Commander Frank Plettner is tracking a container ship sailing in the North Sea via radar, traveling from the Elbe to the English Channel. The ship is about ten miles from the German police patrol boat Bamberg. Plettner aims to measure the sulfur emissions from the ship’s chimney with the help of a helicopter-like unmanned aerial vehicle that will take off from the deck of the Bamberg. Via a pollutant measuring device, the drone will fly through the ship’s exhaust gases and record their environmental footprint.

A challenge for the authorities

The North Sea is one of the world’s busiest shipping lanes. There, as in the Baltic Sea, strict limit values ​​apply for sulfur emissions: Marine fuels are only permitted if they have a maximum sulfur content of 0.1%, as opposed to the internationally applicable value of 0.5%. “The less sulfur a fuel contains, the more expensive it is,” says Carolyn Abromite of the Federal Maritime and Hydrographic Office (BSH). That is why offenders are often found.

These kinds of controls are a challenge for the authorities, as they are time-consuming and expensive. For this reason BSH has installed fixed measuring stations at various locations, such as in Bremerhaven and the Kiel Canal. If limits are found to be exceeded there, the authorities take samples of the fuel at the next port of call.

But what about the tankers, bulk carriers and “giant” container ships that sail between the English Channel and Denmark – far from German shores? This summer authorities in Germany are using a surveying drone that takes off from a ship in the middle of the sea.

Environmental violations are common

In the North Sea, after three months of drone inspections, seven violations were detected in 50 missions. The results were each made available, along with the ship’s data, to control authorities in all European ports, Abromite says. In cases where violations are finally proven, shipping companies face fines of up to 50,000 euros.

For several years, the European Maritime Safety Agency (EMSA) has made survey drones available to all European member states upon request. One of EMSA’s drones has also been in use on the federal police ship “Bamberg” since June.

Getting data right is hard

Flight professionals sent by EMSA are involved in the take-off process. One of them, Alexander Ludwig, oversees it from the platform forward of the ship’s bridge, with the aircraft’s control unit strapped to it. When given the green light to take off the drone takes off quickly. It then flies towards the selected container ship, which it keeps in its line of sight. A colleague of Ludwig’s, Roman Nagy, watches the drone’s camera on a screen and controls the aircraft with a controller. When it reaches the ship, it flies into the exhaust, where it remains for a few minutes. “It’s not easy to find the right spot,” as Nagy explains. That is why only half of the measurements of the last three months could be evaluated.

The drone does not come closer than 100 meters to the ship because, as Commander Pletner explains, “the crew can hear it.” In any case, however, “everyone is informed that drone surveillance is possible at any time,” as Plettner emphasizes.

When the drone is placed in the right spot, the data is quickly evaluated. In the event that no violation of the limits is found, Carolyn Abromite is not disappointed: “It’s positive that we don’t find anything.” Checks are carried out daily, and the drone can be used up to twice a day, completing up to six hours of flight time.

Despite the current limits, in 2018 around 140 million tonnes of carbon dioxide emissions were caused by ships calling at EU ports. and the E.O.H., as shown by a report by EMSA and the European Environment Agency. At the end of August drone checks in the North Sea will be completed. Abromite says it is very pleased with how the inspections have progressed, adding that “we have already submitted an application to EMSA to use drones again in the North Sea in 2024”.