Neville has noted that iron chaplets exposed at the surface would have rusted away if submerged for a long period.

18/9/2025

Michael Owen

18/9/2025 08:16:42 am

The gun was submerged in the intertidal zone of sand, shell and fine grained clay with only the crown of the muzzle exposed. The gun was pulled up by the muzzle likely resulting in the corresponding bend in the barrel as the breech was upright and fully embedded. The chaplet would therefore have been enclosed in the anaerobic mud - starved of oxygen.

Neville

18/9/2025 10:33:02 am

Sorry, I misread your comment . Yes to your knowledge the chaplets were encased in mud devoid of O. Diffinatley yes someone pulling on the barrel of a 30 % lead bronze would very likely bend it.
Cheers.

Neville

18/9/2025 09:47:35 am

Or the gun was located in an erosion zone on the foreshore and avoided the effects of sea water and mud. .
Pb in more noble and referrence is made to it's possible corrosion in that gun. In that case , was the gun buried breech end down as the chaplets extended to the surface in both sides of the casting ?
I think an exhumation of WW2 star pickets from Nightcliff Beach would strongly indicate the presents of O ions in Darwin Mud. That is ( star picket) the effect i would envisage on the Dundee chaplets if immersed for the same period.
The Cannonaid Island guns of Napier Bay near Broome were found buried barrel down. The metal is a much higher quality than the DG..less bendy. Why not the Dundee gun, later to errode into the sea. ?

Another point of interest ( though maybe unrelated to corrosion) analysis of the Iron rich chaplet area sample. ...10 % iron which seemed to be alloyed with 6 % Mn.

Michael Owen

18/9/2025 10:28:02 am

Buried breech up in fine blue clay that is what impounds the freshwater - that is likely why the ship was there. It is a significantly different environment to Port Darwin.

The Pb XRF analysis is not reliable - it was done opportunistically by inexperienced, unsupervised personnel & should not be relied upon.

I thought the Carronade Is. cannons (not carronades) were buried stern first - bore deeply scarred indicating use as supports for twin poles indicating freshwater.

UK ore is 8%Mn which is what attracted the Romans - Mn was found stacked ready for export at a Macassan site in Melville Bay. We need to note these anomalies and get a decent XRF assay.

Neville

18/9/2025 11:18:12 am

Yes the Cannonade were Lantaka. I have to read again...my memory has them as muzzel down....would not be the first time I was wrong.
The DG is an unimpressive casting. I think it is a 19th century cheap weapon. The Lantakas from Broome had better diffinition.
IF the lack of oxygen preserved the chaplets in the DG it should have done wonders to the finish of that same gun. I seriously doubt it was ever near Europe and there will be explanations for the reason Isotopic lead clearly from Andalusia was used to dilute a feed stock or raw tin and copper ingots or redundant cannon etc. Antomony seems generally higher in Spainish casts and Arsenic lower in Spanish , than in Asian casts....though generally.....
It might be possible if it were of European origin that this Gun was like a Temu product, produced only to stay together long enough to sell, infact the same would be true if it were of Asian origin, which I think it is.
Yes, I read the PM find of a stock of Maganese ore. Indonesia had a fantastic iron industry. I think they may even had made Wootz. However, I think it is a long shot they added MnO to get bloom or used it their possible wootz types. Not when they had access to nickel. I need to check.

I think the macassians thought they had found Tin or perhaps the Manganese was for pottery...Maybe it was to lash up for an anchor ?. High purity Mn pebbles
could be had by the bucket load. why put great big lumps of really heavy rock in your ship when you can find the same rock already pea size in the same place.

Mn and Iron are rather close on the spectrum , I suspect it's an overlap. Mn is probably purtibated by the iron.
Cheers

Neville

18/9/2025 12:11:48 pm

Cannonade. I read the introductions of several papers . They recount the Naval account. It does not specify muzzel or breech. Their election is seen as " leading" a navigation aid for shipping, I think. The AI search said" muzzel up " then " muzzel down, breech up "...i kid you not in the same sentence.....i tend to leave AI alone.

Michael Owen link

20/9/2025 10:14:48 am

Agreed - Jeremy Green & the WA maritime folk appear to be the experts - a sampling strategy and scope is a mandatory first step. There may be grants available for such analysis as well as conservation - those chloride ions are going anywhere by themselves.

Neville's comment re the deposition site & echo recent ones on the Beauty Trees being lost on a friable coast. If the gun was left ashore the material in the barrel should contain seeds & land snails etc. If the mug was in the chamber then the earliest deposits would be at the breech end of the barrel not the middle - which is where the OSL test sample originated. 50% resides of the crud in still in the barrel & 50% from the muzzle inwards was removed for the test - does that material still exist?

Neville has noted that iron chaplets exposed at the surface would have rusted away if submerged for a long period.

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