The first thing that hits you when you enter the Eastney Gas Engine House museum is the smell of diesel oil and metal.
Then it’s the huge, bright-red flywheels, the pistons firing and the gentle whirr of the enormous brass crank shaft.
Even for someone with no interest in engineering, the sights, sounds and smells are intoxicating. It’s like stepping back 100 years – in glorious technicolour.
‘We call it Portsmouth’s best kept secret,’ says volunteer John Watkins. ‘It is totally unique, the most superb example of early Edwardian engineering. We think it's one of the most important engine houses in the country.’
It is part of the sprawling Eastney pumping station site, off Henderson Road, which pumps Portsmouth’s waste water out to sea once it has been cleaned and treated by Southern Water.
Following the 1845 Sewage and Drainage of Towns Act, the council built a huge underground sewerage system.
The steam-powered Beam Engine House – which is currently closed – opened in 1868. And in 1904 the Gas Engine House opened next door with three 180 hp Crossley Y2 gas engines with Tangye pumps. There are now just two remaining as the third was cannibalised to keep the others running. The engine house was held in reserve until 1971.
John, 82, is the longest-serving member of a 13-strong group of volunteers who have been working doggedly for 10 years to restore the engine house to its former glory.
It is owned by Portsmouth City Council but was officially handed over to the volunteers to look after in 2017.
‘When I first walked in here a decade ago it was all shut up and the roof was destroyed,’ says John with a smile. ‘Everything was covered in rust but I knew it was special and it had to be saved for Portsmouth.
‘The engines are unique. You will never get casting like this again in the UK. This is part of Portsmouth’s history and children should know about it.’
What does a pumping station actually do?
Waste water from every home in the city – including waste from toilets, baths, sinks, washing machines and dishwashers – is screened in what is essentially a huge rotating colander to get rid of all non-liquid waste.
It then goes through an even finer filter to get rid of tiny particles of grit and sand.
From there it is sent to Budds Farm for aeration and filtration.
The water then flows underground through the vast network of sewage pipes, back to the Eastney pumping station site, where it is pumped 5.5km out to sea through the outfall pipe.
All of this is done by Southern Water.
Everyone here has a passion for engines and machines. And while the engines are no longer gas-powered – thanks to some mindless vandalism – an ancillary engine that the volunteers put together starts them up and they are truly a sight to behold.
The flywheel weighs more than 5.5 tonnes and took two men eight weeks to clean.
Every lever, nut and bolt shines.
The green paint which dominates the engine house is flawless.
Nearly all the volunteers are retired engineers and the pride they take in their work is evident.
They spend a couple of days a week at the museum, powered by lots of strong tea, chicken wings and custard doughnuts.
And there is plenty of banter served up while they polish, paint, and clean the machines.
The visitors’ book is bulging with top reviews from people from as far away as Italy, New Zealand and even Malaysia.
One entry that John is particularly proud of, written by a young visitor from New York, simply says: ‘Now I want to be an engineer more than ever!’
And that is all John and the team are after.
Ron Shipp, 74, worked at the pumping station site for 40 years and knows the workings of all the pumping stations in the city – the old and the new.
He says: ‘I really wanted this place to work. I still get a thrill when the engines start up.
‘To see the children’s faces when they see a big piece of kit moving is wonderful.
‘When we start up the engines with the touch of a button their little faces light up.
‘Hopefully we will inspire another generation of engineers.’
They now plan to open the museum up for school visits because they think it is vital that youngsters learn about the past.
George Barrett, 68, from Old Portsmouth, is working on leaks in the cooling system of one of the smaller engines when we meet.
He started off as an apprentice as Fawley Power Station and ended up as a technology teacher.
He is now retired and began volunteering at the Gas Engine House 18 months ago.
‘I came here on an open day and fell in love with the place,’ he says.
‘It’s a way of putting my experience to good use and gets me out from under my wife’s feet.
‘On open days we get quite a lot of young people in with their parents.
‘It is so important that we get the engineering message over to youngsters.
‘Getting a machine working again is very satisfying.
‘And if by watching us in action it sparks the interest of even just one child to become an engineer, that is all worth it.’
The Gas Engine House is in Henderson Road, just past the stone masons.
It is open on the last Sunday of every month, from 11am until 5pm. Pop by to find out more.
Museum is perfect for steampunk photoshoots
The renovation work at the Eastney Gas Engine House was made possible thanks to generous donations from Friends of Portsmouth Museums and Rolls Royce.
The group also received a lot of help from Portsmouth Steel Fabrications with a free supply of steel and welding expertise in getting the engines revolving by ancillary electric motors.
They are now looking for help in acquiring a mannequin which they will dress to make look like an Edwardian engineer.
Photographers are welcome at open days but for health and safety reasons they cannot use tripods.
There are also looking at hosting steampunk photo session.
Pop by on the monthly open days for more information.
Donations can be made at the museum.