I have long had great affection for O. V.Bulleid's "Battle of Britain" class engines of the Southern Railway. One of their number, proudly steaming at the head of The Golden Arrow, adorned the wallpaper of my bedroom when I was five. A few years later, by then a fully fledged trainspotter, I had my first 'cop' of one - 34066, Spitfire, simmering at the head of an express in Victoria Station. (The "Schools" Class 4-4-0 Bradfield was on another platform. Odd how one remembers these things after nearly half a century.) My fondness for the class attaches especially to Tangmere, the locomotive numbered next in sequence to Spitfire. Lovingly preserved through the four decades since most of its sister engines perished to the cutter's torch, it remains one of the most popular steam engines still gracing the tracks. A couple of years ago, I enjoyed my first trip behind her on a midweek 'journey to nowhere' aboard the English portion of the Venice-Simplon Orient Express. The train, made up of beautifully restored Pullman coaches, took a circular course through Surrey, while its pampered passengers ate a superb five-course lunch, revelling in the luxury of travel as it used to be (for some).

I described the outing later in an article that amused a colleague with its description of the sure-footed way this compact locomotive had lifted its tremendous load out of Victoria. "Didn't you know there was a blooming great diesel on the back pushing for all it was worth?" he chortled. In fact, he has since confessed that he only knew because Alan Pegler happened to be sitting opposite him when he took a ride on the train. On this occasion, the legendary Gresley Pacific was at the front and Pegler, its former owner, admitted that it couldn't have managed without the diesel.

With The Flying Scotsman out of action since 2004 and unlikely to return to traffic until late next year, Tangmere has continued to be a regular performer on the Orient Express steam excursions. Rosemarie, her mother Olive and I had been eagerly looking forward to reacquainting ourselves with the engine on a journey to Bristol early in the summer. Alas, the locomotive developed a fault a few days before the trip, and substitute steam power could not be found at short notice. Rather than make do with diesel, we asked for our money (in fact, Olive's money) back and resolved to wait for another chance.

It came last Saturday in an Orient Express run from Victoria to Bath. As the day approached, it became clear that this, too, was to be with Tangmere, now fully back to health, we hoped. Arriving at Victoria, I was delighted to find that we had been allocated seats in the first-class parlour car, Cygnus. There were a number of reasons why this pleased me. First, the 26-seat coach is the same age as me, having been completed by the Birmingham Railway and Carriage Company in 1951. Construction had actually begun in 1938, but completion was deferred because of the war.

Having been part of the Festival of Britain rake of coaches in 1951, Cygnus began duties on The Golden Arrow, which took me back to that childhood wallpaper again. It formed part of the train on its very last run in 1972. That it was often used by royalty and visiting heads of state brings a snob appeal of its own. There is a more sombre association in the fact that it formed part of the train that passed through Oxford, where muffled bells rang across the city, carrying Sir Winston Churchill to his final resting place at Bladon on January 30, 1965. At its head was Sir Winston Churchill, an unrebuilt "Battle of Britain" Pacific identical to Tangmere.

Finally - which connection I remembered the first time I visited the loo - the coach possesses a fine example of the work of the Long Crendon-based mosaicist Marjorie Knowles. She supplied the decoration for the lavatory floors in most of the restored Pullmans. Her depiction of Cygnus, the Swan, was the very mosaic she was working on when I interviewed her about the job in May 1983 - and the one featured in the photograph that accompanied my resulting article.

It seemed as the trip began, however, that we were not destined to spend long aboard the coach. For with much harrumphing and wheezing, Tangmere made a laborious climb from Victoria, only to stop dead, perhaps no more than a mile out, beside a carriage shed. After 20 motionless minutes -" We are obviously waiting for a clear path," I confidently informed my companions - the train starting moving again . . . the wrong way. Soon we were back precisely where we started, beside platform 2 at Victoria.

Before long, the train manager arrived with news of the trouble. There had been an engine failure. No it wasn't the 59-year-old Tangmere that had packed up, but the state-of-the-art Class 67 diesel at the back, which had seen just six years in service. We had come back to the station to leave the diesel, and Tangmere was going to try to make it alone. The 11 heavily laden Pullmans, plus the three support coaches, were a massive load for the engine to haul - at least six times its own weight at more than 500 tons. "When there was a diesel failure four years ago," we were told, "the steam engine didn't make it."

This time, however, Tangmere did. Its crew coaxed a brilliant performance from her as she climbed steadily out of the station and into the first of the 217 miles were were to cover under steam power that day. Many of these were at thrilling speed, especially as we raced back towards London along Brunel's superbly engineered line from the West. As we hurtled through Slough at 70mph, my only regret was that I couldn't be on the platform witnessing the magnificent spectacle. Then I had another sip of wine - and the moment passed.