Cost of LHCWith a budget of 7.5 billion euros (approx. $9bn or 6.19bn as of June2010), the LHC is one of the most expensive scientific instruments[56]ever built.[57]The total cost of the project is expected to be of the order of 4.6bnSwiss francs(SFr) (approx. $4.4bn, 3.1bn, or 2.8bn as of Jan2010) for the accelerator and 1.16bn (SFr) (approx. $1.1bn, 0.8bn, or 0.7bn as of Jan2010) for the CERN contribution to the experiments.[58]The construction of LHC was approved in 1995 with a budget of SFr 2.6bn, with another SFr 210M towards the experiments. However, cost overruns, estimated in a major review in 2001 at around SFr 480M for the accelerator, and SFr 50M for the experiments, along with a reduction in CERN's budget, pushed the completion date from 2005 to April 2007.[59]The superconducting magnets were responsible for SFr 180M of the cost increase. There were also further costs and delays due to engineering difficulties encountered while building the underground cavern for theCompact Muon Solenoid,[60]and also due to magnet supports which were insufficiently strongly designed and failed their initial testing (2007) and damage from amagnet quenchandliquid heliumescape (inaugural testing, 2008)(see:Construction accidents and delays).[61]Due to lower electricity costs during the summer, the LHC normally does not operate over the winter months,[62]although an exception over the 2009/10 winter was made to make up for the 2008 start-up delays.