Sailors onboard HMS Prince of Wales are testing her state-of-the-art pyrolysis plants, say the Royal Navy.

The system – already fitted to the ship’s older sister HMS Queen Elizabeth say the Royal Navy – is designed to keep the tonnes of rubbish generated by the 600 sailors and 400 industry engineers and experts on board to a minimum.

“During her first two visits to Invergordon, the ship offloaded several tonnes of rubbish – ‘gash’ in Royal Navy parlance – a manual, labour-intensive process given that the 1,000 souls aboard produce upwards of nine tonnes of waste every day, stored in shiny metal drums. Enter the two pyrolysis plants – which cause material to decompose under extreme temperatures.

Most waste – including food, sewage and waste oils, including those from the galley, but not metals or glass – can be processed by the plants, which can deal with 150kg of rubbish every hour. The only flame comes from a burner which initially heats the ‘oven’ to 1,100°C – as hot as a large bonfire.

The waste then becomes the fuel; the burner switches off and the plant becomes self-sustaining using minimum fuel.”

Basically, 150kg of waste becomes 1½kg of waste.

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What happens to the waste, is it dumped or used for the garden,so to speak?


It’s vital it works too. My “greatest achievement” 😀 as an early member of the USS Missouri’s volunteer engineering crew when she arrived at Ford Island, Pearl harbor was to help get the ship’s disposal and storage system back online. It was myself, and 3 elderly retired USN Chiefs laboring in the bottom levels of the ship (no air conditioning on yet) block and chain hoisting massive 1 ton waste grinders (two per side and we called them something else entirely) up through hatch after hatch, level after level to get them to the Navy who rebuilt them for us.… Read more »


So the systems can deal with 150kg per hour …that’s 3600kg in 24 hrs with 9tonnes (circa 9000kg) of rubbish being produced each day by the carrier ……is there a system shortfall somewhere here or a typo?


Gash and the onboard waste systems are briefly mentioned in the first episode of the second series of ‘Britain’s Biggest Warship’ – though I suspect most of you have seen it!

Fantastic bit of kit to have.

Bloke down the pub

It also featured heavily in the first series, usually in a bad light, as it seems to be very reliant on human sorting to remove noncompliant material, and broke down a lot.


The best thing you can do in that circumstance is make sure everyone onboard does a few shifts sorting waste, not for extra pay either.

Compliance with waste segregation would skyrocket overnight…

andy reeves

didn’t like beer cans apparently


Honestly thought it was a steam locomotive for a moment, and was considering it’s use on an aircraft carrier.
The idea of a waste disposal system powered by the exact waste it is disposing – using the waste to destroy the waste – is very cool.


Knowing what we pay for even the smallest bit of equipment will make it totally cost prohibitive for most civvie applications but the technology sounds as if it could be a savior for some of the worlds waste disposal woes.


Waste incineration with energy recovery and alternative treatment facilities are fairly common onshore. Most of the UK’s medical, offensive, cytotoxic and hazardous waste go through it already.

andy reeves

not at B A E prices


It sounds like rubbish to me!


Pyrolysis is just one in a long line of gash disposal systems that the RN has used. Outside of the 12 mile limit back in the day we ditched over the side. Brown paper gash sacks straight off the back end floating off into the sunset before sinking. The fish and nobby’s where very happy with the food waste. Then as the RN became more environmentally compliant due to IMO rules it was incinerators and compactors.Incinerators are now gone and its compactors and shredders on most vessels depositing the waste in metal tins for disposal ashore. However, and there is… Read more »


Hi Gunbuster, good info. Does anyone know what happens to the waste? I take it, it’s just dumped in the landfill tin’s an all


Each person on board produces upward of 9 kg of waste each day? That seems rather a lot…