Volvo Ocean Race - Playing with weights

by Team Brunel - Robbert-Jan Metselaar on 5 Feb 2015 Volvo Ocean Race - 'We have to save diesel,' reported onboard media reporter Stefan Coppers during the last leg. At which fans and sponsors immediately wondered why a professional sailing team took so little diesel. Team Brunel’s boat captain Jens Dolmer explains.

'In this race, we are sailing with six identical boats that all weigh exactly the same,' says Jens Dolmer. 'It’s up to the individual teams to decide how much extra weight they take with them on board for each leg, in the form of food, spare parts, diesel and personal effects. On the second leg, we were the lightest boat in the field. And that turned out to be very successful. In light winds, it’s easier to keep a lighter boat moving. The downside is that when there’s more wind and you’re close hauled, you’re at a disadvantage compared with heavier boats. You can’t sail the boat as straight. And the more obliquely you sail, the slower you are. We had less ‘movable’ weight on board to use as counterweight. Because the weather conditions on the last leg were going to be more or less similar to those on the leg to Abu Dhabi, we decided to start as light as possible again.'

This is the time when Jens and skipper Bouwe Bekking take a look at what personal items and spare parts are really needed. 'Bouwe makes a list of all the personal effects that the men can take with them. As boat captain, I’m responsible for what spare parts we bring and how many of each. I also decide how much diesel we are going to take on, based on the estimated time of arrival as calculated by Andrew Cape.'

'It’s always difficult to calculate the right amount of diesel. In a normal situation, we use the diesel engine to charge the batteries every day. At the same time, we switch on the watermaker that turns salt water into fresh water. That takes about an hour. In light winds, we use considerably more power than in strong winds because we have to use the keel a lot more to trim the boat. The keel’s canting system is driven by an electrically powered hydraulic pump. So if you get less wind than you expected – and you have to cant the keel more often – you use a lot more diesel than you calculated in advance. This is also what happened on the last leg. Because of the extremely light winds, we used a lot more diesel than expected. To save diesel, we used less power by switching off the fans in the bunks and the interior lights.'

'If you use up all of the diesel, you’ve got a big problem. According to the rules, you can use your reserve diesel supply only in an emergency. That’s why I always devote a lot of time to calculating the fuel. There’s no room for mistakes.'