Blog Archive

Tuesday, 13 February 2024

A kind of magic or Châteaux Shimshal

A line from the rhyme of the ancient mariner goes "water, water everywhere but not a drop to drink",. This would be the case here on Shimshal as well were it not for her 600l water tanks and the magical piece of equipment called a watermaker which produces what is known on board as Châteaux Shimshal 
This collection of pipes, pumps, valves and dials lives deep in the stern cabin called "Simons workshop ". It works using the principle of reverse osmosis, just Google it if you have to understand or just believe in magic as I do.
Basically you take sea water and with a small low pressure pump you put it through some very fine filters to get super clean but salty water. Next the water goes through a high pressure pump where it reaches about 900psi. This still salty, high pressure water is then sent to where the magic happens,  the osmosis membrane.  A small amount of the salty water passes through the membrane leaving all its salt behind, the rest goes back to the sea taking the excess salt back to where it belongs. 
The now salt free water is tested and sent to the boat tanks for future consumption. 
This sounds like a great solution but as well as been greedy for Amps from the batteries the watermaker is like a petulant child, all happy when the centre of attention but misbehaving as soon as you turn your back. Thus to keep the tanks full the hour or so of operation it needs every other day requires significant input if a howling child is to be avoided.
Don't believe we all have daily bubble baths, between the 4 of us we consume about 25l a day most of which is drinking, cooking and washing. Initial washing is called a swim then a wipe over with fresh to get rid of the salt. The skipper was treated to a hair wash today as it is his birthday soon.
The watermaker is going to be essential for our next long passage after the Galapagos so we need to develop some confidence in its reliability. 

Tim