Control over the logistics behind an offshore wind farm

The Belgian company DEME specializes in maritime construction projects: dredging, offshore installation and marine engineering. DEME is currently building the Nordlicht offshore wind farm in the German North Sea. Seven barges and five tugs are underway to transport the foundations. The tugs tow the barges between the steel manufacturers, the Kiel Canal, Rostock and Eemshaven. With GPS-Buddy, DEME keeps control of all those moving assets, from the quay at the manufacturer to the installation vessel at sea.

The project team uses Flowter, the GPS-Buddy platform, for four tasks: tracking barges and tugs in real time, checking port invoices afterwards against the recorded movements, reporting daily to the client, and keeping DEME's own management informed of what is en route. Eighteen people from logistics and project controls look at the same picture.

Tugs can be tracked via AIS. That is standard in the maritime sector. Barges cannot. In Lucas's words, they are steel shoeboxes with no system of their own to transmit their location. There is no engine, no battery and no socket to plug anything into. Yet every barge can be tracked, and the solution fits exactly how DEME works, in three ways.

First of all, it also works without power on board. Every barge carries an RFID tag that runs for years on its own battery. The tag sends its signal to an XT-4 gateway that plugs into a socket in the tug captain's cabin. That gateway forwards everything to Flowter. That way, an asset with no power supply becomes visible through the vessel towing it.

Second, nothing needs to be permanently installed. The tugs are chartered. They are not DEME's property, and the fleet may look different after this project. A fixed installation was therefore not an obvious choice. The gateway simply comes out of the socket and moves along to the next vessel.

Finally, the solution fits how barges and tugs are actually deployed. Any tug can tow any barge, and there are more barges than tugs. The combinations therefore change constantly.

Henri Casteleyn, responsible for logistics on the project: "Tug A sails with barge 1, then tug B sails with barge 1. You didn't always know very well which barge was being towed. With a tracker on that barge, you can see exactly which tug is sailing with which barge. We have seven barges and five tugs sailing around, plus two installation vessels. That's simply a lot to keep track of, especially with a team that rotates."

2. Checking port invoices against the history

The second application was not on the list beforehand. Ports invoice with a delay. A berth, or a shift from one quay to another, sometimes only appears on the invoice two weeks later, sometimes only after two months. Then someone has to check whether it is correct.

Henri: "I'm now getting invoices in from the end of June. The port will say: you arrived on the 15th of June and left on the 18th. Then I go and check in Flowter whether that's right. I have too many movements to keep track of all day, who lay where. That's simply not possible, I have other things to do. For that kind of check, I still use it a lot."

Because the history is kept, the team can also check months later exactly where the barges and tugs were sailing. "Within a few months you still know exactly where the tugs and barges were sailing in July," says Lucas.

3. Reporting daily to the client

Every day, DEME reports to the client which movements the barges made between the various ports and how long the loadouts at the manufacturers took. The data from Flowter is the basis for that.

That saves back-and-forth. Questions about a transport less often end up with a colleague or an external party, because the answer is already on the screen. The figures that go into the reporting come from the same source as the picture the team itself steers by.

After three months in operation, the project team sees the following results:

• One central source for the location of barges, tugs and logistics assets, with eighteen people looking at the same information.
• Visibility of assets with no power supply of their own, via tags and the gateways on the chartered tugs.
• Less time spent collecting and verifying location data by email, phone or external parties.
• Deviations, standstills and unexpected movements become visible faster to logistics and project controls.
• Port invoices that arrive months later can be checked against the recorded history.
• Daily reporting to the client on movements and loadout duration, based on recorded data.