PEEPING behind the scenes is always fun, and that is part of the appeal of the now well-established heritage weekends - and there's also the matter of free entry to some places.

Having developed a taste for high places on some Highland passes this summer, Spectator opted for an excursion to the Transporter bridge at Middlesbrough - an industrial marvel which remains the enduring symbol of the town.

A listed building with entries in several record books, plaques bearing names of founding fathers of Teesside industry and built using the skills of Cleveland Bridge, the Darlington-based firm which has records of its own and whose expertise helps safeguard London with the elegant Thames barrage, the transporter bridge remains an eye-catching monument as well as a thing of purpose.

The attraction was being able to climb the flights of metal steps and then, if nerve held, walking out across the Tees to the other side. Return was by the same route, the steps on the other side having been dismantled.

The highest part of the structure is 225-feet and the walkway is less than that, but still feels dramatically high, especially after the last two particularly steep flights. Sunshine and blue skies meant terrific views although with eyes watering in the wind landmarks were tricky to identify.

The scudding clouds gave an uncanny sensation of movement, belying the stability of the walkway even when the transporter was in use.

There wasn't an "I did the walkway" T-shirt as a memento, but Spectator exchanged cameras with a fellow adventurer while both recorded their feat. Back on earth enthusiastic staff explained as often as required how the winching gear worked and it could be seen in action each time the transporter crossed.

The fascination of machinery built, as this was, at the turn of last century, is that you really can see what it's doing: this drives that and the other pulls the lever which winds the drum. Beats a computer motherboard any day on that score.