Battery AMTB 6 - Clatsop Spit

Battery AMTB 6 - Clatsop Spit (1943-1947) - Battery AMTB #6 Clatsop Spit was a World War II Period reinforced concrete Anti-Motor Torpedo Boat Battery located on Fort Stevens, Clatsop County, Oregon. Construction on the Battery began 10 Jun 1943, was completed 30 Jun 1943 and the guns installed 24 Dec 1943. The Battery was activated on 12 Jan 1943 and officially transferred for use on 5 Apr 1944, total cost $9,856.82. The guns were removed after the end of World War II in 1947 or 1948. World War II (1941-1945) Part of the Harbor Defense of the Columbia. The AMTB battery at Clatsop Spit 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 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. AMTB Front View AMTB Interior View AMTB Side View AMTB Back View The above photos were taken at Fort Monroe, Battery Parrott 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) Battery AMTB #6 Clatsop Spit Armament (edit list) Empl No Caliber Type Barrel Length Model Serial No Manufacturer Carriage Service Dates Notes 1 90mm Rifle 186.15" M1 7139 General Motors Fixed 90mm M3, #219, General Motors 15 Dec 1943-1945 2 90mm Rifle 186.15" M1 6927 General Motors Fixed 90mm M3, #128, General Motors 15 Dec 1943-1945 M 90mm Rifle 186.15" M1 3171 Watervliet Mobile 90mm M1A1, #3821, WP&M 15 Dec 1943-1945 M 90mm Rifle 186.15" M1 3531 Watervliet Mobile 90mm M1A1, #1558, Watervliet 15 Dec 1943-1945 Source: 1. CDSG. 2. 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, 218. 3. Rounds Fired - Seacoast Artillery Including Proofing Rounds, HQ Harbor Defense of the Columbia, undated, NARA RG165, E257 Box 68 - Bolling Smith. Current Status Only the wooden blocks where the guns were mounted remain. {"selectable":false,"height":"-500","width":"-500"} Location: On Fort Stevens, Clatsop County, Oregon. Map point is approximate and not accurate. Maps & Images Lat: 46.228837 Long: -124.012213 Multi Maps from ACME Maps from Bing Maps from Google Elevation: 28.76' GPS Locations: 46.22884, -124.01221 Sources: Hanft, Marshall, Fort Stevens: Oregon's defender at the river of the West, Your Town Press, 1980. U.S.Army, Supplement to the Harbor Defense Project Harbor Defenses of the Columbia, (CCA-AN-CR), 12 Aug 1946, CDSG. Rounds Fired - Seacoast Artillery Including Proofing Rounds, HQ Harbor Defense of the Columbia, undated, NARA RG165, E257 Box 68 - Bolling Smith. 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, 218. Links: CDSG Fortification ID: OR0010 - Battery AMTB 6 - Clatsop Spit Visited: No