Wikipedia: The Ordnance BL 15-inch howitzer was developed by the Coventry Ordnance Works late in 1914. History and use The weapon was operated by Royal Marine Artillery detachments of the Naval Brigade, with 1 gun per battery. One gun was sent to Gallipoli but not used there. They were later transferred to the British Army It operated successfully where it was needed to destroy deep fortifications on the Western Front, but was limited by its relatively short range compared to other modern siege howitzers. The size and weight made it difficult to move and emplace. No further development occurred after the first batch of 12, and instead Britain continued to develop and produce the 12-inch howitzer and 12-inch railway howitzer.