CA2065235C

CA2065235C - Roadway

Info

Publication number: CA2065235C
Application number: CA002065235A
Authority: CA
Inventors: Lewis Lesley
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-26
Filing date: 1990-08-28
Publication date: 1999-11-23
Anticipated expiration: 2010-08-28
Also published as: ES2073033T3; DE69018265D1; AU636389B2; EP0489100A1; EP0489100B1; JP2900090B2; JPH05500092A; CA2065235A1; ATE120506T1; DE69018265T2; AU6336790A; WO1991002843A1

Abstract

A rail for vehicles to travel on is supported from a surface (14) by flanges (17) extending transversely from the top of the rail (11). The rail has a groove (16) for the road wheels. The rail is recessed into the road surface in a relatively shallow recess (12).
The rail has a low profile since the loading on the rail is taken on the surface and is not carried down as usual to a substrate for the surface.

Description

ROADWAY
FIELD OF THE INVENTION
The present invention concerns a roadway having a rail installed in it . Such roadways are used in particular f or j oint use by road vehicles and railway vehicles especially light railway vehicles.
BACKGROUND OF THE PRESENT INVENTION
The rails for a railway are I-beams supported by transverse sleepers on a bed of ballast on a prepared base.
Where a road crosses a railway, the surface of the road is level with the tops of the rails and the space between the rails is then built up. These rails have a high profile in that the width of the rail is very much less than the depth. For street railways or tramways a similar high profile rail is used. Thus tramways used a so-called phoenix rail which is generally an I-beam but with a groove for flanges of the vehicle wheels formed in the upper flange. To install such a rail in a road, it is necessary to excavate the road surface to a depth of at least 50 centimetres to provide for a sleeper or bed of concrete under the rail which itself would be 18 centimetres depth. Such a deep excavation entails re-routing underground services such as water and electricity mains and destroys the integrity of the road construction. Ways of reducing the depth of excavation have been developed in Dresden in the late 50' s wherein the rail was cast in concrete panels about 20 centimetres deep (but this involved shortish lengths of rail which had to be welded together) and in Budapest by Dr. Zahummensky in which rails are inserted in steel-lined channels in concrete panels with the rails being 7 centimetres deep and the panels 18 centimetres deep. A snag with such panel systems is that the panels have a tendency to settle or rock, in the Dresden system this is resisted by the rigidity of the phoenix-type track. In International Patent Publication WO 84/00391 there is described a phoenix-like rail consisting of an I-beam with a small foot and a large head. This is said to lead to a reduction in the number of sleepers and other bed structures because flanges forming the head take substantially or essentially all the loading onto the roadway which is of crushed stone structure possibly bound by a surface coating of bitumen. It is said that the depth of excavation needed to install the rail is reduced but as illustrated it shows that the excavation is more than twice the depth of the rail. It would seem moreover that the rail has to be rather deep since crushed stone would tend to settle unless the stiffness of the rail resisted such settling.
U.S. Patent 3,089,650 shows a rail with flanges towards the top but these flanges are to provide a suitable area moment in a weighing device. This rail would not be suitable for use in a roadway since the groove is large being intended to receive the entire wheel width and not merely a wheel flange and such a large groove would tend to trap road vehicle wheels and be dangerous.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a roadway having a recess in which is installed a rail, which rail has an upper surface for supporting vehicle wheels, a groove in that surface for receiving wheel flanges of those wheels, a bar portion providing that surface and that groove, and a pair of flanges extending integrally from the bar portion to spread the rail's wheel loading over part of the roadway's surface characterized in that the rail has a depth substantially less than its width and in that the recess, whilst shallow, has a depth such that the rail can settle into the recess so that the rail is effectively suspended from the flanges.
More specifically, there is provided in a first aspect of the invention, a roadway for rail and road vehicles having a pair of rails recessed into a road surface, each of which rails consists of a central squat bar portion and a pair of flanges extending integrally sideways from the top of the bar portion, the bar portion serving to provide a groove in an upper surface of the rail for supporting road wheels of a rail vehicle, which groove is for receiving flanges of the wheels, characterized in that each rail has a depth substantially less than its width and has its bar portion installed in a relatively shallow recess preformed in the road surface to a depth so as to receive the bar portion with the flanges effectively supporting the rail.
According to a second aspect of the invention, there is provided a method of constructing a roadway for rail and road vehicles comprising a pair of rails recessed into the road surface proper by forming a road surface with shallow performed recesses and then inserting the rails which have central squat bar portions, each defining an upper surface for wheels of the rail vehicles and a groove for flanges of said wheels and flanges extending integrally sideways from the top of the said bar portion, and each rail having a depth substantially less than its width and each recess being sized so as to receive the bar portion of the rail with the flanges supporting the rail in the recess.
Modern roads in cities where light railways are more likely to .share a road with road traffic are built to high standards capable of carrying 40 tonne vehicles with 11 tonne wheel loadings. These roads are expensive to construct and the present invention minimizes the amount of excavation needed to install rails. The flanges serve the functions of spreading vertical loading, gripping the roadway to resist cross-loading, and to minimize damage to the roadway due to water seeping down the sides of the bar portion. The flanges can have ridges to bite into the roadway and/or a sealant can be used to provide a water seal and to absorb sideways loading. Where sideways loading is expected to be very large, sections of phoenix track can be used.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a section of a rail fitted in a roadway, Figure 2 is a perspective view of a pair of rails fitted in a roadway, and Figure 3 is a perspective view showing a rail intersection.
DESCRIPTION OF AN EXEMPLARY EMBODIMENT
Figure 1 illustrates on a large scale a rail 11 in a shallow recess 12 in a roadway 14. The recess can be, for example 4 centimetres deep and 10 centimetres wide. The rail has a central bar portion 15 which is generally a regular trapezium in section but with a groove 16 for a vehicle wheel flange in the wider surface which in use is the uppermost surface of the rail. Extending integrally sideways from the bar portion, there is a flange 17 on each side of the rail. The recess is preferably cut out by suitable cutters such as disc or other cutters cutting the sides of the recess and such as a plane or other cutters removing the material remaining between the cut sides of the recess. The recess is then partially filled with a suitable material 18 so that when a rail is inserted in the recess the rail can be settled into the material 18 so that the vertical loading is effectively taken by the rail being suspended from the flanges. The rail can be of steel, iron or another material rolled, extruded or otherwise fabricated into the squat T-shape illustrated. The rail can be secured in place by mechanical or other means such as an adhesive bond which preferably has a degree of resilience as is provided by Corkelast. It is possible to provide ribs or a shallow groove in the underside of each flange to improve the sealing and the resistance of the rail to sideways movement.
Rails can be welded or otherwise joined end-to-end to form a continuous track and can be laid under tension to avoid thermal expansion problems. As shown in Figure 2, a pair of rails will normally be used and a pair of recesses can be cut simultaneously using ganged cutters to ensure correct spacing.
Cross ties not illustrated can be provided at intervals to form gauge defining devices and these can be recessed below the roadway surface .
To avoid crossing road traffic and in particular two-wheeled vehicles such as pedal and motor cycles being inconvenienced by the smooth metallic bumps formed by the rails, the space between the rails 11 is built up to the top of the rails by .a thin layer of tarmac 20 or other road facing material. It would be possible to recess the flanges slightly in the road surface so that they are substantially flush with the roadway and then merely fill the seam alongside the flanges with tarmac or the like. It would also be possible to have the flanges slightly down from the top of the rails with tarmac or other material on top of the flanges to minimize the amount of metal exposed.
Figure 3 illustrates a junction piece which would be cast or otherwise formed and comprises two rails 21 and 22 crossing at an angle with the grooves in the two rails extending across the central intersection 23. Where more complicated arrangements are involved such as junctions, special provisions might be made such as the provision of sections of conventional phoenix tracks but a suitable adaptation of Figure 3 is possible.
The present invention is mainly for use where road vehicles and track vehicles share road space. Such situations arise where there are tramways or light urban railways. The invention can be used even when such tramways or urban light railways run on segregated tracks and even for mainline railways. Where segregated tracks or mainline railways are involved the roadway in which the rails are laid can be made of heavy concrete or stone slabs or panels or even on a continuous concrete bed laid in situ; with such concrete roadways there would have . to be expansion j oints but the recesses can be formed during manufacture or laying wet concrete. For example the recesses can be formed by a slip-form paviour or other machine.
The low profile rail according to the present invention offers advantages due to the reduction in rail height over traditional railway track especially when a track is being adapted for electrification or gauge conversion since it would not be necessary to lower an existing track bed possibly exposing wall foundations in existing tunnels.
The rails can be used for signalling or electric power supply if the rails are insulated. However it is probably not possible to supply sufficient power to drive a vehicle in this way but only to use the rails has a return path and then it would be desirable to bond the rails to a low resistance earth cable at intervals to avoid earth leakage currents interfering with other services.
The cross-section of the rails depends on the use. The groove is shaped to suit the intended traffic and can for example not only engage those wheels supporting a vehicle but also steering wheels which engage the groove and transmit steering information to the supporting wheels. The central bar portion would be deep enough to provide an adequate groove and typically would be about 7 centimetres deep with 4 centimetres recessed in the roadway, and would be typically 10 centimetres wide with the flanges extending further out by sufficient distance bearing in mind the substrate load-bearing capacity to suspend the rails from the roadway so the vertical and horizontal loading on the rails is taken on the upper surface of the roadway without appreciable settlement unlike the previous systems where the vertical loading was taken to the bottom of the rails.
Even when the flanges are offset or recessed down the bar portion and the flanges as well as the bar portion are recessed in the roadway, the vertical loading is taken near to the top surface of the roadway. It is thought that having the flanges recessed into the roadway will only be practical when the recesses are preformed during roadway laying or when the rails can ~be laid during roadway construction with the final surfacing burying the flanges without raising the intended level of the roadway.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A roadway for rail and road vehicles having a pair of rails (11) recessed into a road surface (14), each of which rails consists of a central squat bar portion (15) and a pair of flanges (17) extending integrally sideways from the top of the bar portion, the bar portion serving to provide a groove (16) in an upper surface of the rail for supporting road wheels of a rail vehicle, which groove is for receiving flanges of the wheels, characterized in that each rail has a depth substantially less than its width and has its bar portion installed in a relatively shallow recess (12) preformed in the road surface to a depth so as to receive the bar portion with the flanges effectively supporting the rail.

2. A roadway according to claim 1, characterized in that each rail has a generally trapezoidal bar portion, the depth of which is less than its width.

3. A roadway according to claim 1 or claim 2 further characterized in that each rail is secured in place by mechanical or other means.

4. A roadway according to claim 1 or claim 2, further characterized in that the rail flanges seal onto the road surface.

5. A roadway according to claim 1 or claim 2 wherein each rail is formed from lengths of rail welded together.

6. A roadway according to claim 1, having rails crossing at an angle with a junction piece for the rails comprising an integrally cast or otherwise formed member with intersecting bar portions crossing at said angle with grooves in the intersecting bar portions extending across the central intersection and in line with the grooves in the rails.

7. A roadway according to claim 1 wherein the bar portion is roughly 7 centimetres deep with 4 centimetres recessed into the road surface and roughly 10 centimetres wide with the flanges extending further out by sufficient distance bearing in mind the load bearing capacity of the road surface to suspend the rail without appreciable settlement.

8. A roadway according to claim 1 wherein the road surface between each pair of rails is built up to the level of the top of the rails.

9. A method of constructing a roadway for rail and road vehicles comprising a pair of rails recessed into the road surface proper by forming a road surface (14) with shallow performed recesses (12) and then inserting the rails (11) which have central squat bar portions (15), each defining an upper surface for wheels of the rail vehicles and a groove (16) for flanges of said wheels and flanges (17) extending integrally sideways from the top of the said bar portion, and each rail having a depth substantially less than its width and each recess being sized so as to receive the bar portion of the rail with the flanges supporting the rail in the recess.