London is loaded with unknown and unspoken historic technology. It is almost alarming how long you can live in the city without knowing how some of its most iconic structures use tech to function. It is also fascinating to discover the ways in which some technology has adapted to changing times. To find out more about London’s historic relationship with technology, and to understand the then and the now, London360 caught up with three experts in the field. Specializing in different areas, each expert helped us delve into the intriguing evolution of London’s tech usage. In this piece, we look at how some of London’s earlier technology still works in the original way it was designed to when it was built, like Parliament’s extractor fan system. We then explore how some tech has had to adapt, focusing on Tower Bridge and London’s sewage system. Finally, we reflect on tech that has unfortunately failed to survive the demands of change. We look at Battersea Power Station which, although under massive redevelopment, is regarded by many to be one of London’s most iconic and historic technological losses.


Timeless Tech: Parliament

Parliament was originally a medieval-type complex.  In 1834 it burnt to the ground and was replaced with what we see today. The rebuild was an immense project and planning to heat it, ventilate it and take the sewage away from it was a massive technological undertaking.

We have previously looked into the timeless tech behind Big Ben and discovered that it uses an originally very unique gravity and special weights system. You can read more about Big Ben’s Tech here.

We met with Laurence Scales, who is a London Science and Technology Guide. He explained some of the other ways parliament has and continues to use the same tech from years gone by. To ensure effective ventilation, a giant extractor fan was integrated into the design of the building. Laurence revealed that the ‘ornate pointy aperture in the middle, between the two towers, is really an extractor fan, it’s just a rather beautiful one’. It doesn’t have any moving parts but the idea was that all the hot air, and a lot is produced in parliament, should come out of it. Interestingly, Big Ben itself is a glorified stink-pipe, ‘ok it has a nice clock at the top, but we have stink-pipes around London’s streets for ventilating the sewers, Big Ben just happens to be a particularly big one which the sewers vent up’!  The main sewers were built slightly after the Houses of Parliament, which meant all of the lavatories drained slightly below the level of the sewer. In 1887 the MPs could stand the smell no longer and invested in a great ejector.

Parliament Joseph Aspinall


We asked Laurence why places like Parliament and London as a whole have always been ahead of the tech game. He felt it was due to freedom of thought both politically and religiously that London had been gifted with for quite some time. This, he said, allowed inventors the space to think and businessmen the space to plan and invest. Most of the inventions likely came from craftsmen initially, but later science began to take the lead. London was very well placed with the Royal Society and University College, which was founded way back in the 1820’s. With this combination, London had ‘the right intellectual chemistry’.

Laurence doubts that London will ever lose the great legacy that the Victorians and even their predecessors left. He hopes that London will keep ‘at least some of the original tech created by our forbearers’.  It would be also be much too expensive to replace everything. He regards it as something of a personal mission ‘to keep alive the story of the fabulous tech that London has and has developed and sometimes developed before other cities.


Future-Proof Tech: Tower Bridge

Glen Ellis, who works as a senior technical officer at Tower Bridge, told us of his continual surprise at how few people who live and work in London actually know about this absolute landmark. He is shocked at how few realize that the bridge actually opens and how even less seem to know it takes under ten minutes to do so.  According to Glen the biggest thing people miss out on is learning about how it uses technology to work and the relevance of what is below the bridge. Glen noted ‘they just don’t imagine that all that machinery and equipment is down there below the bridge’. Helpfully, he is used to breaking it down into a simple, easily understandable explanation. If this is all sounding new to you, you’ll be impressed to find out exactly how it works.

Tower Bridge Joseph Aspinall

Tower Bridge

The first thing to understand is that this has changed. ‘The technology we use today is oil powered hydraulics, and that’s driven by electric motors, whereas before that it was water powered hydraulics, the pumps then were driven by steam engines’.


The old system used to open the bridge was powered by steam. There were four Lancashire boilers generating steam pressure at 50 pounds per square inch. These would have then operated steam engines, using that same pressure, but developed a water pressure of 750 pounds per square inch. That was then used to raise six hydraulic accumulators. A hydraulic accumulator is basically a hydraulic ram with a hundred tonne weight on it. When a bridge driver went to open the bridge, all six accumulators would force the water out and operate the pumping engines. These would turn the gears and the quadrants, raising the bridge.


Due to a cultural shift in the mid 1960’s to late 1970’s towards using electricity, the London hydraulic company that powered Tower Bridge’s back-up supply went out of existence. With that in mind the corporation of London decided to electrify the bridge. The demise of bridge lifts, which went from an initial six thousand a year to only about two hundred and fifty, as well as the ability with new equipment  to employ less staff, a mere twelve compared to the required eighty, were also major factors involved in the decision to update the lift technology.

Today, the two bascules, which weigh twelve hundred tonnes each, are powered independently by hydraulic power packs. Each power pack has got two 50 horsepower electric motors. These drive hydraulic motors (a rotary type of motor) which turn the original gears and quadrants on the back of the bridge. This raises the bridge during a lift. The reason it can move so easily and quickly in that time is the fact that the bascules are counterbalanced. Glen explains ‘it is purely like a seesaw, with one end a little bit shorter than the other. In the back end of the bridge, in the bascule chamber, the tail end of the bridge is counter-weighted with four hundred and sixty tonnes of pig iron and lead, just to make it so it’s perfectly balanced’.


Adapting Technology: London’s Sewage System

‘The importance of the development of the main drainage system in London shouldn’t be underestimated, without it the population couldn’t have grown to where it is now, the health of the population would have been much worse’. David Perrett, Past Chair of the Newcomen Society, the International Society for the History of Engineering and Technology.

Western Pumping Station Joseph Aspinall

Western Pumping Station


‘All the developments came after a thing called the great stink of the 1850’s, and Basel Jet built interceptor sewers’. David Perrett took us to the lower of these and talked us through the technology behind its lift station. Western pumping station, which opened in 1873 with an extension of the sewer, was introduced a little later than the main system, which opened in 1864-65.  The sewers of London ran under a slight downhill slope under gravity, but as they got lower and lower, they got to a point where, to get all the way to the east end of London, they would get so deep down that they wouldn’t be able to pump out. So, at this point, technology would lift the sewage up in a lift station so that it could fire it back down, again using gravity. This would enable the speed of sewage travel to be significantly increased and thus allow it to reach places further out. The lift station was originally steam powered. It had big beam engines in, and that’s the reason why it stands so tall. The boilers were steam-powered, hence the big chimney. They would raise steam which would drive the beam engines.


Sixty to seventy years ago the steam powered system was updated and today the pumping station works in a very similar way, but now uses modern diesels. ‘There is still the need to pump sewage along, so now it’s done by these modern electric pumps’. These are, however, considerably smaller compared to beam engines and ‘you could probably fit them in a building a quarter of the size of the one we see at the moment’. Luckily, the chimney hasn’t been replaced in this way. It has been preserved and, with it, a little of London’s tech history.


Lost tech: Battersea Power Station

The iconic power station was built by the London Power Company, with the foundations laid in 1931, it officially opened in 1933. Its initial building was the need to rationalize small power stations here in London.

Battersea Power Station Joseph Aspinall

The Original Battersea Power Station


It was a coal powered station. Coal came into jetties in front of the power station, and was then taken inside where it was burnt in boilers which made the steam. The steam then worked giant British Thompson Houston turbines to generate electricity.

It started as only half of the station you are now familiar with. It only had two chimneys, one at the front one at the back, and it only doubled in size with two new additional chimneys after the Second World, re-opening in 1953. David Perrett tells us that ‘It became one of these early central heating power plants’. Although the power station was built on the Southside of the Thames, it was built to supply electricity to feed places in the north of the Thames. So they had to get the cables under the river.  It in fact heated the blocks of flats which had gone up opposite the station simply using the excess steam from the turbines.


After years of operation, it finally closed in 1983 and it stood derelict for over thirty years, being vanadalised, losing its roof and open to the weather. It is now under a massive redevelopment and will be home to many modern day tech giants including notable resident Apple. David, like many in London is concerned about the authenticity of what will be left. ‘Apple could have just as easily been built in a brand new office building, like Google at Kings Cross, rather than in what is actually going to be a pretty big sham building’. All four of the historic chimneys are being replaced with concrete replicas. But then again, as David put it, it’s actually not too bad considering it only had two to start with!

London360 series twelve are currently making a television special about London’s use of technology. The experts featured in this piece will also be appearing in the special, in a feature focusing on the city’s tech history.

This piece is also published at

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