WesWorld

July 4, 1925

The Chilean Government has put out a request for bids on 210mm Cannon from nations that manufacture such arms.

The proposed order is for 30 x 210 mm/50 caliber barrels to be delivered within the next four years. The first four barrels to be delivered by March 30, 1926.

Variations on this weapon type in terms of length and weight of shell will be reviewed before acceptance on an offer.

I think Greece only does upto 6" but get this, Greece has; 3",4",5",6",7" and 8" guns in service - beat that?

Cheers,

The SAE produces and operates 210mm guns but being away from my sources right now I can´t tell if those are of 50 caliber length.

Ithekro, is there any reason why they have to be L/50s?

Normally the country requesting such guns would offer stats which the gun in question would have to exceed - no matter what length it has. You could also dictate what kind of shell should be used or tell us something about barrel wear (closely related to muzzle velocity) etc.

Regards,

HoOmAn

Imperial Ordnance Works of Pondicherry is pleased to offer the 21/1918 to the Chilean Navy.

This weapon is derived from pre-war German 21 cm designs used on armored cruisers such as the Blucher , Scharnhorst , and Gneisenau . It is currently in service on three Indian cruisers, Hyderabad , Bangalore , and Male . The weapon is combat tested, having seen action last August when Hyderabad and other Indian forces engaged Danish cruisers off Siam during the Andaman Sea situation. Hyderabad 's 21 cm shells sank the old cruiser Gejser and inflicting significant damage upon the cruiser Jutland (to the point that the Danes are rebuilding her as a light aircraft carrier).

This gun has a length of 45 calibers, and fires a 108 kg shell to a range of 17,800 m at the current maximum elevation of twenty degrees. The shell will penetrate 10 cm armor plating at a range of thirteen kilometres. Rate of fire is typically three to four rounds per minute in Hyderabad's turreted mounts, but more likely two rounds per minute in a shielded mount reliant on more manual labor.

Please note: should Chile accept IOW-P's bid, IOW-P would require authorization under Article 14 of the South Asian Trade, Scientific Undertaking and Military Accord (SATSUMA) before concluding a deal.

(See "F.2 Medium Guns" in the Indian Encyclopedia for additional data on the gun).

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Please note: should Chile accept IOW-P's bid, IOW-P would require authorization under Article 14 of the South Asian Trade, Scientific Undertaking and Military Accord (SATSUMA) before concluding a deal.

The Philippines has no objections at this time, but reserves the right to change that at any time prior to the delivery of the guns.

Although not of 210mm calibre, OTO would like to offer its new 203mm(8") / 53 weapon that shall be present on the next class of heavy cruisers.

This weapon improves on the earlier 50-calibre 1921 model gun, with larger muzzle velocity. It fires a 125.3kg shell at 900m/s.

Rate of fire is from 2-4 rpm.

4 guns can be delivered for March 1926, but the remainder will be delayed a few months due to domestic considerations.

Obukhov Works of Petrograd, Russia are pleased to offer M1921 210mm/56, which fires 135kg shell at 920m/sec, with superior armor-penetrating qualities, penetrating 20cm belt armor at over 11,000m and 15cm belt armor at over 15,000m.

And in view of fact that Chile is not a signatory to Cleito Treaty, Obukhov Works are in a position to offer M1919 234mm/54, which fires 200kg shell at 868m/sec. This gun was to be main armament of Sviatoslav class heavy cruisers, but Cleito Treaty prevented completion of Sviatoslav class with this gun. Instead, Sviatoslav class was delayed until 210mm/56 came available. Original 234mm/54 turrets have been incorporated into Russian Federation Coast Artillery, but spares are available to meet initial Chilean requirement.

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Originally posted by AdmKuznetsov
Obukhov Works of Petrograd, Russia are pleased to offer M1921 210mm/56, which fires 135kg shell at 920m/sec, with superior armor-penetrating qualities, penetrating 20cm belt armor at over 11,000m and 15cm belt armor at over 15,000m.

That´s a rather heavy shell for such high muzzle velocity. Is there any historical precendence? The charge for that gun must be really powerful and barrelwear enormous....

Barrelwear and high mv are also always good for great dispersion. Even the slightest variance in burst from the charge will comulate into quite a difference in range.

However, I could be wrong. Is there any historical data about such a gun?

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Barrelwear and high mv are also always good for great dispersion. Even the slightest variance in burst from the charge will comulate into quite a difference in range.

Best comparison would be the Italian cruiser weapons.

The 8"/50 used on Trento firing a 125.3kg shell at 840m/s caused really excessive dispersion.

The 8"/53 used on Zara fired a 125.3kg shell at 900m/s. There were few dispersion problems, but the turret was much heavier.

The 6"/55 used on Condottieri 5th group, again had few problems with dispersion, but it was a heavy mount with a low rate of fire.

The idea of the 210mm/50 was to get longer range than the German 210mm/45 used during the Great War.

The Chilean Government would like a weapon that fires a 117.93-126.78kg (260-279.5 lb) shell and can penetrate at least 13cm of belt armor at more than 14,000 yards. The Navy would also like the weapon to have a long barrel life to save on replacement costs and reduce time needed to be in dock to re-line the barrels.

An final requirement, the navy would like a high projectory ability for the turrets. The Chilean shipyards insist that they can produce the turrets, but the navy wishes to be sure that the barrels produced can be elevated up to 40 degrees. It has been assumed that with spotting planes it would be possible to fire over the horizon or with other spotters that shore bombardment might be possible. Plus firing on high cliffs would be much easier in the confines of such a place as Tierra del Fuego with a higher degree of elevation.

At this time the Italian 8 inch/53 cal seems to come the closest to these requirements. The Russian weapon seems good but the extra weight of the shells and barrel were not designed into the vessel these guns are for. (the new Protected Cruiser Maunga Terevaka that is under construction will be the one that needs the four barrels by the end of March 1926) The next set of barrels will not be required to be delivered until the end of 1926, but more will be expected from the original order than just four.

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An final requirement, the navy would like a high projectory ability for the turrets. The Chilean shipyards insist that they can produce the turrets, but the navy wishes to be sure that the barrels produced can be elevated up to 40 degrees.

The 8"/53 in Italian turrets elevates up to 45 degrees, though naval officials deride anyone who thinks that they can hit a target at 32.000m.

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Plus firing on high cliffs would be much easier in the confines of such a place as Tierra del Fuego with a higher degree of elevation

What happens when an infantry Jon gets a 4" mortar and starts putting rounds through your deck armour?

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What happens when an infantry Jon gets a 4" mortar and starts putting rounds through your deck armour?

If you are attacked in a narrow area (like a fjord or straight) you might as well be able to shoot back. We think of it as a safety measure rather than a standard tactic.

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The 8"/53 in Italian turrets elevates up to 45 degrees, though naval officials deride anyone who thinks that they can hit a target at 32.000m.

Well we were looking at hitting...or at least intimidating targets at a range of 25,000m...or to be able to, in theory, penetrate 102mm of deck armor.

The Dutch KFA (Koninklijke Fabriek van der Artillerie) is proud to offer the 21cm Mark VIIe gun, a slightly modified version of that on board the dutch "Friesland" CAs.


- the Mark VIIe is a 21cm/54 piece.

- standard shell weights 140kg

- and is fired at a MV of 882m/s

- maximum elevation is 40º. Max range around 31000 yards

- penetration performances satisfy chilean demands

- immediate supply of 12 guns available before the end of 1925. The remaining 18 guns can be delivered during 1926.

You could always try something like Japan's special 203mm Model 1918 gun... if you think you will be able to fit such a gun on your ship. :-)
(The Model 1918 is the second gun in this list)
Of course if you want to penetrate 13cm of deck armor with this gun, you'll have to hit your target at a distance of over 48,000 yards. At 25,000 yards, the trajectory will be fairly flat (coming it at about 21.5 degrees) so it's more likely that you'll score a hit on the enemy's side than on the deck at that distance.
Perhaps I should have reduced the caliber even more to 3 inches...

Jeez Walter, you've made yourself a Paris gun. I think barrel wear might pose a problem;

The Paris gun in WWI was of varying calibre ~210mm and a huge rifled & smoothbore barrel. You had to fire the shells in the correct order to fit into the barrel because it wore out that much. Using it for coastal artillery doesn't make much sense.

Well, it isn't called "test gun" for nothing. Barrel wear would definitely be a problem and already instaling them as coastal artillery doesn't make any sense at all.
So I wouldn't be surprised that within a few years they would be removed and replaced.

Tempting....Somehow I don't think the Protected Cruisers will be able to handle the weight of the barrels in their single mounts. And any twin turret would have to be nearly as large at the historical Nagato. Still it is tempted to receive them...then remove the liners...and plan for a small battleship....or at least a production line of heavier guns. Or a siege cruiser. (why would I need a siege cruiser...I don't know..just thinking of what such a long reaching gun could be used for at 8 inches). El Cid would have problems facing a ship with these on it.

Chile might order a smaller number of those from Japan if allowed by the other SATSUMA nations.

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Somehow I don't think the Protected Cruisers will be able to handle the weight of the barrels in their single mounts.

I don't think so either. I did som calculating, together with my Yamato sim (altered to get something close to the real ship; this sim was used to compare the data with what I have in a book). A 41cm turret with 12 inches of face armor and 10 inches for the "other gunhouse" armor will be a few dozen tons heavier compared to what your 1925 destroyer Capitan Simpson displaces at standard displacement.

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Chile might order a smaller number of those from Japan if allowed by the other SATSUMA nations.

Might not be that big a problem if it were a small gun, but since it is a rather big gun, I think it would be a big problem.

IC:

"Under the terms of Part III, Article 14 of the SATSUMA Treaty, the Filipino Government denies a license for exporting the Japanese 8"/100 cannon to Chile."



OOC:

The grounds for denial is that FINK can conceive of no earthly reason for the Chileans to want a gun of such magnitude, unless they do indeed want to build a "siege cruiser", and since we're currently constructing the Concrete Castle of Corregidor, the idea of a dedicated fortifcation-buster being loose in the Pacific makes the Filipinos nervous.

The 8"/53 (or whatever it is) cannon, however, is OK.