Hybrid propulsion: 40% more economical
Some 30,000 seagoing ships and 110,000 inland vessels arrive at the Port of Rotterdam each year. To manage this fleet, the Port of Rotterdam Authority has a number of patrol vessels. One of these vessels is the RPA 8, launched in 2018, a 25-meter vessel that can run on both diesel and diesel-electric (hybrid). Controlin supplied ComAp generator controllers for synchronization and load sharing for this vessel.
An economical and sustainable ship
Challenges for the construction of the ship were requirements to reduce the cost of the ship throughout its life cycle, reduce emissions and reduce wave action. The realization of the RPA 8 therefore fitted seamlessly with the policy of the Port of Rotterdam Authority to stimulate sustainable sailing.
The RPA 8, built by the Kooiman Group and installed by Holland Ship Electric, was to replace the RPA 3. The RPA 8 only needs 60% of the power of the RPA 3 to reach the same speed of 35km/h. In addition, the RPA 8 consumes as much as 40% less fuel and causes significantly less wash of the waves. The RPA 8 produces 29cm high waves when patrolling at 20km/h, while the waves for its predecessor were 58cm high.
Efficient Patrol
The fact that the RPA 8 is so economical has to do with a number of things. For example, the ship's hull is made of aluminum. Aluminum is three times lighter than steel, which means the vessel consumes less fuel. In addition, the special underwater spoiler provides a fuel saving of 22% at top speed and at 20km/h a resistance reduction of 20% and fuel saving of 25%. The hybrid propulsion system, for which Controlin supplied a trio of ComAp IG-NT-GC controllers installed by Holland Ship Electric, allows efficient patrolling at low speeds. In fact, this type of controller contributes to lower fuel consumption, fewer pollutant emissions and a reduction in the number of running hours at low load. In short, generator deployment can be handled more efficiently. The hybrid propulsion is made possible in part by shutting down one main engine. In this case, a magneto engine acts as a dynamo and drives both the other propeller and the on-board power supply, so only 1 diesel engine keeps everything running. Finally, residual heat from the main engines is used to heat the ship.
Green passport thanks to hybrid propulsion
The environment was considered during the construction of the RPA 8. The main engines equipped with an exhaust aftertreatment system, a particulate filter on the port generator and NOx emissions of only 90mg/m3 in hybrid mode (22km/h) ensure that the RPA 8 is labeled with a green passport.
