Mortier 120mm Rayé Tracté Modèle F1

The MO-120 RT-61 (factory designator) or MO-120-RT is a heavy mortar of French origin. It was designed by Thomson-Brandt as the successor for the MO-120 AM-50. The RT in the designator stands for rayé, tracté which means rifled, towed.

The RT-61 is currently used by the French Army (where it is known as RT F1 or Mortier de 120mm Rayé Tracté Modèle F1—"120 mm rifled towed mortar, model F1"), and is produced under licence by Germany, Italy, Belgium, the Netherlands, Brazil, Japan and Turkey (as HY-12 "Tosam" ). The MO-120 RT-61 is issued to artillery units, where it augments the 155 mm towed artillery.

In French service, this weapon is normally towed by the VTM 120 (Véhicule Tracteur Mortier de 120 mm), wheeled armored vehicle that is a derivative of the VAB 4x4 series of armored personnel carrier. Towing is accomplished by a towing hitch that is screwed onto the muzzle of the weapon. The VTM 120 carries 70 mortar rounds of 120 mm and also offers basic ballistic protection from small arms fire and shrapnel for the mortar's crew. The RT-61 can also be towed by the AMX-10 TM (Tracteur de Mortier) which is a version of the AMX-10P tracked APC. The Japan Ground Self-Defense Force have a self-propelled version of the RT-61 with 50 rounds, the Type 96 SPM.

Currently, there are eight 120 mm mortars assigned to each French Régiment d'Artillerie.

Normally not deployed during peacetime, all of the infantry's 120 mm mortars have been transferred to artillery regiments where they augment the 155 mm towed artillery. This allows both the towed 155 TR-G2 artillery guns of 155 mm caliber and the 120 mm mortars to be deployed simultaneously.

The RT-61 uses standard NATO rounds as well as the specially designed PR-14 (HE) and the PRPA (HERA). The weapon can be fired either by dropping the round down the tube (after aligning of the rifling bands) resulting in an automatic firing once the bomb hits the tube base, or by a controlled firing by dropping the bomb down the tube and pulling on a lanyard that will in turn set off the triggering mechanism in the base of the tube.

Manufacturers other than Thomson-Brandt as mentioned above include Thomson-CSF/Daimler Benz Aerospace (France/Germany(?)), Hotchkiss Brandt (Netherlands) as the "HB Rayé" and under license by MKEK in Turkey.

Users

 * 🇨🇴 Colombia
 * 🇨🇾 Cyprus
 * 🇫🇷 France (192 in 2011, 128 in 2014)
 * 🇮🇱 Israel
 * 🇮🇹 Italy
 * 🇯🇴 Jordan
 * 🇳🇱 Netherlands
 * 🇹🇳 Tunisia
 * 🇹🇷 Turkey
 * 🇺🇸—in service with the US Marine Corps as the M327 120mm Expeditionary Fire Support System
 * 🇳🇱 Netherlands
 * 🇹🇳 Tunisia
 * 🇹🇷 Turkey
 * 🇺🇸—in service with the US Marine Corps as the M327 120mm Expeditionary Fire Support System

Variants

 * MO-120-LT—This is a smooth-bore version for the mountain artillery.