This year, Sif started the production of 70 TP-less monopiles for Hollandse Kust Noord, a Van Oord project. The monopiles are scheduled to be ready at the beginning of 2023. Stefan Sturm (Manager Operations Office) and Ralph Lacroix (Project Manager) explain how they translate the customer's wishes into an efficient production process.
Insight through simulation
“We did a simulation prior to production,” says Ralph. “We simulated the factories to scale and started moving through the halls with mini-cans. That has provided a lot of insight.' All cans for HKN are made in Roermond. The first seven cans, flange and Airtight ring for the top sections are welded together in Roermond and then go to Smulders (Hoboken) where the connection points (Boatlanding and Main Access Platform stabbings) for the secondary steel are welded. From there, we transport the top pieces to Rotterdam where they are combined with the bottom sections. The cans for the bottom sections go directly from Roermond to Rotterdam. “We try to have the top and bottom sections arrive in Rotterdam at the same time,” says Stefan. “We use the transport containers as floating storage.”
“The bottom sections of the monopiles have two different diameters (7.4m and 7.8m), which the customer wants to install in a different order,” Stefan continues. ‘For the production flow, however, it is more pleasant to first make everything from one diameter in order to limit factory conversion times as much as possible. The simulation gave the insight that the difference in diameter for the coating halls is not a problem. So we produce in the order that is convenient for us, store the monopiles and bring them to the coating halls in the order of installation as desired by the customer!'