Anyone who has travelled on the Eurostar rail service linking London with Paris knows what happens after the sleek TGV-style train pulls out of Waterloo. It plods its way through the Kent countryside and picks up speed only after entering the Channel Tunnel to emerge like a bullet on the other side.

Unlike the British, the French believe in their railways; indeed, they were the first element of the country's infrastructure to be restored after the second World War. More recently, SNCF has invested billions in the development of its high-speed TGV network, which now extends its tentacles from Paris in almost every direction.

At a time when British Rail thought it could get away with running high-speed trains on existing rail lines, with "tilting" carriages to negotiate bends, SNCF was already planning its TGV project based on building entirely new railway lines for trains that would whizz through the countryside at 300 k.p.h.

The first line, between Paris and Lyons, proved so successful after it opened in the early 1980s that Air Inter (the French internal airline) had to cut back on its scheduled services - because the TGV was faster. Travellers found they could get from the centre of Paris to the centre of Lyons in just over two hours.

TGV lines, all involving completely new routes, were later installed between Paris and Bordeaux, Nantes, Lille, Geneva and Toulouse. Now the Belgians have picked up the baton, with the first phase of a new railway line which will ultimately provide a high-speed train service linking Paris, Brussels and Amsterdam.

These Thalys high-speed trains run at 300 k.m.h. and have already reduced the journey time between Paris and Brussels to just one hour and 25 minutes. There are also Eurostar services linking Brussels with London in two hours and 15 minutes, which again makes rail much more competitive with air services.

So far, the Belgians have spent £1 billion on the Thalys project - and there's more to come. Work is in progress on a second line from Brussels via Liege to the German border, and detailed design work is completed for a third line linking Antwerp, Rotterdam and Amsterdam, which is due to open in 2005. These ambitious schemes, which are all parts of a trans-European high-speed rail network in the making, would not have been embarked upon if there were doubts about safety. Indeed, the evidence shows that high-speed rail travel - in France, Germany and Japan - is actually safer than the conventional alternative.

The Japanese, who pioneered high-speed rail services with the Shinkansen, or "Bullet Train", have never lost a passenger on their network since it was introduced in 1964 on a new line between Tokyo and Osaka. Since then, six more Shinkansen routes have been installed and passenger numbers now exceed three billion.

In the late 1960s, the image of the "Bullet Train" speeding past a snow-capped Mount Fuji became the very symbol of modern Japan. Travelling at a maximum speed of 270 k.m.h. - now exceeded both by the TGV and the Thalys trains - the Shinkansen once carried a record one million passengers in a single day.

Thousands of Japanese use the high-speed trains to commute to work every day, despite a relatively expensive fare structure. Monthly tickets can cost up to £500 and an ordinary single fare between Kyoto and Tokyo, as I discovered last December, cost around £70. But it was well worth it just to experience the famous "Bullet Train".

HIGH-speed rail services are viable, of course, only in countries with large centres of population - such as Japan, Germany and France - where there are sufficient pools of potential passengers to make a two-way service economic. Ireland does not have that, except perhaps on the Dublin-Belfast and Dublin-Cork routes.

Though some environmentalists have queried the benefit of high-speed rail travel, it clearly makes sense on the continent, where there are numerous cities with more than one million people. This is recognised by the EU Commission, which has provided funding for projects which help realise the trans-European network.

Ironically, in view of last Wednesday's horrific accident near Hanover, it was a similar inter-city express train which set a new European railway speed record of 406 k.m.h. in May, 1988, on the then newly completed line between Fulda and Wurzburg in Germany. Service speeds are, of course, considerably lower.

It is also important to point out that the accident at Eschede was the first involving loss of life to passengers on any high-speed train in Germany - or, indeed, anywhere in Europe where such services exist. Rail experts are still mystified about why it happened, because the trains are specifically designed not to "jack-knife". The most likely explanation is that, for some unknown reason, the first carriage derailed and hit one of the concrete piers supporting the bridge. This caused the locomotive to split off as well as putting the remaining carriages out of line, with the result that they crumpled like a concertina while the bridge itself collapsed. It is ironic that the accident coincided with the British government's announcement that it was prepared to provide £150 million towards the cost of a high-speed rail link between London and the Channel Tunnel - which had been long-fingered by a Thatcherite insistence that it must be financed entirely by the private sector.

New Labour's commitment to this much-needed rail link will finally end the embarrassment of having Eurostar trains moving so slowly through Kent. But it will be seven years before it is finally realised - a delay which could have been avoided if the previous Tory government took a more positive view of Britain's railways.

Meanwhile, although Ireland will never have to worry about high-speed trains, it can no longer ignore the safety problem inherent in running some of its rail services - even at snail-like speeds - on clapped-out jointed track and rotting wooden sleepers, many of which are more than 50 years old. A report from consultants Arthur D. Little, commissioned by the board of CIE and leaked to the Sun- day Tribune last week, has suggested the risk of death or serious injury to rail passengers is likely to breach acceptable levels within two years on the worst sections of the rail network unless urgent action is taken.

The lines most at risk are: Mullingar-Sligo, Mallow-Tralee, LimerickEnnis, Waterford-Limerick Junction and Athlone-Westport, where a serious derailment happened last November. It was as a direct result of this accident that Arthur D. Little was called in to carry out a comprehensive survey of the rail network.

The signalling system was also examined and found wanting - even at Heuston Station, the hub of most inter-city train services. CIE estimates that at least £10 million per year over the next seven years is required to repair the signalling defects and replace old jointed track with continuous welded rail on concrete sleepers.

The company's chairman, Mr Brian Joyce, said yesterday that a total investment of around £650 million would be needed between now and 2006 to upgrade the rail network - including the replacement of much of its rolling stock. It will be up to the Government to decide whether the railways are worth it.