EFSS/ITV: The US Marines’ Mobile 120mm Mortar System

EFSS Concept

The U.S. Marine Corps sees the 120mm Expeditionary Fire Support System (EFSS) mortar as the 3rd leg of its expeditionary fire support triad. EFSS will be the short-range but easily transportable counterpart to the reduced-weight M777 155mm towed howitzer, and the truck-mounted M142 HIMARS rocket system.

Accompanying Marine Air Ground Task Forces (MAGTFs) in expeditionary operations, EFSS will be the heliborne Ship-To-Objective Maneuver (STOM) force’s primary fire support, before the larger and longer range systems can move into position. As such, the EFSS launcher, its Internally Transportable Vehicle (ITV) carrier, a portion of the basic load of ammunition, and a portion of its crew, must all be transportable by a single CH-53E Super Stallion or future CH-53K heavy lift helicopter, and/or a single MV-22 Osprey tilt-rotor aircraft. The program’s path has not been smooth, and its vehicle choice in particular has come in for criticism, as it heads toward full-rate production.