Both these ships have especially been built to transport parts of the Airbus A380 on the river Garonne in France. To be allowed to navigate here, they had to meet a big number of requirements set by the French authorities as well as by the French environmental movement.
Some of the requirements the ships had to meet were: no bow wave, also not at high speed. To achieve this, the shipbuilding yard developed a special head with which at the Marin in Wageningen tug trials were done to check the calculations.
Practically no sound was allowed at some distance of the ship. The only way to meet this requirement was to drive the ship electrically. Because of the fact that the generators have a fixed rpm and accordingly a fixed volume, it was possible, by means of isolation, to comply with this requirement.
In Bordeaux a historical bridge had to be passed, which under no circumstance could be damaged. That is why very high demands were set to the certainties with regard to the drive; if a drive or a generator stopped, the ship would have to stay well navigable. The passing under the Pont De Pierre happens completely on autopilot and is steered from 2 GPS systems. To be sure that the ship cannot hit the bridge under no circumstance, a complete slackening structure has been constructed under one of the spans of the bridge and the ship has been designed in such a way that the wheel house and the cargo cannot hit the bridge.
There are in total more than 50 cargo options possible; every option was a challenge for the designers in itself. The big circular shapes of the plane itself required a special bottom in the cargo hold. The parts are driven on board of the ship by means of platform carts, the cargo floor goes up and the pallets with cargo are received by a number of hydraulic nibs. The floor can go down and the platform carts leave the ship. Now the floor goes up again, lifts the pallets with cargo, the hydraulic nibs go back to rest and the cargo can go down under in the ship. To load the wings, the depth of the cargo hold was not that important but now the width was crucial; at every side of the wing there is approximately 10 cm space left. Because the cargo comes on board over the stern and might weigh a few hundred tons, the ship has been equipped with a fully automatic ballast system that, while the cargo is slowly driven on board from the loading pontoon, it is kept in balance lengthwise as well as beam wise. Eventually the ships are also electrically driven. In the engine room there are three Caterpillar generators with a capacity of 900kW each which, load dependently, automatically switch on and off. At the rear of the ship two completely separated engine rooms have been made, where the drive is constructed. The drive comes about by two 700kW electric motors which are connected to frequency drives. Also the bow thruster of 400kW is driven by means of a frequency drive.