Mortier 120mm Rayé Tracté Modèle F1

Mortier 120mm Rayé Tracté Modèle F1
MO-120-RT-61 mortar
Type	Heavy mortar
Place of origin	France
Service history
In service	French Army United States Marine Corps
Used by	France, among others (see below)
Wars	Gulf War War in Afghanistan Operation Serval
Production history
Designer	Thomson-Brandt
Manufacturer	TDA Armements (France), Thomson-CSF/Daimler Benz Aerospace (Germany), Hotchkiss Brandt (Netherlands), MKEK (Turkey), Howa (Japan)
Produced	1973
Specifications
Weight	582 kg (1,283 lb)
Barrel length	280 cm (9 ft 2 in)
Crew	4 gunners, 2 vehicle crew
Shell	18.7 kg (41 lb)
Calibre	120 mm (4.7 in) NATO mortar round
Carriage	wheeled
Elevation	30–85°
Traverse	±14° from centreline
Rate of fire	6 to 10 rpm
Effective firing range	8,140 m (8,900 yd) with standard projectile 12,850 m (14,050 yd) with rocket projectile

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 to 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), a 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 also carries 70 rounds for the mortar and offers basic ballistic protection from small arms fire and shrapnel for the 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.

The mortars, which originally equipped infantry regiments, have now all been transferred to the artillery regiments, where they augment the 155 mm towed artillery. Currently, there are eight 120 mm mortars assigned to each French Régiment d'Artillerie - although they are not deployed during peacetime.

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.

Rounds fired from the mortar can reach as high as 8,000 ft (2,400 m) and hit the ground with an effective kill radius of nearly 250 ft (76 m).