FreeSpan is a set of complex computer program based on DNVGL-RP-F105 and DNVGL-ST-F101. It is specially developed for the analysis of vortex induced vibration and stability caused by free span of offshore pipeline.

For the pipeline span caused by scouring, it is necessary to analyze the span. The pipeline free span analysis is performed in accordance with the methodology described under DNVGL-RP-F105 for VIV criteria & DNVGL-ST-F101 for ULS static criteria. The pipeline free span analysis has considered the variation of inputs parameter along the pipeline route such as wall thickness, concrete coating thickness, metocean data, soil characteristic etc. The following criteria have been assessed:1. VIV criteria 2. ULS static criteria