British 4,5 inch casing for naval gun.

[Replace]

Hi,

In my Collection I have this rare British 4,5 inch casing - got it for free.
...no one really know what this is.

A Danish fisherman caught this casing on the position for the "battle for jutland - WW1"(worlds largest naval battle).

I have shown Imperial War Museum in London this casing - their munitions dept. says, the 4,5 inch gun was the standard medium-gun calibre of the Royal Navy for use against surface, aircraft and shore targets since 1938.
They suggets me to contact:

Explosion!
The Museum of Naval Firepower.

They agree with the IWM that the casing is for a British 4,5 inch Naval gun.
The 4,5 inch gun using this sort of casing was developed around 1935, so they do not dispute the IWM's 1938.
The 4,5 inch calibre was in service in WW2 as a single gun on an open hand operated mounting
Because the Shell weighed 56lb(25,5kg) the combined weight of shell and casing was too heavy for a man to load.
...the Shell and casing were therefore brought to the gun separately and placed on a loading tray before being rammed together into the breech.
Later in the war the mountings were upgraded with remote power control systems.
The power operated single gun mountings continued in service until late 1970's.
In the late 1940's a twin gun enclosed mounting using the same type of casing and shell was introduced. This continued in service, again with modifications, until 1992.

Still no one can explain the markings on the base.

The casing is 640mm in lenght and about 160mm wide(on the body)
Because the markings are hard too see on the pictures, I have made a drawing of the base.

Regards
Replace

[Torch]

They used the same 4.5in round on NZ navy frigates up until probably 10-15 years ago..upgrading to the 5in

[thekees]

I think it's a Dutch manufactured case. The AI stands for artillery inrichtingen. See the link for the gun:

Britain 4.5"/45 (11.4 cm) QF Mark V