In-motion charging electric buses, Prague

[tonyp]

Here is an interesting video of an electric bus journey in Prague, route 58 from near its inner suburban terminus at Palmovka Metro station, out to the suburb of Čakovice on the eastern outskirts of the city.

https://www.youtube.com/watch?v=SvxjbQOFEQY

The background is that the city has decided that the entire bus system will be converted to electric drive. The operator, DPP, has had some experience of electric bus, having operated a trolleybus network until the 1970s and. more recently, trialled numerous battery buses. It was found that battery buses have their severe limitations with the weight/range trade-off and the possibility of loss of passenger capacity. Other issues are that the bus system is increasingly reliant on high-capacity artics (representing more than half the fleet) and these cannot run on battery without having their operation interrupted by having to top-up charge (a disadvantage of the Brisbane double-artics); and that Prague is built in a deep river valley surrounded by a high plateau containing much of the suburbs, therefore there are some stiff climbs into many suburbs.

So the solution is to operate in-motion charging battery/trolleybuses that have infinite range without compromise to passenger capacity. The Czech industry has quite a bit of experience in this as it has supplied such technology for some 20 years, an early example being the Rome system of 2005. The fact that a trolley system is the cheapest to build and operate of any any electric bus technology is also a significant influence on the decision.

So the first route to be converted is 58, which is about 12 km long and is only about 50% wired, much of the route (once it surmounts the plateau) being wire-free, including the end of the route that extends to two rural villages on the outskirts. 58 is normally being operated by in-motion charging 18 metre artics supplied by the Czech bus manufacturer SOR, but in this video they're testing in passenger service Škoda/Solaris 24 metre double-articulated buses that are to be used on a route to Prague Airport being completed on the western side of the city (59).

Points to note in this video are:

1. The journey starts on wires soon after it leaves the Palmovka terminus, but about 10 seconds in (hear the beep) it lowers the poles to transition to a wireless section because of low bridges. Later in the video, when the cameraman moves closer to the driver, you will see a small CCTV screen above the driver's left showing him that the trolleypoles have successfully lowered or raised.

2. At 1:10 min the bus pulls into a stop at the bottom of the steep climb to the plateau. Here the poles are raised to reconnect to the overhead power (you can see the "hats" on the wires to receive the poles). Note that there are also wires on the other side of the road running down the hill in order to enable regeneration and assist braking as the bus descends the hill.

3. At about 4:30 min the bus has reached the top of the grade and the poles are lowered (you can also see the hats on the wires across the road where buses going the other way connect). From now on there's a long wireless section.

4. At 12 min the bus goes on the wires again at Letnany Metro station and will stay on the wires until the Globus shopping centre at Čakovice, after which it runs wireless to the end of the route. However, in this video, the roundabout at Čakovice is as far as a double-artic can go as the streets after that become very tight in the old village centres at the end of the route and can only take normal artics.

5. So, after 22 min, the bus goes around the roundabout at Čakovice and heads back to Letnany Metro, where at 30 mins the photographer disembarks and we finally get a good pan of the exterior of the bus - note the rear-wheel steering on the back end. Then from 31 minutes we get a good interior ride from the back seat of the bus (no engine noise sorry!) until the end of the video. Fully low floor of course and all-door loading.

The Brisbane bi-artics will be very much like this bus, except two less doors and tied down for recharge at each terminus.

I think another unrelated point of interest (from an Australian perspective) is the extensive use of bus lanes to keep buses out of the traffic.