HORNBY OO 21T Coal Wagon, P200781 - Era 4HORNBY OO 21T COAL WAGON, P200781 ERA 4 Supplying vital fuel for many hundreds of steam locomotives, the Coal Wagon is a practically universal feature of the railway, part of the scenery as surely as the sight of a station or a locomotive. Tied to British Railways and part of its countrywide operations for decades, P200781 matches well with BR products and other rail utility vehicles, wagons, and more. Tech Specs Item Length Without Packaging (cm) 15.