| 10"/40 caliber Mark 3 Naval Gun | |
| Origin: | United States |
| Type: | Naval gun |
| Is Ranged: | YES |
| Is Artillery: | YES |
| Service: | 1902 |
| Wars: | World War I |
| Designer: | Bureau of Ordnance |
| Design Date: | 1899 |
| Manufacturer: | U.S. Naval Gun Factory |
| Number: | 21 (Nos. 27–47) |
| Variants: | Mark 3 |
| Weight: |
|
| Part Length: | bore (40 calibers) |
| Cartridge: | armor-piercing |
| Rate: | 2 – 3 rounds per minute |
| Range: | at 14.5° elevation |
| Elevation: | -3° to +14° |
| Traverse: | −150° to +150° |
The 10"/40 caliber gun Mark 3 (spoken "ten-inch-forty-caliber") was used for the main batteries of the United States Navy's last generation of armored cruisers, the . The Mark 3s were the last, and most powerful, 10adj=on0adj=on guns built for the US Navy.
The Navy's Policy Board call for a variety of large caliber weapons in 1890, with ranges all the way up to 16adj=on0adj=on, to use the new smokeless powder that had recently been adopted by the Navy. Because of this new propellant, projectiles could accelerate all the way along the gun barrel, which allowed for barrels of 40, or more, calibers long. This led to the development of the 10-inch/40 caliber gun.
The Mark 3 was specifically designed for the Tennessee-class armored cruisers, numbered in order after the Mark 1 and Mark 2s, Nos. 27–47, with No. 27 being delivered in February 1906. Nos. 27–31, 36, and 45 were all Mod 0s, with Nos. 37–44, 46, and 47 being Mod 1s. The initial Mod 2s were Nos. 32–35, with other later converted to Mod 2. These were all constructed of gun steel. The 10-inch Mark 3 Mod 0 was built in a length of 40 calibers, had a tube, jacket and four hoops with a locking ring, and a screw box liner, all of which were manufactured out of nickel-steel. The Mark 3 Mod 1s only differed from the Mod 0 in the shape of the front of their chambers and the Mod 2 had a conical nickel-steel liner that was the same length as the tube, with the chamber volume being slightly reduced.
| Ship | Gun Installed | Gun Mount | |
|---|---|---|---|
| Mark 3: 10"/40 caliber | Mark 6: 2 × twin turrets | ||
| Mark 3: 10"/40 caliber | Mark 6: 2 × twin turrets | ||
| Mark 3: 10"/40 caliber | Mark 6: 2 × twin turrets | ||
| Mark 3: 10"/40 caliber | Mark 6: 2 × twin turrets |
. Naval Weapons of World War One . Seaforth Publishing . Norman Friedman . 2011 . 978-1-84832-100-7 .