Bespoke flange stud cutting for Subsea 7

Scope of works:

James Fisher Offshore were asked by Subsea 7 to design and provide a means to cut the flange studs on a subsea pipeline should conventional methods fail. The flanges (3 requiring separation from the seabed) were constructed circa 1980 so were deemed potentially difficult to remove.

Subsea 7 tasked us with engineering a solution to enable both speedy and safe works execution. The requirement was to cut up to twenty 3.5" Ø studs on each 36" 900lb flange.

Scope of supply:

James Fisher Offshore (JFO) were tasked with supplying the following to form part of a contingency cutting spread:

  • Four circular saws with bespoke fabricated frames
  • Equipment to be automatic as much as possible to ensure diver safety
  • Extensive in-house testing of equipment using JFO technicians
  • Hyperbaric centre* used to provide realistic creation of subsea environment with divers carrying out work
  • Final design and saw blade combination gives a cutting time of around three minutes with five minutes preparation time to fit saw jig to flange assembly

* The National Hyperbaric Centre is part of JFD Global, sister company to James Fisher Offshore. For more information please visit JFD Global's website.

For more information on how James Fisher Offshore can add value to your offshore operations contact us.

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