Battery 217 (1943-1946) - Battery 217 was a reinforced concrete, World War II 6 inch coastal gun battery on Fort Terry, Plum Island, Suffolk County, New York. Battery construction started 18 May 1943, was completed on 31 Oct 1943 and transferred to the Coast Artillery for use 1 Jul 1944 at a cost of $ 249,478.00. Never armed. Deactivated in 1946.
Originally built as a World War II concrete coastal gun battery with two 6" rapid fire M1 guns mounted on M4 Shielded Barbette Carriages (SBC) placed on either side of an earth covered reinforced concrete magazine and support structure. Power was supplied by internal generators and commercial power.
The M4 carriages were mounted in 1944 but the two 6" M1 guns were never delivered and the battery was never armed.
These 6" World War II coastal gun batteries were designed to replace obsolete Endicott Period Batteries. Of the 87 planned only 45 were completed and many of those were not completed until late in the war (1944-1945).
The 6" guns fired a 105 pound armor-piercing projectile with a range of over 15 miles at a rate of up to 5 rounds per minute. The gun crews were protected by a thick shield around the gun. Only six of these guns remain in the world, two at Fort Columbia in Battery 246, two at Fort Pickens in Battery 234, and two at Fort McAndrew in Battery 282 in Argentia, Newfoundland and Labrador, Canada.
Source: RCW Form 1, Aug 1944, Coast Defense Study Group, Berhow, Mark A. ed, American Seacoast Defenses: A Reference Guide, 2nd Edition, CDSG Press, McLean, VA, 2004, ISBN 0-9748167-0-1, pages 104-105, 206 Note 1: CDSG Gun Card Collection from NARA