watcher

Last photo shows the beacon assembled upside down! Yep, used as a beacon on a director, obviously only at night. Some sort of beacon arrangement probably goes back about a century, I think the model shown goes back to the 1930s. Which explains the OS number. Directors were used to orient the guns of a battery, see http://nigelef.tripod.com/fc_laying.htm and Figures 22 and 23, the bracket indicates it was for a No 7 Director IIRC, which basically went out of service in 1966, IIRC the bracket for the L1A1 was held by a couple of lugs on the side. The old bracket seems a bit odd for the date, but its possible that with L1A1 directors the beacon mount was part of the director kit, thinking about it I'm fairly sure this was the case, it was a properly engineered item not a bit of pressed metal The beacon was used when the battery occuppied a position at night, it enabled the guns to point their dial sight at the director in order to receive their angles to orient them in centre or arc (or zeroline pre-1956ish). Light discipline was an important matter in a night occuppation (well some armies made it like a well light circus, but not the Royal Artillery). Directors (aiming circle in USspeak) were used throughout FA until guns, etc, became autonomous, eg MLRS early '90s, AS 90 mid '90s, L118 2001. So never used with AS90. Also used for FA radars, OPs from c.1978 until Warrior OPV, and I think R Sigs with some sigint devices. UK infantry mortars never used them but some nations' mortars do. Different colour beacons were used to distinguish main director from check director, and if btys (or troops in days of tore) were close together to identify which was which - coloured skirts were used on director tripods in daylight for the same reasons.

Hopefully I can cast light on a few matters