So the concept does have a future after all!
For a long time, the increasing popularity of electric buses seemed to spell the end of the use of bus trailers, as the development of the corresponding adaptations to the existing e-bus models was not considered very lucrative due to the low quantities. It was also considered too complex to accommodate the batteries required for the high performance of a towing vehicle. But now Solaris has surprised the experts: a first Urbino 12 electric with a passenger trailer is in operation in the Swiss canton of Zug. Here, the ‘Zugerland Verkehrsbetriebe AG (ZVB)’ operate a very important part of the local public transport system. The company is 68% owned by the canton of Zug, 29% by the canton’s municipalities and 3% of the shares are privately owned.
Busverkehr in Zug
ÖPNV im Kanton gibt es schon seit August 1904, also – abgesehen von den Postkursen – seit 120 Jahren. Damals eröffnete die „Aktiengesellschaft für Automobilverkehr im Kanton Zug“ eine Buslinie von Zug nach Menzingen. Schon im Oktober wurde auch die Gemeinde Oberägeri angeschlossen. Und am 01. November 1905 übernahm die Gesellschaft auch die Postkurse auf diesen Relationen.
Bedient wurden die Strecken mit fünf Bussen der Schweizer Marke Orion, die neun Sitzplätze boten. Sie hatten – damals noch völlig normal – Vollgummi-Reifen, die „Straßen“ waren noch Schotterwege, kurz: die Reise mit diesen Bussen war noch eher unkomfortabel.
Public transport in Zug
Public transport in the canton has existed since August 1904, i.e. – apart from the postal services – for 120 years. At that time, the ‘Aktiengesellschaft für Automobilverkehr im Kanton Zug’ opened a bus route from Zug to Menzingen. The municipality of Oberägeri was also connected in October. And on 1 November 1905, the company also took over the postal services on these routes.
The routes were served by five Swiss Orion buses with nine seats. They had solid rubber tyres – still completely normal at the time – and the ‘roads’ were still gravel paths, in short: travelling on these buses was still rather uncomfortable.
So it was that on 9 September 1913, the ‘Electric Trams in the Canton of Zug (ESZ)’ opened three lines:
- Zug – Oberägeri
- Zug – Baar – Talacher
- Nidfurren – Menzingen
These replaced the Orion buses, as the trams offered significantly more comfort at the time. And the ‘electric trams’ (Swiss spelling with a double ‘s’) are legally the forerunner of today’s Zugerland Verkehrsbetriebe.
Since 1 November 1951, the company has officially operated under the name ‘Zugerland Verkehrsbetriebe’. In the meantime, the bus had become so important in the company’s transport services that this should also be reflected in its name. Especially as the tram service was discontinued on 21 May 1955 and the ZVB has been a bus-only company ever since.
Since the closure of the tramway, buses with passenger trailers have also been used by the ZVB on the lines to Oberägeri and Menzingen. Trailer buses were not uncommon in Europe at the time. And even if the bus trailer gradually died out – for example, the ban on bus trailers in the Federal Republic of Germany from 1 July 1960, which still applies today – although exemptions can be granted again today – there have never been any restrictions on bus trailers in Switzerland. So the ZVB also remained (and remains) loyal to the bus trailer. However, it should not be concealed that the bus trailer has also largely disappeared from the streets of Switzerland today.
Zugerland Verkehrsbetriebe, however, even relied on ‘maxi-trailer combinations’. A two-axle bus was the first to pull a two-axle passenger trailer, and behind it ran a two-axle luggage trailer (Postfourgon). With a special permit, the entire train was allowed to be 2.50 metres wide – at that time the maximum width in Switzerland was actually 2.30 metres – and even 29 metres (!) long. And that on the winding roads of the Swiss mountains!
One special feature of Swiss bus trailers should also be mentioned: while trailers are actually much shorter than their towing vehicles everywhere, in Switzerland they can be as long as 11 metres. This means they are almost as long as the buses they are pulling. The steering on all four wheels makes this possible.
The technology of the ‘bus trains’
The Zug ZVB remained faithful to the trailer. Initially, the trailers came from the Swiss manufacturers Moser and Ramseier & Jenzer: Moser supplied the chassis, on which Ramseier & Jenzer placed the body. A construction method familiar to us from traditional bus construction: a commercial vehicle manufacturer supplies the chassis, a coachbuilder the body. Trailers, on the other hand, actually always came ‘from the first screw to the complete vehicle’ from a single manufacturer: Kässbohrer, for example, supplied its complete trailer types PA 3, PA 4 and PA 5, Bonn had trailers of the type OA 5, which were 100% products of Bauer in Cologne, East Berlin had trailers of the type ‘W 700’, which were built entirely by Lowa.
The buses that served as towing vehicles were characterised by underfloor engines. This made it easier to install the towing device for the trailer, as there was no engine in the way at the rear. The manufacturers of their chassis were initially Saurer and Berna.
Then, at the end of the nineties, came bus combinations whose superstructures for both the front section and the trailer came from the Swiss bus manufacturer Hess. The towing vehicles were based on NAW chassis (type ‘BU 5-25’), while the chassis for the trailers were supplied by the Swiss company Lanz & Marti (type ‘APE 5.6-13’).
The trailers in Zug were always characterised by the fact that they were steered on all four wheels. This means that the trailer runs exactly in the track of the rear axle of the towing vehicle when cornering – this prevents the bus train from needing more space in the bend because the trailer runs in more towards the centre of the bend.
The Solaris Urbino 12 electric as a towing vehicle for trailers
By 2035, Zugerland Verkehrsbetriebe wants to convert its entire bus fleet to electric drive. If they do not want to replace the trailer combinations with articulated buses, this means that they will need an electric bus as a front carriage that can also pull trailers.
Solaris proved to be flexible enough to build such a vehicle for the ZVB. After a lengthy test phase, during which the bus showed that it does what it is supposed to do, it has now gone into service as coach 178 with trailer on routes 1 (Zug – Oberägeri) and 2 (Zug – Menzingen).
The vehicle is 12,000 mm long, 2,550 mm wide and 3,300 mm high. The front axle is the ‘RL 82 EC’ from ZF, while the drive axle is the conventional ‘AV 133’ drive axle, also from ZF. Two electric motors mounted on the rear wheels deliver 125 kW each, giving the bus a drive power of 250 kW. This corresponds to 340 hp and is also sufficient on hilly roads and with a trailer – articulated buses also travel with comparable engine power. What’s more, an electric motor in a road vehicle is generally more uphill-friendly than a diesel engine.
The ‘Solaris High Energy’ batteries have a capacity of 440 kWh. Recharging takes place via cable and CCS combo plug or via Schunk SLS 102 pantographs with up to 400 kW charging power.
The total weight is 20,000 kg, including the trailer, it is 34,400 kg. The unladen weight is approx. 15,000 kg, which is approx. 2.5 tonnes more than the comparable diesel bus model, but is of course dependent on the selected battery size.
Other operators of bus-trailer combinations, of which there are approximately 220 throughout Europe, should also be happy: the switch to electric operation is possible!
