Mystery inspection stamps – PBY Cats – can anyone please help identify?

That WDC stamp is very reminiscent of a Western Defence Command stamp I have seen somewhere… Can’t seem to refind it though.

Ooh, thank you! That sounds rather interesting indeed. I’ll see if I can track down anything.
Thanks again 🙂

That WDC stamp is very reminiscent of a Western Defence Command stamp I have seen somewhere… Can’t seem to refind it though.

Hi Mark,
Firstly, thank you very much for such an interesting and informative response. I really appreciate your time and the knowledge you’ve shared. And you’re making me think about all sorts of research avenues now 🙂
You’re right in that all the PBY wrecks have now been identified. These stamps do indeed come from what we’ve identified as dumped surplus parts – most were found in clumps or piles on the seabed, often in clusters of the same part type [e.g. we found one big mountain of exhaust collector assembly components] and several showing signs of intentional damage such as puncture marks, axe marks etc.
There’s a handful of unidentified parts that could definitely be Martin Mariner – I’ll have to look into that. We’ve also found a small number of Spitfire spares. However, the bulk are almost certainly PBY, showing the “28” prefix to part numbers.
Regarding Cat type, a small number of the parts are definitely at least PBY-5 or 5A based on part type or number, including a bug-eye bow turret, a brake pedal from a rudder control assembly, a hydraulic filter etc. And strangely enough, I found one elevator fragment that had a part number which the manuals state is only a PBY-6A number; although that’s very unlikely as you say and I’m not entirely convinced as I’ve found the numbering systems seem to have varied slightly in actual practise. Finally, there is definitely at least one complete section of leading edge from a PB2B, which very nicely still had a data plate on it! And Boeing stamps and a RCAF broad arrow stamp. Otherwise, the majority of parts could be either PBY 4 or PBY 5, or perhaps even 0A-10. I’ll have to look into that last one – I haven’t found any classic Vickers stamps so far [other than on one Spitfire bit], but I hadn’t really considered it for the Cats, thank you for that idea.
Those Boeing stamps have shown up a lot and I’ve found a very small amount of actual Consolidated stamps, which is leading me to think that most parts were Canadian contract built. I’m not sure if that’s a safe assumption?
At the end of the day, I think I probably won’t be able to work out where all these parts came from, were manufactured or used and / or by whom. It’d be great if I could, but I think I’d be very lucky to do so. At the moment I’m just trying to draw out as much possible information and interpretation as I can – but I’m fairly new to aircraft studies so the learning curve is quite steep!
I would love to find that treasure map to factory inspection stamps! Or manage to find an ex-inspector – that would be an absolute goldmine. I’ll see if I can get in touch with Consolidated / Convair – I would like to think that there just has to be some records / archives surviving somewhere….
Thanks again for all your help 🙂
Best wishes,
Caroline.

Most of the round ones such as NBA2 and DOL14 seem to be individual inspector’s marks.

Hi eric, thank you.
I was wondering if that might be the case. I’ll mark those down and try to see if there’s any way of researching actual inspectors IDs [fingers crossed!].
Thank you 🙂

The ‘N’ stamp denotes that the part has ben Normalised, i.e. has been through a heat treatment cycle as part of the manufacturing process.

In the case of a complex sheet metal part temporally softened to allow it to be formed to shape, or after welding etc.

The N stamp is certainly as used by the UK aircraft industry, presume the U.S. did the same?..Though in their case Normalized!

Hi Chumpy,
Aha! Fantastic!! Thank you so much for that! That’s wonderful, I can now knock that one off my list!
Thank you 🙂

Hello,
I’ve found a bunch of inspection stamps on some PBY Catalina parts dumped in Darwin Harbour post WWII that I can’t identify. Starting to do my head in and I was wondering if anyone here might be able to help? Any help would be greatly appreciated 🙂
These Cat parts have numerous Boeing inspection stamps but there are several others that keep showing up – these include “MBA 2” “RMC 2” “SCL 2” “DOL 14” “$” “N” “WSPV 14” and “WOC” / WDC” ? – this last one is hard to read but the shape / writing looks quite distinctive.
Thank you 🙂

Caroline,

I understood most of the wartime sunken PBY Wrecks in Darwin Harbour were largely identified and although its difficult to confirm if you are referring to surplus parts being dumped or the wreck of a specific airframe being dumped post WW2?, the clarification of the model and identity might close the gap.

If its a unique wreck it should be easy to narrow down its factory but if its from a pile surplus parts (new or salvaged) then they could be from the remains of an ex RAAF PBY-5 or PBY-5A, both Consolidated built, or even late model PB2B which was Boeing built?, then there is the risk of remains of a Consolidated built PBY-4 from the USN or Dutch, PBY-5, PBY-5A from USN, or a Canadian Vickers OA-10 from USAAF?

If this is simply being recovered from a dump of surplus wartime flying boat material into Darwin Harbour there may even be a risk there is also some Martin Mariner parts (RAAF or USN) among your haul? and in anycase if you simply have a pile of disparate spares, not from the same airframe or sub-model or even manufacturer, the task is even more complicated as you could therefore still have parts from all three Consolidated, Boeing and Canadian Vickers production lines.

Unfortunately, like most factory inspection stamps as shown on the linked site, there is no universal/military/standardised “AN” type approach to them.

I have always wondered if they were carrying the initials of the inspector as against the abbreviation of the production unit, or inspection group?

The Consolidated PBY Catalina line started in 1936 and was a very old and well established production line by the time the PBY-5A was rolling out to meet wartime orders, and so they would likely have developed their own unique stamp identifications prior to, and remote from Consolidated’s later wartime B-24 production lines, and such records are now lost in time unless someone finds the factory records, or a key employee / manager has left some historical testimony in oral histories etc.

We are rapidly loosing the generation who were actually there, and its only through the collection and preservation of factory records as archival material that there is any real chance of discovering and understanding unique production stampings etc.

The main Consolidated PBY plant in San Diago become Convair and was finally sold to McDonnell Douglas by General Dynamics, – perhaps there is some type of historical archival records held in San Diago or an ex-employee group who might hold the treasure map to the factory’s inspection stamps?, at one time that factory had 45,000 employees!, but the PBY production there gave way to B-24 and then post war jets etc.

Consolidated’s PBY production ceased in May 1945 inclusive of the PBY-6A, which despite having 3 now residing in Australia, is one model which is very unlikely to have seen service in Darwin in WW2.

Regards

Mark Pilkington

Most of the round ones such as NBA2 and DOL14 seem to be individual inspector’s marks.

The ‘N’ stamp denotes that the part has ben Normalised, i.e. has been through a heat treatment cycle as part of the manufacturing process.

In the case of a complex sheet metal part temporally softened to allow it to be formed to shape, or after welding etc.

The N stamp is certainly as used by the UK aircraft industry, presume the U.S. did the same?..Though in their case Normalized!

Try taking a look at:
http://www.aviationarchaeology.com/src/astamps.htm
Lots of American types listed.

Ah yes, that’s an awesome site. Thank you 🙂 Unfortunately I can’t find any of my mystery ones on there, the plot thickens….

Ask it on the WIX forum. maybe someone there will know.

Ok, will do – thank you for that suggestion 🙂

These may be sub contractor inspection stamps : it is hard to pursue this logic without understanding what the parts are, but it is reasonable to assume that large quantities of parts were manufactured and internally approved by large numbers of sub contractors, ranging in size from small family businesses to large concerns, then supplied to the final assembly plant. A good example of this are the Bendix wheels that feature on many US aircraft of the era, radially arranged around the spokes are cast in numbers and contractor inspection stamps for casting, heat treatment, machining and assembly.

Thousands of subcontractors were drawn into supplying the war machine and the documentation of these hurried arrangements is limited and opaque. Sometimes the abbreviations on the stamp can be readily matched with a company name. Somebody more familiar with the Catalina story may be able to make some connections with the abbreviations. Some of the stamps refer to overhaul records and maintenance workshops.
“$” is a great stamp. I think this was some toothless old mechanic in a shed somewhere in California who overhauled milking machines and the odd Navy aircraft fuel pump for the son in law quartermaster at the local base.

Hiya,
I think you’re right about subcontractors – I haven’t been able to match any of these stamps to either Consolidated or Boeing, or any other major aircraft manufacturer. None of them seem to match the subcontractors listed for various Cat parts though, so I am completely stumped.
I do like your interpretation of the $ stamp though! Sounds pretty spot on 🙂

Try taking a look at:
http://www.aviationarchaeology.com/src/astamps.htm
Lots of American types listed.

Ask it on the WIX forum. maybe someone there will know.

Sub contractor inspection stmps

Hello,
I’ve found a bunch of inspection stamps on some PBY Catalina parts dumped in Darwin Harbour post WWII that I can’t identify. Starting to do my head in and I was wondering if anyone here might be able to help? Any help would be greatly appreciated 🙂
These Cat parts have numerous Boeing inspection stamps but there are several others that keep showing up – these include “MBA 2” “RMC 2” “SCL 2” “DOL 14” “$” “N” “WSPV 14” and “WOC” / WDC” ? – this last one is hard to read but the shape / writing looks quite distinctive.
Thank you 🙂

These may be sub contractor inspection stamps : it is hard to pursue this logic without understanding what the parts are, but it is reasonable to assume that large quantities of parts were manufactured and internally approved by large numbers of sub contractors, ranging in size from small family businesses to large concerns, then supplied to the final assembly plant. A good example of this are the Bendix wheels that feature on many US aircraft of the era, radially arranged around the spokes are cast in numbers and contractor inspection stamps for casting, heat treatment, machining and assembly.

Thousands of subcontractors were drawn into supplying the war machine and the documentation of these hurried arrangements is limited and opaque. Sometimes the abbreviations on the stamp can be readily matched with a company name. Somebody more familiar with the Catalina story may be able to make some connections with the abbreviations. Some of the stamps refer to overhaul records and maintenance workshops.
“$” is a great stamp. I think this was some toothless old mechanic in a shed somewhere in California who overhauled milking machines and the odd Navy aircraft fuel pump for the son in law quartermaster at the local base.