Subsea cable repair · Falmouth Report a fault

The repair · after you call

The repair

A repair is four jobs in a row: find the break, lift both ends, splice in new cable, lay it back. Below is what each one needs from you and how long we plan for it.

On screenTwo cut ends, fibres lined up, the arc that melts them together

From you

Three things
before we sail

  1. 01

    Distance to the fault

    From your shore station's reflectometer, in kilometres, with the fibre pairs that went dark.

  2. 02

    The route position list

    The cable's as-laid positions, so a distance along the cable becomes a point on the chart.

  3. 03

    Cable type at the fault

    Deep-sea or armoured shore end, and where your spare cable is held if it isn't aboard with us.

Our planning figures

On station by

Sailing within 24 hours, then 12 knots to your position

Call-out to sailing
24 h
Transit at 12 kn
25 h
On station within
49 h

Weather and the state of the sea on station come first. If she is already at sea on another job, we tell you that on the first call.

At sea

Find · lift
splice · lay

JobWhat happensWe plan for
FindWe run to the position from your trace, check it against the route list and drop a marker buoy near the break.Hours
LiftA grapnel runs across the route until it holds. In deep water a cutting grapnel brings up one end at a time; each end is tested toward its shore station, sealed and buoyed.1–3 days per end
SpliceIn the jointing room each fibre pair is fusion-spliced, the new length of cable is jointed in, and both shore stations test through the repair.About a day
LayThe joined cable is lowered under control and the extra length laid beside the old route in a U. We fix its position as it lands.Hours

Afterwards

What you
get back

  • A splice record for every fibre pair, with loss at each joint.
  • Traces from both shore stations, before and after.
  • The as-laid positions of the repair and the U of spare cable, for your route list.
©BIGHT 2026 BIGHT and CS Helford are fictional. The facts about cables are real: see the sources. Sources & credits