the pointed arched backplate cast with stylised foliate ornament and centred with an heraldic cartouche of three cannons, the railed basket with knopped finials, a central pierced lozenge and dog-tooth ornament, all raised on outset supports with scrolled hook finials,

The history of this hob grate design isn’t known. We assume to be a limited issue for perhaps a regiment with connections to the Royal Ordnance.

The Three Cannons is long established as an heraldic device for the Royal Ordnance – originally the Crown department for supplying munitions to the Navy by at least Tudor times – and later, when established, the Army. The device is found in Irish and Australian Ordnance departments too – often with three cannon balls.