WO1995013948A2 - Improvements in or relating to transportation - Google Patents

Abstract

The objective is to provide a solution to the urban traffic congestion of major cities by fast park-and-ride links into major towns and cities and then distributive links each end. The first step is to provide 'Track Selection' (alias 'On-Board Switching') for Compact Automatic Railways ('CAR's) CARs. The selector wheel is mounted centrally underneath, and pivots between the two positions shown, preselecting to engage either of the two selector rails (14) or (16), and so guiding the vehicle to the right or to the left. They still need adequate stopping distance when the mechanism operates, but convoys can separate laterally actually at the points (both sides are open). Such CARs are for new construction, computer or manually driven, and provide a self routed direct, non stop service from start to finish. A 'Distribution Network' at the inner end may follow in the same system, starting with a single station and developing 'PRT-Fashion', but overhead, at ground level and/or in tunnels. Initial applications of CARs are for airports, shopping areas and the like.

Description

Description.

Improvements in or relating to Transportation.

Technical Field.

My invention relates to railways, and other forms of guided vehicular transportation.

Due to the separation between consecutive trains, which is made necessary by the use of moving switch points, it has not hitherto been possible for railways to use most of their track productively. From 95E to 97 is necessarily wasted in combined separation distances.

Moreover, it is inconvenient for passengers to have to wait for large coupled trains to fill, before individuals already waiting can depart. It also wastes platforms and rolling stock. Finally, long trains cannot take each individual passenger close to his or her desired destination.

Due to the need for railways to relieve road congestion, new Compact Automatic Railways ("CAR"s) may be considered. The requirements are high capacity in relation to the land used, a "passenger orientated" operating strategy (this means minimal waiting or changing or intermediate stops), unobtrnsiveness and affordable costs. My invention relates primarily to such CARs, enabling them to operate "Convoys" of separate independently routed automotive vehicles, instead of coupled trains. Its object is to enable them to do so in a manner the better to meet those above requirements.

This concept has five stepping stones for crossing a single river; complementary inventions give synergy. Perhaps the major area is a convoy operation. This is complemented by special railway switching, by electronic controls, both for convoys as such and for individual vehicles operating in convoys, by hydraulic damping within such convoys and by tramlines especially for their use.

Background Art.

Convoys are known, but only for vehicle steered by horizontal guide wheels.

Track selection is known for trams, but it operates too slowly to be used for convoys of the present type.

Disclosure of Invention.

Convoys" of automobiles have had good publicity recently, and it is widely felt that some such system of coordination may become important in the future. However, automatic guidance is a new feature needing special development: it doesn't touch the parking problem: the maintenance of privately owned automobiles to the required standards may be difficult, and in many ways, many people feel that rail convoys would be better, were they possible.

Unfortunately, that has not hitherto been the case. Moving points have to be locked into a safe position while safe stopping distance remains. This makes it impossible for any individual railcar to leave a convoy laterally, and virtually rules out rail convoys altogether.

According to this invention there is provided a system of routing railways without moving points. This is designated "Track Selection" (alias "On- Board Switching"). It makes Convoy Rail possible.

By eliminating moving points, it eliminates the primary need for "distant signals". This allows more of the track to be actually used by running vehicles, giving more line capacity, if required. Without moving points, convoys can run more frequently than trains. One can devise a through routing technology, avoiding or reducing the need for passengers to change vehicles. Off line stations may be used, if desired. Finally, the potential increase in capacity may be converted into real reduction in vehicle unit size, giving reduced axle loading, reduced track cost, and a less intrusive track.

According to one feature of this invention there may be provided a system of routing railways without moving points. This is designated "Track Selection" (alias "On-Board Switching"). It makes Convoy Rail possible.

It is felt that Track Selection may be used in special instances, with conventional and relatively large railway systems, but to obtain the full advantages, other back up features are required,. This invention is concerned with the whole Convoy Technology, especially for railways, but not wholly to be limited thereto. As such, the technology as a whole is probably best used in relatively small vehicles, which may be conveniently designated "Compact Automatic Railways". Accordingly, this invention features the following:-

1. Track Selection, to replace moving points.

2. "Computer Convoys", allocated on a computer map and scheduled to coordinate departures, joining up, diverging, crossing and the like. Means is provided to keep "Traffic Convoys" within them.

3. "Status Monitoring". Real time, position, speed and acceleration (or deceleration) are continuously measured (practical means provided) and monitored against "Commanded " (i.e. programmed) values, with negative feed back.

4. "Bridging Dampers", a practical devise to stabilise long convoys and help forming them quickly, without shock.

5. A novel tramline for light vehicles, which can be manufactured, and installed at a fraction of the usual cost.

In overall performance, the upshot resembles "Personal Rapid Transit" (or "PRT"), but is simpler, less expensive, less vulnerable to icing and with more capacity. Furthermore, it differs fundamentally from PRT in that double tracks including crossings are possible. PRT uses horizontal guide wheels which need tallish side members, which preclude crossings. Its capacity is commonly considered, at one car per ten seconds, to be 600 cars per hour per line. Convoy rail, as herein, at 50% track utilisation and 112 km/hr, with cars 3m long, represents (0.5 x 112 x 1000 = ) 19 000 cars per hour per line. Its track costs appear to be approximately 1/lOth of PRT's, elevated compared to elevated, or 1/100th comparing Convoy Rail's ground level rails with PRT's necessarily elevated track.

"Convoy Rail" is a "Key Technology", any railways can use. "Convoys" is an even more versatile technology. Indeed, much of it is applicable to road, monorail, people movers and the like as well.

Figures

Fig 1 is a plan view of a turnout for track selection.

Fig 2 is a transverse section through on board track selection mechanism.

Fig 3 is a plan, showing the elimination of the special clearances.

Fig 4 is a transverse cross section through selection mechanism and its associates rails.

Fig 5 is a plan showing stock rails 1 and 2, and fixed points 3 and 4.

Fig 6 is a simplified section through track selection mechanism, when in approximately the plane 31-32.

Fig 7 is a side elevation of portions of a bogie.

Fig 8 is a diagrammatic transverse view.

Fig 9 is a scrap section to illustrate the redundant disengagement mechanism, not to scale.

Fig 10 is a diagrammatic plan of a turnout.

Fig 11 is a plan, showing through-line passing off-line station.

Fig 12 is a plan showing main line 59-60 passing turnout 61-62.

Fig 13 is a plan, showing a station with platform.

Figs 14 shows one of the simplest applications this invention, with a convoy 81 and 82 moving off, and leaving 83 to 86 to move along.

Fig 15 is a plan, showing unidirectional tracks, 89 and 90, joining platforms 91-94, with junctions 95 and 96 each end. Fig 16 is a diagrammatic plan of real track, 99 and associated computer map 100.

Fig 17 shows the principal members provided for program-άng

Fig 18 is a plan showing means of position information

Fig 19 is an elevation, of position measuring means.

Fig 20 is a side elevation showing bridging dampers for two abutting vehicles 137 and 138.

Fig 21 represents a typical bridging damper hydraulic circuit.

Fig 22 shows a section through a rail and implant.

Fig 23 is a longitudinal scrap section through a beam 167, showing piles such as 168 and 169

Track Selection for Railways..

1. According to one feature of this invention there may be provided a railway system comprising a plurality of self driven cars, electronically operated track selection means on board the cars, and a track system over which they route themselves.

2. As above, with means whereby said track selection means is caused automatically to clear the point rail of the side of a divergent junction not selected.

Railways have hitherto been routed by moving points. In case the points fail to operate properly, they have had to be locked into a safe operating position while emergency stopping distance remains between them and any approaching train. This renders a great deal of track virtually sterile. It makes it impossible to operate differently routed trains or rail cars closely following one another and allows, in practise, less than five percent (usually more like 2 percent) of the track to be actually used for carrying moving vehicles, at any given time.

According to this invention there may be provided a junction with two point rails permanently fixed in the open position and a vehicle or vehicles which are provided with on board "Track Selection" means, electronically controlled and operable to select pre select and guide the vehicle the right and or the left hand side of the said junction.

By this means, and when used in conjunction with other features of this invention, over 50 % of the track may be actually carrying vehicles. I.E. A full order of magnitude increase in capacity.

Stations and exit roads would be needed, to handle the people, of course, but no fundamental reason is known, why this should not be used. However, in practise, such a large increase in capacity is not often required.

Nevertheless, in certain not too uncommon conditions, increased capacity may be "converted" into reduced track costs, reduced intrusiveness and an improved quality of service. All three of these are potentially very useful. This so called "conversion" would be simply reducing the vehicle unit size, as below. To illustrate the effectiveness of the cost savings, I hold a quotation for entirely suitable track, with fishplates, fishbolts, spikes and sleepers, (but without ballast) for £22.45 per metre.

At the same time, quality of service may be improved by adding features "2" to "4" (above) and hence the reduction - elimination almost - of waiting and direct through routing, in some circumstances. Even for high speed trains, the use of this invention would seem to extend some prospect of better track utilisation and safety, by keeping both sides of the junctions intact at all times.

See Fig 1. This is a plan view of a turnout, in accordance with this feature. Stock rail 1 leads to the turnout, and stock rail 2 to the main line. Points 3 and 4 are fixed, remaining open at all times. The necessary check rails 5 are also provided. In addition to clearances at 3, 4 and 5, for the flanges of the weight support wheels, the running rails are divided at 6 and 17, to allow the flanges of the track selection wheels to pass through them.

Fig 2 is a transverse section through on board track selection mechanism, 7. This is situated between and above the rails carrying the vehicle, e.g. central to a four wheel bogie.Track selection wheel 11 is free to rotate about trunnion mounted shaft 20, axis 12-13. It is shown, Fig. 2, engaging selection rail 14 (see also Fig 1) leading to the right (vehicle moving from left to right of Fig 1 and into the paper, in Fig 2). It will be seen that this holds the vehicle or bogie to the position leading to the right. Note also that the trunnion stop 21 abuts fixed stop 22, being held in engagement by the lateral load imposed on the selection wheel by the rail

14. Being thus locked in position, it cannot become disengaged until the rail 14 is discontinued, when an on board motor (not shown) may rotate the trunnion in the clockwise direction, (i.e. the direction towards the side of engagement of the rail concerned) bringing the wheel towards, and ultimately past the horizontal position.

Selection wheel trunnion, 23, is itself rotatable about longitudinal shaft

15. , whose axis cuts the point 26. By this means the selection wheel may be brought to the position corresponding to the broken line to the left, whereby it engages selector rail 16, which locks it in place, and whereby the transverse load imposed by said rail holds trunnion stop 24 in engagement with fixed stop 25, constraining the vehicle to the left and leading into the turnout. Rails 14 and 16 are inclined, as shown, so that proper bearing surfaces are provided for the selector wheel and the geometry is worked out so that the selector wheel is not substantially loaded until adequate rail width is engaged.

According to another feature of this invention, the special clearance needed for the selector wheel to pass through the support (i.e. ordinary) rails may be eliminated.

Fig 3 is a plan, showing the elimination of the special clearances, referred to above.

Fig 4 is a transverse cross section through selection mechanism and its associates rails.

The selection rails, 16 and 14 are mounted upon pad pieces, such as 18, above the level of the sleeper, so that the running surfaces are higher than those of the rails at the side. Thus the track selection wheel, being properly raised to suit the surfaces of the selection rails, can pass clear above the surfaces of either support rail (the side rails). The clearance is marked 19. Fig 3 shows how, the support rails are simpler and stronger, due to their not having to be cut, as in Fig 1. It will be seen that this feature requires the tops of the selection rails to protrude above the level of the support rails. This may sometimes be inconvenient (e.g. when tramlines are used, and the support rails are at the road level. Accordingly, this invention provides another feature which eliminates this drawback.

Fig 5 is a plan showing stock rails 1 and 2, and fixed points 3 and 4 and rails 29 (leading to main line) and 30, leading to turnout.

Fig 6 is a simplified section through track selection mechanism, when in approximately the plane 31-32.

When the railcar passes the selection rails 14 and 16, the selection wheel, being preset to select left or right, constrains the bogie or vehicle to the left or right, whereby the support wheels engage either the rails 29 and 2, or the rails 30 and 1. The trunnion member 23 may be spring loaded so that, in the absence of constraint from the operating mechanism, the selector rail 20 automatically returns to the horizontal, or neutral position.

The operation is thus.

Vehicle approaches divergent junction with selector wheel held horizontal, by said spring loading.

Shortly before reaching the selector rails, its actuating mechanism constrains one side or other of the selector wheel downwards, so that it subsequently engages the selector rail.

Shortly after such engagement, the actuating force is caused to cease. The selector rail cannot retreat, because the rail holds in position. Thus it does its job, leading the vehicle to the left or right. Then the selector rail is discontinued, and the selector wheel automatically springs upwards, to the horizontal position. Having thus set the support wheels on the right track, the selection mechanism is normally caused to take up a neutral horizontal position, which it retains until it is required to preselect for the next divergent turnout (convergent turnouts, or trailing points, do not need the selection rail). However, if the spring loading mechanism failed, leaving the selector wheel in the active position, it might subsequently engage one of the support rails, causing damage or a derailment.

Accordingly, the rails 1, 29, 30 and 2 are elongated enough to provide ample time for said selection wheel to be moved to the horizontal, neutral position. Then as a redundant safety measure "disengagement rails" 27 and 28 are provided. These are shaped to engage the outer surface of the selection wheel, pushing it into the disengaged position, as shown in Fig 6. It will be seen that, once thus pushed into disengagement, it may be kept clear of the rails by means such as friction, or a detent, until next required. Also note that the disengagement rails have overlapping active zones, but they are successive, as the vehicle moves, so that if, for example the wheel was in the "select right" position, it is pushed completely across to the left, and is then clear the second disengagement rail, 28. Similarly, if in the select left position, it initially clears the disengagement rail 27, but is subsequently pushed right across by rail 28.

According to another feature of this invention, there may be provided a further optional track selection mechanism, as shown in Figs 7 to 10.

Fig 7 is a side elevation of portions of a bogie, showing support wheels 35 and 36, support rail surface 37, and effective track selection wheels 38 and 39.

Fig 8 is a diagrammatic transverse view, showing support wheels 35 and 40, support rail surfaces 37 and 41 and track selection wheels 38 and 42, mounted on opposed crank pins 43 and 44, on transverse two throw crankshaft, 45.

Fig 9 is a scrap section to illustrate the redundant disengagement mechanism, not to scale, showing cut away support rail 45, portion of support wheel 35 and disengagement rail 46.

Fig 10 is a diagrammatic plan of a- turnout, showing stock rails 1 and 2, as above, and two points of engagement of the two disengagement rails, as arrows 34 and 35.

SUBSTfTUTE SHEET (RULE 26) The two throw crankshaft is provided with spur wheel 47, bearings 48 and 49 and screwed nut member 50.Electronicaly controlled motor (not shown)m operates through the spur wheel, to rotate the crankshaft, well before a turnout, to bring the desired track selection rail to the lower position. Then, on reaching the turnout, it engages the outer surface of the appropriate stock rail (arrow 39 or 40) and guides the bogie through the turnout. Subsequently, the normal procedure is to rotate the crankshaft, bringing the two cranks to the horizontal position, with both selection wheels disengaged.

However, fail safe provision is made by the subsequent provision of disengagement rails, one of which is 46. Should the normal retraction procedure fail, the appropriate disengagement rail engages the outside of the appropriate selection wheel, at a position when the rail head of the support rail is appropriately narrowed. Thus the disengagement rail bodily pushes the selection rail to the right (as shown in Fig 9, and with it the crankshaft and the other wheel. In sliding through the nut member, it is rotated, withdrawing the selection wheel, so that it reaches a safe position above the upper surface of the support rail.

At the same time, the failure of the selection motorised function is electronically noted, so that appropriate action may be taken.

Similar provisions are made for the other side, so that the selection wheel may be lowered in good time before a turnout, normally withdrawn by electronically controlled on board motor, but withdrawn by fail safe provision, as for the left hand side, in case of failure of the motorised function.

The selection wheels are operated in good time, and an emergency stop is automatic, should they fail to reach the correct engagement condition.

Computer Convoys and Traffic Convoys.

To start with an example, Figs^" 14 and 15 show one of the simplest applications this invention. Track Selection rail-vehicles such as of 81 to 86 queue for passengers at a station, bringing the front of the leading vehicle to the marker 88. They are all automotive, but not coupled together.

Passengers, admitted from the right, board the nearest vehicles first. Means is provided to detect them when they get in, and occupied vehicles such as 81 and 82, move off at frequent intervals, say every 15 seconds. They remain together as a convoy and the remainder of the vehicles waiting at the station then move up to the marker 88.

To summarize what follows below :-

1. "Computer Convoys", are scheduled by computer on a "Computer Map" held therein and means is provided whereby "Traffic Convoys" of real vehicles are caused to conform thereto.

2. Means is provided whereby the position of an individual vehicle is individually controlled, within said Traffic Convoy.

This has various advantages. For example, Track Selection obviously lends itself to computer control. If, there is a microcomputer on board a vehicle, then that microcomputer can be caused to route the vehicle and control its speed, giving it a good deal of the route choice freedom of an automobile.

A further advantage of Track Selection is that the mechanism requiring maintenance is all on board: maintained in depot, without shutting down the line.

However, the chief advantage is that it becomes possible to verify that the Track Selection mechanism has operated properly, and to stop before the junction if necessary, without widely separating two consecutive vehicles which are differently routed. This applies to individually automotive vehicles as well as to trains and it enables "Traffic Convoys" of individually automotive and self routing vehicles to replace coupled trains, giving a better service.

Individual vehicles cannot be allowed to join and leave Traffic Convoys randomly at will, but means is provided whereby they can route themselves safely, right through a complex journey, branching left and right as appropriate, and starting and stopping at off line stations when required.

SUBSTITUTΕ SHEET (RULE 26) For off line stations, through traffic not stopping there can exceed the capacity of any one station. Due to the absence of moving points, Traffic Convoys can be more frequent than trains and means may be provided, whereby a vehicle or a Traffic Convoy can leave an off line station to join another passing Traffic Convoy.

In practise, this requires a high degree of traffic coordination and according to another feature of this invention, means may be provided to operate a continuous schedule of "Computer Convoys" on a "Computer Map" and to restrict Traffic Convoys to the space represented within Computer Convoys, conforming to their movements.

Said "Computer Map" may comprise a digital representation to scale within the computer concerned. Characteristically it holds enough information concerning the real track layout, to carry out the functions of a map and receives the required information to represent real vehicles thereupon. The said computer may be mounted beside the track and designated the "Central Control Unit" or "CCU". It may be communicated additional information, relating to gradients, safe speed and the like. Also continuously updated information on the condition of (defects or otherwise) and weather currently being encountered by vehicles in transit.

Computer Convoys may be scheduled and coordinated for starting, stopping and joining together end to end with other Computer Convoys; diverging laterally from them and safely crossing a line carrying one or more of them in a different direction at the same level.

Means is provided to restrict Traffic Convoys to the space within Computer Convoys and thereby to ensure safety, but at the same time, to provide a pair of end to end or side by side Computer Convoys, when and where required, with means whereby said vehicles can then be transferred from one to the other, to provide freedom of individual routing, always within scheduled convoys.

Fig 11 is a plan, a portion of a computer map, showing through-line passing off-line station, 52. Travelling from right to left, Computer Convoys 53 and 54 by-pass said off line station and Computer Convoy 55 is accelerating away from the station to merge onto the main line, into the space between 53 and 54. Computer Convoys 53 to 55 respectively contain representatiOons of Traffic Convoys 56 to 58. Means may be provided to keep individual vehicles within such Traffic Convoys close to each other without shock and to close up each Traffic Convoy to the front of a separate Computer Convoy.

Fig 12 is a plan, a portion of a computer map, showing main line 59-60 passing turnout 61-62. On approaching said turnout (from left to right) all vehicles are caused to select whichever side is desired and the original Computer Convoy 73 splits along its longitudinal axis to provide another such Computer Convoy, 74, which follows the turnout. At the turnout, individual cars are kept within sections of track represented by Computer Convoys either 73 or 74, depending upon their preselected routes.

Fig 13 is a plan, another section of a computer map, showing a station with platform 75 extending from 76 to 77. A static Computer Convoy extends from 76 to 77 and contains representations of vehicles waiting at the platform. From this, Computer Convoys such as 78-79 periodically depart as shown, with representatioOns of Traffic Convoys such as 80 and 81 therein. Arriving Computer Convoys join onto the rear portion of the static Computer Convoy and traffic convoys are caused to close up their vehicles so that the representative computer convoys are closed up, with vehicle representations at the front. When the vehicle representations have all moved along in to the one in front, each arriving Computer Convoy is eradicated.

To return for a moment to Fig. 14. This is a side elevation, showing Traffic Convoys, 81-82 and 83-86, uncoupled, but fitted with "Bridging Dampers" such as 87 and 88.

Fig 15 is a plan, showing unidirectional tracks, 89 and 90, joining platforms 91-94, with junctions 95 and 96 each end, with sidings beyond them. Vehicles not immediately needed remain in the sidings, and those already there may move along to make room for them. When the queue of cars at any platform all move off, fresh cars move down from the siding. There is virtually no waiting and passengers can be taken away as rapidly as they can arrive.

Fig 16 is a diagrammatic plan of real track, 99 and associated computer map 200. On the real track, the lengths corresponding to the Computer Convoys are designated 100-108. These contain real vehicles, such as 119. Said vehicles each carry an on board computer, designated the "Vehicle Control Unit" ("VCU), which is joined by a telecommunication links such as 120 to "Central Control Unit" (trackside computer, "CCU") such as 121, causing it to retain a symbol, 122, representing said real vehicle on said computer map. Such representations age similarly generated for each real vehicle, on the said computer map.Computer Convoys are controlled and "driven" by a real time clock and computer software and are coordinated to maintain safe movements without waiting.

Status Monitoring.

Block control has neither the accuracy, nor the continuity, to meet these requirements. Furthermore, vehicle following is unsafe for long convoys. Accordingly, another feature of this invention provides something safer, simpler and more accurate than block control, with no wires, no breakers and inherently fail safe.

Every vehicle is provided in advance with a programme or programmes for its journey. This may comprise consistent and continuous commands for time elapsed, position, velocity and acceleration. These are designated "Commanded Status".

Similarly, every vehicle may be provided with accurate and continuous means to measure time elapsed (synchronised real time clock), position (electronic counting of close pitched track markers), velocity (change in position divided by time) and acceleration, or deceleration (change in velocity divided by time). These are designated "Real Status".

Means is also provided continuously, or practically continuously, to monitor Real Status against Commanded Status and automatically to provide Negative Feed Back, whereby said vehicle is caused to modify its real status in order to conform to Commanded Status.

Fig 17 shows the principal members provided for programing. The Central Control Unit ("CCU"), 123, holds detailed programmes for a plurality of different possible journey in the system concerned. Although digital, these are graphs, for practical purposes, providing the Commanded Status.

Each vehicle carries its own Vehicle Control Unit ("VCU"), such as 124 to 28. These are computers, with synchronised real time clocks. Two way telecommunications links, such as 129, join each VCU to the CCU.

Before a journey commences, the CCU transfers the programme to the VCU.

In transit, a handshake sequence provides fail safe coordination.

E.G. VCU "Identity, freedom from defects (or not). Real status.

Request permission to proceed."

When it receives the real status, the CCU compares this with its own Commanded Status, as transmitted. Thus its response will contain the Negative Feed Back correction to Commanded Status. Simultaneously, the VCU also compares Real and Commanded Status and figures out its own version of the required negative feed back.

CCU "Increase speed to X kph. Granted. "

On receipt, the VCU compares its own with the CCU Negative Feed Back, and then executes it, if compatible, or queries it, if not.

The frequency of this handshake depends upon circumstances. Say very approximately once every three seconds, for every vehicle, for normal running; perhaps once every half second when forming a convoy.

It will be seen that this is fail safe, because failure of the CCU or Telecommunications links can be made to lead to a "graceful shut down" procedure; while the redundancy of two different types of computer figuring out the negative feed back makes certain software errors very improbable.

Fig 18 is a plan showing means of position information. Fig 19 is an elevation.

Fixed mild steel strip 129 is parallel to the rails. It has punched holes, such as 130 regularly pitched. It branches when the track branches, and may be secured to the sleepers, between the rails. Counter member 131 is vehicle mounted above the strip and situated sufficiently close to the strip for inductive detector heads 132 and 133 to count the holes as they pass. Said counter member mounts two heads, to avoid a miscount. Detector heads are connected by wires 135 and 136 to VCU 134. According to an additional feature, coded omissions of holed may be used to convey the exact position, regardless of the previous count. E.G. Dot = hole, dash = where there should have been one and it was omitted. Dot dash dash dot dash dot dot, may be a binary code to a specific position.

This is capable of very great accuracy - certainly to within a few centimetres, and it is intended that convoys may be formed, and managed by a sequence of status commands from the CCU.

Any markers may be used; e.g counting white marks on sleepers optically or counting hob nails driven into the sleepers, inductively or magnetically. Alternatively, joints between rails may be counted, with oddometer interpolation.

Quicker response may be provided, when forming convoys, by a short range direct distance measurement, such as ultrasonic or radar, to give the homing vehicle, which is presumed to be the rear one, a direct reading of its distance from the vehicle in front. This is to help forming convoys quickly and without shock.

Bridging Dampers.

Bridging Dampers are needed, for several reasons. A vehicle can rapidly be brought to within about 600mm of that in front, but to establish buffing, without shock, takes a good deal longer. Without bridging dampers, the convoy is at risk, during this period. In any case should an accident occur, the total space between the vehicles of a long convoy, may become dangerous.

The forces electronic control can deploy for safety are limited by wheel friction and that is not enough. Certain momentary loads, such as wind gusts and the commencement of a gradient, are prefetβblye distributed amongst several vehicles. Finally, with long convoys, instability may develop. For all these reasons, robust hydraulic damping is to be provided between vehicles. Figs 20 is a side elevation showing bridging dampers for two abutting vehicles 137 and 138. Rubber coated buffer heads 139 and 140 are extended on rams 141 and 142 from pistons 143 and 144 which are slideable in cylinders 145 and 146, which are filled with pressurized hydraulic fluid as at 147 and 148. Buffing springs, 149 and 150 limit the travel, but are not in contact until the end of the stroke is reached.

The operation is as follows. Pressurized fluid keeps both rams extended until buffer heads make contact. Then, unless something intervenes, they are freely compressible until the pistons make contact with buffing springs. This length of free compression provides a "Homing Tolerance", for example 300mm for each damper, giving a combined tolerance of 600mm.

However, electronic control normally eliminates relative motion within that range. If and when relative motion ceases, a pilot valve closes, in each fluid circuit, instantly introducing stiff oil damping to any further displacement of the buffer heads.

There can be no shock, because there is no relative motion when the valve closes, but the hydraulic damping immediately provides safety. It permits both vehicles subsequently to be closed up to the buffing position, under electronic control. The "homing tolerance" enables the vehicles to be closed up rapidly without shock.

Fig 21 represents a typical bridging damper hydraulic circuit. Initial depression of buffer head 149 starts with piston 150 at the left hand end of cylinder. Hydraulic fluid is displaced through port 152. Some of this returns through port 160, but the right hand side of the piston has more effective area, and so a net flow is displaced to pilot cylinder 153, where it lifts leaky plunger 154 against spring 155. This opens port 156 admitting fluid displaced from the right hand end of the cylinder, via pipe 162. Through port 157 said fluid reaches pressurized fluid reservoir 158. Pressure is maintained by an inert gas admitted through pipe 159. Meanwhile, fluid replenishes the left hand end of the cylinder through port 160.

When motion ceases, spring 155 depresses leaky plunger 154, closing port 156. Further motion to the right can then only take place by forcing fluid past the leaky plunger, past the piston 150 and/or through special port provided in the piston, 163.

When released, fluid pressure leaks past plunger 154 enabling initial motion of the piston to the left. Then fluid is displaced through ports 152 and 160 to pilot cylinder 153, lifting the plunger and speeding up the return of the piston to the left hand end of the cylinder, and full extension of the buffer head again.

Low Cost Tramlines.

This invention may need tramlines, and these are commonly very expensive indeed, both to buy and to install. This high cost is due to two reasons, as follows:-

1. The traditional rail profile has to be hot rolled, thick and heavy. One cannot use a lighter cold rolled section because the metal distorts longitudinally and transversely under load.

2/. Gauge must be accurately maintained and the only practicable method has hitherto been transverse sleepers. For trams, this means digging a sleeper width trench deep enough to accommodate both sleepers and foundation material to perform the function of ballast.

According to this feature there may be provided an improved tramline which is inexpensive and easy to install.

The cardinal cause of expense is mass of steel required to dissipate relatively high Hertzian pressures away from the point of contact, wheel- to-rail, into the compressible soil.

Fig 22 shows a section through a rail and implant, according to this feature. Rail 164 is a cold rolled section, symmetrical in form, to facilitate bending, and one side supports wheel 165. It is. embedded in concrete 166, in milled grove 167. Typical reinforcing bars are shown as 168. Fig 23 is a longitudinal scrap section through a beam 167, showing piles such as 168, which penetrate into the subsoil and maintain the gauge. The head of the pile is high enough to be automatically cast into the beam. Now the fault of this design would be that Hertzian stress from the point of contact would repeatedly induce extension of the inner surface of the rail, at 169, causing fatigue in shear, of the concrete bond, and ultimately loosening the rail. Accordingly, cavities in the concrete are deliberately left at 170 and 171. Holes are provided at 172 and 173, through which mortar or epoxy resin are subsequently forced. The epoxy has a lower Young's Modulus than the steel, through which the shear force is applied, and consequently there would be no tendency to shear. At the same time, the relatively low direct loads, resultant from light vehicles, will be directly transmitted to the concrete underneath. The reinforce concrete is stiff enough, judged as a beam, to transmit the load to the soil.

Claims

Claims .

1. A transport system comprising a convoy of individually routed automotive vehicles, and means whereby each such vehicle is caused to conform to an individual computer programme, whereby is maintained a predetermined clearance one from another.

2. A transport system as for Claim 1, in which bridging dampers bridge said clearances.

3 A transport system as for claim 2, in which one such bridging damper is provided with hydraulic damping which becomes stiffer from the the moment when relative velocity between a pair of adjacent vehicles ceases.

4. A transport system as for claim 2, whereby a convoy of independently routed vehicles is each provided with means of damping, comprising buffers lightly spring loaded into contact with each other, and slideable transversely relative to each other, with hydraulic damping.

5. A system generally as in any above claim, in which a single transversely slideable member is provided at each end of at least two of said vehicles and said slideable members also provide longitudinal damping between adjacent vehicles, which damping is made to stiffen after relative motion ceases.

6. A transportation system according to any preceding claim, whereby a vehicle is provided with means provided continuously to measure real time, position, speed and acceleration or deceleration and to monitor them against commanded values of the same variables, and means for a negative feed back whereby to bring the operation of a vehicle closer towards said commanded values. 7. A transportation system comprising a track, vehicles and on board guidance means, in which means is provided to keep all such vehicles within lengths of track represented as "Computer Convoys", as described herein.

8. A transport system as for any above claim, whereby there are provided "Computer Convoys" generally as described herein, being representations upon a "computer map" which are caused to move around said computer map to schedule, whereby to coordinate departures, arrivals, crossings, joining up and the like, together with computer means to keep real vehicles, within "Traffic Convoys" corresponding to those sections of track represented by "Computer Convoys".

9. A railway system comprising a convoy of self driven cars, electronically operated track selection means on board the cars, and a track system by means of over which they route themselves.

10. A railway system as for Claim 9, with means whereby said track selection means is caused automatically to clear the rail of the side of a divergent junction not selected.

11. A railway system comprising a track which branches and a plurality of automotive vehicles which are individually self routing by on board means and which traverse said track; automatic means whereby a plurality of said vehicles are brought together in light end to end contact as a "convoy" and on board means whereby at a leading junction with two permanently open point rails, at least one vehicle within a convoy is caused to preselect to be routed to the right and at least one other vehicle within that same convoy is similarly caused to preselect to be routed to the left.

12. A railway system with means of routing comprising a turnout with a pair of point rails which are both simultaneously open, two additional "selector rails", each leading respectively to either side of the turnout and an on board selector member with means to lower a portion of it to preselect subsequently to engage a said selector rail and thereby to cause the vehicle to preselect to be led to right hand or to the left hand side of the turnout, depending upon which portion of said selector is lowered..

13. A railway system as for any above claim, in which further means is provided automatically to raise the said on board selector member, after engagement has taken place, so that it subsequently passes clear above a rail associated with the turnout.

14. A railway system as for any above claim, in which additional fail safe back-up means is provided, whereby the selector rail may be bodily pushed upwards, to clear the said support rail.

15. A railway system as for any above claim, in which said selector member comprises a wheel rotatable about a generally transverse axis of rotation, which axis of rotation can itself be pivoted about a longitudinal axis, to bring one side or other of the said selector wheel downwards into engagement with one or the other of the selector rails.

17. A pair of separate tramlines each comprising a rolled channel member of the shape shown herein, set into a reinforced concrete beam, cast in position into a milled slot and supported at intervals on piles, whereby said piles and beam maintain the gauge

18. A tramline comprising a cold rolled section beneath which a layer of a solidifying adhesive with a low Young's Modulus is inserted, between said section and a concrete beam cast around it.