Historic context :

France delivered some dozens of its 58Nr2 (Dumézil) trench mortar to its Russian ally in early 1915, whose design was adapted by the Captain K. A. Likhonin. The new material, named '58 mm Minomet FR' (58 mm mine launcher FR - Franco-Russian) was launched in massive production the same year in two different Petrograd plants, Nevsky and Izhora works, for a total manufacturing of a little more than 3400 weapons until 1917.

The main adaptation was the fact the barrel was now mounted on a massive base made in wood (Nevsky design) or in steel (Nevsky and Izhora designs), that could be equipped with two solid wooden wheels (diameter 535 mm or 306 mm) for transportation. Both Nevsky variants were also equipped with an elevation screw system linking the base to a flange around the barrel.

The 58 FR mortars were firing various types of fin-tailed projectiles similar to the ones of the ammunitions of the French 58 Nr 2 mortars, of different masses. The more commonly used were the ones of 36, 28 and 23.4 kg

Technical data :

• Complete description : 58 mm mine launcher system French-Russian
• Design year : 1915
• Calibre : 58.00 mm (tail of the projectile)
• Weight in firing position : 142 kg (Nevsky, wooden base), 197 kg (Nevsky, steel base), 241 kg (Izhora, steel base)
• Weight for transportation : 192 kg (Nevsky, wooden base), 247 kg (Nevsky, steel base), 271 kg (Izhora, steel base)
• Tube length in calibres : 8.00 (550 mm)
• Grooves : 0 (smooth bore)
• Projectile weight : 23.4 kg, 28 kg, 36 kg
• Initial speed : 70 m/s (28 kg projectile, full propulsive charge)
• Fire rate : 2 to 4 rounds / minute
• Range : 350 m (42 degrés, 28 kg projectile, full propulsive charge)
• Elevation range : +40 to +75 degrees
• Direction range : none

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