Jamestown Manufacturing - Shaping Steel to meet your Requirements. Bespoke manufacturer of Plate Girders, Box Girders & Cellular Beams. Complex and heavy structural fabrications including Road & Rail Bridges, Grillages, Crane Gantries, Spreader Beams and Marine & Offshore Structures up to 100 Tonnes unit weight. We can also offer trial assembly of larger structures up to 150 metres and 250 Tonnes. Constantly re-investing in our business to drive quality, capacity and capabilities. We pride ourselves on being willing and able to take on jobs that other companies cannot or will not.