A new log of incidents obtained from the MoD reveals vehicles have suddenly broken down, fuel has leaked, brakes have overheated, alarms have malfunctioned and many other vital systems have failed in convoys on the move between July 2007 and December 2012.
The convoys, which ferry Trident nuclear warheads to and from the Royal Naval Armaments Depot at Coulport on the Clyde, have also gone the wrong way, been delayed, been diverted and lost communications. Incidents have happened on average more than once a month, with by far the highest number - 23 - logged in 2012.
The revelations have drawn fierce criticisms from Scottish Nationalist and Labour politicians, as well as campaigners concerned that the convoys' cargoes pose unique and unacceptable dangers, but the MoD insists they are safe.
Glasgow Labour councillor and former MSP Bill Butler, who convenes Scotland's nuclear-free group of local authorities, said: "I urge the MoD to improve its safety record."