UFX022 TOILET VACUUM FLUSH

I was recently travelling on the Bluebridge ferry, on the way back to Wellington. Its a 3 hour trip from Picton in the South island, through the Marlborough Sounds, across Cook Strait and in to Wellington Port. I usually book a cabin for the trip, as it means I can have a sleep and charge my laptop etc…

But I noticed that the toilet is a vacuum pressurised system, the same as is used on aeroplanes. I had my Sony D100 recorder with me, so I recorded vacuum flushing the toilet as it is such an aggressive sound – my neighbour was probably wondering what was with all the multiple takes! I also recorded an ambience of ferry rumble from in the bathroom, as use for fill incase it is needed.

“Airplane toilets use an active vacuum instead of a passive siphon, and they are therefore called vacuum toilets. When you flush, it opens a valve in the sewer line, and the vacuum in the line sucks the contents out of the bowl and into a tank. Because the vacuum does all the work, it takes very little water to clean the bowl for the next person. Most vacuum systems flush with just half a gallon (2 liters) of fluid or less, compared to 1.6 gallons (6 liters) for a water-saving toilet and up to 5 gallons (19 liters) for an older toilet.”