Rail company GNER has promised to slash train times after completing a £30m three year project to refurbish its high speed fleet.

The East Coast Mainline operator says work to upgrade its fleet of 31 electric class 91 locomotives will "dramatically improve" reliability and cut delays.

The locomotives, which were introduced between 1989 and 1991, typically cover 1,100 miles a day on the route between London King's Cross, Yorkshire, the North-East and Scotland.

They have undergone extensive mechanical and electrical re-engineering as part of a mid-life refurbishment programme which began in June 2000.

GNER says the project has been so successful that each locomotive is now covering about 15,000 extra miles before requiring maintenance work which could cause delays.

Only two locomotives were released at a time from regular services for the work so GNER could maintain its full passenger timetable.

GNER chief executive Christopher Garnett said: "This has been a tremendous team effort which is already beginning to make a significant difference to the performance and punctuality of our services and the quality of journeys enjoyed by our passengers."

The refurbishment involved HSBC Rail, which leases the locomotives to GNER, and their original manufacturers Preston based Alstom and Bombardier in Doncaster.

It is expected to add about another 20 years of life to the whole fleet which has accumulated nearly ten million miles of service.

Peter Aldridge, head of HSBC Rail will officially hand over the final locomotive to be overhauled to GNER chief executive, Christopher Garnett, at London King's Cross station in a ceremony to be held this morning.

The heavy overhaul programme has also included fitting train protection and warning system (TPWS) equipment to all locomotives ahead of the national December 2003 deadline imposed by the Strategic Rail Authority.

TPWS, which has been criticised in some rail industry quarters for its ineffectiveness at very high speeds, causes trains to brake automatically if they pass signals at red or danger.

Fellow train operator Arriva Trains Northern recently completed work to fit TPWS equipment to 360 of its train driver cabs.