running through the streets of Swiss Lausanne. “Unfastened” by specialists of the company “Neoplan”.
We have already reported about this unusual development (ЗР, 1998, No. 12). Now there is an opportunity to talk about it in more detail. Recall that Russia is one of the few countries where trolleybuses are made and operated.
In the terms of reference received by Neoplan from Lausanne transporters, it was said: the machine must overcome a 12 percent rise at a speed of at least 30 km / h, have a total weight of 30 tons and work in areas with elevations of 500 meters. Moreover, these parameters must be maintained, even if … the wires break!
None of the previous models met such requirements, and a group of designers led by Karl-Heinz David began work from scratch.
Four traction engines of 80 kW each, integrated into the hubs of the second and third axles, were installed as a drive. They receive current either from the contact network or from a diesel generator set based on the Mercedes-Benz V-shaped eight-cylinder OM 442 LA turbodiesel (power - 390 kW / 530 hp). The latter drives two water-cooled generators of 150 kW each. The remaining 90 kW go to the power of other consumers (lighting, hydraulic pump, etc.), and can also be used in case of peak loads, when up to 200 kW is required from each generator.
The design of the motor wheels is very original (by the way, the rear ones are made by bow thrusters so that the articulated colossus can fit into the mountain serpentines). If necessary, they can be easily removed for maintenance and repair without dismantling the axles - the splined connection is simply disconnected. Special electronics ensures that the torque transmitted to each of the wheels is the same (a spread of no more than 3% is allowed) - a sort of analogue to the usual differential. This ensures good driving performance in difficult weather conditions.
Motor-wheels, however, serve not only as a source of traction on climbs, but also as wear-resistant brakes on long descents. The principle of energy recovery has been known for a long time, but everything is not so simple in this amazing machine. After all, there may not be a contact network that takes away the released energy. Then smart electronics will direct the generated current to special ballast resistors on the roof of the trolley, where it will turn into heat - almost like in ordinary brakes. If heating and lighting work in the cabin, then only the excess braking energy will get to the roof. Well, when the current collectors are connected to the wires, the braking trolley will help the brothers climbing uphill.
If the prototype Neoplan N 612DE works well, another 28 vehicles will be manufactured at a cost of about $ 1 million each. However, with an increase in the number of orders, the cost should decrease.
The working volume of the diesel engine is 14 618 cm; maximum torque - 2300 N.m at 1100 rpm; generators type G20–4; voltage - 660 V; constant / peak power - 150/200 kW at 2100 rpm; traction engines of type M50-4; maximum torque - 730 N.m; maximum rotation speed - 4350 rpm; dimension (length, width, height) - 17852x2550x3550 mm; wheelbases (front and rear) - 6050/8057 mm; overhangs front / rear - 2700/1045 mm; the number of seats sessile / standing - 37/90; curb weight - 20 500 kg.