Battery AMTB - Amaknak Spit (1944-1950) - Battery AMTB - Unalaska Spit was a reinforced concrete World War IIAMTB rapid fire 90mm gun battery on Fort Schwatka, Aleutians West Census Area, Alaska. Battery construction started ....., was completed ..... and transferred to the Coastal Artillery for use ..... . Deactivated in 1950.
Part of the Harbor Defense of Dutch Harbor.
The AMTB battery at ..... consisted of two 90mm guns mounted on 90mm M3 fixed gun mounts, two 90mm guns mounted on 90mm M1A1 mobile gun mounts and two 37mm guns mounted on M3 mobile mounts. Concrete pads were provided for both fixed guns and often wooden gun platforms were provided for the mobile guns. Two earth covered concrete magazines provided protection for the ammunition. Electric power was provided by M-7 portable generators.
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 or 4.5 miles. Each weapon required a crew of 15, 9 men in the gun squad and 6 men in the ammunition squad.
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)
U.S.Army, Supplement to the Harbor Defense Project Harbor Defenses of Dutch Harbor, (SRHDDH), 1944, CDSG
Berhow, Mark A. ed, American Seacoast Defenses: A Reference Guide, 3rd Edition - PDF, CDSG ePress, McLean, VA, 2012, ISBN 0-9748167-0-1, page 80-81, 254-256,