and GEC, submitted tenders for the design and construction of the Class 91 locomotive. On 14 February 1985, the BR board approved the substitution of the Class 91 for Class 89 for the ECML programme. The tendering process was relatively complex, but a decisive move appeared to have been GEC's offer of a sub-contracting arrangement to BREL for the construction of the locomotive's mechanical elements. It would be GEC's submission that would be selected as the winner; after which a contract for the construction of 31 Class 91 locomotives, along with an option for 25 more for the WCML, was awarded during February 1986. Shortly thereafter, BREL established a production line for the type at its Crewe Works. Operations The InterCity 225 entered service with InterCity on the East Coast Main Line (ECML) in 1989. In service, the InterCity 225 sets were used alongside other rolling stock, including locomotives and electric multiple units. The displaced diesel trains were reallocated predominantly to the Midland Main Line. The InterCity 225's introduction correlated with a significant increase in passenger numbers using the ECML within two years; one station recorded a 58 per cent increase in passengers. The InterCity 225 was designed to achieve a peak service speed of ; during a test run in 1989 on Stoke Bank between Peterborough and Grantham, an InterCity 225 was recorded at a speed of . Its high speed capabilities were again demonstrated via a 3hr 29mins non-stop run between London and Edinburgh on 26 September 1991. British regulations have since required in-cab signalling on any train running at speeds above preventing such speeds from being legally attained in regular service. Thus, except on High Speed 1, which is equipped with cab signalling, British signalling does not allow any train, including the InterCity 225, to exceed in regular service, due to the impracticality of correctly observing lineside signals at high speed. The InterCity 225 has also operated on the West Coast Main Line (WCML). In April 1992, one trainset achieved a new speed record of two hours, eight minutes between Manchester and London Euston, shaving 11 minutes off the 1966 record. During 1993, trials were operated to Liverpool and Manchester in connection with the InterCity 250 project. In 1996, as part of the privatisation of British Rail, all InterCity 225s were sold to Eversholt Rail Group. Since then, the trains have been leased to all operators of