Lancaster chordwise "reinforcing" straps on the upper wings

[leyreynolds]

Lancaster "G for George" in the AWM has what appear to be chordwise reinforcing straps on the upper wing surfaces. None of my references describe or illustrate these - any thoughts on the matter please?

[Ossington 2]

https://ibb.co/TYygptk

 

I thought I had a photo of this mod in my Lanc file. I hadn't, so went hunting. This image is from the Late W. Taylor's "Royal Air Force Winthorpe 1940-1945" p.30.   It affects the transition panel between the rear of the outer nacelles and the wing leading edge. A series of chord-wise reinforcing strips rivetted to the upper surface. I think it was introduced on high-hour B.I's or at least on high-landings HCU machines. 

Maybe it was a 'quick fix' and subsequently replaced by panels with interior and thus not visible reinforcement? It doesn't seem to be that common in photos, but few shots are angled to show it. Were they on Admiral Prune?

Sorry I can't paste the image up directly. 

[BritJet]

This previous discussion might be useful.

 

Steve

[Alex Gordon]

46 minutes ago, Ossington said:

https://ibb.co/TYygptk

Sorry I can't paste the image up directly. 

 

 

 

[leyreynolds]

Thanks for all the info'.

 

Ley

[junglierating]

Whats the AWM ?....something war museum obs but A 🤔

[leyreynolds]

Australian.

[Ed Russell]

7 minutes ago, junglierating said:

Whats the AWM

https://www.awm.gov.au/

 

A very useful site.

[Admiral Puff]

I know that Alan Yee did a lot of work to try to find out what those strakes were for, but I don't think he got anywhere with it (he hadn't the last time we spoke about it, anyway). Sadly, we'll never know now.

[junglierating]

1 hour ago, Ed Russell said:

https://www.awm.gov.au/

 

A very useful site.

Oh I see .....very good carry on no 1

[Phoenix44]

I wonder given how small they are whether they were for the erks? 

[Ed Russell]

On 1/1/2022 at 8:46 AM, Admiral Puff said:

Sadly, we'll never know now.

Check out @BritJet's quote in the thread he linked to.......... I think this is the explanation. G-George is really a Manchester!

 

Those strakes on the AWM Lancaster, G-George, were a short lived solution to the early engine mount weaknesses suffered by the first batch of Lancasters off the production line. The second production Lancaster (really a Manchester that had been converted on the production line) had its No.1 engine fall off upon take-off from Boscombe Down and, following its repair, then had a mainwheel fall off as the gear was lowered on another flight soon afterwards! The first dozen or so Lancasters also had their wingtips snap upwards when flying loaded - many snapped off completely, and all three 'teething problems' were quickly solved by modifications introduced on the production lines. G-George was ordered as a Manchester but converted to Lancaster configuration on the production line, hence the wing strakes which have been on the aircraft since she was built. She is the oldest surviving Lancaster airframe and the only one left with the strakes.

[Admiral Puff]

Thanks, Ed. If only Alan was still around ...

[Dave Swindell]

13 hours ago, Ed Russell said:

Check out @BritJet's quote in the thread he linked to.......... I think this is the explanation. G-George is really a Manchester!

 

Those strakes on the AWM Lancaster, G-George, were a short lived solution to the early engine mount weaknesses suffered by the first batch of Lancasters off the production line. The second production Lancaster (really a Manchester that had been converted on the production line) had its No.1 engine fall off upon take-off from Boscombe Down and, following its repair, then had a mainwheel fall off as the gear was lowered on another flight soon afterwards! The first dozen or so Lancasters also had their wingtips snap upwards when flying loaded - many snapped off completely, and all three 'teething problems' were quickly solved by modifications introduced on the production lines. G-George was ordered as a Manchester but converted to Lancaster configuration on the production line, hence the wing strakes which have been on the aircraft since she was built. She is the oldest surviving Lancaster airframe and the only one left with the strakes.

I think we have to be a little careful here, I doubt very much G-George was ever a Manchester apart from production slot paperwork and individual components common to both types - when construction began on the production line it  would have been as a Lancaster.

Of the sub-assemblies forming a Lancaster, apart from the engine nacelles, the most changed sub-assembly from Manchester production is the outer wing panels on which the subject modifications were made. Apart from the Manchester ribs, which were spaced further apart to give the increased span, pretty much everything else is new, spars, skins, ailerons engine mounts, etc.

The rest of the airframe design had already undergone development through Manchester production, with the speed of design of the Lancaster it's hardly surprising that there were teething problems that needed sorting on the new Lancaster outer wing panels.

The strakes are thus a re-enforcing mod for initial production Lancaster outer wing panels produces before a modified production design was introduced

[Ed Russell]

10 hours ago, Dave Swindell said:

I doubt very much G-George was ever a Manchester

I think you are taking my tongue-in-cheek comment too seriously! G-George is an iconic aircraft in Australia, particularly amongst modellers so think of it as a bit of fun.

 when construction began on the production line it  would have been as a Lancaster.

You may well be right but what you are saying contradicts the quote above.

[Dave Swindell]

17 hours ago, Ed Russell said:

I think you are taking my tongue-in-cheek comment too seriously! G-George is an iconic aircraft in Australia, particularly amongst modellers so think of it as a bit of fun.

 

 

You may well be right but what you are saying contradicts the quote above.

Hi Ed, I wasn't taking your tongue-in-cheek seriously, I'd recognised that as a bit of fun 😀

 

It's the quote that I'm contradicting, as there appears to be a general misconception from poorly worded accounts such as this that conversion of aircraft from one mark to another on the production line was commonplace. I won't say that it didn't happen but if it did, it wasn't common. 

 

MAP was very keen on maintaining or increasing production rates of all types, any changes on the production lines would have to be justified and implemented with the minimum possible impact. Doing conversion work on a production line would have a significant impact on production rates, conversions where needed were done in separate facilities, either by the manufacturer or at an MU or similar - eg Tropical Spitfires were built as standard Spitfires, then converted to Tropical standard at separate facilities after completion.

 

What was relatively common was for the later part of a large order for one mark of aircraft to be built as another mark as changes in design were implemented. Allocated serials would remain the same, and the contract would be amended as necessary. How the change was implemented would depend on the circumstances, but if any specific airframe build had progressed beyond the point of the mark change I'd say it almost invariably would complete it's run down the production line as the earlier mark, with the changes being implemented on airframes following it that had not yet reached the point in construction where the engineering differed. They may have been ordered as a Mark 1 and completed as a Mark 2 but there hasn't been any conversion work done on the airframe. The earlier completed Mark 1's may at a later date be converted to Mark 2, and this may be before delivery for operational use, but it's not a production line conversion.

 

The 3 Lancaster prototypes were built under a separate contract to covering Manchester MkIII (renamed Lancaster before it flew), so the name changed during manufacture, and no doubt large parts of the airframe shell were built on Manchester MkI jigs, using Manchester components, but the airframes wouldn't have been completed on the Manchester production line, the components would have gone to the experimental shop for bespoke completion instead.

Likewise, the first Lancasters would have followed the last Manchesters down the production line, and whilst they were on a contract and carried serials initially intended for Manchester production, and contained subassemblies and components common to Manchesters, I believe there wouldn't have been any changes to the airframes to remove Manchester specific features and replace them with Lancaster features on the line ie they started out down the line as Lancasters and weren't converted from Manchesters to Lancasters part way down the line.

The only real conversion here would have been a paperwork exercise to convert the "all Manchester" contract into a "remaining unbuilt airframes as Lancasters" contract. 

 

As regards G-George W4783, this was part of contract B69275/40 for 400 Lancaster I and III from Metro-Vick to be constructed at Mosley Road Works, so it wasn't even a paper exercise conversion from a Manchester, it was always a Lancaster.

[Geoffrey Sinclair]

Agree with the above, though I suspect there is a slight twist to the story.  Using the book The Avro Manchester by Robert Kirby and the RAF list of aircraft contracts as of end 1939 the following orders had been placed for Manchesters

200 from Avro, between L7276 to L7584, contract 648770/37
200 from Avro, between R5482 and R5763, contract 982865/39
100 from Metrovic, between R5768 and R5971, contract 982866/39

Also 150 from Fairey and 300 from Armstrong Whitworth which were ultimately cancelled.

 

Then came 450 from Avro, between W4102 and W4758 contract 69274/40 in January 1940, some ultimately cancelled.
Also 200 from Metrovic, between W4761 and W5012, contract 69275/40, the Metrovic serials are earlier, contract later than the 1940 Avro order.

 

Next in contract number order is 135521/40 the order for Lancaster prototypes, well known first flight 9 January 1941.

 

Based on the contract numbers every aircraft up to W5012 was ordered as a Manchester, but only some from the first orders from Avro and Metrovic were built as such.

 

The last Manchester from Avro was in November 1941, a month after the first Lancaster, for Metrovic last Manchester in March 1942, two months after the first Lancaster.

 

The Lancaster Contract Cards do not have any notes or explanation cards.  Two such cards for the Manchester,  First card has the original Avro order for 200, then 145 (Between L7276 and L7497) then 157 then 156.  The Metrovic order is 55 changed to 43.  There is a requisition E.1(A) 15 November 1940, not sure what quantities that refers to.  However both contracts have the entry Amendment 9 April 1941 and E.1 10 April 1941, which I think is the official change over to Lancasters.

 

Second card headed Manchester and Lancaster General Notes.  Manchester L7285, L7289, L7293 and L7297 had been diverted to contract 10962/39 for armament development have been returned to the original contract for completion as standard Manchester, E1(a) minute of 17 December 1940.  "Contracts 982866/39 and 69275/40, 300 aircraft in components to be produced by Metropolitan Vickers for assembly by A.V. Roe.  41 Group are (A) allot from Metrovic to Avro as aeroplanes completely unassembled.  (B) Allot from Avro when assembled and flight tested by normal allotment.  (Points of interest for D.G.? 7 March 1941.)"

 

The RAF Contract Cards list all Lancasters built by Avro ordered on contract 648770/37 under 69274/40, this may be a simple mistake.  Similarly they list the Lancasters built by Metrovic on contract 982866/39 under 982666/40, which is clearly an error.

 

Is anyone interested in a detailed break down of Lancaster weights?  For example Canopy weight 180 pounds?

Edited January 9, 2022 by Geoffrey Sinclair
Corrected 3rd Avro, 1st and 2nd Metrovic order serials.

[Dave Swindell]

On 06/01/2022 at 06:48, Geoffrey Sinclair said:

Using the book The Avro Manchester by Robert Kirby and the RAF list of aircraft contracts as of end 1939 the following orders had been placed for Manchesters

Hi Geoffrey

Interesting. Kirby gives a good account of the Manchester, but understandably only mentions the Lancaster in passing. Comparing the above with contract info in Putnam's Avro entries for the Manchester and Lancaster is a bit more revealing

 

On 06/01/2022 at 06:48, Geoffrey Sinclair said:

200 from Avro, between L7276 to L7584, contract 648770/37

Contract terminated at 156 aircraft, L7526 being the last aircraft on this contract, all Manchester I or Ia

Remaining serial allocation L7527 to L7584 moved to Contract B69274/40 - 1070 Lancaster B.I from Avro.

 

On 06/01/2022 at 06:48, Geoffrey Sinclair said:

200 from Avro, between R5482 and R5763, contract 982865/39

Kirby states contract number not recorded. None built, contract presumably cancelled.

Full serial allocation R5482 to R5763 moved to Contract B69274/40 - 1070 Lancaster B.I from Avro.

 

On 06/01/2022 at 06:48, Geoffrey Sinclair said:

100 from Metrovic, between R5768 and R5841, contract 982866/39

Kirby gives serial allocation for 100 between R5768 and R5917 - Contract terminated at 44 aircraft, R5841 being the last aircraft on this contract, all Manchester I or Ia, Putnam gives contract No B108750/40 for these aircraft

Remaining serial allocation R5842 - R5917 built as Lancaster B.I, Putnam states these were originally ordered as Manchester on contract B982866/40.

 

On 06/01/2022 at 06:48, Geoffrey Sinclair said:

Also 150 from Fairey and 300 from Armstrong Whitworth which were ultimately cancelled.

150 from Fairey, no contract no, between R42525 and R4744, cancelled, serials not re-used

150 from A/W, contract no 982865/39, between R5273 and R5477, cancelled, serials not re-used

150 from A/W, contract no B982865/39, between W1280 and W1498, cancelled, serials not re-used

 

On 06/01/2022 at 06:48, Geoffrey Sinclair said:

Then came 450 from Avro, between W4102 and W4758 contract 69274/40 in January 1940, some ultimately cancelled.

Neither Kirby nor Putnam give these as Manchesters, Putnam refers to serials between W4102 and W4384 under Contract B69274/40 - 1070 Lancaster B.I from Avro.

 

On 06/01/2022 at 06:48, Geoffrey Sinclair said:

Also 200 from Metrovic, between W4761 and W5012, contract 69275/40, the Metrovic serials are earlier, contract later than the 1940 Avro order.

Neither Kirby nor Putnam give these as Manchesters, Putnam refers to these serials as half of contract no B69275/40 for 400 Lancaster B.I and B.III from Metrovic, all built as Lancaster I/III

 

Without access to the cancelled, incomplete and Lancaster contracts it's difficult to determine which are for Manchester I's, Manchester III's (which were later renamed Lancaster) and Lancaster BI/III

There does appear to be a change of thinking during 1940 with amendments to original Manchester I contracts and issuing of new contracts which apear to be Manchester III / Lancaster  - was the Air Ministry hedging it's bets between RR sorting out the Vulture and Avro successfully developing the Manchester III / Lancaster? With the termination of Manchester I contracts and transfer of some of the allocated serials to Lancaster production this seems highly likely..

 

 

[Rolls-Royce]

On 1/3/2022 at 9:03 AM, Phoenix44 said:

I wonder given how small they are whether they were for the erks? 

Having owned and worked on a 1964 Austin-Healey Sprite Mk II, I can confidently speculate that no mid-century British designer ever made anything easy for mechanics...😉

Edited January 8, 2022 by Rolls-Royce

[Geoffrey Sinclair]

An apology for the serial number errors in my previous message, I mistakenly part worked from a list of contracts as they ended up as, not as they started out as.  Hopefully I have now corrected those errors, the 1st Metrovic order did end at R5917.

 

I am working off the RAF contract cards which are normally quite contemporary, and usually hand written, however the Lancaster cards are all typed, like most of the post war cards, and have been rearranged not by order but by mark and order.  So it looks like they were transcribed and are not the originals, which makes me cautious about details.  The Manchester cards are all hand written.

 

The list of contracts comes from Air Britain Aeromilitaria.

 

It should be noted once war began many existing contracts were simply left in place with additional requisitions made over time, essentially contract extensions.  For example it looks like every Hawker Hurricane built by Hawker from V7200 on was on contract 62305/39 (except W6667 to 70 (contract 92371/38), the Sea Hurricanes and the mark V prototype.)  Meaning such contracts had plenty of changes over time.

 

I am working from the logic that it would be hard to order Manchester III/Lancaster I before any order was made for the relevant prototypes, plus Kirby's contract list fits with the general increase of orders once war began.  Given details of cancelled contracts can be hard to find they can have a shape and size shifting after life in published works, plus all the changes of other contracts.  So the following is my best fit on the evidence I have.

 

The Manchester Contract Cards.

Contract 648770/37 requisition 12/37 from Avro.  Order for 200, then 145 (L7276 to L7497), then 157 (adding back L7515 to L5726) and the cut to 145/157 covered by amendments of 9 and 10 April 1941, then cut to 156 via E1(A) amendment 19 November 1941 to deal with the deletion from the contract of L7517 damaged beyond repair at Avro.  So as I read it the original order was for 200 Manchester, in April 1941 it was cut to 145 but that proved impractical and another 12 were built, total 157 (but see the Metrovic order)

 

Metrovic order 982866/39 requisition 114/39. for 100, the contract cards have 55 cut to 43 (so a minus 12 to go with the plus 12 at Avro). The order summary card notes the cut from 55 to 43 was on 10 April 1941. R5768 to 97, R5829 to 41.  A total of 100 on order is never mentioned.  The April dates I think are important and probably indicate when the other orders for Manchesters were amended.

 

Switching to the Lancasters the remaining L serials from 648770/37 are listed under 69274/40, which is quite solid evidence these were transferred to the second Avro order, originally for Manchester, but reordered as Lancaster.  The Avro L serials are the start of the 69275/40 mark I orders and are listed as deliveries 1 to 43, out of 588 delivered under the order (to ED782).  According to the contract cards order 69274/40 ended up as 588 mark I and 482 mark III, total 1,070 aircraft.

 

The Metrovic Lancaster W serials are under 69275/40 requisition 2/E 1/41, along with the DV serials.  The R serials as noted are under 982866/40 which is a mixture of the original and second order identifications, the requisition is also 2/E 1/41, R5842 to 68, R5888 to 917.  The Metrovic order 69275/40 has W4761 as its first mark I delivery and tops out at mark I delivery number 268, DV407.  The R serials are in their own sequence numbers 1 to 57. 

 

So it is almost certain the L serial Manchester reordered as Lancaster from Avro were transferred to the second contract, but it looks likely that did not happen for similar aircraft from the Metrovic order.

 

According to the timeline in Harry Holmes
end January 1940, 1,200 Manchesters under order (Kirby lists 1,600)
20 February, Manchester III proposal discussed with Air Ministry.
1 April, Avro appoint a supervisor for the Manchester III project
28 June 1940 Avro "already know" Vulture is going to be cancelled (Vulture production began with 2 in December 1939, another 23 built February to end June)  So interesting it was cancelled that early.
29 July, Avro advised drop Manchester entirely, prepare to build Halifax, hits emergency button.
end July, Air Ministry advised all efforts should be made to develop the Manchester III

 

Ordered in 1937 and 1939, 400 Avro (L, R serials), 100 Metrovic (R), 300 Armstrong Whitworth (R and W serials), total 800, probably the 150 Fairey R serials as well.  Then in 1940 the 450 Avro W serials, which makes 1,400 on order, then the 200 Metrovic W serials, which follow straight on from the Avro serials.  Total 1,600.  All of these have contract numbers well before that of the Lancaster prototypes.  Though Holmes reports the prototype contract did not arrive at Avro until 15 July 1941.  Also I note two references say 454 W serials were allocated to Avro (Including Holmes) and Holmes reports the order for 454 Lancasters arrived on 6 June 1941.  Which I think shows up the role of requisitions, make a contract, requisition against that contract.  Ignoring prototypes the next set of serial numbers allocated to Lancaster orders are the DS ones for mark II from Armstrong Whitworth.

 

As Dave notes without the relevant correspondence we do not know things like when the Fairy order was placed (if at all) or it and the Armstrong Whitworth order cancelled, if they were "replaced" by the 1940 orders from Avro and Metrovic that gives 1,150 on order,  450 from Avro = 150 from Fairey and 300 from Armstrong Whitworth.

 

My conclusion is most to all of the L, R and W serial Lancasters were originally on orders for Manchesters, more information is required to confirm exact numbers.  I stress again this is a best fit.

 

Order 69274/40 had another 620 aircraft added to it, the ED/EE serials, while 69275/40 had another 400 aircraft added, the DV and EA serials.

 

Armstrong Whitworth ended up with the Lancaster II contract 239/SAS/C4(c) requisition 3/E 1/41, for 300 aircraft, first production in August 1942.  Fairey was switched to building Halifax, Contract 891/SAS/C4(c), requisition 1/E1/41, first production October 1942.