The deck of the Ulisse vessel at the shipyard: the round carousel with its gray core, the arched green guide crane, the control cabin on its tower, the red winches and technicians at work.
The Ulisse deck, June 4, 2016.

Project · Prysmian

The cable-laying system on the Ulisse. The cable should never notice.

Carousel, caterpillar, crane and winches all work the same cable as it goes down to the sea. The automation that keeps them in step is ours.

Talk to an engineer See the challenge
Client
Prysmian
Where
Aboard the Ulisse vessel
Carousel
ø 36 m, four motors
Year
2016

The challenge

Thirty-six meters at the rim. Ten at the core. And the cable must pay out evenly.

  1. 01

    The cable is coiled on the carousel, from the rim to the core. Pay-out starts on the outside: 36 meters across.

  2. 02

    As the layer empties, the point where the cable leaves slides toward the center. Each turn pays out less cable than the last.

  3. 03

    At 10 meters, to feed the sea the same meters per minute, the carousel has to turn 3.6 times faster. Then the layer runs out and the one below begins.

The Ulisse carousel in a three-quarter view from above: the cable wound between the 36-meter rim and the 10-meter core, the four motors C1-C4 on deck with C1 as master. The last turn lifts off the coil and rises into the arch of the guide crane, which carries the cable toward the caterpillar; where the cable has already left, the layer below shows.
Cable pays out at
ø 36.0 m
Carousel speed
× 1.0
Cable to the sea
always the same

Meanwhile the caterpillar pulls, the ship moves and the cable sinks to the seabed. No jerks, no slack: for the whole lay, layer after layer.

The solution

Four machines on one cable. One program.

Carousel, caterpillar, brakes and direction of rotation share a single PLC logic, with controlled ramps. No isolated commands chasing each other.

The caterpillar

Two belts. One leads, the other follows.

They grip the cable and control how it leaves for the sea. On board they’re called Master Belt and Slave Belt, each with its torque reference.

Drawing of the caterpillar: two opposed tracks, the upper one (master) in blue and the lower one (slave) on its base, grip the cable running between them on its way to the sea; the torque reference is marked on the master's wheel.
The arched green guide crane above the carousel, with technicians at work on the cabin tower.

The guide crane

It carries the cable from deck to water.

A red winch on the deck of the Ulisse vessel, its drum wound with rope.

The winches

They move only when the logic enables them.

A pendant station with an emergency stop hanging on the fence on board, with its tagged orange cable.

Controls on board

Pendant stations and emergency stops where people work.

What we brought

From the first schematic to start-up on board. One point of contact.

  1. 01

    The electrical schematic

    One number, 315204, and a tag for every panel and every box.

    Electrical engineering
  2. 02

    Panels and controls

    From the main panel to the boxes next to the motors, wired neatly, every cable tagged.

    Control panel building
  3. 03

    Software and screens

    First the maneuvers (loading, running, laying, stopping) as states and permissives. Then one logic for all of it.

    PLC and HMI software
  4. 04

    Tests and commissioning

    Signals, permissives and sequences tested first. Then start-up, on board.

    Testing and start-up

The photos

Eleven photos, all ours. From our workshop to the ship.

Every photo opens full screen.

Along the same chain

Before the sea, the fiber. Two projects close to this one.

Two fiber-optic towers side by side: green frame, furnaces, operator panels and stack lights.

The fiber

The fiber-optic towers

Furnaces, gases and axes in a few meters, readable at a glance.

The project
The tube line in the workshop: a row of green stations with yellow wheels, each with its own motor, and the panels at the back.

The tube

The tube line

Many stations, each with its own motor, and the same pull from the first to the last.

The project

The first step

Is yours a system too, not a single machine? Tell us about it.

Talk to an engineer

Read by an engineer, not an automatic quote tool: reply within 1–2 business days.