Bonn’s SWB (Stadtwerke Bonn) have big plans for their Friesdorf bus depot. Namely: to convert it from a facility for diesel buses with a few charging points for battery-electric buses into a facility for a bus operation that runs exclusively on battery-electric power.
A few words about the history
Bonn’s bus company has several predecessors. Firstly, there is the ‘Bonner Verkehrs Gesellschaft (BVG)’, founded in August 1925 – and therefore four years older than its Berlin namesake. Then there was the private Godesberg city transport company Eßwein, founded in 1931. After the Second World War, the ‘Bonn – Bad Godesberg – Mehlem Tramway (BGM)’ also opened a bus service. And on 1 June 1952, the city of Godesberg and its municipal utilities replaced the Eßwein company in city transport.
BVG and the municipal tram company ‘Bahnen der Stadt Bonn’ were merged in the 1960s to form ‘Stadtwerke Bonn (SWB)’. And with the founding of the new large city of Bonn on 1 August 1969, BGM with its rail and bus operations and Stadtwerke Bad Godesberg were also merged into SWB.
The ‘Bonner Verkehrs Gesellschaft (BVG)’ was thus founded in 1925. It was originally conceived as a company that would connect Bonn’s surrounding areas to the city (the ‘Bahnen der Stadt Bonn’ were to take care of inner-city transport). There were plans for lines as far as Adenau in the Eifel or Altenkirchen in the Westerwald – which never materialised. However, the BVG had numerous lines to the surrounding area and also had depots in Bad Neuenahr-Ahrweiler and Swisttal-Heimerzheim, for example.
In December 1925, BVG opened the first inner-city line 5, from Friedensplatz in the city centre via Nordstadt to Mondorfer Fähre. The idea was that the buses would in future take the ferry to Mondorf on the right bank of the Rhine and connect with the Siegburg – Zündorf (KSZ) light railway.
The second inner-city line was Line 6, a tangential connection from the south via the west to the north of the city. The operational structure was interesting: the concession holder was the municipal tram operator ‘Bahnen der Stadt Bonn’, while BVG operated this line ‘on behalf’.
The first large inner-city bus depot was built in 1952 close to the city centre on Karlstraße; at the time of its opening, its bus hall was the largest self-supporting reinforced concrete hall in Europe.
In 1982, Stadtwerke Bonn withdrew from serving its long-distance routes and handed them over to Regionalverkehr Köln, and the ‘external depots’ were closed. The Heimerzheim depot is now home to the local fire brigade, for example.
At the end of the 1990s, SWB also gave up the Karlstraße depot, the bus depot was demolished and is now a shopping centre. All SWB buses were brought together at the Friesdorf depot. This was originally the BGM depot, but the trams had since moved out and found a home in the new Dransdorf underground railway depot and the Beuel depot. Friesdorf depot was initially located in a sparsely populated area between the two cities of Bonn and Bad Godesberg. After the two cities were merged on 1 August 1969 together with several other municipalities to form the new city of Bonn, it is located quite centrally in the geographical centre of today’s city, which has also completely grown together structurally. There is no longer any talk of the neighbourhood consisting of meadows and fields and nobody being disturbed. But SWB emphasise that the central location is a major advantage of the depot. SWB Managing Director Anja Wenmakers: ‘Thanks to the central location, we save a lot of empty kilometres when moving the buses in and out. Despite the central location, we still have 1.5 million empty kilometres per year. And empty kilometres cost money.’ Another advantage of the Friesdorf depot: the nearby A 562 motorway provides quick access to the districts on the right bank of the Rhine.
This means that Friesdorf is now Bonn’s only bus depot, with all 200 SWB buses parked here. In addition, there are also the vehicles that SWB subsidiary RVK operates on behalf of its parent company SWB on Bonn’s urban transport network. The central workshops for municipal bus operations are also located here, which also look after the RVK buses used in Bonn city transport. For example, there is a separate RVK tyre warehouse here.
The planning
There are 200 SWB buses in Friesdorf – and seven RVK buses. Apart from seven SWB electric buses, all of the vehicles from both companies are diesel vehicles. The seven electric buses (four Solo from Ebusco and three articulated from Solaris) are pure depot chargers and are supplied via cable and CCS combo plugs. Ten more electric Solo buses will be added in 2025: Mercedes will supply cars of its eCitaro type. These will differ significantly from the current seven electric buses in terms of the form of recharging. Although they will also be pure depot chargers that are only recharged during night-time breaks, unlike the previous seven, this will not be done via cables and CCS combo plugs, but via roof-mounted pantographs. We’ll see why.
The Friesdorf depot is being remodelled so that the entire Bonn bus fleet can be stationed here in future once the switch to battery buses is complete. Battery buses now need a little more parking space per bus as a precaution, and the depot is also being divided into several fire compartments as a precaution in case of a fire. In short, the depot will need more space in future. There is a strip of land to the south of the site that belongs to SWB, but which they have not used to date and which was therefore leased out. The leases have now been cancelled and the strip will be incorporated into the depot site. The employee car park to the north will also be integrated into the area for the buses, and there will be a multi-storey car park for the employees’ cars, which will take up considerably less space.
The conversion is due to start as early as November this year and should be completed in spring 2027. All the buildings in the courtyard will have to be demolished and completely rebuilt. However, as emphasised during the presentation, the individual new buildings will be arranged in a more sensible way. Until now, new buildings that were needed (such as a special workshop hall for the electric buses – with workstations for components on the roof that are not needed for a diesel bus) have been built wherever space was available …
In future, each of the Bonn buses that have been completely converted to electric operation will have its own charging area in the yard. The entire parking area will be spanned by traverses with charging funnels, to which each bus will then have its pantograph mounted. Compared to the current recharging concept with cable and CCS combo plug, this is a very significant change to the recharging concept. Why this? Managing Director Wenmakers: ‘In future, we want the driver to park his bus at the depot entrance when he comes off the route. They can then go home. And from then on, the bus will drive around the depot completely autonomously. It travels alone to the maintenance hall, where it is checked to see if it is still in order, it travels alone to the wash bay, and it also reaches its parking space in the depot completely autonomously. And there it also drives its pantograph to the charging station funnel completely autonomously.’ It really does work; RATP, the Paris public transport authority, has already implemented this at one of its depots. There are impressive videos in which you can see how the bus drives to its parking space without a driver (!) and even parks backwards against a wall … this is possible with an electric bus, which produces no exhaust fumes and then blows them against the wall, which would make it very dirty within a very short time. The demonstration vehicle in the video is an electric bus from Iveco.
Wenmakers: ‘You can have an electric bus autonomously connect its pantograph to the charging station and also disconnect it again autonomously. This is not possible with recharging via cable and CCS combo plug. You need someone to do it manually …’
The charging traverses are fitted with solar panels on the top. ‘We generate a good proportion of the electricity we use ourselves.’
Now, you can’t need a yard that is packed full of buses for such a fundamental conversion. So a replacement site was sought for the conversion phase where Bonn’s buses could be parked. And this was actually found in the Beuel district. In the form of a disused industrial company whose site is currently lying fallow. SWB Managing Director Wenmakers: ‘Everything we need to supply our diesel buses is available there. That company also had to supply its lorries.’ He continues: ‘For most of the time during the conversion, a significant proportion of our buses will be able to remain in Friesdorf and only some will have to “move out” to Beuel. But there will also be short phases when we won’t actually need a single bus in Friesdorf.’
