PSM Pre-cast Span Method
PSM is abbreviation of pre-cast span method. It is a new way to build bridge and high speed railway in the shortest possible time. Spans (box girder) are pre-cast in some place near bridge or railway construction site. Operators use sidle carrier (box girder transporter) to transport those spans to under area of bridge girder erection machine one by one. The machine erects a piece of span and moves it to space between next two piers.
In old way, you may need 90 days to build a bridge. You only need 3 days to finish same work if you use PSM.
