Navy began investigating claims that broken bolts for the reactor chamber on Vanguard had insufficiently been repaired using glue, during her seven year refit. After the heads of several bolts had been sheared off after being over-tightened, workers for defence firm Babcock had allegedly glued the heads on the bolts back on, rather than completely replacing the bolts. The glued bolts held insulation in place on the coolant pipes for the nuclear reactor, and were found shortly prior to activation of the reactor. Defence Secretary Ben Wallace demanded a meeting and “assurances about future work” after The Sun reported on the issue. Babcock is one of the United Kingdom's largest defence contractors, with contracts for the maintenance of both the Royal Navy's Astute-class and Vanguard-class submarine fleets. Labour Party shadow secretary of state for defence John Healey stated that "the Defence Secretary must make sure contractors are delivering maintenance to this critical capability safely, on time and on-budget.". See also Letters of last resort List of submarines of the Royal Navy List of submarine classes of the Royal Navy Nuclear weapons and the United Kingdom Royal Navy Submarine Service Submarine-launched ballistic missile Trident nuclear programme References External links Royal Navy HMS Vanguard (royalnavy.mod.uk) Vanguard-class submarines Ships built in Barrow-in-Furness 1992 ships Submarines of the United Kingdom 1992 in England