A whole new slant on turning the tap for freshwater

By June 12th, 2018

By: Simone Burzacott-Gorman

In a country like Australia, we are cognisant of the need for water and how difficult it is to find in places like the desert. Second engineer Mark, considers the ocean in just the same way. Aboard Investigator when we are cosy in our cabins or are mixing in the mess for a meal, accessing water is as easy as turning on the tap. But today on tour of the engine room we were flabbergasted by the science involved in accessing water on this ship.

Investigator can carry 145 tonnes of water when she sets sail and can maintain her supply for months at sea. This water is used for showering, drinking and cooking with 35-40 tonne reserved for fire misting. Not to panic on a state of the art science vessel, Investigator has the means to make water. Fitted with both a desalination and reserve osmosis system Investigator can produce several tonnes of water per day.

The further south she travels however, the harder it is to make water. This is because heat is required from the engines to run the water generator. During very cold weather, the engine reserves its heat, leaving little for desalinisation. In Antarctica, Investigator struggles to make 1 to 2 tonnes of water per day. Comparatively in the tropics she can make 20 tonnes per day. With a full vessel, the water is used relatively rapidly. Consequently, water generation is a primary resource the engineers monitor closely. To assist desalination Investigator was fitted with a reverse osmosis system, which can generate 5-6 tonne of water per day.

Mark explained that water has only been rationed once on the vessel. This occurred in Antarctica when one of the lines burst and 20 tonnes was lost. He described the scene following the ruptured line ‘akin to something from FROZEN’. Unable to make up the lost supply, water was rationed until the crew could repair the damaged line, after travelling north to warmer climes.

Refilling my water bottle later that afternoon, I was left in awe of the science behind the supply this most precious resource.