicated parts to test the airframe, declare it acceptable then move the aircraft to storage and remove the relevant parts.  CCF output is somewhat unique, few of its British order Hurricanes were flight tested in Canada, so produced really means airframe rolled out.  Given the stories of come parts for CCF coming from Britain a ship being sunk, damaged or delayed could affect production and could take weeks to remedy.

 

Agreed the aim was to ensure smooth flowing output but that did not happen thanks to the way the economy was so stretched the spare capacity to deal with a shortfall was not usually available.

 

We have the photographs of *an* assembly hall, I presume it was actually *the* assembly hall and clearly had the potential for two production lines, one on each side, which was used.  Unless there is evidence to the contrary I expect the building was taken over, not put up to enable aircraft production, let alone Hurricane, so it would be a case of making the space work.

 

19 hours ago, ClaudioN said:

Considering one-two weeks by rail from Fort William to Halifax and then loading aboard a ship, and about one month by sea, the Taken on Charge date of 17 December 1941 at 20 MU Aston Down may well mean that delivery of AM299 and AM300 at CCF took place in late-October to early November, that is, as soon as production "restarted".

 

Other dates Geoffrey provided:

AM275 and three AGxxx Taken on Charge 26 and 28 February

AP138 at 13 MU Henlow 28 February

AM295 at 13 MU Henlow on 3 May 1942 but Taken on Charge 11 March.  In this case the latter is likely to be the production delivery date, which gives a reasonable CCF-to-UK travel time of little less than two months.

AG665 Taken on Charge 29 April 1942

AM274 arrived at Liverpool 6 June 1942, to 13 MU Henlow 3 July 1942

Even though some dates are not prefectly aligned, I think there's enough evidence to suggest that, at least from AG665 to AM275, that is 36 airframes, production was indeed "not in serial order".

 

Assuming that AM299 (530th airframe) and AM300 531st airframe) were instead delivered at the earliest possible date, after a production "stop" at the 485th machine, then 529-485 = 44 airframes might have been involved in a possible disruption of schedules caused by priority production of Sea Hurricanes. These might have been delayed, then delivered out of sequence when possible.

As people have noted despite a lack of completed output it is possible CCF completed as many airframes as much as they could given limits on parts and storage area.  Consider the possibility that when completed output restarted the airframes then on the assembly line were completed first followed by the partially assembled ones that had been moved to storage, so the line was kept open and the backlog was then dealt with, or say keep the line flowing and only then allocate resources to the incomplete airframes, with the background idea of shipping (and testing?) them with engines.

 

We actually have a measurement of travel time between CCF and Britain,  CCF need to complete a minimum of 14 mark I in July 1941 and 6 of these were in Britain by the end of the month, so around 4 weeks, certainly others took longer and I doubt any took less time.

The US Army worked out if took around 3 weeks in well equipped port to load and then completely unload a merchant (liberty?) ship.  A US Army study found its dry cargo ships to the UK were taking an average of 59.8 days for a return voyage in 1943.   Army dry cargo ships were taking 76.9 days on average to complete a round trip voyage to England in the period January to June 1944, including 15.4 days in English ports and 27.4 days in US ports.  War Shipping Administration figures for 1,412 ships completing round voyages to England January 1943 to March 1944 gives the average round trip time as 69.4 days including 18.4 days “in overseas area” but with 5 less days at sea and 5 less days in US ports than the army cargo ships.  Certainly 2 months was possible from CCF factory to maintenance unit but that sounds like more likely to be the longest, just like 4 weeks would be the shortest.

[Geoffrey Sinclair]

You certainly have more interest in who made the Hurricanes used by the RN, I used Sturtivant's list then looked at the delivery logs and was given a list of serials where MSFU is mentioned.

Mark and Total
I 53
I/Trop 48
Sea Ia 16
Sea Ib 281
Sea IIb 2
Sea IIc 107
IIA 3
IIB 26
IIB/Trop 4
IIC 76
IIC/Trop 14
IV 1
Total 631
I Airframe 398
II Airframe 232

Of these the actual versions for 3 mark I, 6 I/Trop and 7 Sea Ib are uncertain.  Probable additions 22 mark I, 2 Sea IIc and 1 IIc, probable deletions 1 I/Trop, 2 Sea Ia, 5 Sea Ib and 3 Sea IIc.  Another 87 mark I identified via Air Britain Serials, plus another 3 where the only mention is in the delivery logs.  Sturtivant (therefore the above list) only includes BW841, BW855, BW856 from the CCF built Sea Hurricanes as 2 Sea Ia and 1 Ib.

[ClaudioN]

2 hours ago, Geoffrey Sinclair said:

You certainly have more interest in who made the Hurricanes used by the RN, I used Sturtivant's list then looked at the delivery logs and was given a list of serials where MSFU is mentioned.

Partly so. I'm trying to figure out how many new-build Hurricanes the FAA actually got and I suspect there are more than a few. I also think, and already suggested on this Forum, that CCF contributed rather significantly to the FAA first line.

2 hours ago, Geoffrey Sinclair said:

Total 631

The total seems to agree.

I consider several of the Sea Hurricane identifications unreliable and tentatively accept "Sea" only if operation from a carrier, or by a carrier-based squadron during periods of embarkation is recorded, or can be assumed. Hopefully, a photo of the aircraft might exist. "Real" Sea Hurricane Mk. IBs are far less than 281 (I'm inclined to accept the estimate of around 120 provided, I believe, by Mason).

Training units, mainly Nos. 759/760/761 Squadrons, mostly had plain (and often weary) Hurricanes that are often captioned as "Sea Hurricane" in photos, just because of naval camouflage and code. Maybe they were also called "Sea Hurricane" on official records, but I stick to the rule: "no catapult spools, no headrest = no Sea Hurricane Mark I".

Those of No. 768 Squadron, that did deck-landing training, are much more likely to be Sea Hurricane Mark IBs.

At peak strength, MSFU had about 60 aircraft, plus(?) a few plain Hurricanes as trainers. The idea that around 90-100 aircraft cycled through that unit seems reasonable.

 

A few serials in Sturtivant are probably the result of some confusion in records. For instance, BW856 has the following entry in the R.W. R. Walker web page:

Stored at Dartmouth, as reserve aircraft for the Merchant Ship Fighter Unit of the RAF.  Back to Canada Car & Foundry at Fort William on 21 June 1943, for conversion to Mk. XIIA.  Returned to Eastern Air Command on 5 August 1943.  To No. 1 (F) Operational Training Unit at RCAF Station Bagotville, PQ.  To stored reserve on 26 October 1944.  Available for disposal from 21 April 1945.  Had 698:45 airframe time when struck off.

 

Whereas for BW855:

Served with No. 126 (F) Squadron at RCAF Station Dartmouth, NS in 1942.  Coded "BV*E".  Indefinite loan to British Admiralty from 24 February 1943.  Taken on charge by RAF July 1943, as a Sea Hurricane Mk. Ia.  To No. 768 Squadron, FAA at Abbotsinch January to August 1944. On ferry flight from Sealand to No. 731 Sdn.. at Easthaven, hit moor in low visibility at dusk, Hepple Whitefield, Northumberland, Category Z damage, 19 August 1944, Lt. P.N. Medd killed.

 

Hence, no FAA service for BW856.

Edited July 17, 2019 by ClaudioN

[gingerbob]

A lazy question, but the discussion prompted it and this seems a good place to ask:

 

Were there any "hooked Hurricanes", in the way that there were "hooked Spitfires" that were not considered fully modified Seafires?  I don't recall hearing mention of such.

[Graham Boak]

I know of no mention of any.  If Mk.Is, they would have come under the definition (from a much later BAe document) as Sea Hurricane Mk.Ic.

Edited July 17, 2019 by Graham Boak

[ClaudioN]

On 6/30/2019 at 5:48 PM, Geoffrey Sinclair said:

Even with full supplies it still usually took weeks from start of assembly to completion of flight tests.  Put it another way CCF in 1941 and early 1942 was completing around 2 aircraft per day when the line was fully working, there is a good two weeks of output in the photograph.

The Hurricanes in the photograph look well advanced, with engines fitted, but something delayed their completion until November 1941 and beyond.

On 7/17/2019 at 6:00 PM, Geoffrey Sinclair said:

As people have noted despite a lack of completed output it is possible CCF completed as many airframes as much as they could given limits on parts and storage area.  Consider the possibility that when completed output restarted the airframes then on the assembly line were completed first followed by the partially assembled ones that had been moved to storage, so the line was kept open and the backlog was then dealt with, or say keep the line flowing and only then allocate resources to the incomplete airframes, with the background idea of shipping (and testing?) them with engines.

 

We actually have a measurement of travel time between CCF and Britain,  CCF need to complete a minimum of 14 mark I in July 1941 and 6 of these were in Britain by the end of the month, so around 4 weeks, certainly others took longer and I doubt any took less time.

Certainly 2 months was possible from CCF factory to maintenance unit but that sounds like more likely to be the longest, just like 4 weeks would be the shortest.

I agree with your assessment.

Imports to the UK sometimes show greater variability compared to producton deliveries, which makes me think that allocation to suitable ships in convoys leaving Halifax was also a factor.

In some cases, dates show that even unloading from ship, plus the road transport from Liverpool to Henlow, might take nearly one month. A couple of dated references:

Z7015

test flown at Fort William 18 January 1941, delivered to No. 13 MU, Henlow on 18 March 1941

BW836

in photo of CCF final assembly line (no. 602) 18 September 1941, delivered to Halifax, NS by RAF MSFU Pool pilot 17 November 1941

and:

AM274

arrived at Liverpool on 6 June 1942, delivered to No. 13 MU, Henlow on 3 July 1942 for assembly

 

It was possibly the superposition of (planned) transition to Mark IIB production and (unplanned) late priority order for Sea Hurricanes that caused disruption and slowed down CCF production output. On the other hand, I suspect the causes of discrepancy between officially recorded Mark numbers and the actual situation can also be attributed to a combination of external events, e.g., Pearl Harbor.

A "storytelling" attempt:

In mid-1941 it was planned to place 100 Hurricanes into storage in Canada for the EATS. Being trainers, they were probably acceptable as Mark Is. Assuming 100 sequentially, these would be AG287, AG292-AG344, AG665-AG684, AM270-AM295, with production presumably complete by the end of August 1941. At the end of June 1941, CCF had the only production line still active for Mark Is, CAM-ships were serving in increasing numbers and there was still no estimate of Sea Hurricane wastage during catapult operations. This made the Sea Hurricane order a high-priority one, that possibly took precedence over the completion of the planned 100 Mark Is. Compared to the land-based version, some additional production time was required, to fit equipment specific to the Sea Hurricane and reinforce parts of the structure for catapult launching. To some extent, this may have contributed to longer production times.

 

Possibly shortly later, it may have been realised that the intended 100 trainers would be more useful after rework and conversion to Mark II airframes "as and when possible". Afterwards (from AM296?) production would become Mark IIs from the start (the need to resupply the USSR may have had a part in this, as most machines after reaching Britain were sent to Russia).

It might then be the case that at this time  all aircraft, both stored and future production, were put on records as Mark IIs. Indeed, this is how they arrived in Britain: for instance, AG334 was a Mark II with 12-gun wing (on arrival in Britain it was converted into a Sea Hurricane Mark II and flew with 800 Sqn. FAA during Operation Torch).

 

The Battle-Hurricanes were officially taken on strength by the RCAF on 30 April 1942, but the decision to transfer 30 stored airframes was taken after the start of hostilities in the Far East. This was about five months later than the Sea Hurricane order. It is likely that, by this time, the Merlin III was no longer in production, so that the simpler and faster solution for the RCAF to field Hurricanes was to take out of storage those airframes that remained unmodified and source second-hand Merlin III from the Fairey Battle trainer fleet. At this point, perhaps it was forgotten that record cards should have been amended.

Admittedly, another possibility would have been to wait for the Packard Merlins and modify the airframes to Mark II. With Mark XII production about to start in a few months, Battle-Hurricanes were probably a quicker and more cost-effective way to obtain a stop-gap fighter.

 

I hope this may help.

Best regards

 

Claudio

 

 

 

Edited July 19, 2019 by ClaudioN

[Geoffrey Sinclair]

Z7051 is interesting, a significant delay, the question from AM274 is how much of that was in Britain.  For BW836 we have a photograph dated 18 September of the assembly line but it gives no idea how close to completion any of the aircraft were, the Sea Hurricanes could have been waiting on engines from Britain at least.  AM274 shows the delays within Britain.

 

For an idea of average travel times the table is month, the first number is production for the month and the second is production yet to arrive in Britain, as of end of month 
Sep-40 1 / 1 
Oct-40 7 / 7 
Nov-40 13 / 15 
Dec-40 15 / 21 
Jan-41 35 / 40 
Feb-41 46 / 63 
Mar-41 66 / 69 
Apr-41 58 / 73 (4 lost at sea removed)
May-41 72 / 95 
Jun-41 59 / 51 (4 lost at sea removed)
Jul-41 14 / 8 
Aug-41  0 / 0

 

So something over a month on average, with better times in summer.

 

Agreed the training Hurricanes could be mark I, the next 100 airframes end around AM295 and at full production the order should have been filled by around end August 1941, but in fact took until late December numerically and early January after you take into account the Sea Hurricanes, it is unlikely any complete airframes were not counted as produced during the period.  The idea CCF had the only open mark I line at end June is strictly correct, but it was only the last 8 still to be officially built, Glosters output in June 1941 was around 20 to 25% mark I, a matter of weeks difference.

The Sea Hurricane order clearly had an elevated priority, if they were built in order they would have appeared in January 1942, not starting in November 1941.  As to whether they took precedence over the 100 to be stored the numbers say not really, 59 airframes before the break, another 32 October/November versus 5 Sea Hurricanes Taken On Charge, 70 production in December versus 26 Sea Hurricanes Taken on Charge.  By end December 1941 there were over 100 more mark II Hurricane airframes officially produced than had arrived in Britain even after deducting the ones used by the RCAF.  Agreed the need to make changes should have slowed down the Sea Hurricane production versus mark I, it cannot explain such a big gap.

The serial numbers of the first arrivals in Britain in December 1941 could indicate the storage plan was largely done, or alternatively at least some of the earlier official mark II were partially completed airframes awaiting final assembly or an engine or conversion from mark I.

RCAF 1351-80 were Taken on Strength in December 1941 and January 1942, this period clearly overlaps the Sea Hurricane production, so the line was receiving mark I parts.  As noted the Merlin III went out of production in May 1941, Merlin 28 production started in August 1941, shipments of Merlin 28 for the Hurricanes were arriving in numbers in January or certainly in February 1942.  The placing into RCAF service of stored airframes earlier than April 1942 can be evidence the airframes were mark I, on the basis early arrival means less work was involved.  At the same time it was an emergency situation and so far there seems no problems with attaching A wings and mark I forward fuselages to the stronger mark II wing centre section.

 

As noted before for every reason for the stored airframes to be one mark a counter reason can be given for them being the other.

 

For example it is logical to think the Hurricanes destined for the training system in Canada to be mark I given the Fairey Battles present, however the Merlin III engine had ended production but was still in demand for the Battles, Defiants, Hurricanes and Spitfires either still operational or making their way into the training system plus of course the Sea Hurricanes the Admiralty were receiving.  Why set up more demand for the engine when the US was near and able to supply engines?  For example the Anson mark IV airframes sent to Canada to use US engines, the Oxford mark V that did the same thing.  The Merlin 28 and 29 orders for CCF built Hurricanes.

 

To give an idea of the effort required to move all the stuff around.    A convoy from the US to England in March 1944, 18 full and 24 part ship US Army cargoes (1,500 vehicles on wheels, 200 cased, 200 aircraft and gliders, 50,000 tons of supplies).  The Army cargoes took eight days to discharge, 75 trains using 10,000 cars to clear, plus some road transport, these land movements also generated the need for 27 trains with 8,000 cars for things like inter depot movements and rail supplies.

[Carl V]

                I have been following the discussion on Canadian Hurricanes with interest and have finally made up my mind to join Britmodeller and see if I can contribute anything. I will commence with the thirty Hurricane I’s  (RCAF designation) serials 1351 – 1380. I trust that I will not be too prolix.

                I have found over the years that it is useful to look at the historical context on such subjects as it quite frequently provides a basis for the various decisions and actions concerned.

                In this case, we should look at the RCAF’s situation at the time. In early December 1941 the RCAF’s HWE fighter situation was finally looking reasonably optimistic with the RAF supplying 12 Kittyhawk I’s per month since September and with 400 Hurricane IIB (Can.)’s hopefully coming on stream in mid-1942.

                This changed with Pearl Harbor as the US immediately halted Kittyhawk shipments and commandeered those that were ready for shipping. This only lasted for a few weeks, but the RCAF obviously could not know this. Another source of fighters seemed necessary, particularly with the expanding war situation.

                The day after Pearl Harbor the Canadian Minister for Air enquired of the Director General, Aircraft Production as to what Hurricanes were available in Canada. On 10 December the DGAP replied that “the only Hurricanes ready to fly and fight” were the 50 Sea Hurricane’s now being delivered to Dartmouth and 60 RAF Hurricanes stored at Fort William. Another document which I cannot now locate stated that these were awaiting engines.

                The RCAF immediately commenced negotiations to acquire these 60 and a contract for their purchase (designated Program 36) was put in place. That this was a purchase and not some other form of agreement is indicated by the repeated use of the term “purchase” in all the relevant documents and the immediate allotment of RCAF serials.

                The Hurricanes , for the most part, were in the RAF serial ranges AG287 – 342 and AG665 – 671. They were assigned RCAF serials 1351 – 1410 but the RAF serials of the aircraft were not allotted sequentially but, seemingly, at random. I have a list of the sixty serial pairings if anyone is interested.

                In January 1942 ACM Sir Charles Portal, RAF CAS stopped off in Ottawa on his way to Washington. During his visit he made a piteous plea to the RCAF anent the RAF’s desperate need for Hurricanes to such effect that the RCAF agreed to reduce its Hurricane acquisition from 60 to 30. Those kept by the RCAF retained the numbers 1351 to 1380. Serials 1381 to 1410 were eventually allotted to Beechcraft Expeditors.

                The question of obtaining sufficient Merlin III’s from Fairey Battles caused a great deal of heart searching and controversy within the RCAF. The Battle was intended to be the mainstay of the BCATP B & G schools and 854 had been ordered in January 1940 in a contract placed under CD TP 1. However, it was grievously behind schedule (in fact, only 720 were delivered) and the schools were struggling. Eventually, it was decided that the needs of the Hurricanes trumped that of the Battles. Not only the engines and engine instruments were needed but the propellers had to be sent to Canadian Pratt & Whitney to be cut down to size – the dimensions for this resizing are available. The reduction of the order  to 30 undoubtedly eased matters.

                It is interesting that not all of the engines supplied for these aircraft had the Battles as their provenance. Two, at least, were provided by CCF were they had been used for testing newly produced Hurricanes. According to RCAF documents, one had been used for 58 first flights and the other for 30. There is no indication of the motivation for this donation, but it seems to be a nearfetched assumption that the company considered it had no further use for Merlin III’s.

                 All thirty of the Hurricanes were TOS by the RCAF over January and February 1942.These Hurricanes were used to equip the newly formed 125 (F) Squadron at Torbay, Newfoundland and 128 (F) Squadron at Sydney, Nova Scotia in April and June 1942 respectively. The 125 (F) aircraft were shipped to Dartmouth and erected there before being flown to Torbay while the others were erected at Sydney. They served with these units until December 1942 when they were put into storage until being shipped to CCF for conversion to Hurricane XII A’s.

                I know that this does not answer many questions such as what they were intended for and why they were in storage at CCF etc and I would sooner juggle steak knives then have the temerity to tiptoe through the minefield of fuselage lengths. However, I trust that all the above wittering has helped to partially illuminate the big picture.

[ClaudioN]

12 minutes ago, Carl V said:

I know that this does not answer many questions such as what they were intended for and why they were in storage at CCF etc and I would sooner juggle steak knives then have the temerity to tiptoe through the minefield of fuselage lengths. However, I trust that all the above wittering has helped to partially illuminate the big picture.

Your post does answer many questions and provides the essential historical background.

Thank you very much for this.

 

Claudio

 

P.S.: I'd be interested in the serial pairings, if possible (PM ?).

[ClaudioN]

14 hours ago, Geoffrey Sinclair said:

Z7015 is interesting, a significant delay

Z7015 had been flight tested at Fort William. I assume the engine had then to be removed and the aircraft disassembled and crated for transportation. I'd rather think that, in this case, two months from CCF to 13 MU is average/fast.

14 hours ago, Geoffrey Sinclair said:

For BW836 we have a photograph dated 18 September of the assembly line but it gives no idea how close to completion any of the aircraft were, the Sea Hurricanes could have been waiting on engines from Britain at least.

Admittedly the nose of no. 602 cannot be seen in the photo, I assume it has an engine fitted since the next two machines, no. 603 (?) and no. 604 do have their Merlin. Anyway, BW837 (no. 603) was also delivered in flight on 17 November, the delivery flight of BW838 (no. 604) ended in a forced landing on 27 November. The picture was taken two months before flight and the advancement state suggests manufacturing of those machines had started well before (about August, or earlier?).

14 hours ago, Geoffrey Sinclair said:

The serial numbers of the first arrivals in Britain in December 1941 could indicate the storage plan was largely done, or alternatively at least some of the earlier official mark II were partially completed airframes awaiting final assembly or an engine or conversion from mark I.

I think we cannot go any further unless individual histories are considered. This is why I provided what little I have. "On average" both your and my assumptions can be reasonable and we use logic to lean towards one or the other.

 

Post #117 by Carl V (thank you again!) provides a picture of availability in Canada, as of mid-December 1941: 60 Hurricane airframes stored at Fort William and 50 Sea Hurricanes being delivered to Dartmouth. I think this gives two possibilities:

 

Hypothesis 1: stored airframes were Mark IIs. Then:

• 30 RCAF machines: fitting a Merlin III feasible with some minor rework. Second-hand Merlins sourced among engines available in Canada, Fairey Battle propellers cropped to size.
• 30 RAF machines: either wait for Packard Merlin 28, or be sent as engine-less airframes

Hypothesis 2: stored airframes were Mark Is. Then:

• 30 RCAF machines: fitting a Merlin III practically immediate. Second-hand Merlins sourced among engines available in Canada, Fairey Battle propellers cropped to size.
• 30 RAF machines: either remain stored as Mark Is, or reworked to Mark II standard then either wait for Packard Merlin 28, or be sent as engine-less airframes

I have not considered the possibility for the RCAF machines to "wait for engines", as this would have meant a wait for Merlin 29s that were still a few months ahead. Arguably, Merlin 28s would have to be "wrestled from", rather than "obtained", which seems less likely to me.

 

There are several hints that stored machines, whatever their Mark, were delivered "out of sequence". With this in mind, I had a look at the Air Britain book on AA to AZ serials (the only one I have) and it turns out that the dates for allocations to Russia and the Admiralty are also out of sequence compared to serial order, suggesting that several earlier machines were delayed for some reason, although this is not a general rule. I do not know what happened with the BW885-BX134 Mark IIs, it would be useful to see whether they followed, or were mixed with machines from the previous order.

 

Again, several hints (and some photos) make me consider Hypothesis 2 the more likely. An additional clue, in my opinion, is that Sea Hurricanes and Battle-Hurricanes were both into the CCF conversion programme to Mark XIIA, that I presume achieved a common configuration. If the Battle-Hurricanes had already been Mark II airframes, their "conversion" would have required little more than an engine change, making them Mark XIIs.

Edited July 20, 2019 by ClaudioN

[ClaudioN]

Forgot to add... fitting a Merlin III to a Mark II airframe (BD771) was an improvisation by HMS Indomitable engineering department. Not sure a constructor would have taken it so easy.

Anyway, that was done in early 1942 and probably unreported until some time later.

[Graham Boak]

I understand that it was done at Aden rather than on-board.  Either way the engine change was probably the least difficult part compared with the strengthening to add the arrester hook and the catapult spools.  I assume that the radio fit may have been different too, but don't imagine this was difficult.

[Geoffrey Sinclair]

Thanks very much Carl for a very informative contribution.

17 hours ago, Carl V said:

                 In this case, we should look at the RCAF’s situation at the time. In early December 1941 the RCAF’s HWE fighter situation was finally looking reasonably optimistic with the RAF supplying 12 Kittyhawk I’s per month since September and with 400 Hurricane IIB (Can.)’s hopefully coming on stream in mid-1942.

                This changed with Pearl Harbor as the US immediately halted Kittyhawk shipments and commandeered those that were ready for shipping. This only lasted for a few weeks, but the RCAF obviously could not know this. Another source of fighters seemed necessary, particularly with the expanding war situation.

The Kittyhawk I order was delivered as RCAF 1028 to 1099, so 72 aircraft, Taken on Strength dates were Oct-41 16, Nov-41 11, Dec-41 12, Jan-42 15, Feb-42 10, Mar-42 2, Apr-42 2, Nov-42 2, assuming the November 1942 are not typos for 1941, the 12 or so per month continued until February, giving 66 Kittyhawk.  Also another 12 Kittyhawk IA, RCAF720-31 were Taken on Strength on 10 April 1942.  So the RCAF was certainly right to be worried about supply but the deal, presumably with the British, was essentially continued until April.

 

The mid 1942 date for the RACF Hurricane order is interesting, it actually began in June despite 100 RAF order aircraft still outstanding, sounds like the date mattered more than finishing the RAF orders.  I wonder if the date was long planned assuming no 1941 delay, but the delay meant the decision was taken to switch before finishing all RAF orders.

17 hours ago, Carl V said:

                 The day after Pearl Harbor the Canadian Minister for Air enquired of the Director General, Aircraft Production as to what Hurricanes were available in Canada. On 10 December the DGAP replied that “the only Hurricanes ready to fly and fight” were the 50 Sea Hurricane’s now being delivered to Dartmouth and 60 RAF Hurricanes stored at Fort William. Another document which I cannot now locate stated that these were awaiting engines.

                The RCAF immediately commenced negotiations to acquire these 60 and a contract for their purchase (designated Program 36) was put in place. That this was a purchase and not some other form of agreement is indicated by the repeated use of the term “purchase” in all the relevant documents and the immediate allotment of RCAF serials.

                The Hurricanes , for the most part, were in the RAF serial ranges AG287 – 342 and AG665 – 671. They were assigned RCAF serials 1351 – 1410 but the RAF serials of the aircraft were not allotted sequentially but, seemingly, at random. I have a list of the sixty serial pairings if anyone is interested.

                In January 1942 ACM Sir Charles Portal, RAF CAS stopped off in Ottawa on his way to Washington. During his visit he made a piteous plea to the RCAF anent the RAF’s desperate need for Hurricanes to such effect that the RCAF agreed to reduce its Hurricane acquisition from 60 to 30. Those kept by the RCAF retained the numbers 1351 to 1380.

Any idea of the date when RCAF were allowed to take over the Hurricanes or at least the agreement date?  Thanks for confirming they would be RCAF, not RAF on loan.

 

Not sure how the ready to fly and fight would apply to the stored aircraft, I can only assume they were ready to go except for engines, so armament etc. fitted.  Meantime the RCAF took its first 5 Sea Hurricanes on Strength on 9 December 1941, by which date the RAF had Taken on Charge another 6.  There would be around another 40 airframes built by CCF since the line restarted in October 1941, including some of the above Sea Hurricanes, less any airframes already exported to Britain, which received 7 in December 1941.

 

The 60 airframes in storage should have been mostly the 59 built in July/August, the document stating they were awaiting engines is actually important, as the only engines currently known as being supplied to Canada for RAF order Hurricanes are Merlin 28, making the airframes mark II, does the document indicate the mark of Merlin being supplied?  So all 60 aircraft in storage were allocated an RCAF serial, and the document you have also gives the RAF serial as well , if this is correct please post the list, it will be of great use in figuring out what was going on, starting with what airframes were being stored.  AG341 is of particular interest.  I note AG287 – 342 and AG665 – 671 is 63 airframes, but we know the 4 airframes AG288-91 were shipped to Britain as mark I in mid 1941, but this serials list omits AG343 and AG344.  AG671 is number 486 in the RAF serial number list, taking off the 426 mark I leaves 61 airframes, taking off AG341 leaves 60.

17 hours ago, Carl V said:

                  The question of obtaining sufficient Merlin III’s from Fairey Battles caused a great deal of heart searching and controversy within the RCAF. The Battle was intended to be the mainstay of the BCATP B & G schools and 854 had been ordered in January 1940 in a contract placed under CD TP 1. However, it was grievously behind schedule (in fact, only 720 were delivered) and the schools were struggling.  (snip)

                It is interesting that not all of the engines supplied for these aircraft had the Battles as their provenance. Two, at least, were provided by CCF were they had been used for testing newly produced Hurricanes. According to RCAF documents, one had been used for 58 first flights and the other for 30.  (snip)

The 125 (F) aircraft were shipped to Dartmouth and erected there before being flown to Torbay while the others were erected at Sydney. They served with these units until December 1942 when they were put into storage until being shipped to CCF for conversion to Hurricane XII A’s.

Yes CCF were known to have had some Merlin III to test some mark I airframes, the 88 flights for 426 mark I is at best 1 in 5 of the airframes receiving 1 test flight each, more like 1 in 10 were tested.  Agreed that with mark I production over CCF had no need for any Merlin III, presuming Britain shipped a quantity of Merlin III for the Sea Hurricanes.  Agreed also the supply of Merlin III was proving a problem for places like Canada and Australia as the Battles were being flown so much.  Also the supply of Battles was running out, with a total of 2,200 built over 1,300 were exported from Britain from April 1940 onwards, and others before that date, most exports done by end 1941, only another 15 would be shipped to Canada in 1942.

The statement the airframes had to be erected rather contradicts the "ready to fly and flight" claim, it does fit with them being broken down to an extent to enable efficient storage, you would expect CCF to put them back together rather that freight them from Ontario to Nova Scotia for presumably RCAF units to do the work, but then CCF were under considerable pressure at the time.  One point is the photographs of RCAF1351-80 show A wing armament as far as I am aware, and it would be remarkable if the wings in storage were not shipped along with the fuselages, so IIA in storage, with those exported reworked to IIB?

 

So as of early December 1941 the RCAF says 60 airframes were in storage, at least partially disassembled, they do not mention around another 40 that had been built mostly in November, nor indicate if CCF had some partially assembled airframes over and above those on the assembly line.

8 hours ago, ClaudioN said:

Z7015 had been flight tested at Fort William. I assume the engine had then to be removed and the aircraft disassembled and crated for transportation. I'd rather think that, in this case, two months from CCF to 13 MU is average/fast.

Admittedly the nose of no. 602 cannot be seen in the photo, I assume it has an engine fitted since the next two machines, no. 603 (?) and no. 604 do have their Merlin. Anyway, BW837 (no. 603) was also delivered in flight on 17 November, the delivery flight of BW838 (no. 604) ended in a forced landing on 27 November. The picture was taken two months before flight and the advancement state suggests manufacturing of those machines had started well before (about August, or earlier?).

Look at the averages from the export list, 2 months is slow in terms produced to arrived in Britain, the US Army example then shows the sorts of delays between the British docks and the reception areas, in this case the Maintenance Unit.  The trouble is the production pause, everyone agrees the number of Hurricanes in the September photograph is less than 1 months production at early/mid 1941 pace, so they could have been started in early September for example, we simply have no evidence, only that something was preventing any completed production of both mark I and II variants August to October 1941.  Airframes on the line in mid September , assuming the photograph is of the entire assembly hall, should have all been assembled by around the end of the month. At some point CCF would have run out of storage space for partial airframes, more so if they wanted them under cover.

8 hours ago, ClaudioN said:

Hypothesis 1: stored airframes were Mark IIs. Then:

Hypothesis 2: stored airframes were Mark Is. Then:

I have not considered the possibility for the RCAF machines to "wait for engines", as this would have meant a wait for Merlin 29s that were still a few months ahead. Arguably, Merlin 28s would have to be "wrestled from", rather than "obtained", which seems less likely to me.

 

Again, several hints (and some photos) make me consider Hypothesis 2 the more likely. An additional clue, in my opinion, is that Sea Hurricanes and Battle-Hurricanes were both into the CCF conversion programme to Mark XIIA, that I presume achieved a common configuration. If the Battle-Hurricanes had already been Mark II airframes, their "conversion" would have required little more than an engine change, making them Mark XIIs.

I am not sure the dates of allocation after arrival in Britain can tell us much about CCF production order, the taken on charge etc. dates are best for that.  After import the CCF Hurricanes would enter the general pool of Hurricane II.

 

Actually unless there was another engine order around we do not know about the stored machines which were for the RAF, not RCAF, when stored, were waiting for Merlin 28, the 144 we know were on order, the Merlin 29 were committed to the RCAF order and the US could not use Merlin 28 with their shafts meant for British propellers, while the British could not use Merlin 29 with their shafts for US propellers.  Part of the reason for the stronger mark II centre section was to carry external loads.  Were any RACF Hurricanes fitted with wing racks?  I have not seen any such photographs.  In which case the converted Sea Hurricanes would be the equivalent of a mark II series i, while the mark XII would be the equivalent of a mark II series ii.  Also as part of the conversion did the Sea Hurricanes stay as the sea version, with the relevant radio, arrester hook etc.?

 

On the in service mark II to I conversion,

1 hour ago, Graham Boak said:

I understand that it was done at Aden rather than on-board.  Either way the engine change was probably the least difficult part compared with the strengthening to add the arrester hook and the catapult spools.  I assume that the radio fit may have been different too, but don't imagine this was difficult.

I am told the RN radios were heavier than the RAF ones, and this hurt given the radio was aft of the cockpit.  Keeping the forward fuselage extension would have helped.
 

https://www.thunderbay.ca/en/city-hall/canadian-car-and-foundry-.aspx

 for a couple of CCF pictures that call into question how many Hurricane lines there could have been.

 

https://www.google.com.au/search?=canadian+car+and+foundry+fort+william+ontario&tbm=isch&source=univ&sa=X&ved=2ahUKEwi5w5CCz8PjAhXymeYKHWlrCJsQsAR6BAgJEAE&biw=1366&bih=695#imgrc=Bp_Vb9p4K8UjTM:&spf=1563629988703

 

If the second link does not work it came up when I went searching for CCF Hurricanes.

 

Does anyone know what is the time out for a log in is? I find I am logging in to compose a reply, then having to log in a second time to post it.

[ClaudioN]

4 hours ago, Geoffrey Sinclair said:

Meantime the RCAF took its first 5 Sea Hurricanes on Strength on 9 December 1941, by which date the RAF had Taken on Charge another 6. 

At first Sea Hurricanes were taken on strength by No. 118(F) Sqn. RCAF only in support of MSFU. Actual date of transfer to the RCAF might be later. I seem to recall there was a Hurricane flight within 118 Sqn. first, then the units that eventually operated with them, mainly Nos. 126(F), 127(F) and 129(F) Squadrons RCAF were not formed until Spring 1942.

 

4 hours ago, Geoffrey Sinclair said:

The 60 airframes in storage should have been mostly the 59 built in July/August, the document stating they were awaiting engines is actually important, as the only engines currently known as being supplied to Canada for RAF order Hurricanes are Merlin 28, making the airframes mark II, does the document indicate the mark of Merlin being supplied? 

One can see it another way. Predictably, that's how I'd been thinking of it, hopefully Carl V can help us?

 

Having no less than 60 Mark II airframes in storage in early December, and waiting for engines that would be arriving three months later, would be rather poor production management. It would have made much better sense to send them without engines, as most of the planned Mark II production was.

If the stored airframes were Mark Is, they would have been set aside waiting for Merlin IIIs to be obtained from some second-hand source, or to be shipped in from Britain. Indeed, 50 had been imported from the UK, but they went to the Sea Hurricanes.

If Merlin III production ended in May 1941, we may assume that even those Sea Hurricane engines were overhauled, but probably not strictly "new".

Edited July 20, 2019 by ClaudioN

[ClaudioN]

31 minutes ago, Geoffrey Sinclair said:

The trouble is the production pause, everyone agrees the number of Hurricanes in the September photograph is less than 1 months production at early/mid 1941 pace, so they could have been started in early September

Sorry, I'd take this to mean those closer to the camera could have entered the final assembly line in late August to early September.

[ClaudioN]

6 hours ago, Geoffrey Sinclair said:

I am not sure the dates of allocation after arrival in Britain can tell us much about CCF production order, the taken on charge etc. dates are best for that.  After import the CCF Hurricanes would enter the general pool of Hurricane II.

Agreed that dates of allocation, in most cases to Russia, do not tell us much.

Still, if AM349 is given as "to Russia 17 April 42" (Air Britain), this means it was produced before that date, even though I do not know whether "to Russia" means "allocated to Russia" or "dispatched to Russia".

In the case of AP138 you provided separate dates: allocated to Russia 20 May 1942, lost at sea 30 December. If 17 April refers to "allocation" we may perhaps assume AM349 arrived in Britain one month earlier than AP138?

 

From what you report in your mails, I suggest "taken on charge" is rather too vague, as we do not know where this occurrred. In some cases it seemingly refers to delivery at CCF, in other cases to arrival at 13 MU, sometimes another MU is recorded. In the latter case this may mean another MU helped with the work of reassembling fitting and testing the Canadian Hurricanes (which 13 MU Henlow was tasked with) or, alternatively, that "taken on charge" was, for instance, the date when the aircraft went into RAF storage.

 

Here are some cases we have been discussing.

• you said AM299 was "taken on charge" in December 1941, but the date refers to No. 20 MU, that usually was one of the Hurricane storage units.
• AG680 was lost in a crash on 12 June 1942, while ferrying from No. 13 MU to No. 22 MU (another storage unit).
• for AP138 you reported that the "taken on charge" date refers instead to arrival at 13 MU on 28 February (which, incidentally, means a really long stay in Britain - 10 months - before dispatch to Russia).
• by comparison AM274, of which Riley provided the full record in his book, was delivered to No. 13 MU Henlow on 3 July 1942, required repair in works and was awaiting collection on 28 November, was transferred to 10 MU (an Aircraft Storage Unit) on 5 December, but then to 76 MU (a Packing Depot) on 10 December. Here it must have been disassembled and was at Hull Docks on 28 December. It's still nearly 6 months from arrival to actual dispatch.

There's plenty of disruption to the serial order there, but:

• why did AP138 stay so long? Did it also require repair in works, like AM274?
• if AG680 was lost in June, is it safe to assume it arrived at No. 13 MU in May, or did it also need repairs and its arrival date was earlier?
• was AM299 with 20 MU after fitting out at 13 MU, or did it go to 20 MU for fitting instead?

An answer to any of these questions involves differences by one month or more. That's why I am asking: paper records are not necessarily accurate.

Edited July 20, 2019 by ClaudioN