What do the Dome and the Railways have in common? Is it just that they are both financial disasters? Or is there more to it than that? Can we say they are both political experiments?

I hope I am not in a minority in thinking that there is a fundamental difference between public service and private enterprise. The purpose of private enterprise is to make money and that involves taking risks. People expect the public services to be run in a businesslike, economic and efficient way, but the rule is "safety first", and nobody expects public services to take risks or make a profit.

So, if one can imagine a world where these principles are reversed, you would find risk takers running a public service, and public service management running a commercial concern: you would ask private enterprise to run the railways, and public servants to produce the concept of a theme park and run the Dome!

Politicians thrive on new ideas: the world must never be allowed to stand still, or it could be difficult to justify their existence! Change for the sake of change and new ideas can divert public attention from their obvious shortcomings and produce an illusion of progress!

And look at the consequences: the much maligned Dome was actually last year's greatest tourist attraction in this country, and received nothing but praise from most people who visited it - but it was also a financial disaster: twice or three times as much public money was wasted in propping it up as the extra money that the government have said they will make available for flood prevention schemes over the next three years. If the Dome had been entrusted to private enterprise at the outset, the Dome could well have turned out to be a financial success.

Now consider the railways. Privatisation was not enough. Competition and risk taking had to be introduced into every aspect of the system. And so we have the paradox of Railtrack whose task is to make money out of maintaining and running the railway line, but who are not responsible for the running of the trains which use it, and the railway companies, whose task it is to make as much money as they can out of running trains, without any responsibility for the care of the track. It is the sort of recipe for disaster, which one might expect of a political genius who is also an accountant, but would never have been the brainchild of an experienced railway engineer - particularly when the people who knew the job best ( the old management of BR) were not even allowed to put in a bid.

So should it be such a surprise, if the mangement of Railtrak sought to maximise their profits by economising on the maintenance of the track, while the train operators sought to maximise their profit by running as many overcrowded trains as possible, over the most popular routes - presumably at minimum cost to themselves?

Of course, the system is now so well established that it is easier to blame Railtrack executives for badly maintained track than to try and change the system - railway privatisation might work much better, if the track is maintained by public servants, who are under no pressure to make a profit and are able to charge the train operators licence fees which are commensurate with the cost of track maintenance.

And the consequences of this political experiment? Fortunately, so far very few people have actually been killed. But the cost? Those of us who have been involved in the old local government compulsory competitive tendering process know how important it was to ensure that contract specifications were drawn tightly in such a way as to leave no loopholes which private contractors could exploit in order to maximise their profits - because, otherwise, it would be possible for them to put in artificially low bids to provide the service. A short while ago, Railtrack was reported to have asked the government for a billion pounds to cover the cost of restoring the track to a satisfactory condition. I do not know if this money was paid, but what I would like to know is whether Railtrack's contract specification was tight enough to compel them to do the job without asking for more money.

Do politicians ever learn by their mistakes? The political colour of the leadership of the House of Commons may change, but the government always wins an election - and, by the government I mean the Whitehall mandarins. And we can be sure that the same officials who privatised the railways will now be busy privatising Air Traffic Control. This is a very serious cause for concern.