Buoy Turret Connector (BTC)



Although the BTC was originally designed for submerged buoy turret moorings it is very versatile and can be used in variety of applications. It can be mounted on Buoys, Plugs, Hulls etc.


The major challenge, particularly on submerged turret buoys is how to pull in and disconnect the line with the buoy connected to the hull with the FPSO in production. Space is extremely tight and the only intervention possible is by ROV.

The BTC system uses a ROV insert-able sheave locked in position above the BTC female mounted on trunnions. This sheave allows a manmade fibre rope to be led through the bore of the BTC female and connected to the BTC male mid water. Pulling on the rope brings the male into engagement with the female and a cam mechanism rotates the two halves such that the pin can be inserted into the assembly. The sheave is removed by the ROV and rope disconnected.

Disconnection is simply reversing of this sequence.


The BTC can be used together with an ILMT to create a simple mooring line arrangement for connection and tensioning without using valuable deck space. It offers a simple robust pinned connection.  The BTC is available with a top loading pin or as with a side entry pin through the trunnion mounts.

  • 2 Axes of rotation
  • Small footprint
  • ROV operable

Permanent or temporary sheave options.

Available for Chain, Wire & Polyester ropes.


In 2013 Equinor was planning the installation of the Mariner field which uses a submerged turret buoy to connect to the FSO. Equinor had collected their field experience and concluded as a previous study compiled for the UK HSE by Nobel Denton that a mooring line failure of some form would occur every 8 project years. Over the life of the field therefore multiple interventions were likely to be required and a simple method of disconnection of the mooring lines was required. It is also a requirement that the connection must have two articulations – one for inclination and the other for azimuth rotation. Where there is chain in the top line a means to overcome out of plane bending is also required.


The BTC is a scalable connection solution. Please contact us with your MBL and vessel requirements.

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