GB2270663A

GB2270663A - A single bogie rail vehicle.

Info

Publication number: GB2270663A
Application number: GB9219883A
Authority: GB
Inventors: Joseph Latham
Original assignee: POWELL DUFFRYN STANDARD Ltd
Current assignee: POWELL DUFFRYN STANDARD Ltd
Priority date: 1992-09-19
Filing date: 1992-09-19
Publication date: 1994-03-23
Anticipated expiration: 2012-09-19
Also published as: GB2270663B; GB9219883D0

Abstract

A rail vehicle for carrying a rectangular goods container comprises an elongate vehicle body 10 having a single bogie assembly 22 at one end. A first coupling 26 at the end of the vehicle adjacent the bogie 22 connects to a corresponding coupling 28 at the opposite end of a similar vehicle, the coupling 26 being so located that the end of the other vehicle does not overlap the bogie assembly 22. The distance of the first coupling 26 from the axis 24 of the bogie 22, and the locations of the ends of a container carried by the vehicle, are so selected that the inner overthrow and outer overthrow when traversing a curved track are substantially equal. <IMAGE>

Description

"Boqie Rail Vehicles and Methods of Desianina such Vehicles" The invention relates to bogie rail vehicles and in particular to the design and construction of vehicles for carrying goods containers and road vehicles for the transport of goods.

There is currently a requirement to transport by rail goods containers and road transport vehicles which are box-like units of very substantial length and width. For example one standard size of goods container has an overall length of 13.6m.

When a train of rail vehicles is traversing a track there is normally a limit, imposed by the railway authorities, on the extent to which any part of any vehicle, including the load carried by the vehicle, may project laterally beyond the track. Such limit must be imposed in order to prevent any part of the rail vehicle, or of the load carried by it, colliding with trackside fixtures. The extent to which any rail vehicle projects laterally beyond the track is at a minimum when the track is straight, but increases when the vehicle is traversing a curved portion of track, due to the length of the vehicle. This increase is known as the "overthrow". The "inner" overthrow is the increase in lateral projection, between the bogies, on the inside of the curve, whereas the "outer" overthrow is the increase, beyond the bogies, on the outside of the curve.

The overthrow generally increases with the length of the vehicle and with reduction in the radius of curvature of the track. Any rail vehicle must therefore be so designed that its maximum lateral projection beyond the track, including the overthrow, is still within the imposed limit even when traversing a portion of track of the smallest radius to be encountered.

Designs of rail vehicle already exist for the transport of large rectangular box containers and road vehicles, but it has been found that where conventional designs of rail vehicle are used for very large box containers or vehicles the overthrow is so great, due to the necessary length and width of the rail vehicle, that there is an undue limitation on the radius of curvature of track which the rail vehicle can traverse without exceeding the specified lateral projection.

The present invention therefore sets out to provide a novel form of rail vehicle for carrying containers and road vehicles, and methods of designing such a rail vehicle, that overcome the problems of conforming to imposed width limits when carrying large containers or road vehicles of the kind referred to above.

The type of bogie rail vehicle provided by the invention comprises an elongate vehicles body, a single bogie assembly supporting the vehicle body adjacent one end thereof, there being a mounting controlling lateral, longitudinal and rotational movement between the vehicle body and the bogie assembly and having a vertical axis, a first coupling part at the end of the vehicle body adjacent the bogie assembly, and a second coupling part at the end of the vehicle body remote from the bogie assembly, the second coupling part being adapted for operative coupling engagement with a first coupling part on a second, similar rail vehicle.

In operation, a plurality of such rail vehicles are coupled together end-to-end, so that the end of each vehicle remote from its bogie assembly is supported by the bogie end of the adjacent vehicle to which it is coupled. An extra bogie assembly may be provided to complete the train by supporting the end of the endmost vehicle. Alternatively a vehicle having two bogies may be located in an intermediate position in the train, supporting the ends of two end vehicles in two oppositely-facing sets of vehicles.

In a rail vehicle of this kind, most of the critical dimensions of the vehicle are predetermined by the size of the box container or road vehicle which it has to carry, and by the necessary physical constraints applied by the construction of the rail vehicle body and the bogie assembly. However, one dimension where the designer has some freedom is in determining the distance between the vertical axis of the bogie assembly and the pivot axis of the coupling at the adjacent end of the vehicle. In a single-bogie vehicle of the kind provided by the present invention, of a given overall length, such dimension determines the inner overthrow of the vehicle.

Another dimension over which the designer has some freedom is the location along the vehicle of the ends of the container. The outer overthrow of the vehicle is determined by the location of the ends of the container in relation to the bogie, in combination with the other variable mentioned above, namely the distance between the pivot axis of the bogie assembly and the pivot axis of the adjacent coupling.

According to the present invention the two variable dimensions referred to above are so selected, when designing the vehicle, as to provide an inner overthrow which is substantially equal to the outer overthrow at the location of one end of the container, whereby each such overthrow is kept to a minimum.

In existing single-bogie rail vehicles of the kind referred to above, each bogie normally overlaps both of the adjacent ends of the two vehicles which it supports. Consequently the effective coupling axis between the two vehicles is usually very close to the vertical axis of the bogie mounting. Such conventional arrangement therefore allows little freedom in the location of the coupling axis with respect to the bogie mounting axis, and it may be difficult or impossible to select appropriate dimensions to achieve the result last referred to. The invention therefore also provides a modified and improved single-bogie rail vehicle which facilitates achievement of this desired result.

According to this aspect of the invention, there is provided a single-bogie rail vehicle of the kind first referred to wherein the first coupling part of the vehicle, at the end of the vehicle body adjacent the bogie assembly, is spaced at such a distance beyond the vertical axis of the bogie mounting that when the second coupling part of a second, similar rail vehicle is connected to the first coupling part, the end of said second vehicle does not significantly overlap the bogie.

Such arrangement may then allow sufficient variation in the distance between the coupling axis and the bogie mounting axis for the dimensions of the vehicle to be so selected as to achieve the desired result referred to above.

The methods and calculations involved, according to the invention, in designing a rail vehicle for transporting very large rectangular box containers or road transport vehicles will now be described, reference being made to the accompanying drawings in which: Figure 1 is a diagrammatic side elevation of a rail vehicle in accordance with the invention; Figure 2 is a diagrammatic plan view of the vehicle of Figure 1; Figure 3 is a diagrammatic side elevation of a plurality of vehicles coupled together to form a train; Figure 4 is a diagrammatic side elevation of a single rail vehicle according to the invention, showing the dimensions imposed by operating requirements; Figure 5 is a similar view to Figure 4 showing dimensions employed in the design calculations; and Figure 6 is a diagrammatic plan view of two coupled vehicles according to the invention on a curved track, also showing dimensions employed in the design calculations.

Referring to Figures 1 and 2, the rail vehicle has a body 10 comprising a flat bed portion 12 and opposite raised end portions 14 and 16. Side walls 18 extend longitudinally along each side of the flat bed portion 12 to form a well in which is received the lower part of an elongate rectangular box container, indicated in chain lines at 20.

The larger end portion 14 of the vehicle body is supported on a single four-wheel bogie assembly 22 which, in known manner, is connected to the vehicle body by a mounting so that the bogie may pivot about a vertical axis 24 relatively to the vehicle body, as well as being capable of limited lateral and longitudinal movement.

The end of the vehicle body adjacent the bogie 22 is provided with an upwardly facing socket part 26 of a ball coupling. A co-operating ball part 28 of the coupling is mounted on the opposite end of the vehicle body, on the body part 16 remote from the bogie 22.

Accordingly, the coupling part 26 on each vehicle may be coupled to the coupling part 28 on the adjacent vehicle, so as to support the end of the adjacent vehicle which is not supported by its own bogie.

It will be seen that the coupling part 26 is spaced some considerable distance beyond the vertical axis 24 of the bogie mounting, so that when a second vehicle is coupled thereto the end of the second vehicle does not overlap the bogie 22.

Figure 3 shows diagrammatically six vehicles of the kind shown in Figures 1 and 2 coupled together end-to-end to form a train. It will be seen that the train comprises a group of three vehicles 30, coupled together as described above, and a second group 32 of three vehicles facing in the opposite direction to the group 30. The two groups are connected by an additional wagon 34 which is a two-bogie wagon of more conventional design, and is provided at each end thereof with coupling socket parts 26 to which are coupled the ball coupling parts 28 on the end vehicles of each of the two groups 30 and 32.

Figure 4 shows typical basic dimensions for a rail vehicle of the type shown in Figures 1 to 3 where the container 20 is a large rectangular box container of the kind referred to above. The dimensions a to f indicated in Figure 4 are largely determined by the requirements of the container and the predetermined dimensions of the components making up the vehicle body and bogie.Typically, these dimensions a to f may be as follows: a ( = length of container) = 13.6m b ( = half wheel spacing on bogie) = l.0m (or O.9m) c ( = distance of coupling axis from front of container) = 0.2m d ( = half wheel diameter) = 0.4385m (or 0.47m) e ( = clearance to end wall of body) = O.lm (say) f ( = thickness of end structure of body + clearances) = 0.1615m (say) Thus, the length g (the distance from the pivot axis of the bogie 22 to the pivot axis of the coupling 28, is equal to 15.5m.

Figures 5 and 6 show the dimensions relevant to the optimum design of the rail vehicle, in accordance with the invention, as follows: N = the distance from the pivot axis of the bogie 22 to the pivot axis of the adjacent coupling part 26.

Although each vehicle has only a single bogie, the point where the longitudinal centre line of the vehicle crosses the centre line of the track may be regarded as the pivot axis of a second, "virtual" bogie.

The distance between the pivot axes of the actual and "virtual" bogies is constant for a given design of vehicle. Thus: A = the distance between the pivot axis of the actual bogie 22 and the effective pivot axis of the "virtual" bogie.

It will be seen from Figure 6 that, due to geometrical constraints, the distance of the pivot axis of the "virtual" bogie from the adjacent coupling must also be equal to N.

I = the inner "overthrow" between the bogies, i.e. the maximum lateral displacement of the centre line of the vehicle from the centre line of the track between the bogies X = the distance from the "virtual" bogie axis to the end of the container (i.e.

the location where the maximum lateral projection beyond the track will occur) O = the outer "overthrow" outside the bogies, i.e. the maximum lateral displacement of the centre line of the vehicle from the centre line of the track at the location of the end of the container.

Comparing Figures 4 and 5 it will be seen that: A + N = g = 15.5m From conventional rail vehicle design calculations (MT 235) the inner overthrow I between the bogies is given by: A2 I = 4x720 (below l000mm ARL) and the outer overthrow 0 is given by: X(A + X) O = 720 But from Figure 5:X = N - C = N - 0.2m therefore (N - 0.2) (A + N - 0.2) O = 720 For minimum lateral projection both inside and outside the curve the overthrows I and 0 must be equal, therefore: A2 (N - 0.2) (A + N - 0.2) = 4x720 720 and A2 = 4 (N - 0.2) (A + N - 0.2) but A + N = 15.5m so that A = 15.5 - N therefore: (15.5 - N)2 = 4(N - 0.2)(15.5 - N + N - 0.2) = 4(N - 0.2) 15.3 240.25 - 31N + N2 = 61.2N - 12.24 N2 - 92.2N + 252.49 = 0 Solving this equation gives:: N = 2.826m and therefore A = 12.674m Since it may be possible to obtain a slight reduction in the required length of g = A + N, let A = 12. 6m The central inner overthrow I (below 1000 ARL) is then A (12.6) O = = = 0.055m 4x720 4x720 Since this must equal the overthrow 0 outside the bogies X(A+X) O = = 0.055m 720 therefore AX + X2 = 39.6 therefore X2 + 12.6X - 39.6 = 0 Solving this equation gives: X = 2.6m the resultant dimensions for a wagon design which conforms to the imposed dimensions of Figure 4, and has equal inner and outer overthrow are therefore as follows: A = 12.6m N = 2.9m X = 2.6m The purpose of these calculations is to design a vehicle which will carry a box container of specified width without exceeding the safe width limitations imposed by the railway authorities. This is given as follows: Imposed width limit = container width + (2 x overthrow) + (2 x lateral clearance (CL)) + (2 x lateral travel (LT)) Typical dimensions may be: Imposed width limit = 2700 mm Container width = 2500 mm Overthrow = 55 mm Accordingly: 2700 = 2500 + 110 + 2X(LT + CL) Thus (LT + CL) = 45mm But the lateral clearance (CL) = lOmm clearance + lOmm wall thickness. Therefore lateral travel (LT) = 45 - 20 = 25mm (Tare or Laden)

Claims

CLAIMS 1. A bogie rail vehicle comprising an elongate vehicle body, a single bogie assembly supporting the vehicle body adjacent one end thereof, there being a mounting controlling lateral, longitudinal and rotational movement between the vehicle body and the bogie assembly and having a vertical axis, a first coupling part at the end of the vehicle body adjacent the bogie assembly, and a second coupling part at the end of the vehicle body remote from the bogie assembly, the second coupling part being adapted for operative coupling engagement with a first coupling part on a second, similar rail vehicle, and the first coupling part being spaced at such a distance beyond said vertical axis of the bogie mounting that when the second coupling part of said second rail vehicle is connected to the first coupling part, the end of said second vehicle does not significantly overlap the bogie assembly.
2. A bogie rail vehicle according to Claim 1, wherein the vehicle body is adapted to receive a separate generally rectangular elongate goods container, means being provided to locate the container laterally and longitudinally on the vehicle body.
3. A bogie rail vehicle according to Claim 2, wherein the vehicle body comprises a flat bed portion at opposite ends of which are raised end portions whereby, in use, an elongate goods container is received on the flat bed portion and is located longitudinally of the vehicle between said raised end portions.
4. A bogie rail vehicle according to Claim 2 or Claim 3, for use with a generally rectangular elongate goods container of a selected size, wherein the dimensions of the vehicle are so selected as to provide an inner overthrow which is substantially equal to the outer overthrow at the location of one end of the container, when such container is mounted on the vehicle.
5. A bogie rail vehicle substantially as hereinbefore described with reference to the accompanying drawings.
6. A method of designing a bogie rail vehicle, to carry a generally rectangular elongate goods container, substantially as hereinbefore described with reference to the accompanying drawings.

6. A method of designing a bogie rail vehicle according to Claim 4, comprising the steps of calculating the inner overthrow and the outer overthrow in terms of the distance of the first coupling part from the vertical axis of the bogie mounting, and the location of the ends of the container on the vehicle body, and so selecting said distance and locations as to provide an inner overthrow and an outer overthrow which are substantially equal.