18" naval projectiles

I just got reminded that the US and the UK developed some 18" guns during WW1.

There is a bit of info on the guns but I would be looking for diagrams, manuals and photos on the actual ammunition.
Anybody out there who has documents?

Some sources:

https://www.navsea.navy.mil/Home/Warfare-Centers/NSWC-Dahlgren/Dahlgren_Centennial/Blog/18_Inch_Gun/

http://www.navweaps.com/Weapons/WNUS_18-48_mk1.php

Alex, nothing on the projectiles, but here is a small bit on the gun from the USN Bureau of Ordnance:

Of historical interest only is the fact that the Bureau developed an 18-inch gun. Lined down to 16 inches after the 1922 disarmament treaty, the 16" /57 fired the longest shots ever ranged at Dahlgren. So tremendous was the gun that a ship of about 70,000 tons would be required to use it profitably. No production was ever planned for this weapon.

From this book:

The RN 18" gun briefly saw service in the light battlecruiser Furious but proved to be a bit of a handful (I recall talk of rivet heads being sheared off around the ship when the gun fired) so the ship was converted as an aircraft carrier instead.

A couple of the guns were mounted on monitors, one of which bombarded targets on the coast of NW Europe towards the end of WW1.

I used to have a photo of an 18 inch gun mockup at a 1920s exhibition, with a shell and a stack of charges next to it. However, some caution is needed in identifying this as the British also had an 18" railway gun, which was less powerful, and this survived to see action in WW2. The shell in my photo was labelled “shrapnel” which suggests that it was for the army gun.

More information about the RN 18" gun, mountings and ammunition here - but no illustrations: http://www.navweaps.com/Weapons/WNBR_18-40_mk1.php

Didn’t the Yamamoto class battleships use 18" shells?

I managed to locate the postcard I mentioned, which shows an exhibit in the Crystal Palace in London, probably during the Great War Exhibition of 1920. The photo’s title is:

REPLICA OF THE WAR’S BIGGEST GUN, ITS PROJECTILES AND CHARGE

The four projectiles shown are stencilled as follows (from left to right):

18 IN MK 1A A.P.C. FUZED

18 IN MK 1A H.E. FUZED

18 IN MK 1A SHRAPNEL FUZED

18 IN MK 1A C.P.C. FUZED

The topmost of the six propellant charges stacked up is labelled: 18 IN BL 105 LB CORDITE MD SIZE 45 1/6 CHARGE

A comparison with other gun photos, plus the six charges (which represent the full charge: 6 x 105 lb = 630 lb total charge) confirm that this replica is of the 18 inch naval gun which saw service in WW1, not the later, less powerful, howitzer. The shrapnel shell was presumably developed for its ultimate purpose of shore bombardment.

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I assume that would have been a wooden replica.

As an aside, also see the flag of Imperial Japan in the background. To me it seems surprising how few people today know that Imperial Japan was a British ally in WW1.

Falcon, very true. I think there are plenty of alliances and enmities in “recent” history of which people are not aware of!