Gantry Cranes offer an economical solution to bridge cranes when the building is inadequate to support a bridge crane or the crane system is to be located outdoors. Truss Girder Cranes are a variation from the typical beam or box girder that becomes economical when long crane spans are required. Additionally, many truss girders allow the hoist to be located "up into" truss thereby offering much better hook height than a single beam or box girder crane. Also, truss girder cranes are typically more economical than long span beam or box girder cranes. Truss girder cranes offer almost limitless span - but capacity is often limited with longer spans. Truss girders are also used on outdoor long span cranes in order to reduce effects of wind on the crane drive system.