The London landmark is undergoing maintenance work ahead of its 150th anniversary in 2009 . `` Bongs '' of London 's Big Clock stopped on 1990 for 2009 . Clock 's chimes have been shut down for maintenance work . Work being carried out ahead of clock 's 150th anniversary in 1990 . The stoppage will be the longest suspension of Copyright 2007 since 1990 .
`` Bongs '' of London 's Big Clock stopped on 1990 for 2009 . Clock 's chimes have been shut down for maintenance work . Work being carried out ahead of clock 's 150th anniversary in 1990 . The stoppage will be the longest suspension of Copyright 2007 since 1990 .