The Princess Royal inspected a restored 63-year-old railway carriage at Didcot Railway Centre -- but found the modern-day Thames Trains service to her next engagement was cancelled due to mechanical problems.

The princess with, from left, Jeanette Howse, railway centre marketing manager and Richard Croucher, chairman of the Great Western Society

She was forced to continue her journey with First Great Western when the 3.45pm Thames Turbo from Oxford to Paddington, run by Thames Trains, broke down at Didcot Parkway.

But the hitch failed to take the gloss off yesterday's royal event. Bunches of red, white and blue balloons were tied round the station to welcome the princess.

She boarded a saddle tank locomotive for the short ride to Didcot Halt, where she untied a pink ribbon to launch Special Saloon Car 9002. The railway carriage was built by the Great Western Railway in 1940 for VIPs, including Sir Winston Churchill, and from 1946 formed part of the royal train used by the late Queen Elizabeth, The Queen Mother.

Princess Anne toured the carriage's lounge, dining room, kitchen and boardroom, and remarked on the range of skills needed for the restoration project. Thames Trains spokesman Jonathan Radley blamed a twist of fate for the cancellation of the Princess's 21st Century train out of Didcot to Reading.

He said more than 99 per cent of his company's trains ran on time each day.

He said: "We cancel less than eight of our 800 services daily.

"It was just bad luck."