Subway on tires

The subway on tires is a system of Métro which circulates on wheels equipped with pneumatic, in opposition to the travelling traditional railway material on wheels in Acier. It requires an especially arranged way and of this fact the material is captive lines with lequelles it is compatible, constraint which is not really a disadvantage for a subway, especially if there are several lines using the same system and that they are connected.

The system

The oars are equipped with bogies whose Essieu X preserve the Roue S out of steel traditional and comprise moreover two wheels, of the same diameter, are equipped with tires located outside the preceding ones. The wheels with tires provide the functions of traction and of braking, those out of steel are used in the event of help (puncture) as for guidance in the Aiguillage S. the Bogie S also comprise smaller horizontal wheels ensuring the side guidance of the vehicles.

The way comprises two Rail S out of steel, like all Railway, and of this fact authorizes the circulation of railway material traditional, in particular for the operations of maintenance, and two tracks of bearing whose width is adapted to that of the tires. It comprises moreover a side rail being used at the same time with collecting of the current by wipers and track as bearing for the horizontal wheels. The return of the current of traction is carried out by the traditional rails.

This system differs appreciably from that of the Pneurail implemented by Michelin in the Années 1930 on its famous Micheline S, which had the advantage of being able to roll on a banal way but presented the disadvantage of a too narrow track of bearing, from where a load at the axle too limited.

Applications

With the RATP

With its study in the years 1950 by the RATP, the objectives were to have better performances that what one could at the time have in traditional material on iron.

Because of a contact/rail offering coils a quite higher coefficient of adherence, one can hope:

  • a better acceleration with starting,
  • a better braking,
  • the crossing of uneven more important (12% for the m2 with Lausanne),
Moreover, from the nature of materials one improves:
  • behavior on the air lines in the event of bad climatic conditions,
  • weaker noise of bearing (important for the air lines) and a less squealing and friction in the curves with weak ray

the RATP studied for that the prototype motor coach MP 51 on the shuttle Pré St Gervais - Porte of the Lilacs (see Haxo).

The system proving to be conclusive, the RATP converts the line 11, which became a test laboratory to large scales, with its severe slopes and its sinuous layout.

the RATP envisaged to convert all the lines of the Parisian subway to the tires, there but after the difficult building sites of conversion of the line 1 and the line 4, only the building site of conversion of the line 6 was maintained because of great air part of the line, finishing conversions of lines iron into tires.

There should be said that meanwhile, the material iron had caught up with a good part of its delay acceleration braking, while remaining less powerful.

The line 14 was built directly in tire, proof that even if conversions are not interesting any more, this technique remains the best for a subway.

Other MP of the subway of Paris: MP 59, MP 73, MP 89 and MP 05 inter alia).

Cities having at least a line in tire

Canada:

Chile:

France:

Italy:

Japan:

Mexico:

Singapore:

Taiwan:

  • Taipei
    • Muzha Line (VALLEY 256*)
will *sera replaced by the CITYFLO650 of Bombardier in 2009

In construction

Swiss:

Taiwan:

  • Taipei
    • Neihu Line (Bomber, envisaged in 2009)

Envisaged

HongKong:
  • South Island Line (section is and western section) off MTR

Macau:

  • Macao Light Transit System

Related articles

  • See the articles of the : Category: Subway on tires and : Category: Railway rolling stock on tires for an exhaustive list.
  • Pneurail
  • light automatic Vehicle (VALLEY)

External bonds

  • See a detailed diagram of a Bogie
  • principle of the pneumatic subway and brief history.

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