The Tresidders Cartridge store that was proposed by Captain Tresidder, R.E. for use in sites where there was a high water table and underground magazines cannot be dug deep enough to ensure adequate overhead cover. A single version was constructed for a 10-inch BL gun mounted in the Left Battery at Landguard Fort.
The magazine is 49 feet and 6-inch long and about 4 feet and 6-inch wide. Rails are placed in the tunnel, some 23 feet long, with capacity to carry 25 charges on a narrow-gauge trolley. This trolley is moved with a hand winch and wire cable. The tunnel is partially covered by a concrete roof some 10 feet and 4 feet 6-inch wide. The issuing hatch is built into this concrete area for unloading the cartridges. There is thick overhead concrete protection, and a davit crane for lifting the cartridges.
Based on the description in “Permanent Fortification for English Engineers”, 1890 by Lewis.
