Object Title

Garrison sliding carriage and traversing platform - No. 6 Medium Carriage

Garrison sliding carriage and traversing platform - No. 6 Medium Carriage

Date

1878-1866

Object Number

XIX.345

Provenance

Old Tower Collection

Physical Description

The carriage consists of two triangular brackets, a forward transom and a bottom plate of heavy sheet wrought iron, rivetted together. A heavy iron trunnion-bearing-cup is rivetted to the apex of each bracket, and a length of angle-section iron is rivetted to the bottom of each bracket to form a flat bearing surface. Iron pads flank steps cut in the upper edge of each bracket, adjacent to the breech of the gun barrel, to provide broader bearing surfaces when using a handspike in laying the gun. Pivoting on a heavy iron rod passing between the brackets is a heavy cast-iron paddle-shaped stool bed. Its forward end is formed into a flat horizontal fork, and a vertical pin through these jaws, ahead of the pivot rod, prevents the stool being dislodged when the gun was fired. The rear end of the stool bed is supported by a waisted cylindrical block of wood, a turned spigot on the lower end of which sits loosely in a hole in the bottom plate which has a liner cut with a heavy square-section thread. This was originally for a conventional elevating screw. Near the bottom edge of each bracket are two iron eyes for the attachment of control ropes. The heavy iron capsquares are attached by two L-shaped keyed locking pins retained by security chains. Adjacent to the left bracket's upper edge, between the trunnion-cup and the upper handspike pad, is a brass plate bearing a bell-mouthed tube, designed to house the cartridge pricker. Also on the left bracket is a brass information plate.
The platform consists of two parallel and inclined I-section rolled steel girders (bearing in raised letters 'ROUND OAK IRON WORKS'), spaced at forward and rear ends by curved wrought-iron plate transoms. The front transom supports a flat plate projecting forward horizontally and pierced with a hole, this being the pivot point about which the carriage and platform would traverse. A pair of small trucks beneath the front end of the platform, and a larger pair of taller supports beneath the rear of the platform gave the platform a 10 degree incline. The truck brackets and most of the spindles survive, but all of the trucks are missing. At front and rear of the platform, inside the side beams and adjacent to the transoms, are two pairs of Wood-block-faced spring buffers. The pair at the forward end are fixed, while those at the rear may be hinged downwards to allow the carriage to be dismantled by being slid off to the rear. An information plate is attached to the rear of the left beam.
The function of carriages and platforms of this design was very simple: The gun, once loaded, would be placed at the forward (and therefore the lowest) part of the platform. The carriage was not equipped with rollers, but simply sat on the lubricated rails of the platform. On firing, the recoil would be absorbed by the carriage having to travel up an incline. Excessive shock in recoil, or in running up the gun was absorbed by the spring buffers

Component parts

Inscriptions and Marks

CARRIAGE: Information plate reads' 32 pr 42 cwt SBBL gun/W arrow D I.R.C.D/1882/ Reg No.828 wt 14 and 1/4 cwt'. Left trunnion bearing has an arrow, possibly giving the point for zero elevation. The number 3 is stamped upside down on the carriage under the trunnion bearing, and on the top face of the trunnion.PLATFORM: Information plate reads 'PLATFORM MEDIUM No.6/ W arrow D I.R.C.D/1885/ Reg No.A542 WT 13 cwt

Associations

Places Britain

Notes

One of seven: XIX.342-348.
These carriages are fitted with the 32 pdr smooth-bore breech loading iron guns ( converted MONK Pattern) Nos. XIX.335-341 are presently on loan to Fort Nelson. The guns and carriages were formerly on loan to two Scottish sites. Five examples being in Edinburgh Castle, and two in Fort George.
The guns for which these carriages were designed were cast iron smooth-bored pieces cast during the 1840's to Monk's pattern introduced into British service in 1838. The conversion of these guns to breech-loading, but left smooth-bored, was for the sole purpose of providing canister-shot guns for caponiers for the defence of the dry ditches, which were a charactaristic of British fort design of the 1860's.
The actual conversion, by the Royal Gun Factory, of these guns, however, did not get under way until the early 1880's and the carriage design was still current in the 'Treatise on Military Carriages and other Manufactures of the Royal Carriage Department' (HMSO) of 1888 (qv). The Armouries group of seven guns and carriages seems to be unique.