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Object Title

Blanch-Chevallier grenade launcher

Development

The proliferation of complex trench systems led to the widespread reintroduction of hand grenades like the British 'Mills bomb' from 1914. These provided a means of attacking an enemy otherwise protected by the cover of a trench, but had a very limited range of 30 m (33 yd) or so. This in turn led to the 'Hale' No.3 Mk.I rod-type rifle grenade of 1915, developed to convert infantry rifles into makeshift grenade launchers. Grenades launched from a rifle could reach perhaps 140 m (153 yd), but still lacked an effective sighting system and had to be braced into the ground for firing. They could not be fired from the shoulder due to punishing recoil, which limited their usefulness in the attack. They also wore out the barrels and cracked the stocks of the rifles used. One solution was to develop a dedicated grenade launcher weapon.

Engineer Arnold Louis Chevallier immigrated to Britain prior to the War and came up with a wholly new design. He chose Herbert John Blanch of the London gunmaking firm J. Blanch & Son to build this, the only known prototype. The rear half of the launcher comprises a Martini tilting-block action previously used by the British army in the Martini-Henry and Martini-Enfield rifles. In this case, a commercially produced .450 rifle made in the 1880s by the Braendlin Armoury Company was used. The rifle's barrel was replaced by a large barrel of 6.35 cm (2.5" in) bore. This featured retaining clips at the muzzle and a sprung piston platform at the base. The grenade would have been launched by a .450 blank cartridge, with the large coil spring acting to dampen the resulting recoil along with a thick rubber butt-pad.

Use and effect

The Blanch-Chevallier was never issued. In fact, there is no evidence to suggest that it was even trialled by the British War Office. Instead, they persisted with improved rod grenades and repurposed a much older solution in the form of the grenade cup discharger, introduced in 1917 as an accessory for the SMLE rifle. It is not possible to evaluate the effectiveness of Chevallier's design, but two drawbacks are evident. Firstly, to soak up the recoil of firing, it had to be extremely heavy, and a supply of grenades would have added to the weight. This would have made the carrying of a rifle impossible, though a revolver could have been supplied for close-range fighting and self defence. Secondly, the weapon as constructed could not load the standard No.5 hand grenade or the No.3 rifle grenade. It would have required either that Britain tool up for production of its proprietary grenade, or that the weapon be redesigned to accept an existing type. Due to a lack of safety features, it would also have to carried without a blank cartridge in the chamber.

Despite its failure to attract official attention, Chevallier's idea for a shoulder-fired grenade launcher was ahead of its time. Whereas rifle grenades had to be fired braced into the ground, the recoil reduction system and tall tangent backsight were intended to allow the weapon to be fired from the shoulder. This would allow arcing indirect fire like a rifle grenade, but also permit launching at a shallower angle to land grenades in specific parts of a trench system. It could even be used for direct fire against groups of the enemy or targets behind cover. This flexibility prefigured the American M79 launcher of the 1960s, used to great effect in Vietnam. In this, the huge weight of the weapon and large dampening spring were replaced by a lightweight break-action launcher and a clever high-low pressure ammunition-based solution. This 40mm grenade is still in use today in under-barrel grenade launchers and grenade machine guns, the ultimate expression of the grenade projector concept.

Statistics

Action / Operating system Lever-operated tilting block

Calibre / Bore 6.35 cm (2.5 in)

Capacity (rounds) 1

Country of manufacture Britain

Crew 1

Date entered service Not issued

Effective range Unknown

Feed muzzle-loaded

Manufacturer John Blanch

Maximum range Unknown

Muzzle velocity Unknown