The bus that made the EU rewrite its rules

The German bus manufacturer, which has operated as MAN’s prestige brand since 2001, unveiled the Skyliner, the world’s first double-decker coach, 55 years ago — a model that has had a fascinating history over the decades. The realised thesis project of the young Konrad Auwärter caused a huge stir in the bus world of the 1960s: very few believed that the 12-metre double-decker concept he had envisioned could be of any practical use in everyday operation. The type’s intellectual father, however, firmly believed in his idea and ultimately made it a success, as is amply demonstrated by the fact that more than 5,000 examples of the founder of the double-decker coach category — now in its seventh generation — have found owners from South America to Saudi Arabia. The type has been produced in countless versions over more than half a century, but perhaps one of the most noteworthy was its four-axle version, the Megaliner, which was a landmark model on the European bus market in the 1990s and, in addition to the Western European countries primarily targeted, was even delivered to Japan in right-hand-drive form.

In Neoplan’s heyday, the company was known as one of the great innovators in bus manufacturing. It always strove for innovation, was not afraid to push the boundaries — including those of vehicle size — and Konrad Auwärter, the creator of the Skyliner, would not have been himself had he not come up with more and more concepts that seemed impossible to realise. Auwärter, the son of Neoplan’s founder, began work in the 1970s on a four-axle, high-capacity, 15-metre double-decker coach, which the manufacturer intended for the North and South American markets, where there was particularly strong demand for vehicles designed for high-capacity, long-distance services. The first example of the 15-metre monster, built by Neoplan for a Chilean customer, was completed in 1975, and the type continued to be delivered until the late 1980s to Argentina, Brazil, Peru, Libya, the Cape Canaveral space centre, the fleet of a casino in Philadelphia, Saudi Arabia and also Sweden, which at the time was the only country in Europe where vehicles of this size could be put into service.

Until the early 1990s, Neoplan was unable to register its four-axle model for road use either in its home country or elsewhere in Europe because of the narrow limits imposed by road-traffic approval regulations, even though this had been the intention from the very beginning with the type created in the 1970s. In most European countries at the time, the length of a solo bus could not exceed 12 metres, and the maximum permitted turning-circle diameter could not be more than 25 metres. Neoplan, however, was determined to force the type onto the German and European markets.

Neoplan finally built the version of the four-axle Skyliner intended for the old continent in 1990, the Megaliner (N128/4), with a maximum permitted gross weight of 30 tonnes, as part of a strategy to use the vehicle to lobby German and European Union officials to extend the 12-metre limit for solo buses to 15 metres. At the same time, in order to demonstrate the Megaliner’s maturity and safe operability, it offered the type — which could only be operated to a limited extent even with a special permit — to several operators in Europe at unrealistically favourable prices, thereby also putting pressure on the approval authorities. The next task was to overcome the German and European approval hurdles, which, as with any bureaucratic route, took some time. Neoplan’s initiative ultimately achieved its goal in 1993, when both Germany and the EU approved an exemption regulation under which buses longer than 12 metres but no longer than 15 metres could be registered in the European Union and Germany, albeit only subject to defined requirements and certain conditions. These included, for example, the presence of four steered axles and a minimum 4,000 mm wheelbase between the axles designated B and C.

During the procedure, Neoplan had to prove with millimetre-accurate calculations, tests and facts that the vehicle genuinely complied with the applicable cornering requirements, that the outer radius of its turning circle fitted within the maximum 12,500 mm and its inner radius within the minimum permitted 5,300 mm tracking value, and that its tail swing did not exceed 800 mm from standstill or 600 mm in straight-line running.

For the versions intended for the European market — unlike the four-axle models exported up to that point, on which only the front tandem axles were steered — the German manufacturer had to equip the vehicle with four steered axles, and also had to trim the front and rear overhangs as well as the wheelbases. In order for the type to comply with the turning-circle regulations, Neoplan had to improve the steering angle of the front twin axles and make both the driven C axle and the trailing axle designated D positively steered.

The front axles with trapezoidal control arms could be turned through 55°, while in the case of the driven axle with a hypoid-drive rigid axle, a 4° displacement became possible by mounting the axle assembly on a triangular subframe, which was connected to the body at three maintenance-free bearing points. After the redesign, the Megaliner was able to turn within a swept path with an outer radius of 12,490 mm and an inner radius of 5,320 mm, while its tail swing also remained well below the prescribed 800 mm value (433 mm). The wheelbase and overhang dimensions of the vehicle, exactly 15,000 mm long, were as follows: 3065/1230/6100/1300/3305.

The Megaliner, capable of accommodating up to 100 passengers, was part of Neoplan’s range between 1990 and 2000, and in addition to the Western European markets primarily targeted, it was also delivered to Turkey and, in right-hand-drive form, even to Japan. After launching the Megaliner, Neoplan presented two further versions: one was the Megashuttle, designed specifically for urban operation, while the other was the Megaspace, which differed little from the Megaliner and had its lower deck converted into a kitchen and lounge. In its standard version, the model was offered by the manufacturer with a 14.6-litre, 500 hp Mercedes-Benz engine, but it could also be ordered with MAN, DAF, Detroit Diesel, Deutz, Gardner and Steyr drivetrains.

On paper, the type was removed from Neoplan’s product line at the turn of the millennium. This was justified partly by deteriorating sales figures, as EU regulations on buses after the millennium already allowed 15-metre, three-axle buses to be put into service as well, provided they complied with the rules on axle loads. On the other hand, the manufacturer, which was in a deteriorating financial position, was acquired by MAN in the early 2000s, and during the restructuring Neoplan’s production activities were significantly rationalised. Alongside several other interesting Neoplan types, the Megaliner also fell victim to this streamlining. The manufacturer discontinued sales of the model in 2000, although a few examples were still built in 2003, ordered by one of Neoplan’s returning customers, the Japanese state railway company. These vehicles, together with their earlier exported counterparts, were withdrawn from service in 2008 in connection with two earlier fire incidents involving the type.