No.1 Grenade

The No.1 Grenade was designed by Martin Hales at the Royal Laboratory, Woolwich in 1908 and was the first hand grenade used by British Army during the First World War. Loosley-based on grenades used during the Russo-Japanese War of  1904-05, the No.1 would soon prove costly to mass-produce, in addition to being unsuited to the cramped conditions of trench warfare, and was eventually replaced by the No.2 in 1915.

Featuring a brass cylinder body mounted onto a wooden block, the No.1 had a 16 inch cane handle attached that enabled it to be thrown at a target and had an impact-detonated percussion fuse. It was filled with the explosive lyddite and weighed 2 lb when complete with handle and cloth streamer that enable it to stabilise during flight and land nose down on its target. The grenade was fitted with a cast iron percussion ring around its body and a removable cap on its nose.

To prepare the No.1, the cap was removed and then replaced after the detonator had been inserted. The cap was then set to “secure” position ready for use. To fire the grenade, the cap was turned to “fire”, the chord becket was taken out and the streamers unfurled, and the safety pin removed. The grenade was then thrown into the air where its handle and streamers enable it to land nose-down to detonate the percussion fuse.

The design of the No.1 soon proved problematic with the onset of trench warfare, and it was culpable in the accidental deaths of a number of its users. Despite reducing the length of its handle, thus making it easier to throw in confined conditions, the grenade continued to perform badly on the battlefield and it was soon decided to look for an alternative. The No.1 was also difficult and expensive to produce and a major shortage of the weapon finally led the British Army to purchase large stocks of the No.2 “Hales Pattern” Grenade from the Mexican Government in 1915.