A bus route in southeast London is testing an electric doubledecker bus that is thought to be the world’s first to use a reverse pantograph to top up the batteries.
Battery powered buses that are recharged overnight is not a new thing in London, and their use is spreading, but the experiment at Bexleyheath garage is testing a method of topping up the battery during the day. Topping up the battery during the day reduces the amount of charging needed overnight, and hence the number of buses needed to operate the service.
The reason for switching to electric power is that it eliminates road pollution at the point of use, and depending on how the electricity is generated, will reduce the reliance on fossil fuels to power London’s public transport.
Reducing road pollution is both something that’s good for London in general, but also locally very beneficial for people who live close to busy roads, which tends to be people at the lower end of the economic scale, who are therefore disproportionately affected by poor air quality. This was highlighted when I got a mouthful of fumes from a particularly dirty bus that was pulling out of a bus stop as I walked past on my way to see these new pollutionless buses being trialled.
There are currently 850 electric buses in London, which are usually charged overnight, but it can offer more flexibility if they could be topped up through the day, and if the buses can run further between charges, on some longer routes it would be possible to run the same service without needing to buy extra buses to fill gaps while buses are being recharged.
The experiment at Bexleyheath taps into what’s known as “opportunity charging”, where the bus drives pass the bus garage, and pops and stops at a charging point for a quick top-up.
Unlike old trolleybuses and modern trains, rather than putting the pantograph on top of the bus and raising it up to the charger, they’ve installed a reverse pantograph that drops down to the bus.
A 10-minute top-up can recharge the battery by about 20%, giving them around 20 miles more running time.
In use, it’s very simple – the bus drives up to the charging unit, and a couple of small bumps on the ground help the drivers park in the correct spot, then the driver has some switches on the bus to lower the pantograph for a top-up. The bus is disabled during charging to prevent accidental driving off, and when the bus is ready to start the next run along its route, the driver releases the pantograph and drives off.
Based on their existing bus timetable, each bus has roughly an hour of time during the day when the bus is idle between routes, and that gives them on average 6 opportunities each day to top-up the battery.
The fleet of buses being used on route 132 have been supplied by Alexander Dennis / BYD, and there’s 18 of their Enviro400 EV double-decker buses being used. The battery chassis comes from BYD, with the bus coach on top built by Alexander Dennis in the UK.
Go Ahead London, contracted to Transport for London, operates buses on route 132 and originally sought out the pantograph charging solution to deliver the battery top-ups. Suffolk-based EO Charging installed the charging infrastructure at the Bexleyheath bus garage.
Although single-decker buses with reverse pantographs are in use in many cities, this is thought to be the first trial using double-decker buses.
Louise Cheeseman, TfL’s Director of Bus, said: “The threats of toxic air, climate change and congestion are becoming clearer every day, and it’s vital that we find technical solutions that help us run clean, green services that get Londoners where they need to be. When buses can travel further each day, as they do with this exciting pantograph technology, we can deliver the same service that Londoners rely on without increasing the number of buses and invest in other routes.”
There’s more coming soon
One of London’s longest bus routes, also in South London, will soon start testing two pantograph chargers at either end of their long route, between Crystal Palace and Orpington.
A brand new fleet of 20 ieTram buses is being supplied by Spanish bus and coach maker, Irizar, with the first due to arrive in the UK next week, and the intention is that their batteries will be topped-up at either end of the bus route.
A standard garage charge alone would not sustain a zero-emission bus the entire day. Due to the length of the route, a pantograph at each end of the route, rather than back at the garage, will mean buses receive a quick boost on the spot. With minimal turnaround time, fewer buses can again provide the same level of service.
The 15-mile bus route 358 is currently served by a fleet of single-deck diesel buses but will see the electric buses introduced early next year once they have all arrived from Spain.
Irizar ieTram bus – source: TfL
Can I go into the Bexleyheath bus garage to see it in action? Or is it not open to the public?
It’s out the front anyone can watch it in action
I saw a similar system in use in Geneva a few years back, albeit the buses were single-deck artics rather than double-deckers.
I’m intrigued by the tram-bused. They look like pretty standard buses with covers to hide their wheels. What tram features do they have to merit the name?.
According to the manufacturer’s website, it seems the interior of the bus is very tramlike with a low accessible floor throughout:
“The Irizar ie tram is a 100% electric, zero-emission bus with the appearance of a tram that combines the large capacity, ease of access and internal configuration of a tram with the flexibility of a city bus… Accessibility and passenger flow are further enhanced by up to four sliding doors, the integral low floor”
https://irizar-emobility.com/en/vehicles/irizar-ie-tram
You have answered your own question. Cover the wheels and everyone knows a bus stops being a bus and turns into a tram. I suspect it will be rather like Swansea’s “ftr” service which was bendy buses with covered wheels operating a frequent service between slightly upgraded bus, sorry, tram, stops (which were spaced further apart than normal bus stop). It only lasted a short while and reverted to normal buses once the initial funding ran out.
I feel like we could just bring trolleybuses back and have a backup diesel generator in case of having to get off route rather than relying on batteries for everything.
You ignore the visual intrusion of overhead wiring and the infrastructure costs of installing and maintaining it. I used to be an advocate for reintroducing trolleybuses, but the new generation of electric buses is so good – and still improving.
The whole point is to get away from fossil fuels, not make things worse by using inefficient and costly diesel generators.
There is no such thing as visual intrusion from trolleybus wires. The wiring gives the streets it serves a purpose and tells intending passengers that a high quality service is provided there. In Europe, trolleybuses with back-up batteries use the overhead wiring in main thoroughfares in town centres, with batteries in use in the suburbs. It allows battery charging while the vehicle is in-motion – requiring fewer buses to provide the service. Can be seen in Prague, Solingen, Bergen, Eberswalde, Zlín, Teplice. Other cities are making plans to use this method.
I once rode the whole route of the 358 in around 1996, took nearly 90 minutes in total.
Around 40 years ago LT were considering the COMBAT, a combined battery and trolleybus. The idea was to charge the bus on a main or busy section of the route, then for it to be used on batteries at either end of the route. It never made it past the idea.
Bordeaux has a tram network which uses this combined technology very successfully.
CRRC double-deck electric buses introduced by Tranzurban on Metlink services in Wellington, New Zealand in 2018 initially had roof-mounted pantographs for charging at Island Bay terminus.
After a short time they were removed and replaced by retractable contacts fitted to the rear of the bus because the pantographs were susceptible to damage from low-hanging trees etc.
Not a world first. I saw this in Biarritz this summer. Charging an electric bus from a pantograph while waiting at turnaround.
But was it a double-decker bus?
Some of the single decker buses in Harrogate use this charging system in the bus station. Good to see it being used elsewhere.