Work on the tunnel is due to start on 17 January and last 12 months

Rail passengers in Kent are set to face delays for a year when a tunnel is closed for major repairs.

The Strood tunnel will shut in January 2004 for work which Network Rail estimate will last a full 12 months.

Passengers on a busy line into London's Charing Cross terminal will have to leave the train to catch a bus for part of their journey.

Rail operator Connex say it will add 30 minutes to journey times in both directions.

Major landslide

The two-mile tunnel, which was built in 1847, runs through chalk land.

It was the scene of a major landslide in 1999 in which four carriages of a train were derailed.

When we've finished the work, we will never have the trouble again Dave Ward, Network Rail

Further smaller landslides since then have led to a 20mph speed limit being introduced through the tunnel.

The work, due to start on 17 January, will see the tunnel completely rebuilt into a steel and concrete structure.

The rails and rail beds will be replaced and a new drainage system built.

But passengers will have to use longer alternative routes or catch a bus between Strood and Higham.

No financial compensation

Network Rail and Connex say commuters will benefit in the long run because the changes will mean trains can once more run at full speed through the tunnel.

Dave Ward of Network Rail said: "Let's just reflect that this tunnel was opened in 1847 and it's been a taxing problem for engineers for generations.

"When we've finished the work, we will never have the trouble again."

Connex, which runs train services in the South East, said it realised passengers would be inconvenienced but would not be offering financial compensation.

Communications manager Sarah Boundy said: "Our passengers have had to put up with a slow journey and unplanned ad-hoc closures for some time.

"So although we do acknowledge it will be inconvenient for passengers for a year, this work is seriously needed.

"The real compensation will come when the work is over and the train service can return to 70mph."

But she did tell the BBC compensation was something Connex might look at on a "case-by-case basis".

Tim Nicholson, chairman of the Rail Passengers Committee, said: "It's going to be disruptive, it's going to be a nuisance, but it has to be done.

"I expect there will be complaints, but do you think it's unacceptable for a tunnel that old to be shut from time to time?"