Strong, expensive cables meant to last several decades, must all the way, from factory delivery to laying, be handled according to the manufacturer’s demands for both minimum bending radius, max concentrated load and max local stretch and more. This to make sure that the cable is laid down unharmed.
After Seløy Undervannsservice had ordered both side thrusters and traction winch systems from us, we got the pleasure of developing our first cable quadrant.
In reality, this is a very large snatch block that is suspended over the cable carousel on the cable laying vessel, and which the cable passes over on its way from factory and down on the carousel, and up into a put out device over board from the stern.
As mentioned, the dimensions and the complexity are unusual:
* Outer measurements about 12 x 6 m.
* Radius cable track 5.2 m
* Many support wheels for cable, distributed on the circumference
* 4 hydraulic pull units with coordination, dispersed on the circumference
* 2×1 tons per pull unit. Opening 50 – 350 mm
* 20 ton max load, cable piece included
* Hydraulic jib for cable control under laying
The entire structure is made from sea water resistant aluminium.
The same structure in steel would probably have been too heavy for the crane.