CANADA - THE DIEFENBUNKER

Even by the end of 1948 Canada found herself vulnerable to attack from the Soviet Union. This was not due to any overt beligerence on her own part but to two outside influences. The increasing presence of American early warning radars on her soil made Canada a target in her own right, and the risk from radioactive clouds drifting northwards from Soviet targets in the industrial and administrative north eastern United States called for strong passive defence measures.

Early in 1959 work started on construction of a massive, semi-underground Emergency Government War Headquarters at Carp, just outside Ottawa. The bunker is a four storey concrete monloith, 350 feet square and partially burried in a sandy escarpment. The building is proof against a 5Mt nuclear weapon at a range of 1.1 miles and has a radiation protection factor well in excess of 1000.

The 'Diefenbunker' was opened in December 1961 and ceased to function in 1995. It is now undergroing restoration and is open to the public as a heritage site

ABOVE and BELOW: the 'Diefenbunker' under construction in 1960. Note the mushroom-shaped heads on the support pillars required to spread the floor load

BELOW: the limited space within the bunker called for slender support pillars taking up little space, but they had to be immensly strong, hence the deeply flared tops and bases

ABOVE and BELOW: the unprepossessing entrance to the Diefenbunker leads into a long through-tunnel which has the main bunker doors to the side, thus allowing the blast wave from a nuclear detonation to disipate through the open end of the tunnel

ABOVE LEFT: two of the bunker's four 327 Kw diesel alternators

BELOW LEFT: An extension to the lower floor of the bunker contains a vault built to house the gold reserves of the Bank of Canada in wartime. This photograoh shows the massive safe-door protecting the vault