System and autonomous method for securing a riser support

A method for securing a riser support, wherein the method comprises the steps of:

• passing, through a through-hole of a supporting ledge, at least part of a riser support connected at its bottom end to a submerged riser and at its upper end to a tensioning element;
• and
• sliding, along the supporting ledge, a securing device located on the supporting ledge, from an upper position to a lower position, said securing device being driven by an actuator;
• wherein the securing device slides between an unlocked position and a locked position relative to the through-hole, and
• wherein, in the locked position, the securing device can engage with a connector of the riser support after the connector has passed through the through-hole of the supporting ledge, so as to prevent the connector from returning through the through-hole.

A method for releasing a riser support, wherein the method comprises the steps of:

• providing a securing device in a locked position on a supporting ledge, engaged with a riser support, so as to prevent the riser support passing through a through-hole of the supporting ledge, wherein the riser support is connected at its bottom end to a submerged riser and at its upper end to a tensioning element;
• sliding, along the supporting ledge, the securing device, from an upper position to a lower position, said securing device being driven by an actuator, wherein the securing device slides between the locked position and an unlocked position relative to the through-hole in the supporting ledge, so as to disengage from the riser support;
• and
• passing, through the through-hole of the supporting ledge, at least part of the riser support.