“Sonic Hellcat”

The most secret version of the M18 was the “Sonic M39” one of a number of vehicles configured with a large retractable loud-speaker for broadcasting tank sounds to deceive enemy forces about the location of US units. The vehicles in the background are Sonic M10 tank destroyers, which were used in combat in 1944-45 in Italy and the ETO on these deception missions.

M-39 Armored Utility Vehicle (AUV)

The M-39 Armored Utility Vehicle (AUV) was a variant of the M18 Gun Motor Carriage, a 76mm self-propelled tank destroyer (Hellcat). With the turret and gun removed, the light weight chassis and hull made an excellent choice for a multi-purpose utility vehicle used as an ammo carrier, personnel carrier, ambulance, prime mover and other duties. The open top cargo area had a ring mount for a .50 cal. machine gun.

The M39 Armored Utility Vehicle (AUV) was designed during World War II, known as T-41 during development. The M-39 AUV saw limited service in WW II as well as in the Korean War.

The most serious drawback to the M-39 was its open top without topside armor. The M39 was superseded by enclosed Armored Personnel Carriers beginning with the M75 APC.

The M39 was originally designed as a prime mover for the 3-inch Gun M6. Approximately 650 (640 utility/APC variants, 10 command and reconnaissance) were modified from M18 chassis between October 1944 to March 1945. They saw service in Europe during the last months of World War II and were widely used during the Korean War. The M39 was withdrawn from service in 1957.

Specifications of the M-39 Armored Utility Vehicle (AUV)

Crew      3 + 8 passengers

Weight 33,450 lbs.

Height   6 ft, 8 in.

Width    9 ft, 5 in.

Length   17 ft, 4 in.

Engine   Continental R975-C4, 9 cyl, radial gasoline

Horsepower 400

Road Speed 50 mph

Range    100 mi.

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