07 August 2023
How DMC’s smart dock winches work
Dock 7 at Damen Shiprepair Rotterdam has recently acquired an innovative system of intelligent dock winches. Made up of four powerful winches, the system works so perfectly that it can pull any floating object into the dock, whatever the conditions. And this fine piece of work by Damen Marine Components (DMC) has many additional advantages.
At 405 metres long and 90 metres wide, Dock 7 at Damen Shiprepair Rotterdam is the largest dock in the Netherlands. The Emerald Princess cruise ship measures 290 by 36 metres, with space for more than 3,000 passengers. So how do you manoeuvre such an enormous ship into such a huge dock?
Markus de Jong can still chuckle about the solution, which ultimately lay partly in a computer chip less than one square centimetre in size. This processor controls the four dock winches that can pull in colossal vessels like the Emerald Princess smoothly and in a controlled manner, as they did during their ‘baptism of fire’ on 11 October 2022.
‘It’s unbelievable that you can achieve something so big with something so tiny,’ says De Jong, Product Group Manager Controls at DMC in Hardinxveld-Giessendam. In close cooperation with colleagues from DMC’s winches product group, a unique system was designed, developed and built.
Four winches, each with 40 tonnes of pulling power, do the hard work with one in each corner of the dock. Two winches pull the ship in, while the other two regulate the speed and the correct position of the ship by providing the exact amount of counterweight required to prevent the ship from veering sideways or floating in too quickly. While these winches slowly ease out their cables, energy is recovered and used again by the pulling winches.
What makes this exceptional system intelligent is the fact that all four dock winches are in contact with each other. The software in the winches continually calculates the power and tension of the cables – not just once, but 25 times a second – in order to be able to respond as quickly as possible. If a problem arises, it is shared centrally and the software calculates a solution that is then applied to all four winches. They therefore function as a single unit.
‘A high ship like the Emerald Princess can catch a lot of wind and create large forces that must then be controlled by the winches’, De Jong explains. ‘To avoid peak loads on the winches and anticipate shocks on the cables, the four winches need to communicate with each other extremely fast. That’s why a fibre-optic cable network has been laid around the dock.’
Easy to use
Since then, he has used the system regularly, including to pull even larger container ships into the dock. ‘It’s very easy to use’, he says. ‘And safer too. If I am operating two of the winches while my colleague on the other side of the dock is operating the other two, each of us can see what the other is doing via the monitor. That way, you avoid any mistakes that could happen through lack of communication.’
The computer also contributes to safety. ‘The people remain the operators’, says De Jong. ‘They take the decisions, but the computer does help enormously by continually monitoring everything. On the basis of those continual calculations, the system can also intervene if a particular safety margin is exceeded. For instance, if there is a gust of wind just as the operator wants to pull in the ship and the joystick pulls back, the winch will not pull in the cable, but let it out. In that way, the technology complements the work of the people.’
According to Ibourk, the system is also considerably more environmentally-friendly and far quieter than the hydraulic system which it replaced. ‘You have to be standing right next to it to hear it working’, he says. It also needs less maintenance. ‘Before, our people often had to come in to repair failures. With the new system, the DMC electronic engineers can monitor the software and watch what’s happening with us from a distance. It’s all become a lot easier for us.’
Each DMC intelligent dock winch system is a ‘one-off’, developed and set up specifically for the requirements of the client. In other words, a customised system. ‘It starts with listening very closely to what the client wants, and then advising them’, De Jong says, ‘on what is impossible, and above all, what is possible.’
So will DMC Dynamics ultimately manage to do everything the client wants? De Jong laughs. ‘A lot of people ask me that’, he says. “’Try us’, is what I always say. I don’t know if we can achieve everything. No-one can guarantee that. But now we can achieve an amazing amount in the field of electronics.’
That is the strength of Damen in general, and of DMC in particular, he adds. ‘Our skills are very broad. We can not only conceptualise and design something, we can also build, test and deliver it. Together, we can start with an idea and end with a tangible result. That’s what I like best about our work.’