MonoMetro

MonoMetro is a transportation planning company formed in 1997 to promote a new design of suspended narrow-gauge monorails, with Y-shaped pillars. Its main activity has been to promote this as an answer to London's congestion problems, but interest has also been shown in the system by other cities. MonoMetro claims its system would be cheaper to introduce than a tram as it would not be necessary to divert or strengthen sewers along its route and that it is also superior to monorail systems.

The system infrastructure costs calculated on mean fabricated tonnage of steel and construction quantities reference a twin track system with a parallel platform station located every 750 metres. Costs including planning, required Acts of Parliament, professional and tendering costs, electrical supply costs and street diversion costs for central London implementation were estimated at £15 million per kilometre (2005 estimate). Costs outside London must be based on approx 1000 tonnes of fabricated steel per km plus the local cost of planning etc. By comparison to tramway implementation MonoMetro costs around 60% of the cost of building a tramway. The difference however is that MonoMetro is a mass transit system offering 20,000 passengers an hour capacity, trams offer 3000 - 7000 passengers an hour capacity.

The paradigm precedent for MonoMetro is that of the Wuppertal Schwebebahn, but the technology of MonoMetro is quite different. The trains are suspended from six-wheeled bogies (or trucks [North America]) running along a narrow gauge pair of rails; MonoMetro is thus a railway and not a monorail. The rails have a concave cross section and the wheels a corresponding convex profile. The vehicle load hangs centrally from a pivoting joint located at the intersecting radial load lines of the wheels. According to the patent "[t]his configuration moves the pivot point away from the wheel-track contact point (as in the Wuppertal Schwebebahn) to the point of intersection of the radial loads through the wheels. There is no torque acting on the bogie frame causing loss of contact with the track raceway as would happen if the load and bogie assembly were rigidly connected". The patent compares this to monorail technology that instead require a much heavier guideway and heavier bogies to overcome torsional forces and also need complex superelevation to provide passenger comfort on corners. The patent says propulsion will be provided by linear induction motors.

The rails have special end junctions and are laid along continuous rubber cushions along the beams, held in place by regular (Pandrol) railway torsion clips. No details appear to have been published as to how track switching is effected.