Head of Steam, Darlington Railway Museum, County Durham

The Stockton and Darlington Railway was authorised by parliament in 1821 as a horse-drawn operation. On the day the act received Royal Assent, George Stephenson was able both to change the route and to get permission for the use of "loco-motive or movable engines". The latter provision narrowly escaped being struck out by disbelieving civil servants, as did the right to carry passengers.

On the 27 September 1821 the first steam-hauled passenger train ran with a reported load of up to 600 passengers, mostly sitting in open coal wagons. One coach, the Experiment, resembling a wooden shed on wheels, carried the dignitaries.

Though it took two hours to cover the first 12 miles, at one point the train reached a speed of 15 miles per hour with perfect safety. In the course of the next 50 years the mileage of public railroad rose from 25 to 160,000 miles and continued to expand rapidly. The railway age had begun.

I am not a railway buff in the sense of wielding a spanner, squeezing an oil can or owning an anorak and a notebook, but I do believe rail travel to be the most sublime form of transport. I share with EM Forster the belief that railway termini are our gates to the glorious and the unknown.Like US playwright and poet Edna St Vincent Millay, there isn't a train I wouldn't take, no matter where it's going.

It was good news, therefore, to learn that the Darlington Railway Centre and Museum was at long last to be refurbished at a cost of £1.7m. After a year's closure it has reopened as Head of Steam - Darlington Railway Museum, though the new title seems to have escaped the notice of those responsible for council publications, road signs and the front of the building itself.

The main museum building and train shed have been re-roofed, which means that visitors once more have access to the wonderful interior of the old station - one of the last and most complete of its kind. It's a privilege to view once more the period ticket office, vintage loos, waiting room and to see again Locomotion (1825), Derwent (1845), and the mainline express 1463 (1885).

Alas, very little money seems to have been spent on them or on the period ephemera and artefacts - signals, barrows posters, uniforms and nameplates - that gave the place character and atmosphere.

Instead, Darlington has undergone an exercise in rebranding, in which it has deliberately shunted railway enthusiasts into the sidings. The prioritised target markets are now declared to be family fun and children.

I have no problem with the concept of family fun, except to say that the new exhibitions, abysmally poor in quality and patronising in tone, should never have been put inside the period station building, but adjacent, where there is ample space.

We confront a series of displays framed in brash colours and materials, which clash, compromise and violate the period artefacts and the integrity of the place itself. There is no apparent narrative flow or coherence to these displays.

They represent a series of "wouldn't it be good if" initiatives or "how do we fill this corner" challenges. There is little overall vision or design concept. Scattered throughout the displays are a number of visual, auditory and sensory features described as "intertracktives", aimed, we are told, at providing a "traintastic" experience. Copywriters' clever-dickery has run unchecked.

The games ask children to guess the job, take part in a two-train race, learn how to build a railway and to identify unseen objects by feel. I watched with interest six young families. They appeared to find most of the exhibits banal and easy.

Some displays had become interinactives. A five-fold invitation to build an impression of the Head of Steam Train Trail, a locomotive and four carriages, while progressing through the exhibits failed to impress either literally or metaphorically.

An audiovisual in the waiting room jumped and skipped and the period platform ticket machine had a hand-scrawled "out of order" notice. Children were sated after less than 20 minutes, asking if they could leave. Despite the new branding there is no head of steam, no sense of speed, excitement or power.

Films do exist, both old and new, of working locomotives. Why were they not used? Is this a lack of imagination or budgets? For Darlington the train has not so much "taken the strain" as gone down the drain.

The refreshment room has been rebranded as the Coffee Shop, with a menu carrying the merry slogan "yum in your tum!". Though it did offer delectable home-baked scones, we experienced a new kind of brief encounter. The embarrassed staff told us that coffee was not available - the machine was malfunctioning. They could offer only a pot of tepid tea.

Darlington, if you believe the press releases, is proud of its origins - of being at the birth of the revolution that changed the world. It wants visitors to explore the railway heritage of the north east of England.

The Bible records that Esau sold his birthright for a mess of pottage. Darlington has sold a proud inheritance for a mess - of teddy bears' picnics, face painting and Santa's grottos, for whimsical displays that owe more to the tawdry tales of the Rev Awdry than to the inspiration of George and Robert Stephenson.

The volunteers of the Darlington Preservation Society, the North Eastern Locomotion Trust and the A1 Steam Locomotive Trust, located within the grounds, have the highest reputation for their scholarship, maintenance and restoration work.

One can only hope that they can continue to thrive, that they have not been overlooked in the council's decision to dumb down the style of the museum.

Intriguingly, the trust is building a Peppercorn Class A1 Pacific steam locomotive, the first in Britain for 40 years. The cost is £1.7m, the same as Head of Steam. There can be no doubt which is the bargain and which the bungle.

Peter Lewis is a writer and a past director of Beamish, the North of England Open Air Museum