A contract to survey a 900 meter tunnel using the Seaeye Falcon ROV necessitated the purchase of over 1Km of Umbilical.
Two challenges had to be overcome.
Firstly : The practical limit of cable distance for Video and Serial data telemetry
Secondly : Management of the cable length at the launch point
Solved by adopting optical fibre communications. The umbilical was specified with 4 x Single Mode Fibres and 4 x Multi Mode Fibres.
A Focal 907 optical multiplexer fitted in the ROV with a partner unit in the control room provides 3 Video channels, Two x RS485 and Four x RS232 serial communications links.
The result is noise free video of much improved quality and two further continuous video channels. The serial data capacity is also increased from Two x RS 485 channels.
Consequently there is significant capacity for sensors such as Altimeter, Doppler, Gyro for example.
All of the capacity described is supported on one Single Mode fibre.
A second single mode fibre provides an Ethernet link from the control room to the ROV. Thus the Vocean Falcon can support any sensor or subsystem requiring high volume data transfer by IP.
Using in house resources and expertise, an umbilical winch was designed and manufactured. See, 1100M Umbilical winch for the full description.