The patented system is designed with an innovative cassette system to maximise the efficiency of installation and recovery activities. The cassette system is designed for pipelines in the range of 2” to 14” diameter. Anything above this would reduce the efficiency and use of the cassette system due to the increased change-out frequency.
We have developed a larger cassette for pipelay diameters of up to 22” for shallow water Lay and in Decommissioning mode we substitute the cassettes for deck trolley’s which can handle product diameters of up to 2m for bundle recovery.
The system was originally designed for a maximum dynamic line tension of 120 tonnes. We also developed a lower capacity unit with circa 80 tonne for several of our target markets and have investigated and concluded the feasibility of a 400 tonne bundle recovery system on behalf of a European client for a deeper water project.
Our higher specification unit can work from angles as low as 5 degrees to the horizontal to 5 degrees past vertical (105 degrees from horizontal) providing a wide range of installation options for a variety of water depths.
Our lower capacity unit is targeted towards shallower waters and works from 5 degrees through to 45 degrees though additional angles can be accommodated via an upgrade.
A fixed angle system with reduced functionality can be supplied for angles between 5 degrees and 30 degrees.
The system is primarily a J-Lay system, designed for a range of water depths. We use the term S-lay to define a pipeline being constructed or recovered parallel to the deck of the vessel. This requires the pipe to bend on both the seabed (touch down or pick up point) and as the pipe leaves or approaches the stern of the vessel where it needs to bend to accommodate the change in angle. In J-Lay mode the pipeline leaves or arrives at the vessel parallel to the lay tower which is inclined at an angle relative to the deck (see FAQ #3) resulting in a single bend at the touch down or pick up point on the seabed.
If you are unaware of the differences please See FAQ #4. With our shallow water J-lay system we only have a single bend during the recovery process with the most stressed point in the pipeline on the seabed. In S-lay there are two stress points both on the seabed and on the vessel where the pipeline bends into a horizontal axis.
With the Laytrix system any pipeline failure due to the applied bending, stressing and perhaps corrosion in the pipeline during recovery will occur on the seabed clear of all personnel, deck equipment, and the recovery vessel.
We use tried and tested pipe cutting equipment such as hydraulic shear cutters, circular-saw or high-performance cutting discs provided via our partners who have proven track records in supplying cutting equipment for decommissioning projects.
The higher specification unit weighs in the region of 100 tonnes with the fixed angle system around 30 tonnes. Our reduced capacity system has a mass of around 70 tonnes.
The systems are defined by a maximum line tension which includes dynamics and is derived from the size of pipeline, its wall thickness, environment conditions and the maximum water depth.
Our higher specification unit was designed for North Sea projects with water depths of up to 200m. Our reduced capacity system and fixed angle system are designed for water depths in the region of 80m and below.
All of our systems were designed with cost effective vessels of opportunity (VoO) in mind and as such the deck footprint is suitable for use with anchor handlers, supply vessels or smaller construction assets.
Yes!! The system can easily be converted into a handling tool allowing it to self-load or unload cassettes or other pieces of deck equipment onto a quayside. When offshore the unit can be utilised as a launch and recovery system (LARS) allowing tools or vehicles to be deployed to the seabed and can be used to recover subsea hardware such as end terminations and in line features.
The system is designed to allow for a wide range of 3rd party cutting tools to be integrated into the structure such as, diamond wire saws, hydraulic shear cutters, high performance cutting discs in single or twin formats, allowing clients to stipulate their preferences, allowing for the recovery of a wide range of different products such as pipelines, SURF umbilical’s, Underwater Cables and TLP tendons.
The full system has been designed with both the environment and health and safety in mind. All cutting work is undertaken in a fully bunded work platform ensuring that all cutting debris and any fluids which escape during operations are captured and drained to a tank. Each end of the cassette system is blanked and wrapped once removed from the tower preventing any further escape of fluid. The hydraulic systems used to articulate the main tower structure and secondary functions utilise water based hydraulic fluids with the mechanical components greased using environmentally acceptable lubricants (EALs).
The base system requires a minimum deck space of approximately 190m2 and a further 30m2 for each additional cassette to be used with the system. The design premise was based on the use of smaller vessels of opportunity such as anchor handlers and platform supply vessels and as such we have developed a wide range of layouts for our cassette skidding system based on these differing vessel envelopes.
The system can be utilised for a wide range of installation functions ranging from laying of pipes for traditional oil & gas projects, through to hydrogen and carbon capture & storage applications. In its decommissioning mode it can be used for recovery of rigid pipes, flexibles and umbilical & cables.
The system can be converted into a handling tool and used for deployment or recovery of subsea packages or for loading / unloading in smaller ports or harbours without dedicated quayside craneage.
Finally, the design is currently being developed for a number of different offshore wind applications and as a method of mooring installation for aquaculture projects.