W407 was the main computer room at Ordnance Survey and was built in the mid 1970s. It was still in use until a few weeks/months before the move to a new purpose-built data centre at Adanac Park.
W407 was on the 4th floor of West Block and was built next to the original computer room (where W404 was later). It was a purpose-built computer room with most of the facilities needed for a server room – its own dedicated air conditioning plant, a raised floor allowing cables to be ran below the floor and flexible power supplies.
W407 would originally have contained mainframes; I believe the late 1960s ICL mainframe was in use until the 1980s or 1990s although I am unsure as to whether that was in W407 or the original computer room.
As technology moved on, the computers got a lot smaller but the room was flexible enough to allow for the installation of the modern rack-mounted equipment that became standard, backup tape ‘jukeboxes’, the patch panels connecting to the data racks in the office areas, a WAN connection and various other kit.
W407 – LAN infrastructure cabinets 
W407 – LAN infrastructure cabinets 
W407 facing SW from high level 
W407 facing S from high level 
W407 central aisle 
W404 main entrance/exit doors 
W407 computer room, SW wall 
W407 fire suppression cylinders 
W407 facing SE from elevated position 
W407 server racks 
Centre aisle of W407 facing SE towards main doors 
W407, DDMS servers 
W407, DDMS servers 
W407 inside main entrance 
W407 server racks 
W407 server racks 
W407 server racks 
W407 fire suppression cylinders 
Central aisle in W407 
W404 main entrance/exit doors 
Entrance ramp to W407 from W404
A second computer was built on the ground floor of the WRB by A core in the mid 1990s and the purpose of that was a failover for business continuity reasons. This was smaller than W407 but had a mezzanine floor.
Concerns about the reliance on a single air conditioning unit (on the roof of West Block) led to the installation in W407 itself of several individual air conditioning units (about the size of two server racks) in around 2004; these were cooled by rooftop air-cooled condenser units. If one broke down then there should have been enough cooling capacity provided by the other units.
Original air handling unit for W407 
Original air handling unit for W407 
W407 temperature and humidity recorder 
New air conditioning units in W407 
New air conditioning units in W407
The power supply was also upgraded in the 2000s, with several new power distribution units (large cabinets) installed in W407 itself and the adjacent engineers’ room. It was also connected to a containerised emergency generator located by F door.
W407A – UPS 
W407A – UPS 
W407A IT engineers’ room 
W407A – UPS
Several large UPS battery units were also installed in the rooftop plant room to maintain the power to W407 between a power cut and the emergency generator kicking in.
Last updated on Friday 14 December 2018 by GaryReggae