Cost-effective and high-availability ramp control on a RoRo ferry Determine the status of various items quickly and easily
✔ Ship supplier MacGregor was looking for a new solution to
control ramps, doors, and movable car decks.
✔ ILC 370 PN/M Inline controllers now provide cost-effective connection of the distributed I/O modules
to the control system.
✔ Since the Ethernet network and control technology have a redundant design, a high degree of availability is ensured for the automation solution.
As a subsidiary of Cargotec Oyj, MacGregor, based in Gothenburg, Sweden, is one of the world’s leading ship suppliers for cargo and cruise ships.
The company has specialized in the development and manufacture of cranes, ramps, and bulkheads.
In the past, the various ramps installed on a ferry were always operated remotely by hand. In order to move the ramps, a central controller read the input signals from the operator interfaces and controlled the corresponding hydraulic drives directly. When the drives reached their end position, the hydraulic system was switched off. To do this, all signals had to be wired in parallel through the entire ship, a process that was prone to errors, expensive due to the length of some of the cable routes, and time-consuming when it came to troubleshooting.
In addition, as the automation system that had been used up until then was to be discontinued by the previous controller supplier, it was time for MacGregor to look for a new ramp control solution. With the new approach, it had to be possible to mount the distributed I/O modules directly next to the respective ramps and bulkheads. The outfitting specialist chose an Ethernet-based protocol to redundantly connect all signals of the distributed I/O devices to the control system.
Following extensive market research, the team at MacGregor chose Phoenix Contact as the system supplier. The openness and flexibility of the PC Worx programming software and the Visu+ visualization tool mean that all the requirements are covered. Furthermore, many devices in the automation specialist’s comprehensive product portfolio have the necessary maritime approvals. One example of this successful cooperation is the Ark Dania RoRo ferry, which was fitted out by MacGregor.
A wide range of MacGregor systems – referred to as items – are installed on the Ark Dania, including stern ramps, hatch and ramp covers, doors, and movable car decks. High-availability communication between the items and the control system is essential, so that in the event of an error all systems can still be operated without having to switch to manual operation. An Ethernet network designed as a redundant ring structure is therefore used to connect all the items together. The RSTP redundancy protocol with fast ring detection ensures switching times of less than 500 ms.
Depending on the customer’s requirements, the control system can also be implemented redundantly by MacGregor. High-performance ILC 370 PN/M Inline controllers are used on the Ark Dania. In the control cabinets belonging to each individual item, there is a PROFINET bus coupler to which the sensors (buttons, limit switches) and actuators (hydraulic valves) installed on the ferry are connected via I/O modules. In addition, the bus coupler forwards the recorded data to the control system via PROFINET in real time. However, the control unit of the likewise redundantly designed hydraulic pump is not controlled via a bus coupler, but via an ILC 170 ETH small-scale controller. Like the bus coupler, in normal operation it exchanges data with the two main controllers. However, in the event of an error, it can control the hydraulic pump autonomously.
The crew diagnoses the status of all items installed on board via a visualization system. This means that members of staff can detect whether ramps or doors are still open. The visualization created with the Visu+ tool runs on a panel PC with touch operation and maritime approval. It loads the values to be represented from the redundant controller pair via an OPC server and displays them.
If necessary, additional panel PCs can be installed in other areas. The ship’s black box – the voyage data recorder (VDR) – also has access to the controllers and logs the status of the installed equipment.