Attempts to inflict serious damage on infrastructure have never been a major feature of Irish republican terrorism.
Attacks on London Underground (LU) and mainline railway stations have usually featured fairly small bombs intended to inflict civilian casualties and cause maximum disruption to urban life.
Between 1881 and 1885 the Irish Republican Brotherhood carried out attacks on public buildings, bridges and LU stations, using the newly perfected explosive dynamite.
In 1939, in an abortive campaign allegedly funded by the Nazis, the Irish Republican Army (IRA) attacked at least one LU station.
When the Troubles started in the 1970s the IRA included attacks on 'economic targets' in its repertoire, devastating Irish town centres with car bombs, causing massive damage repaired at the UK government's expense. Attacks on the mainland were usually directed at military barracks.
October 1971 saw a rucksack bomb attack on the Post Office Tower in London.
Damage was minimal, but the visitor centre and world-famous revolving restaurant at the top of the tower never reopened.
Twelve people were injured in September 1973 by small bombs at Kings Cross and Euston mainline stations.
One civilian died in October 1975 when another small device destroyed a bus stop close to Piccadilly underground station.
During the 1980s the IRA focused its attention mainly on military and political targets.
But it gained worldwide publicity when it detonated a car bomb outside Harrods department store in London in December 1983, killing three police officers and three civilians, and injuring more than 90.
In July 1990 a small bomb left in a toilet damaged the London Stock Exchange. There were no injuries. Damage and disruption were limited.
In February 1991 attacks on London's Paddington and Victoria stations killed one and injured 40.
A year later, in February 1992, another small device injured 28 commuters at London Bridge station.
The first big strike at what the IRA defined as economic targets came on 10 April 1992, when a massive car bomb outside the Baltic Exchange in the City of London killed three and caused around £800M of damage to office buildings and underground services.
A day later, on 11 April, a van bomb detonated beneath a viaduct carrying the A5 at Staples Corner in north London, causing serious damage but no casualties. This was the first direct strike aimed to cause major disruption to road transport links.
February 1993 saw an abortive attack on gasholders at Warrington, Lancashire.
A month later, IRA bombs planted in city centre rubbish bins injured 50 and killed a young child.
In April 1993 came the massive Bishopsgate truck bomb in London, which killed a photographer and caused an estimated £850M of damage.
A subsequent IRA ceasefire was broken in February 1996 by another truck bomb, this time close to Canary Wharf in London's Docklands. Two were killed and destruction was estimated at £85M.
In April the IRA planted a bomb on the historic Hammersmith Bridge in London. It failed to detonate.
A large truck bomb in Manchester, in June 1996, injured more than 200 and there was widespread devastation. Rebuilding the city centre eventually cost £700M.
In June 2000 came the IRA's last attack in infrastructure before the current ceasefire. A second attack on Hammersmith Bridge caused some damage but no casualties.