CA3004116C

CA3004116C - Method for retrofitting a monorail guide beam and retrofitted monorail guide beam

Info

Publication number: CA3004116C
Application number: CA3004116A
Authority: CA
Inventors: Peter Timan
Original assignee: Bombardier Transportation GmbH
Current assignee: Alstom Transportation Germany GmbH
Priority date: 2018-05-07
Filing date: 2018-05-07
Publication date: 2020-01-21
Anticipated expiration: 2038-05-07
Also published as: CN110453545A; CA3004116A1; CN110453545B; CN210797122U

Abstract

A method of retrofitting an existing guide beam of an existing guideway to accept a second model of monorail. The method comprises installing a second top running surface above an existing top running surface of an existing guide beam of the existing guideway. The second top running surface is adapted to receive a load wheel of a second model of monorail. The second top running surface is installed at height H above the existing top running surface so that a second passenger floor level of the second model of monorail substantially corresponds to a first passenger floor level of an existing model of monorail supported by the existing top running surface.

Description

METHOD FOR RETROFITTING A MONORAIL GUIDE BEAM AND
RETROFITTED MONORAIL GUIDE BEAM
FIELD OF THE INVENTION
[0001] The present invention generally relates to the field of monorail guideways. More specifically, the invention relates to a method of retrofitting a guide beam of a monorail guideway allowing the travelling of a different monorail on the retrofitted guide beam.
BACKGROUND OF THE INVENTION

[0002] The beams and switches of a monorail guideway on which travel monorail vehicles do not have to respect standard dimensions. In fact, monorails and the infrastructure they travel on are usually provided as a system, meaning that both the monorail and the guide beam on which it travels are specifically designed for each other and are specific to each manufacturer.

[0003] However, monorails, like any other vehicle, end up showing the wear of time, and need to be eventually replaced by new vehicles. Because the monorail and its guide beam are specifically designed to work with each other, and because all passenger platforms are designed to be compatible with the original monorail, transit authorities are constrained to select a new monorail that is compatible with their existing guideway when replacement time comes. Such a compatible monorail is often only available from the same manufacturer that provided the original vehicle, thereby limiting the pool of available manufacturers and consequently decreasing significantly the negotiation leverage of the transit authority.

[0004] There is therefore a need to provide a way of making an existing monorail guideway compatible with a monorail that is different from the original monorail the guideway was designed for.
SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to provide a method of adapting an existing monorail guideway to accommodate a monorail for which it was not originally designed for, thereby overcoming or mitigating one or more disadvantages of known guideways, or at least providing a useful alternative.

[0006] The invention provides the advantages of allowing a transit authority to choose between potential different new models of monorails from different manufacturers when comes times to select a replacement for old monorails that are to be retired.

[0007] In accordance with an embodiment of the present invention, there is provided a method of retrofitting an existing guide beam of an existing guideway to accept a second model of monorail. The existing guide beam has an existing top running surface adapted to receive a first load wheel of a first model of monorail. The method comprises placing a second top running surface above the existing top running surface by installing a second guide beam atop the existing guide beam. The second top running surface is then operative to receive a second load wheel of the second model of monorail.

[0008] The placing may further comprise locating the second top running surface at a height H above the existing top running surface so that a second passenger floor of the second model of monorail rests substantially at a same height above the existing top running surface as a first passenger floor of the first model of monorail. This height H corresponds to a distance between the second top running surface and the existing top running surface and is equal to FH1 ¨

FH2 where:

[0009] FH1 is a first floor height of the first model of monorail. The first floor height is a design characteristic of the first model of monorail which corresponds to a height of the first passenger floor above the existing top running surface; and

[0010] FH2 is a second floor height of the second model of monorail.
The second floor height is a design characteristic of the second model of monorail which corresponds to a height of the second passenger above the second top running surface. The second floor height is smaller than the first floor height.

[0011] Optionally, the second guide beam may be of a height H. Also, the placing may further comprise placing the second top running surface substantially 550 mm (21.7 in) above the existing top running surface or even substantially 750 mm (29.5 in). The second top running surface may range between 75% and 100% of a width of the existing top running surface.

[0012] The second guide beam may be made of concrete. The second guide beam may then be poured in place in the shape of the second guide beam and may include the pouring concrete over reinforcement rods inserted in the existing guide beam.

[0013] Alternatively, the second guide beam may be a pre-fabricated guide beam such as a concrete pre-cast guide beam or a pre-fabricated beam made of metallic materials such as steel or aluminum.

[0014] The method may further comprise mechanically attaching the second guide beam to the existing top running surface of the existing guide beam or to any other convenient area of the existing guide beam, such as lateral guiding surfaces. For this purpose, mechanical fasteners or adhesives may be used on the existing top running surface of the existing guide beam.

[0015] Optionally, the method may further comprise providing two opposed lateral guiding surfaces parallel to each other and perpendicular to the second top running surface. Also, these two opposed lateral guiding surfaces may be provided at a different side edge of the second top running surface.

[0016] In accordance with another embodiment of the present invention, there is provided a method of building an improved monorail guideway based on an existing monorail guideway. The method comprises installing a second top running surface above an existing top running surface of an existing guide beam of the existing guideway. The second top running surface is adapted to receive a load wheel of a second model of monorail. The second top running surface is installed at height H above the existing top running surface so that a second passenger floor level of the second model of monorail substantially corresponds to a first passenger floor level of an existing model of monorail supported by the existing top running surface. Height H is equal to FH1 ¨ FH2 as described above.

[0017] Optionally, the installing further comprises attaching a second guide beam atop the existing top running surface of the existing guide beam. The second guide beam extends at least along a portion of a length (at least along platforms at train stations), or a whole length, of the existing guide beam of the existing guideway. The second guide beam has the second top running surface, which may be installed at substantially 550 mm (21.7 in) above the existing top running surface or even substantially at 750 mm (29.5 in) above the existing top running surface.

[0018] The method may further comprise providing second parallel lateral guiding surfaces which depend from each side of the second top running surface and extending downwardly to the existing top running surface.

[0019] Typically, the width of the second top running surface ranges between 75% and 100% of the width of the existing top running surface.

[0020] In accordance with another embodiment of the present invention, there is provided a method of operating a transit system having a monorail guideway on which travels a monorail. The method comprises:
a) operating a first monorail on a first guide beam having a first top running surface adapted to receive a first load wheel of the first monorail. The first monorail has a first passenger Floor height above the first top running surface;
b) updating the first guide beam with a second support structure, thereby defining an updated guide beam. The second support structure has a second top running surface placed at a height H above the first top running surface. The second top running surface is adapted to receive a second load wheel of a second monorail. The second monorail has a second passenger Floor height above the second top running surface.
This second passenger Floor height is smaller than the first passenger Floor height. The height H substantially corresponds to a difference between the first passenger Floor height and the second passenger Floor height; and c) operating the second monorail on the updated guide beam made of the first guide beam and of the second support structure.

[0021] Preferably, the support structure is a second guide beam.

[0022] The operating the second monorail typically occurs within 1 years of the operating the first monorail.

[0023] In accordance with another embodiment of the present invention, there is provided a monorail guide beam for supporting and guiding a monorail, where the monorail has a load wheel, guide wheels and stabilizing wheels. The guide beam comprises:
a) a lower beam portion having a flat top surface and two lower lateral guiding surfaces extending downwardly from side edges of the top surface and perpendicularly to the top surface. The two lower lateral guiding surfaces are operative to receive the monorail's lateral stabilizing wheels;
b) an upper beam portion atop the lower beam portion. The upper beam portion has a flat top running surface for receiving the monorail's load wheel and two upper lateral guiding surfaces for receiving the guide wheels of the monorail. The two upper lateral guiding surfaces extend downwardly from side edges of the top running surface and perpendicularly to the top running surface. The top running surface extends between 50% and 100% of a distance between the two lower lateral guiding surfaces. The upper beam portion is mechanically and optionally removably attached to the lower beam portion.

[0024] In accordance with another embodiment of the present invention, there is provided a monorail vehicle adapted to travel on a guide beam. The guide beam has a top running surface, two opposed and parallel upper lateral guiding surfaces, and two opposed and parallel lower lateral stabilizing surfaces.

The two upper lateral guiding surfaces are distant by a first distance and the two lower lateral stabilizing surfaces are distant by a second distance larger than the first distance. The monorail vehicle comprises a body, two bogies and a propulsion system. The body is supported at each end by the two bogies. The body has a passenger compartment to carry passengers. Each one of the two bogies supports a different end of the body on the guide beam. Each bogie has:
a) a load wheel. The load wheel has a transversal spinning axis so as to roll along the top running surface of the guide beam. The load wheel supports its bogie on the guide beam;
b) at least two guide wheels. The at least two guide wheels are located below the load wheel. Each guide wheel, which spins on its own vertical axis, is attached to the bogie on a different side of the bogie so as to contact the guiding surface at the first distance from each other when rolling along the two opposed lateral guiding surfaces of the guide beam;
C) two stabilizing wheels. The two stabilizing wheels are located below the two guide wheels. Each stabilizing wheel, which spins on its own vertical axis, is attached to the bogie on a different side of the bogie so as to contact the stabilizing surface at the second distance from each other when rolling along the two opposed lateral stabilizing surfaces of the guide beam. The second distance is larger than the first distance;
The propulsion system is connected to at least one of the two load wheels for moving the monorail vehicle along the guide beam.

[0025] In accordance with another embodiment of the invention, there is provided a monorail guide beam for supporting and guiding a monorail proximate a passenger platform. The monorail guide beam comprises an existing portion, originally designed to support a first model of monorail, and a means for supporting a second model of monorail over the existing portion. The existing portion is installed on a ground surface. The first model of monorail has a first passenger floor located at a first floor height. The second model of monorail has a second passenger floor located at a second floor height which is smaller than the first floor height. The means for supporting the second model of monorail is operative to locate the second model of monorail above the existing portion of the monorail guide beam so that the second passenger floor is substantially level with the passenger platform.

[0026] Optionally, the means for supporting the second model of monorail above the existing portion of the monorail guide beam may be a secondary guide beam placed or built, either removably or permanently, on the existing portion.
This secondary guide beam may be made of concrete or of a metallic material.
BRIEF DESCRIPTION OF DRAWINGS

[0027] These and other features of the present invention will become more apparent from the following description in which reference is made to the appended drawings wherein:

[0028] Figure 1 is a side view of a monorail running on a monorail guide beam in accordance with an embodiment of the present invention;

[0029] Figures 2A is cross-sectional end view of the guide beam of Figure 1;

[0030] Figure 2B is a cross-sectional end view of a second model of guide beam different from the guide beam of Figure 1;

[0031] Figure 3 is a phantom side view of one car of the monorail of Figure 1;

[0032] Figures 4a and 4b are cross-sectional end views of respectively a first monorail running on its first guide beam and a second monorail on its second guide beam in accordance with prior art, juxtaposed so that the platform levels and passenger floors are at the same height;

[0033] Figures 5a and 5b are cross-sectional end views of respectively the first monorail on its first guide beam of Figure 4a to which is juxtaposed the second monorail of Figure 4b installed on the first guide beam, highlighting the challenges of using the second monorail on the existing first guide beam in accordance with prior art;

[0034] Figure 6a and 6b are cross-sectional end views of respectively the first monorail and its first guide beam of Figure 4a to which is juxtaposed the second monorail of Figure 4b installed on a retrofitted first guide beam so that their passenger floors are at a same height in accordance with an embodiment of the present invention;

[0035] Figure 7 is a perspective view depicting a step in the retrofit of a monorail guide beam in accordance with an embodiment of the present invention;

[0036] Figure 8 is a perspective view depicting the retrofitted guide beam of Figure 7;

[0037] Figure 9 is a schematic of a method of retrofitting a guide beam in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention relates to a method of refurbishing or retrofitting a monorail guide beam of a monorail guideway so that it can be compatible with a second type of monorail, such a retrofitted monorail guide beam as well as to a monorail adapted to run on such a retrofitted guide beam.

[0039] Figure 1, now referred to, shows a monorail 10 travelling on a guide beam 12. The guide beam 12 typically rests on pillars 14, supporting the guide beam 12 above the ground 16. Typically, the monorail 10 and the guide beam 12 are specifically designed to interface with each other. For example, the guide beam 12 is designed to support the vertical and lateral static and dynamic loads created by the monorail 10 carrying its passengers at speed. These loads and other criteria determine some of the guide beam's characteristics such as width and height. In turn, these dimensional characteristics determine other physical characteristics of the monorail 10 such as the location of the monorail's guide wheels and stabilizing wheels. Consequently, the guide beams making up a guideway and the monorails running on this guideway are specifically designed to work with each other. As shown in Figure 2A, the guide beam 12 typically has a rectangular cross section providing a top running surface 26 and lateral guiding surfaces 28 on each side. Variations on the cross section of the guide beam 12, such as shown in Figure 2B, may be used to save material and to decrease the weight of the guide beam 12. Although the cross section may be different, any guide beam 12 always possesses the top running surface 26 and at least two opposed lateral guiding surfaces 28.

[0040] The monorail 10 depicted in Figure 1 is made of four (4) interconnected cars 18. This is an example only since the monorail 10 could be made of more or less cars 18. Each car 18 is provided with at least one door having a door sill 22 which is vertically aligned with a floor 24. The floor 24 is best shown in Figure 3, now concurrently referred to. A passenger plafform 45 is aligned with the monorail floor 24.

[0041] Each car 18 comprises a body 25 and two bogies 27 located at each end of the car 18. A propulsion system 29 may also be provided, although some cars 18 may be devoid of propulsion system 29. The body 25 has a passenger compartment 31 to carry passengers. Each one of the two bogies 27 support a different end of the body 25 on the guide beam 12. Each bogie 27 is equipped with a load wheel 46, two or four guide wheels 42 (split equally on each side of the guide beam 12), at least two stabilizing wheels 44 (one on each side of the guide beam 12).

[0042] Each load wheel 46 has a transversal spinning axis so as to roll along a top running surface 26 of the guide beam 12. Each load wheel 46 is operative to support its bogie 27 on the guide beam 12, and thereby support its end of the body 25. The two guide wheels 42 are located below the load wheel 46. Each one of the two guide wheels 42 spins on its own vertical spinning axis 76. The two guide wheels 42 are operative to contact the lateral guiding surfaces 28 of the guide beam 12.

[0043] The stabilizing wheels 44 are located below the two guide wheels 42. Each stabilizing wheel 44 spins on its own vertical axis. The stabilizing wheels 44 are operative to contact the lateral guiding surfaces 28.

[0044] The propulsion system 29 is connected to at least one of the two load wheels 46 for moving the monorail 10 along the guide beam 12.

[0045] Figures 4a and 4b, now concurrently referred to, respectively depict the first monorail 30 running on its first guide beam 34 and the second monorail 32 running on its second guide beam 36, juxtaposed so that platforms 45 are shown at the same level and so that, consequently, the passenger floors 24 are also level. Figures 4a and 4b represent two different and representative existing monorail systems, typically marketed by two competitors.

[0046] Such representation highlights the differences in architecture between the first monorail 30 with its first guide beam 34 and the second monorail 32 with its second guide beam 36. As can be observed, the first and second guide beams 34, 36 do not have the same height, the same width, nor even the same cross section. But they both possess a top running surface 26 as well as left and right side guiding surfaces 28. In the present example, the second guide beam 36 is shorter in height and narrower than the first guide beam 34. It can also be observed that the second monorail 32 sits lower on its guide beam than the first monorail 30. This is reflected by the distance from the floor 24 to a top of the guide beam, also known as the Top of Beam (TOB). This distance is known as the Floor Height. The Floor Height is therefore defined as the distance between the floor level of a monorail and the top surface of the guide beam (TOB) on which that same monorail is designed to travel. In the case of the first monorail 30, this distance is FH1 while it is FH2 in the case of the second monorail 32. For example, FH1 may be 800 mm (31,5 in) while FH2 may be 450 mm (17,7 in), which are dimensions that may be representative of reality.
The guide wheels 42 and the stabilizing wheels 44 may contact the respective lateral guiding surfaces 28 of the first and second guide beams 34, 36 at different heights, and of course at different lateral distances since the first and second guide beams 34, 36 have different width. Indeed, in the present example, the first guide beam 34 has a width of W1. For example, the first guide beam 34 may have a width W1 of 800 mm (31.5 in) while the second guide beam 36 may have a width W2 of 690 mm (27.2 in).

[0047] The difference in Floor Height between the first and the second monorails 30, 32 is the main reason why one monorail model cannot readily replace the other on the existing guideway. This is highlighted in Figures 5a and 5b, which are now concurrently referred to. Figure 5a depicts the first monorail 30 running on its existing first guide beam 34 as already shown in Figure 4a.
Figure 5b, depicting the second monorail 32 installed on the same existing first guide beam 34, is juxtaposed to Figure 5a to highlight the impossibility of readily installing the second monorail 32 on the existing first guide beam 34. Indeed, as can be observed in Figure 5b, the guide wheels 42 and the stabilizing wheels may end up being in interference with the first guide beam 34 or may at least not interface properly with the lateral guiding surfaces 28. Most importantly, the passenger floor 24 ends up not being level with the platform 45, which is totally unacceptable. Indeed, because passenger platforms 45 at each station are designed to be substantially level with the passenger floor 24 of the monorails, so that passenger may easily board and disembark the vehicle, simply replacing an existing monorail with a monorail having a different Floor Height may prevent this ease of egress and ingress. Such unevenness between the platform 45 and the floor 24 may result in passengers tripping, falling and could potentially prevent disabled travelers from boarding the monorail.

[0048] It must be noted that, in Figures 5a and 5b, the top of the existing first guide beams 34, have been aligned, reflecting the fact that in real life, both first guide beams would actually be only one, since the objective would be to tentatively install the second monorail 32 on the existing first guide beam 34.
Aligning TOBs also allows to have a common vertical reference for comparison purposes between Figures 5a and 5b.

[0049] Figures 6a and 6b, now concurrently referred to, show a side-by-side comparison of the first and second monorails 30, 32, this time both running on the first guide beam 34, and displayed so that their floors 24 are level, meaning that the floors 24 are located at the same height above the common reference level TOB. As can be seen, when the floors 24 of the first and of the second monorails 30, 32 are located at the same height, a load wheel 46 of the second monorail 32 cannot contact the top running surface 26 of the first guide beam 34. In order to fill the space between the load wheel 46 and the top running surface 26 of the first guide beam 34, an additional guide beam 48 may be installed atop the existing first guide beam 34.

[0050] Hence, in accordance with an embodiment of the present invention, there is provided a method of retrofitting the existing first guide beam 34 to accept the second model of monorail 32 so that its floor 24 ends up being at the same height above a reference level such as TOB, thereby advantageously allowing retaining the existing platforms 45 at train stations. This is achieved by installing the additional guide beam 48 atop the existing first guide beam 34.
The additional guide beam 48 is therefore designed to fill the gap between the top running surface 26 of the existing first guide beam 34 and a required second top running surface 50 on which the load wheel 46 of the second monorail 32 may rest. In this context, the additional guide beam 48 may take any adequate shape that still allows placing the secondary top running surface 50 at the right height so that the load wheel 46 of the second monorail 32 may support the second monorail 32 and travel on it. The additional guide beam 48 has its own second top running surface 50 operative to support the load wheel 46 of the second monorail model 32. This second top running surface 50 is located at a distance H
from the top running surface 26 of the first guide beam 34. This distance H
corresponds to the difference between the Floor Height FH 1 of the first monorail model 30 running on its first guide beam 34 and the Floor Height FH2 of the second monorail model 32 running on its second guide beam 36. Expressed in equation form: H = FH1 - FH2. In the present example, this distance H
corresponds to the difference between FH1 = 800 mm (31.5 in) and FH2 = 450 mm (17.7 in), that is H = 350 mm (13.8 in). Consequently, the additional guide beam 48 must be of height H, or in the present example, 350mm (13.8 in) high.

[0051] In other words, the present method substantially aligns the floor 24 of the second monorail 32 with the floor 24 of the existing first monorail 30 so that the floor 24 of the second monorail model 32 ends up being at the same height above the existing top running surface 26 than the floor 24 of the first monorail model 30. To do so, the method provides a second top running surface 50 above the existing top running surface 26 since the Floor Height FH2 of the second monorail 32 is smaller than the Floor Height FH1 of the first monorail 30.

[0052] As a non-limiting example, the floor 24 of the first monorail 30 may be located 1200 mm (47.2 in) above its TOB (FH1 = 1200 mm (47.2 in)). This means that the second monorail 32 will also need to have its floor located mm (47.2 in) above the existing top running surface 26. If the second monorail has been designed with a Floor Height FH2 of 800 mm (31.5 in), it means that the second top running surface 50 needs to be placed at H = FH2 ¨ FH1 = 1200 mm ¨ 800 mm = 400 mm (47.2 in ¨ 31.5 in = 15.7 in) above the existing first running surface 26. This also means that the additional guide beam 48 must be H = 400 mm (15.7 in) high.

[0053] It may be appreciated that the present method only allows refurbishing the existing first guide beams 34 of guideways to accept a second monorail 32 that has a smaller Floor Height than that of the existing first monorail 30 running on the existing first guide beams 34.

[0054] The additional guide beam 48 may be narrower, the same width, or wider than the first guide beam 30. For example, the additional guide beam 48, and especially its secondary top running surface 50, may be of the same width as the second guide beam 36 (690 mm (27,2 in) in the present example) so that a minimum of modification is required on a bogie 52 of the second monorail 32 to accommodate fit its guide wheels 42 to the updated guide beam. Alternatively, the additional guide beam 48 may be the same width as the first guide beam 34, or any other convenient width such as, for example, between 75% and 100% of the width of the existing top running surface 26 or of the width of the first guide beam 34.

[0055] The additional guide beam 48 may be made of concrete, just like most existing guide beams, of metallic materials such as steel, or of any other adequate material. The additional guide beam 48 may be a pre-fabricated beam which is remotely made in a plant and transported on site where it is installed to the existing guideway.

[0056] The retrofitting method may comprise mechanically attaching the additional guide beam 48 to the first guide beam 34, and particularly on or above the existing top running surface 26. This attaching may be performed by installing mechanical fasteners such as screws and bolts on (through) the existing top running surface 26 of the first guide beam 34. Alternatively, the additional guide beam 48 may also be attached to (through) the lateral guiding surfaces 28. If the existing first guide beam 34 is made of steel, the additional guide beam 48 would typically also be made of steel and both could be welded together.

[0057] The additional guide beam 48 may also be constructed directly on site by pouring concrete over steel rods, or other adequate type of attachment known in the art, embedded or inserted in the first guide beam 30. This comprises removably installing vertical lateral portions of a mold, either to the lateral guiding surfaces 28 of the existing first guide beam 34 or to its top running surface 26, to create lateral walls of the additional guide beam 48 that extend vertically upwardly from the existing first guide beam 34 or from its top running surface 26. Then, using the top running surface 26 of the existing first guide beam 34 as a bottom of the mold, the additional guide beam 48 may be made by pouring concrete in the created mold. Finishing of the second top running surface 50 may be made using known techniques in the art before the concrete completely dries out.

[0058] Figures 7 and 8 are now concurrently referred to. Schematically, an updated monorail guide beam 52 is created from the addition of an upper beam portion 54 to an existing lower beam portion 56 by mechanical means, such as fasteners, or chemical means, such as bonding. This connection between the upper beam portion 54 and the lower beam portion 56 may be permanent or removeable. If the connection is removeable, then it is possible to take the monorail guide beam 52 back to the first guide beam configuration to use the first monorail model 30 again.

[0059] The existing lower beam portion 56 corresponds to the existing first monorail guide beam 34, originally designed to support and guide the first monorail 30. The first monorail 30 has its own design of load wheel 46, guide wheels 42 and stabilizing wheels 44 to match the existing first guide beam 34.

One important design characteristic of the first monorail 30 is its own first Floor Height FH1. The upper beam portion 54 is specifically designed so that the resulting updated guide beam 52, guideway 13 and platforms 45 are compatible with the second monorail 32, even though it has its own different design of load wheel 46, guide wheels 42, stabilizing wheels 44 and second Floor Height FH2.

[0060] Figure 9 is now concurrently referred to. In accordance with an embodiment of the present invention, the first Floor Height FH1 and the second Floor Height FH2 must first be determined or gathered from the monorails manufacturers at steps 60 and 62. At 64, it must be verified that second Floor Height FH2 is smaller than first Floor Height FH1. In other words, the second monorail model 32 must be selected so that its design Floor Height FH2 is smaller than the first Floor Height FH1 of the existing first monorail 30. If none can be found, then the existing first guide beam 34 cannot be updated with the present method. If such a second monorail model 32 may be found, then the position H of the second top running surface 50 of the upper beam portion 54 must be determined at 66 by subtracting FH2 from FH1. It must be understood that the objective is to have the level of the passenger floor 24 of the second monorail 32 end up being level with platforms 45 levels. However, the person skilled in the art will understand that this means substantially level since a small difference may not have a real consequence on the ease of egress or ingress of passengers. Such difference should however be smaller than 25 mm (1 in), preferably less than 13 mm (0.5 in), more preferably less than 6,4 mm (0.25 in), even more preferably less than 3 mm (0.125 in) and yet even more preferably less than 1,6 mm (1/16 in). Then at 68, the upper beam portion 54 must be attached to the existing lower beam portion 56.

[0061] The upper beam portion 54 may include its own two upper lateral guiding surfaces 70 to receive the guide wheels 42 of the second monorail 32.

Such two upper lateral guiding surfaces 70 extend downwardly from side edges of the second top running surface 50 and perpendicularly to it.

[0062] It is possible for the upper beam portion 54, also known as the additional guide beam 48, not to have lateral surfaces adequate to receive the guide wheels 42 of the second monorail 32. Then, these guide wheels 42 may use the two lower lateral guiding surfaces 72 of the lower beam portion 52, also known as the existing first guide beam 34.

[0063] In another embodiment of the present invention, a method of operating a monorail comprises:
a) operating the existing first monorail 30 on the existing first guide beam 34. The first monorail has the first Floor Height Fl-I1 above the first top running surface 26 of the first guide beam 34;
b) having the first guide beam 34 updated with an additional guide beam 48, where this additional guide beam 48 has a second top running surface 50 placed at the height H above the existing first top running surface 26;
and c) operating the second monorail 34 on the updated guide beam 52, the second monorail 32 having the second Floor Height FH2 above the second top running surface 50 of the additional guide beam 48, the height H being substantially equal to the difference between the first Floor Height FH1 and the second Floor Height FH2.

[0064] When a transit authority decides to update its guideway, the whole operation must be conducted in as little time as possible since the transit service must be interrupted at least on a portion of the guideway. The operating of the second monorail 32 occurs within 1 year of operating the first monorail 30.

[0065] In order to be fully compatible with the updated guide beam 52, the second monorail 32 may have to be slightly adapted, especially with regards to its stabilizing wheels 44 and/or its guide wheels 42, which are all connected to the second monorail's bogie frame 74. For example, if the existing first guide beam 34 is wider than the second guide beam 36, a spinning axis 76 of the stabilizing wheels 44 may need to be moved outwardly in the bogie frame 74 of the second monorail 32 to compensate for the fact that the two opposed lower lateral guiding (stabilizing) surfaces 72 are farther apart than those of the second guide beam model 36, for which the second monorail 32 was designed.
Alternatively, smaller diameter stabilizing wheels 44 could also be used to compensate for the wider first guide beam 34. Conversely, if the first guide beam 34 is thinner than the second guide beam 36 for which the second monorail 32 was designed, the spinning axis 76 of the stabilizing wheels 44 of the second monorail model 32 may need to be moved inwardly in the bogie frame 74 of the second monorail 32 to compensate for the fact that the two opposed lower lateral guiding surfaces 72 are closer to each other. Alternatively, larger diameter stabilizing wheels 44 may also be used to compensate for the thinner first guide beam 34. In the same case, another alternative may be to install spacers 78 on the first guide beam 34 to match the width of the second guide beam 36 for which the second monorail 32 was designed.

[0066] As for the guide wheels 42, they may retain their position in the second monorail's bogie frame 74 if the upper beam portion 54 is provided with the same width as that of the second guide beam 36. Alternatively, if the upper beam portion 54 is given the same width as that of the first guide beam 34 (i.e.
that of the lower beam portion 56), the guide wheels 42 may need to be adapted (i.e. their spin axis 74 may be moved inwardly or outwardly or the diameter of the guide wheels may be made larger or smaller) with the same logic as that explained above for the stabilizing wheels 44.

[0067] The present invention has been described with regard to preferred embodiments. The description as much as the drawings were intended to help the understanding of the invention, rather than to limit its scope. It will be apparent to one skilled in the art that various modifications may be made to the invention without departing from the scope of the invention as described herein, and such modifications are intended to be covered by the present description.
The invention is defined by the claims that follow.

Claims

CLAIMS:

1. A method of retrofitting an existing guide beam of an existing guideway to accept a second model of monorail, the existing guide beam having an existing top running surface adapted to receive a first load wheel of a first model of monorail, the method comprising:
placing a second top running surface above said existing top running surface by installing a second guide beam atop said existing guide beam, said second top running surface being narrower than said existing top running surface, said second top running surface being operative to receive a second load wheel of the second model of monorail, said second top running surface being placed at a height H above said existing top running surface so that a second passenger floor of the second model of monorail rests substantially at a same height above said existing top running surface as a first passenger floor of the first model of monorail.

2. The method of claim 1 wherein:
FH1 is a first floor height of said first model of monorail, said first floor height being a design characteristic of said first model of monorail, said first floor height corresponding to a height of said first passenger floor above said existing top running surface;
FH2 is a second floor height of said second model of monorail, said second floor height being a design characteristic of said second model of monorail, said second floor height corresponding to a height of said second passenger above said second top running surface, said second floor height being smaller than said first floor height; and height H is a distance between said second top running surface and said existing top running surface, said height H being equal to FH1 ¨ FH2.

3. The method of claim 2 wherein said second guide beam is of a height H.

4. The method of claim 1 further comprising mechanically attaching said second guide beam to said existing top running surface of the existing guide beam.

5. The method of claim 4 wherein said mechanically attaching comprises installing mechanical fasteners on said existing top running surface of said existing guide beam.

6. The method of claim 1 wherein said second guide beam is made of concrete.

7. The method of claim 1 wherein said installing further comprises pouring concrete in the shape of said second guide beam.

8. The method of claim 1 wherein said installing further comprises attaching said second guide beam to the existing guide beam using mechanical fasteners, said second guide beam being a pre-fabricated guide beam.

9. A method of operating a transit system having a monorail guideway for operating a monorail, the method comprising:
a) operating a first monorail on a first guide beam having a first top running surface adapted to receive a first load wheel of said first monorail, said first monorail having a first passenger Floor height above said first top running surface;
b) having the first guide beam updated with a second support structure thereby defining an updated guide beam, said second support structure having a second top running surface placed at a height H above said first top running surface, said second top running surface being narrower than said first running surface, said second top running surface being adapted to receive a second load wheel of a second monorail, said second monorail having a second passenger Floor height above said second top running surface, said second passenger Floor height being smaller than said first passenger Floor height, said height H substantially corresponding to a difference between said first passenger Floor height and said second passenger Floor height; and c) operating said second monorail on said updated guide beam made of said first guide beam and said second support structure.

10. The method of claim 9 wherein said support structure is a second guide beam.

11. The method of claim 9 wherein said operating said second monorail occurs within 1 years of said operating said first monorail.

12. A monorail guide beam for supporting and guiding a monorail proximate a passenger platform, the monorail guide beam comprising:
an existing portion, the existing portion having an existing top running surface adapted to receive a first load wheel of a first model of monorail, the first model of monorail having a first passenger floor located at a first floor height above said existing top running surface, said first passenger floor being substantially level with the passenger platform, said existing portion being installed on a ground surface;
a second beam portion placed on top of said existing top running surface, said second beam portion having a second top running surface for supporting a second model of monorail, said second top running surface being narrower than said existing top running surface, said second model of monorail having a second passenger floor located at a second floor height, said second floor height being smaller than said first floor height, said new beam portion having its second top running surface located at a height H above said existing top running surface so that said second passenger floor is substantially level with the passenger platform and with said first passenger floor.