Identification of Spitfire part

[cvairwerks]

MiTasol: Backing up to your question #2, re: serial numbers. Generally, unless a part is a custom, one off repair part, the serial number is not aircraft specific.

When I worked the production side of things, our aircraft didn't even get their serial number plate until it was actually on the flight line and being prepped for first engine run. We had paper, card stock and metal tags that were temporarily attached to various fuselage sections as well as stenciled information. None of the parts carried an aircraft serial number at the that point, but rather the aircraft production id number.

Production control is who keeps the serial number record for every part that has one, and what aircraft it is installed on. The records are updated as necessary up to the point the aircraft leaves the factory to the accepting organization. If a part fails, or gets damaged and replaced, the records are changed. As part of the delivery records, a listing of every serialized part on the aircraft is provided. From that point, the owning organization maintains the records per their requirements.

On something else that goes hand in hand with serial numbers, is configuration control. If you chase thru enough IPB's, you will note configuration flags throughout the books. These tell maintainers and parts people what version of a particular part or installation configuration were installed at the factory. For example, a simple one might show that for a particular range of aircraft serial numbers, a particular wire harness was used. Subsequent aircraft used a different harness, which had some sort of change, which was enough to change the dash number of the harness, or be a completely different harness design. It can be a real rabbit warren chasing parts changes!

 

[MiTasol]

Thanks for the reply - you laid out concisely what newbies do not understand. I expand on your reply for the benefit of newbies on the "wonders" of serial numbers. The prime purpose of my initial post was chasing information on the inspection stamps and which component manufacturer they represent and trying to link it to an approximate airframe. That is now known to be Westland from stamps on other parts of the wreckage and will be somewhere in a general serial range as we both know spares do not have separate/special serials so if (for example) every tenth of a specific part is a spare then the numbers soon widely differ from the aircraft number. As we both know spare components are usually built as a batch which further complicates attempting to directly link component serials

MiTasol: Backing up to your question #2, re: serial numbers. Generally, unless a part is a custom, one off repair part, the serial number is not aircraft specific.

Agreed. As a general rule of thumb only parts that are Line Replaceable Units (LRUs - also called Rotables) and life limited parts (overhaul or scrap at x hours/cycles) have serial numbers anyway. This is why the uninitiated often expect the engine or other serial to be the same as the airframe serial. If they thought a little harder then they would realize that a B-52 will not have 8 engines all with the same serial and that when one engine is removed its serial is not transferred to the replacement engine. Nor naturally is any operator going to ground the aircraft for months while an engine or other LRU is overhauled or repaired.

When I worked the production side of things, our aircraft didn't even get their serial number plate until it was actually on the flight line and being prepped for first engine run. We had paper, card stock and metal tags that were temporarily attached to various fuselage sections as well as stenciled information. None of the parts carried an aircraft serial number at the that point, but rather the aircraft production id number.

Again agreed. And the serial on that part is not the serial used on any Spitfire. It probably indicates it was the 191st built by that subcontractor for Westland but that does not automatically mean it was fitted to the 191st Westland built Spitfire, which might have been a Seafire anyway as they built both.

Production control is who keeps the serial number record for every part that has one, and what aircraft it is installed on. The records are updated as necessary up to the point the aircraft leaves the factory to the accepting organization. If a part fails, or gets damaged and replaced, the records are changed. As part of the delivery records, a listing of every serialized part on the aircraft is provided. From that point, the owning organization maintains the records per their requirements.

And the Maintenance Control personnel have to keep a record of these parts so that they are tested/overhauled/scrapped at specific times. Moving a LRU to a different aircraft means moving its "card" to the new aircraft etc

On something else that goes hand in hand with serial numbers, is configuration control. If you chase thru enough IPB's, you will note configuration flags throughout the books. These tell maintainers and parts people what version of a particular part or installation configuration were installed at the factory. For example, a simple one might show that for a particular range of aircraft serial numbers, a particular wire harness was used. Subsequent aircraft used a different harness, which had some sort of change, which was enough to change the dash number of the harness, or be a completely different harness design. It can be a real rabbit warren chasing parts changes!

And that is before you add Airworthiness Directives, manufacturers service bulletins, operator modifications and repairs to the equation. Service bulletins are even more fun as they can say aircraft s/n x to y as built do this, if SB A carried out do something different, if SB A and G carried out do something different again, and then there is the "if the aircraft has done more than x hours/cycles do this but if it has done more do that" fun to sort through - etc etc.
Fun can be a four lettered word.

 

[TheSupermariners]

Hi Tom
I just received this list of known Westland subcontractors, but no inspection stamp details unfortunately. Moffat Garage made sub-assemblies but I consider it highly unlikely that they used TH0 ot THO as a stamp

• Sparrows Agricultural Engineers, Martock, Machine shop
• Yeo Brothers Paul, Martock, Machine shop
• No. 3 Site, Martock Machine shop
• Castleton Caravans, Sherborne, Detail manufacture and sub-assembly
• Odeon Cinema, Yeovil, Detail manufacture
• Preston Stores, for storage of perishable materials
• Southern National Bus Company, Yeovil, Detail manufacture
• Nautilus Works, Yeovil, Sheetmetal stores
• Moffat Garage, Yeovil, Sub-assembly manufacture

I'd be interested in any more you can tell me about the Westland sub-contractors if possible? Is there a good source?

 

[TheSupermariners]

Hey MiTasol,

The British Thomson-Houston (BTH) main site(?) was located in Rugby, Warwickshire. I can find no reference to BTH making Spitfire parts or any other aircraft parts in WWII (other than the Whittle engine) unless it was for electrical equipment (magnetos, generators, distributors, etc), but it was owned/controlled by a company called Associated Electrical Industries (AEI) from 1929, which also owned/controlled Metropolitan-Vickers.

A good write-up on the company on Wiki "British Thomson-Houston - Wikipedia"

Sorry a bit late to the thread, British Thompson-Houston Ltd were a sub-contractor for Supermarine, supplying Engine mounts bulkheads and the ubiquitous "machined parts".

Sub-Contractors (1936-1945)

Overview Subcontracting The Spitfire Spitfire Subcontractors (1936-1938) Spitfire Subcontractors (1939-1945) Sub-contracting The Spitfire In order to meet the demands of Ministry of Aircraft Produc…

supermariners.wordpress.com

 

[TheSupermariners]

This is what I have relative to the Spitfire:

Inspection Stamps related to the Spitfire:

6.S or 6S over xx in circle for Vickers Armstrong Supermarine Works, Southampton
GAL 6S over xx in oval(?) for General Aircraft Ltd (indicated contracted production for Supermarine Division)
CBAF over xx in circle for Castle Bromwich Aircraft Factory
VACB over xx in circle for Castle Bromwich Aircraft Factory
VACH over xx in circle for Vickers Aircraft, Chester
VABL over xx in circle for Vickers Aircraft, Blackpool
WA over xx in circle for Westland
COA over xx in circle for Cunliffe Owen Aircraft, Southampton

WBxx in circle for Westland, Brough???? or Winchester, Broadlands????

Manufacturer's marks related to the Spitfire:

ALD for Aldermaston Aerodrome (final assembly)
AST for Air Service Training, Hamble (Spit Mk V to Seafire Mk IB conversion)
COA for Cunliffe Owen Aircraft, Southampton (Spit Mk V to Seafire Mk IB conversion)
CHA for Chattis Hill Aerodrome (final assembly)
EA for Supermarine, Eastleigh Airport (final assembly)
FL for Folland, Hamble
HEA for Henley Aerodrome (final assembly)
HPA for High Post Aerodrome (final assembly)
KEA for Keevil Aerodrome, Trowbridge (final assembly of Spit Mk V, Mk VIII, etc)
PP or PPSM for Phillips & Powis, South Marston (Vickers owned from 1 April 1943, produced Spit Mk 21)
R-R or R-RH for Rolls Royce, Hucknall (Mk V to Mk IX conversion)
6.S or 6S for Vickers Armstrong Supermarine Works, Southampton
YE for Westland, Yeovil Aerodrome (Spit & Seafire production, final assembly, and repair)

??? for Heston Aircraft Co, Heston Aerodrome, Middlesex (repair of Spit and modification to PR types)

VAHPk for Vickers Armstrong, Hursley Park (I do not know if they actually manufactured parts here or not)

W.B.Ltd/CBAF for Westland, Brough???? (indicated contracted production for CBAF)

WIN for Winchester???? (do not know what was done here) or Swindon, South Marston????? (modification work, Seafire and Spit Mk 21 production)

And now WA for Westland. Do you know if the WA was used as a general stamp or for a specific site/complex?

Pobjoy Airmotors and Aircraft Ltd. was purchased by Short Brothers in 1938, maybe they used a different stamp acronym after that?

Do you have much on the individual Inspection stamps for the Spitfire (or other Supermarine aircraft)? I have regularly talked to relatives of Inspectors and would like to know whether it's possible to trace the individual inspection stamps.

 

[TheSupermariners]

Hi Tom

It is definitely a Mk Vc and many of the inspection stamps are WA which indicates a Westland built aircraft. Westland built both Spit and Seafires. This rudder is probably from Westlands AR212-AR621 contract.

My suspicion is this is the 191st assembly accepted by Westland from TH, or from all rudder subcontractors, but I still have no idea who TH is.

I have a (very poor) undated drawing showing the subcontractors for components on Vickers-Armstrongs built aircraft but that shows their rudders appear to have come from Pobjoy. There is no subcontractor that I can see that could possibly use TH on their stamps.

I can see no way of reconciling TH with Pobjoy and the only organisation I can think of with TH in their name is BTH (British Thompson-Houston) and I can find no Thompson-Houston company in the UK (the original Thompson-Houston was a US company)

View attachment 595680

View attachment 595679

Hi Tom,
Would it be possible to get a better quality image of the picture, or the individual sections, as I'd be very interested in comparing it with the sub-contractors lists I have. Also anything you can tell me about it's origins would be really useful.
Cheers
Dave

 

[MiTasol]

Do you have much on the individual Inspection stamps for the Spitfire (or other Supermarine aircraft)? I have regularly talked to relatives of Inspectors and would like to know whether it's possible to trace the individual inspection stamps.

Unless the relatives have a record that Dad/Mum/Aunt/Uncle/etc used a particular stamp - no.

In many companies, stamps are recycled so that when Joe is replaced by Joyce doing the same set of inspections then stamp ## moves to Joyce. In other companies the stamp would be rested for a short period then issued to someone in any section of the plant. Only small companies can afford to retire a stamp number as otherwise a long standing company like Boeing or Douglas would have inspector stamps with numbers in the tens of thousands instead of just two or three digits.

 

[MiTasol]

Sorry a bit late to the thread, British Thompson-Houston Ltd were a sub-contractor for Supermarine, supplying Engine mounts bulkheads and the ubiquitous "machined parts".

Sub-Contractors (1936-1945)

Overview Subcontracting The Spitfire Spitfire Subcontractors (1936-1938) Spitfire Subcontractors (1939-1945) Sub-contracting The Spitfire In order to meet the demands of Ministry of Aircraft Produc…

supermariners.wordpress.com

BTH were also a major supplier of electrical equipment for most, if not all, British companies. Starters, generators, magnetos for Gypsy and other engines, etc.

They were a division of a major US company.

 

[TheSupermariners]

Unless the relatives have a record that Dad/Mum/Aunt/Uncle/etc used a particular stamp - no.

In many companies, stamps are recycled so that when Joe is replaced by Joyce doing the same set of inspections then stamp ## moves to Joyce. In other companies the stamp would be rested for a short period then issued to someone in any section of the plant. Only small companies can afford to retire a stamp number as otherwise a long standing company like Boeing or Douglas would have inspector stamps with numbers in the tens of thousands instead of just two or three digits.

Cheers,
I suspected as such. Really it was just a case of identifying the general codes for locations which your original post had, I just wondered if there was much (any) more. So good to know. Thanks

BTH were also a major supplier of electrical equipment for most, if not all, British companies. Starters, generators, magnetos for Gypsy and other engines, etc.

They were a division of a major US company.

In that context I would presume they would either fall under the Rolls Royce contractor hat or Embodiment Loan more than Sub-Contract I guess.

 

[Rocketeer]

SMAF - South Marston Aircraft Factory stamp found on my Seafire F46 LA546 cockpit

 

[MiTasol]

Congratulations.

Do you have a list of all the factory stamps?
There is one I would like to narrow down from five possible sub factories