Like many museums, the London Transport Museum in Covent Garden (which re-opened recently), has a large portion of its collection held off-site in a storage facility. Being a transport museum with a lot of very large objects (trains and buses), the storage facility is an ex tube depot in Acton, and this weekend is one of the few weekends each year when it’s open for visitors.

Billed as ‘London’s Transport in Miniature’, the two day event is partly an annual model railway convention, with exhibitors showing off displays of tiny tube trains (and other types of trains) moving around miniature scenes of London from yesteryear. Whilst these are more impressive than they sound, the anorak factor is quite high, and you’ll probably find yourself more drawn to the more life-sized trains from the museum’s collection. If you’re lucky, you’ll even get to walk inside a few of them, evoking memories of old tube train interiors, back when there were leather straps or metal springy bobbles to hold onto.

It’s not just trains and buses, the depot is a treasure trove of all sorts of London transport paraphernalia, including old signs, ticket machines and so on. With the Covent Garden museum having been redeveloped, I wouldn’t be surprised to find bits from old exhibitions and galleries too.

This weekend there will also be a special guest visit by ‘Sarah Siddon’, who’s not a person, but the last working electric locomotive that served on the Metropolitan Railway (the forerunner to today’s Metropolitan line). Electric locomotives replaced the earlier steam engines that ran on the line, but were eventually replaced themselves by the electric ‘powered carriages’ that we see today.

There’s also a rideable minature railway outside the depot, which kids (and unembarrassed adults) will be able to take little mini journeys on for a few pennies. Fun for all the family.

London’s Transport in Miniature is on at the London Transport Museum Depot in Acton on Saturday 8 and Sunday 9 March 2008. Admission charges apply.