The main contractors has many barges most barges are for transport purpose ,however the same barge can be provided with two Rocker-arms and two Skid-tracks and with this provision and a Stouco Jacket-Skidder, Heavy steel trusses and/or Jackets can be pulled out of the fabrication side.
ST has delivered to Heerema the Mac-Skid the biggest Jacket launcher at that time ,barge was H109 & H110. A Jacket can be launched by trimming the barge about 5 degr. with the help of a Ballast system ,the Jacket is supported on grease Teflon pads and tracks ,when the ST Jacket Skidder start to push with abt 5000mT force the jacket start to slide and drop via the Rocker-arms into the sea ,the barge will running away like a speed boat, a wave of abt.2 meters will shown on the deck. Floating and ballasting system are mounted to set jacket in vertical position ,lowering + piling can be started. Contractors are: Heerema ,ZOC , Micoperi , Mac.Dermott , See item 02 for Skidding devices & techniques.