Skip to main content

WATER WATER EVERYWHERE


"Water, Water everywhere
And all aboard did shrink
Water, water everywhere
Nor any drop to drink"
from "The Rime of the Ancyent Marinere" (1797-98)

Today is International Blog Action Day 2010 and the theme is to write about water, not just any water but clean water around the world. For seafarers we are on the water all the time but it is sea water (NaCl+H2O) and so we need places to obtain fresh water (H2O). For thousands of years this was always the seafarers problem how to obtain and then carry clean fresh water for sea voyages particularly the long sea voyages of the world explorers. Then reverse osmosis was discovered at the University of Florida in the 1950's and basically the problem was solved. Now all that sea water could be purified into drinkable fresh water (FW).

Reverse osmosis is the method of forcing solvent from liquids using a suitable membrane. Just about all over the world drinking water purification systems include a reverse osmosis step. On board ship the sea water is pumped through the reverse osmosis system and pumped out as usable fresh water to be stored in the FW tanks. So the old problem of obtaining and using FW at sea is solved, with the system operating continuously the FW is used and replaced.

The system consists of :
  • a series of sediment filters
  • an activated carbon filter
  • a reverse osmosis filter, which is the membrane
  • a second carbon filter, to back up the membrane
  • an ultra-violet lamp for disinfecting any microbes

So there it is potable fresh water from the sea, not exactly free of course but always available. For a full explanation of 'Reverse Osmosis' and the words of "The Rime of the Ancyent Marinere" visit Wikipedia.

Good Watch.

Comments

Popular posts from this blog

PAINT LOCKER FIRES

The photographs above are revealing in several ways, lets have a look. Clearly the Japanese Maritime Self Defence Force (JMSDF) vessel JS "Kurama" impacted the Korean container ship MS "Carina Star" just aft of the turn of the fo'cs'le on the Starboard side. Please note that's the Starboard side, thus it appears JS "Kurama" would have shown "Carina Star" the red port sidelight and "Carina Star" would have shown JS "Kurama" the green starboard sidelight. This impact point would tend to suggest that JS "Kurama" was the 'stand-on' vessel and the MS "Carina Star" is the 'giving-way' vessel. Until there is a complete plot of the tracks made good of both these vessels and the position in the Kanmon Strait of the point of collision no determination can actually be made. As a result of this impact there was severe bow damage to JS "Kurama" and in addition a massive f

HOW TO WEAR A LIFEJACKET

A popular U.S.-based cruise ship style A popular European ferry style Several times during the year NAUTICAL LOG has had visitors searching for lifejacket instructions. With two just over Christmas we decided to publish something for everybody to see and read. Choose a Coast Guard approved life-jacket and make sure it is undamaged. Make sure life-jackets are readily accessible, never locked away. Check the fit, there are adult, child and infant sizes, the correct one MUST be used. Choose bright colour life-jackets so as to be seen easily by Search and Rescue (SAR). Put your life-jacket ON BEFORE you leave the berth. Make sure you have a light and whistle attached AND they BOTH WORK. Good Watch

BOUILLABAISSE

TAAF Service vessel operated by CMA CGM TAAF Regional flag Well now let us see if here at NAUTICAL LOG we have got a grasp on things simmering in the pot. It seems that when the anti-whaling campaign started out some years ago it was between Greenpeace, the Sea Shepherds and the Japanese whaling fleet. The Australians came down to their own Southern Ocean Territory in a chartered civilian vessel one year. Beyond taking photographs and returning some Sea Shepherds to their ship the MS "Steve Irwin" not much was accomplished. The Greenpeace crowd then dropped out and Animal Planet boarded the MS "Steve Irwin" to shoot 'reality TV' and so Whale Wars came into being. This resulted in some deplorable behaviour on all sides and some appalling exhibitions of seamanship - or rather total lack of seamanship by the Sea Shepherds. But now there was money coming in which could be spent on - well nobody really knows what the money is spent on. New Zealand made it q