Renovation on the 20 kilometer-long Simplon rail tunnel began officially yesterday.

Work on the 170 million franc project actually started in March, but yesterday was the official kick-off, on a day associated with the patron saint of miners.

Work on the vital passenger and freight tunnel will take three years, with the first full closure of the rail stretch coming in August this year.

Some of the work was pushed forward after a freight car caught fire in June last year.

The Federal Railways said rail schedules will reflect closures, and delays.