DMC specialists transfer knowledge

All the hydraulics systems on board a vessel that are made by DMC draw their power from a single, central reservoir of pumps and circuits. Our specialists travel the world, accumulating years of experience, equipping hundreds of working vessels with sophisticated hydraulics and providing expert after-sales support. So it’s no surprise that they bring home stories about interesting projects in remote countries.

Cees Hoogvliet and Ray Soumokil have decades of experience in hydraulics under their belts, with Cees progressing to be a Technical Support Manager in the field of hydraulic installations, and Ray now a Commissioning Engineer. The two have been working together since 1995, with Cees making the drawings and calculations and Ray commissioning the hydraulic installations. Ray usually does that at a Damen Shipyards yard, but he also does it in ports where customers’ ships are moored, if that’s more convenient. “We can install the complete hydraulics package on board a ship,” Ray reports. “Once the initial installation and commissioning phases are completed, we can continue to complete the job while the ship is operational. That’s very important to our customers.”

On the road
“We specialise in ocean-going ships,” continues Ray. “That means that the ships can be located anywhere in the world. Most of the hydraulic installations that we provide are on board assistance vessels, which include tugs and vessels that support dredging operations.” These can be intensive projects that run continuously, day and night, until they are completed. “Delays resulting from failing systems is not an option. And if there are breakdowns, their first move is to try to resolve any problems over a phone call. In recent years, assistance over the phone has become much easier and more effective. The vessel’s mechanical engineer can use his phone to photograph or take a video of the malfunctioning installation and send it to us and often that enables us to solve the problem. But if we can’t, we go to the vessel.” Ray is often on the road for work.

Power sources
The hydraulic specialists at DMC focus primarily on the larger systems: man-sized power packs with a capacity of 2 500 to 3 000 litres of hydraulic oil.  Through an elaborate system of valves and circuits, the pressurised oil drives various systems on board. The power packs are the central sources of power for the entire hydraulic system on board: winches, rudder systems, mast lowering systems and bow thrusters can all be powered by hydraulics. The installed power of such a power pack can be as much as five or six thousand kilowatts. On board different types of working vessels there are different types of equipment on deck that require their own delicate adjusting of the power output to drive them efficiently. The loads on towing winches can be very different than the loads on anchor winches, for example.

Sister ships
“We provide complete hydraulic systems for all kinds of ships, for DMC customers as well as for Damen’s shipyards,” Ray explains. “At the moment, we are working on three Damen Multi Cat 3313 SD (shallow draft) workboats. One is being built in Gorinchem, and the other two in Dubai at Albwardy Damen. For these vessels, we are providing the hydraulic systems for the anchor winches on the foredeck, the two towing winches on the stern, and the towing pins and the mast lowering installations.

Rudders
The rudder systems supplied by DMC are also hydraulically controlled. For this purpose, smaller power packs and cylinders are applied, rather than the large-scale hydraulics that Cees and Ray often work with. Of course, the specialists also help ensure that the proper configuration of reservoirs, pumps, piping and cylinders for the rudders are achieved.

Developing over time
Cees started in 1993 as a hydraulics specialist, Ray joined a year and a half later. Together they have completed many projects. When the Albwardy Damen shipyard was starting up and developing in the Middle East, Ray and Cees lived there for months. “We really enjoyed working there. We built the first Shoalbuster at a yard that was still under development.” Another project took the colleagues to Africa, where a two-kilometre-long jetty was being built as a docking facility for huge cargo ships that would be loaded with the ore from a copper mine a short distance inland.

“There was a huge tidal range there,” Ray recalls. “That’s why we had to develop a system that could hold the jetty in position at both low and high tide.” says Cees.  “We call it constant tensioning. The cables anchoring the jetty slacken off at low tide. Sensors in the installation register this and they pull the cables tight again. When the tide comes back in, the floating jetty rises. The sensors register this and pay out the cable just enough to keep the anchorage of the jetty stable, while still allowing it to rise.”

Safe workspace
“Our collaboration as colleagues began in the company WK Hydraulics,” says Cees. “That company merged with DMC in 2019 and we became part of an organisation that specialises in a lot of innovative marine systems, in addition to hydraulics. Because there is also a lot of experience here in developing systems for tugs, we were involved in the development of the Towing Pins.” Usually these are two sturdy bollards on the aft deck of a tugboat that move up and down hydraulically. When they are up, the tug’s towing line can run in between these pins to prevent it from sweeping across the vessel’s aft deck, which could be dangerous for any crew nearby. If the tow rope is not under tension, the towing pins can be retracted into the deck, providing maximum working space.

“Recently we helped develop the second generation of towing pins,” continues Cees. “The latest models can be moved up and down individually, so that a single pin can also be used as a cleat to secure a line. They are available with two, three or four pins and with one or two chain stoppers. These can be used to secure an anchor chain. The line that pulls the anchor chain can then be released from tension, allowing the deck crew to use that line to secure other cables or chains.

Components
The construction of offshore wind farms has been a major source of maritime activities in recent years. “We regularly supply anchor winches and a wide range of other hydraulic installations on board cable-laying vessels,“ says Cees. “They connect the electrical transformers at the wind farms to the power grids on land.” The large power packs are reservoirs of hydraulic oil, to which pumps are connected and a hefty number of valves and switches for all the various hydraulic systems.

The power packs are so large that during the construction of a ship, the basic components of the hydraulics are placed in the hull first, even before the main engine is installed. “We supply the components,” says Cees. “The reservoirs, power packs and cylinders. The shipyard or shipowner purchases the pipes and hoses themselves. These are made to measure. We do the design first and then take care of the commissioning. We also offer service support throughout the lifetime of the installation.”

Digital
The hydraulics department at DMC has a high workload. “It’s difficult to get enough staff,” Ray observes. The two sixty somethings will continue their work for a few more years until retirement, but they are highly motivated to pass on their experience and teach young colleagues the accumulated knowledge which they have gathered over the years. ” The technology of hydraulics continues to evolve in response to new technology,” Cees observes. “Nowadays the installation is controlled digitally by PLCs (Programmable Logic Controllers, small computers with no fans or moving parts). In that respect, the new generation of colleagues can improve on what we do.”

“They are much faster and more at ease with the data and programmes on such a PLC and programme them faster as well.” Ray adds: “The new guys already have a good grasp of the business. I confidently let them go out to customers because I know they have a firm knowledge of hydraulics. Yet I don’t want to stop yet. I think that after I retire, I will still want to be involved with DMC.”

Cross-sector cooperation
Of all the hydraulics on board, the lifting cranes are the only items that DMC does not get involved with. “They are taken care of by the crane suppliers,” says Ray. But he understands the technology that underlies cranes very well. A good example of solidarity in the chain of suppliers in the maritime industry is when Ray does crane repairs on location, so that the engineer from the crane supplier does not also need to travel to some distant place.

“When I’m on board a ship to do repairs on the installations that we supplied, and there is also a problem with a crane, then I will work on that as well. Of course, I first contact the supplier of the crane. If I am there anyway as a hydraulics specialist, it isn’t necessary for them to send their own mechanic. Everyone benefits, especially the customer, who is helped quickly. The crane supplier has been able to use my services and will remember that. And if the reverse happens one day, our willingness to help each other may also come in handy for our ship owner and for DMC.”