No. 15 ball grenade
|No 15 "Ball Grenade"|
|Place of origin||United Kingdom|
|Used by||United Kingdom|
|Wars||World War I|
|Weight||1 lb 11 1⁄2 oz|
|Filling weight||5 1⁄2 oz|
|Timed friction fuse|
The No 15 was a time-fused grenade. It was internally fragmented and incorporated a cast-iron body.
To light the grenade, the user had to remove a covering that was on the fuse, then strike an external Brock matchhead igniter against the fuse.
There were two types of fuses available; the five-second and the nine-second. The former was intended for throwing, while the latter was intended for catapults.
The No 15 was one of the interim grenades created because of the problems associated with the No 1 grenade. Unlike the others, the No 15 had been created specifically for the Middle Eastern theatre of World War I, mostly for the fighting in the Dardanelles.
However, there were a few problems; the explosive charge was too large, which created smaller-than-expected fragmentation when the grenade exploded. In addition, it was considered too large because of its 3 in circumference. These problems were remedied with the No. 16 "oval grenade".
Battle of Loos
The No 15 was first widely used in the Battle of Loos. Tacticians envisioned that the No 15 would be useful in breaching German defenses and trench clearing. The No 15 was used because production of the No 5 "Mills bomb" was running seriously behind planned figures, and not enough of them could be supplied before the start of the Loos campaign.
When the Battle for Loos started, the No 15 was beset with problems, in particular the wet conditions encountered made the fuse almost useless. It was estimated that approximately 18 out of 20 No 15's failed to ignite due to inoperative fuses.
No 16 "oval grenade"
The No 16 is essentially an improved version of the No 15. Instead of a ball shape, it has an oval shape and has less explosive charge. It was planned to completely replace the No 15, but the defeat at Loos caused both the No 15 and No 16 to be withdrawn from service, as they both had the same lighting system.