GB2334542A

GB2334542A - Rail for trams

Info

Publication number: GB2334542A
Application number: GB9803126A
Authority: GB
Inventors: John Kenneth Smith
Original assignee: METALLISATION SERVICE Ltd
Current assignee: METALLISATION SERVICE Ltd
Priority date: 1998-02-13
Filing date: 1998-02-13
Publication date: 1999-08-25
Also published as: GB9803126D0

Abstract

A rail for tramways &c has a base portion 1 and a head portion 3, the head portion 3 having a slot 5 to receive the rim 6 of the wheel 7, and an antiskid coating 4a, 4b of adherent refractory particles is provided on the head portion in a region not in contact with the tram wheel so as to prevent other vehicles from skidding on the rails.

Description

RAIL FOR TRAMS OR THE UKE The invention relates to a rail track especially for trams. Such track comprises parallel lengths of rail embedded in the ground of streets in cities. Trams have become popular in recent times.

There is a tendency for cars to skid on the tram lines, especially in wet conditions. The reasons for this are not entirely clear, but the fact that the rails have a generally flat top surface may be a contributory factor. It is one object of the invention to provide a rail having a permanent anti-skid coating.

According to the invention in one aspect there is provided a length of rail for a tram or like vehicle, the rail having a base portion and a head portion, the head portion having a longitudinal slot dividing the rail into two longitudinal side portions, over which a wheel of the tram will travel, the wheel having a rim which is received in the slot, an anti-skid coating of adherent refractory particles being present on the head portion in the region which will not be in contact with the tram wheel so as to prevent vehicles skidding on the rails.

In another aspect there is provided a method of applying an adherent anti-skid coating to a length of rail forming a track for a tram or like vehicle, comprising applying to a surface of the rail in a region which the wheel of the tram is not in contact, a composition comprising refractory particles and a metal binder therefor so as to cause the particles to form an adherent coating thereon.

While the particles which provide the friction surface to prevent skidding can be selected from a wide range of materials it is preferred to use aluminium oxide or the like. To bond the particles to the surface of the rail a fluxing agent such as aluminium is used.

Most preferably the coating is applied by thermospraying to secure the coating to the rail surface in which case a pre-treatment, e.g. grit blasting should be carried out.

In order that the invention may be well understood it will now be described by way of example only with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a plan view of a length of tram track; Figure 2 is a cross-section of a representative rail in the track of Figure 1 showing also a tram wheel.

The tram track comprises a length of rail R having a base 1, a generally horizontal top 3 and an intermediate portion 2. The top has an upper surface 4. A channel 5 extends along the longitudinal axis downwardly into the portion 2 to receive the annular rim 6 of a tram wheel 7, as shown in Figure 2. The rail is embedded in set material 8 by which the rail is anchored in a channel 9 in the ground 10. Because the upper surface 4 is flat or contoured and polished, either on installation or when used, there is a tendency for the tyred wheels of road vehicles to skid, both when the vehicles are crossing the tram line or when going generally along it. This problem is acute when the ground is wet.

In accordance with this invention part of the top surface, parts 4A and 4B as shown in the drawing and side which in use, is not run over by tram wheel 7, is provided with a friction coating such that the skidding will be reduced. The coating comprises particles of aluminium, in a mixture with a small proportion of aluminium oxide, say in a ratio of 9:1.

The coating 4A,4B to be applied is presented as a wire consisting predominantly of aluminium and a minor proportion of aluminium oxide and this is sprayed by, e.g. flame spraying or arc spraying in such a way that it is firmly connected to the top surface. Our evaluations have established that such a coating will provide the necessary anti-skid properties and traction allowing vehicles, even heavy lorries, to be driven across or along the rails By placing the coating on the surface of the rail, in such a way that contact with the tram wheel and its rim is avoided, so reducing the risk of damage to both tram wheel and coating. The coating of the selected material when applied by thermal spraying, has anti-skid, anti-wear and corrosion resistance characteristics.

The invention is not limited to the embodiment shown. The coating may be applied to one region only, and the rail may have a shape different from that shown. The coating need not be of the specific recipe given.

Claims

CLAIMS 1. A length of rail for a tram or like vehicle, the rail having a base portion and a head portion, the head portion having a longitudinal slot dividing the rail into two longitudinal side portions, over which a wheel of the tram will travel, the wheel having a rim which is received in the slot, an anti-skid coating of adherent refractory particles being present on the head portion in the region which will not be in contact with the tram wheel so as to prevent vehicles skidding on the rails.
2. A method of applying an adherent anti-skid coating to a length of rail forming a track for a tram or like vehicle, comprising applying to a surface of the rail in a region which the tram wheel is not in contact, a composition comprising refractory particles and a metal binder therefor so as to cause the particles to fonn an adherent coating thereon.
3. A method according to Claim 2, wherein the particles are of aluminium.
4. A method according to Claim 3, including a fluxing agent such as aluminium oxide.
5. A method according to Claim 3 and 4 in which the ratio of aluminium to aluminium oxide is 9:1.
6. A method according to Claim 2,3,4 or 5, including performing a pretreatment, such as grit blasting, before applying the coating. LS/BW/13.2.9BP1995.DES