Machine Room.

Most of the servers were in the Machine Room.

This is a general view of the machine room.

The floor was false providing space for cables and return of the air. Chilled air was blown in via a false ceiling.

A good quality electrical supply is vital for computer reliability and data integrity.
This is the UPS (Uninterruptible Power Supply), with its doors open.
Raw mains electricity was fed to the panel on the wall to the left and then via circuit breakers to the UPS.
The 240volt, three phase, 50cps alternating electricity is converted to direct current
by electronics in the left side of the UPS which float charges the batteries to the right.
The direct current is then converted to 240volt, three phase, 50cps alternating electricity
That conditioned supply then goes via the distribution panel to the right then underfloor to the computers.

The batteries isolate the computers from any fluctuations in the mains supply,
indeed it could ride through a complete outage for a short time.

This is the machine room patch panel. The boxes on the left connect to subnets. The cables going under the floor on the right connect to groups of sockets around the machine room. So when a computer is installed it is connected to a socket nearby. The corresponding socket on the panel can be patched to any subnet on the left. (what a mess!)

Finally this is the Operator's console named fleet with its three telephones.