Battery AMTB - Amaknak Spit

From FortWiki
Jump to: navigation, search

Battery AMTB - Amaknak Spit (1944-1950) - Battery AMTB - Amaknak Spit was a reinforced concrete World War II AMTB rapid fire 90mm gun battery on Fort Schwatka, Aleutians West Census Area, Alaska. Battery construction was completed and transferred to the Coast Artillery for use in 1944. Reportedly deactivated in 1950.

Amaknak Spit AMTB Battery, Annotated WWII Map showing Gun Emplacements and BC Station.

World War II

Part of the Harbor Defense of Dutch Harbor.

The AMTB battery on Amaknak Spit 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. Four .50 Caliber machine guns on M2 anti-aircraft mounts were authorized and two were emplaced. The 21-acre site was identified as Battery 1a, Location #6, procured for government use on 14 Jun 1942.

The battery had a dual mission of defense against fast enemy motor torpedo boats and enemy aircraft attempting to attack Dutch Harbor facilities. The effective range of the 90mm 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.

Concrete pads were provided for both fixed guns and often wooden gun platforms were provided for the mobile guns. A single steel 10' by 40' earth-covered magazine was built by Engineers to provided protection for the ammunition. The HD Annex indicates that by 1944 there was a single steel igloo magazine #8, 26' by 30', with a Battle Allowance of 1400 complete rounds and a War Reserve allowance of 1400 complete rounds. Electric power was provided by M-7 portable generators.

A single 10' by 12' frame building was constructed as an improvised Battery Commander's (BC) Station by U.S. Army Engineers. The cantonment area supporting the battery Included seventeen 16' by 36' enlisted barracks, one 16' by 36' officer's barracks, a standard M-118 Mess Hall, a single 16' by 36' latrine and four other support buildings.

By August 1944 the two mobile guns and ordinance were reported in storage at Fort Mears but the Battery was also listed to be retained for the "Duration of Emergency". The battery was reportedly not deactivated until 1950.

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."


  • 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)

Current Status

No period guns or mounts in place. An August 1997 Coast Defense Group (CDSG) visit to the site found no remains of the battery.

Location: Amaknak Spit on Amaknak Island, Aleutians West Census Area, Alaska

Maps & Images

Lat: 53.90168 Long: -166.51180

  • Multi Maps from ACME
  • Maps from Bing
  • Maps from Google
  • Elevation: .....'

GPS Locations:

See Also:


  • 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,
  • Willford, Glen M., Visitation to Alaskan WWII Coast Defense Sites, August 1997, The CDSG Newsletter, The Coast Defense Study Group, Inc., November 1997, page 1.


Visited: No

Personal tools