Battery AMTB 923 (1) (1943-1944) - Battery AMTB 923 was a reinforced concrete World War IIAMTB rapid fire 90mm gun battery serviced by Fort Adams (1), Rhode Island. Battery construction started 26 Mar 1943, was completed 30 Jun 1943 and transferred to the Coast Artillery for use 22 Jul 1943 at a cost of $ 13,450.00. This battery was transferred to Fort Wetherill by June 1944.
The AMTB battery at Brenton Point consisted of two 90mm guns mounted on 90mm M3 fixed gun mounts and two 90mm guns mounted on 90mm M1A1 mobile gun mounts. Concrete pads for these guns were laid at the tip of Brenton Point on Aquidneck Island. The battery had a dual mission of defense against fast enemy motor torpedo boats and enemy aircraft. The effective range of the guns was about 8,000 yards. Each weapon required a crew of 15, 9 men in the gun squad and 6 men in the ammunition squad.
This battery was transferred to Fort Wetherill by June 1944 and emplaced on modified 3 inch anti-aircraft gun positions of anti-aircraft battery #1. See Battery AMTB 923 (2)
From FM 4-91:
"This weapon consists of the 90-mm gun M1 and top carriage M1A1 on the 90-mm gun mount M3. The mount M3 is of the turret type, the shielding being constructed of boiler plates. This boiler plate shield provide fragmentation protection only. No shielding is provided at the rear due to the requirements for service of the piece. A sighting port in the shielding in front permits sighting in direction by the gun pointer."
References:
FM 4-91 - 90-MM Gun, Fixed Mount Service of the Piece
FM 4-126 - Antiaircraft Artillery, Service of the Piece, 90-mm Antiaircraft Gun
TM 9-373 - 90-mm Gun M1 and 90-mm Gun Mount T3 (M3)
Source: RCW Form 1, Aug 1944, CDSG, Berhow, Mark A. ed, American Seacoast Defenses: A Reference Guide, 2nd Edition, CDSG Press, McLean, VA, 2004, ISBN 0-9748167-0-1, pages 80-81, 205
Battery AMTB 923 Plan
Current Status
Remaining gun pads are a part of Brenton Point State Park. No period gun or mounts in place.
U.S. Army Corps of Engineers, Archives Search Report, Findings, Brenton Point Fire Control Station, August 1995, FUDS Report D01RI032401, Newport, RI, U.S. Army Corps of Engineers, New England District.
U.S.Army, Supplement to the Harbor Defense Project of Narragansett Bay, (HDNARB-AP-45), 1 Feb 1945, CDSG