The time converts to an average speed of . Despite these successes, however, Class 91 locomotives have never used their 140mph top speed in regular service, because testing conducted by British Rail in 1988 established that drivers could not interpret and act upon line-side signal aspects with sufficient consistency and accuracy when driving at speeds exceeding . Regulations throughout Britain were subsequently amended to require the use of in-cab signalling whenever running service trains at speeds above 125mph, an option that BR were unwilling to pursue at the time. Fleet When British Rail was privatised, the InterCity livery was progressively removed and new operator GNER applied their corporate livery of blue and red. When GNER lost their franchise in 2007, the red stripe was replaced by a white stripe containing the words National Express and East Coast. National Express East Coast originally planned to repaint all of their InterCity 225 sets in the white and silver NXEC corporate livery within two years. However, the collapse of NXEC in 2009 and its replacement with East Coast saw this repainting programme cancelled. As a result, 91111 was the only locomotive to receive the full National Express livery. In June 2010, a new silver livery with a purple stripe was unveiled by East Coast. By February 2011, locomotives 91101, 91106, 91107 and 91109 carried this livery. Locomotive 91101 was soon given maroon vinyls, with Flying Scotsman branding. Locomotive 91107 was given promotional "Skyfall" vinyls for a time during 2012–3. The locomotive later returned to conventional Virgin Trains East Coast livery. Locomotive 91110 carries 'BBMF' Battle Of Britain Memorial Flight livery. By 2013, all locomotives carried the standard East Coast livery of silver/grey with a purple stripe. 91118 was the last locomotive to carry GNER/NXEC livery. All Mark 4 coaches and DVTs have since been repainted. On 14 October 2014, at Newcastle station, locomotive 91111 was unveiled in a commemorative World War I livery and named 'For The Fallen'. The Class 91 fleet has carried nameplates applied in various batches and themes. Immediately after repainting into GNER colours in the late 1990s, all locomotives were briefly nameless. Having initially been applied to only a few locomotives in the early 1990s using cast-iron plates, eventually the whole fleet was named, many multiple times, until all were removed in 2008. In 2011, in response to customer requests, East Coast resumed the practice. It began by naming