Delta Life 8

DELTARES, OCTOBER 2017 13 T he windscreen wipers are working at full speed, but the sky clears as cranes, quays and containers come into sight. The rain has stopped when we reach the Botlek Traffic Management Centre. An asymmetric mushroom, or a spacecraft with legs, known as ‘the chain guard’. The front has 180 degree views of the shipping in the Botlek. That’s a vital necessity: this centre works with the Hook of Holland Traffic Management Centre to control all ingoing and outgoing shipping for the port of Rotterdam: 29,022 seagoing vessels and 105,000 inland vessels annually. On average, 350 vessels a day have to pass each other, berth, load and unload, and leave again in as quickly as possible. In a port as busy as this, how can you prevent damage to quays, the silting up of the channel, and make sure that the port will still have the most modern facilities in ten or twenty years from now, all without constantly ruffling the waters for the port’s users? Engineering Manager Egbert van der Wal and Asset Management Manager Piet Louwen told us how they manage their work during a boat tour of the Botlek. Berths Some of the assets requiring maintenance by the Port Authority are visible: quays, jetties, radar installations, pipelines, roads. Some are concealed: the authority is also responsible for dredging waterways. That work never stops. The port is constantly being filled with sediment, and roads and quays are used day and night. The Port Authority has to work with leftovers from the past: a large part of the infrastructure was built in the sixties and seventies of the last century. Its planned lifetime is over. That is clear to see as we sail past a concrete quay consisting of an unbroken row of berths. ‘We would never build like this now. There’s too much maintenance,’ says Egbert. But demolition and rebuilding are expensive, and they lead to a lot of downtime for users. In the past, the berths were lined with wooden beams, but high-quality tropical hardwood is not sustainable. And even that material has not been able to withstand the ravages of time everywhere. Modern fenders have been fitted slightly further along: steel beams coated with high-grade plastic. They absorb the impact of the ships and clients will be able to use the quay again soon. Rust holes Many of the organisations who rent quays opt to do their own maintenance. Piet Louwen: ‘You can always spot them.’ He points to rust holes on the highwater line and broken wooden beams. ‘Things have been tough for some companies in recent years,’ explains Egbert. ‘The crisis meant they had to focus on survival, and maintenance wasn’t a priority.’ But if large amounts of sand spill out through a gap like that, a port crane or container can sink into the hole. That doesn’t often happen: the Harbour Master bans the use of quays that are really unsafe. ‘Safety comes first, obviously,’ says Piet. The port wants to maximise the use of existing facilities; many materials are a lot stronger than suggested by the calculations, which are often conservative. Sometimes the port sees this as an extra safety margin; at other times, the extra strength is just a bonus for the client. ‘But strength is important!’, warns Egbert. ‘Safety mustn’t suffer from people pushing the limits.’ Old junk The port does more than patch up ‘old junk’, as Piet calls it. A visible example of innovative technology are the new black and yellow dolphins. Until recently, large vessels were berthed at buoys. An electric winch was used to tighten mooring lines between the buoy and the vessel. There was a cable to supply electricity.