Bletchley Park fires up Big Green-Eyed Monster

Vintage air traffic computer lands at National Museum of Computing

The National Museum of Computing (TNMOC) has announced the revitalisation of two PDP11-based radar stations which, as part of the IRIS investigative radar recording system, for 25 years helped control the UK's airspace from "without a single incident ever being attributed to an Air Traffic Control failing".

TNMOC Trustee and Director Kevin Murrell and TNMOC volunteer Tony Frazer operating a PDP11 radar station computer

With the transfer of ATC operations from West Drayton to Swanwick, the last of the veteran system's radar stations was taken offline earlier this year, and TNMOC secured a pair of them for posterity.

TNMOC director and trustee Kevin Murrell explained: “We first saw the IRIS working at West Drayton in 2001 and we immediately knew that we wanted the decommissioned technology as a working exhibit in the museum.

"IRIS finally came out of service in early 2008 and it’s been a major task to rebuild it, but volunteers Ben Trethowan and Peter Vaughan have succeeded in sparking it into life. The final trick was to replace some wiring that had become faulty.

"The reconstruction feat is truly outstanding because these are highly complex systems that were originally put together by experts trained in the intricacies of the technology."

The two radar displays are known as the Big Green-Eyed Monster (see pic, above) "because of their size and remarkable retro appearance". They can now be enjoyed "replaying historical recordings of flights in and out of London's Heathrow Airport". ®

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