AU603006B2 - Floating bridge - Google Patents

Description

-1 1 1 -7 I I I I 7 III Ii IIIIl~ 11111 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

ralm FOR OFFICE USE Class lilt. Class Application Number- Lodged: Complete Specification-Lodged: Accepted: Published: Priority: a 4 I A Related Art: TO BE COMPLETED BY APPLICANT Namne of Applicant: NORMAN TONKIN Address of Applicant: 27 Park Avenug, Oatley, New South Wale9s, Australia NORMAN TONKIN Actual Inventor: Address for Service: SANDERCOCK, SMfITH BEADLE 7/207 Great North Road, FIVE DOOK NSW 2046 Completo Spoi:lication for tho invontilon entitled- ItFLOATING BRIDGE" t The following statement is a full description of this invention, including the best method of perf~ormibig It known to me:- Complete after provisional PI 4510 dated 18 September 1-187.

1 i ,ca I_ iii I This invention relates to floating bridges.

Conventionally a floating bridge comprises a plurality of, not necessarily identical, modules linked end to end to form a continuous vehicle and/or pedestrian way from one bank of a waterway to the other. Each module comprises a deck sitting upon or integral with ine or more buoyancy bodies, referred to hereinafter generically as "pontoons".

At each end' of the bridge an approach deck spans from '00, the bank of the waterway to the module at that end. Usually 1 iy10 the approach deck is hinged on the bank and rests at its j free end upon the deck of the end module. It may merely 0 slide upon the module deck or may be furnished with support i rollers to permit freer movement between the two decks. In I any event the angle of inclination of the approach deck S varies as the end module rises and falls with changing water level to maintain continuity of passage across the bridge.

In alternative known arrangements the approach deck is hinged at one end to the end module and its other end slides or rolls upon an inclined ramp on the bank. In large scale floating bridges the approach deck may be of two telescopic parts hirged to the bank and end module respectively.

Because they require a minimum of civil engineering or c fixed construction works, floating bridges, as a class, are cheaper and quicker to build than other forms of bridges of comparable capacity, especially when the waterway is wide.

However they suffer from one major disability which inhibits their use, namely that they form barriers across the waterway preventing boat traffic therealong.

Hitherto attempts to overcome that disability have usually comprised the provision of a bascule or elevating span intermediate the ends of the floating bridge. This, of course, requires substantial fixed construction works and powered lifting means and this, in turn, greatly increases the cost of the bridge as a whole.

2 An object of the present invention is to ameliorate the above mentioned disability by means very much cheaper and simpler than those used hitherto.

The invention achieves that object by providing in a floating bridge at least one floating movable module hinged at one corner to anchorage means defining a substantially stationary vertical hinge axis and propulsion means on said movable module whereby it may be driven to turn about said axis between bridge open and bridge closed positions; said L tcE11O anchorage means being such that the movable module may rise Sand fall with changes of water level.

In some instances the movable module may be an end C 'module of the bridge, in which event the anchorage means may be on the bank of the waterway. 2his requires rather elaborate hinge arrangements to accommodate the rise and fall of the module.

Thus, for preference, the movable module is an intermediate module of tue bridge and is hinged to an adjacent module. This enables simple hinge structures to be I -20 used as the movable module and its adjacent modules na'turally rise and fall together.

Furthermore this enables the movable module to be positioned wherever the waterway is the deepest, which is not usually close to the banks.

The modules at each end of thq movable module are preferably held against substantial horizontal movement, by, j for example, piles or other fixed structures adjacent to or co-acting with the modul"es. 7 The terms "open" and "closed" as used herein are used with reference to the waterway. Thus, when a bridge is said to be open, water traffic may move along the waterway 3 l -u i through the bridge, while vehicular traffic may not cross 4 it, whereas when closed the reverse is the case.

By way of example, an embodiment of the above-described invention is described hereinafter in more detail with reference to the accompanying drawings.

Figure 1 is a diagrammatic side elevation of a floating bridge according to the invention, in its open position.

Figure 2 is a diagrammatic plan view of the bridge of figure 1.

Figure 3 is a diagrammatic partly sectioned plan view of the junction of two moveable modules when closed, being modules of the bridge of figure 1 drawn to a larger scale.

The illustrated embodiment has been designed for use as an adjunct to the Sydney Harbour Bridge. Every resident of Sydney is aware that at peak traffic periods the Sydney Harbour Bridge is choked with traffic, and motorists wishing to cross it may experience long delays especially when converging on the bridge along the near approaches to the bridge.

It is known that, at the moment, it is proposed, in an attempt to overcome this overloading of the Sydney Harbour Bridge, to build a tunnel of prefabricated modules sunk into a trough in the harbour floor. That tunnel would require to be provided with through-rock access and outlet tunnels and the cost of th9 proposed works is very large indeed. A floating bridge according to the present invention is seen as a very much cheaper alternative to the proposed tunnel.

In this instance it is proposed that the floating bridge would be closed only during peak vehicular traffic periods, which amount to approximately two hours in the morning and two hours in the evening of weekdays.

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II 3- Each floating module 4 of this exemplary embodiment is basically a rectangular, decked pontoon preferably of prefabricated concrete construction with metal connector devices for fixing the pontoons one to another.

Two neighbouring modules 5 towards the southern end of the floating bridge, which would be positioned adjacent to the existing Sydney harbour Bridge, probably slightly to the west thereof, would be movable. The modules 4 between which Ithe moveable modules 5 extend when the bridge is closed and to which the moveable modules 5 are respectively hinged 1 C t would be secured by means of piles 6 driven into the harbour o floor against movement in the horizontal direction but would S be left free to rise and fall with the tide. That is to Ssay, those last mentioned two modules 4 constitute the anchorage means, as the term is used herein, for the respective moveable modules Each of those anchorage modules is provided at one corner 7 with a hinge element (either a hinge pin or hinge eyes), preferably resiliently mounted in rubber or the like, whereby its corresponding adjacent moveable module 5 may be secured by a co-acting hinge element for swing movement about an upright axis.

Underneath or within each moveable module 5 towards the free, that is to say unhinged, end, a ducted reversible propeller 8 may be positioned with its line of thrust extending transversely of the module, so that operation of the propeller would cause the module to turn about its hinge axis, in particular from a bridge closed position (Fig.3), in which each of the moveable modules 5 extends longitudinally of the bridge into contact with each other at their free ends, to a bridge opened position (Figs. 1 and 2) in which. the moveable modules 5 lie flatly side by side against their respective anchorage modules 4.

r In other embodiments of the invention other marine propulsion means, for example a water jet device, may be used to swing the moveable modules about their hinge axes.

For preference, the entire operation of the bridge is automated under the control of a computer, for example a micro-processor. To that end, it is preferred for the driving unit of the propulsion means to be an electric motor so that the computer can control same entirely by electrical, preferably solid state, switching devices.

oo"I0/ As is well known, modern micro-processors are afrequently provided with a continuously running inbuilt I \clock and may be programmed to take heed not only of the c time of day but also the calendar record. In preferred embodiments advantage is taken of this to effect automatic operation of the bridge at pre-determined times on predetermined days of the week.

The processor may also control the operation of ancillary items such as traffic boom gates 9, audible alarms, warning lights and the like to provide adequate warning to vehicular traffic when the bridge is open or about to be opened.

Likewise it may control the operation of visual and/or audible beacons or other devices to indicate the status of the bridge to shipping using the waterway.

For preference, the micro-processor is fed with signals from appropriate sensors responsive to the angular disposition of the moveable modules 5, or perhaps to the spacing between the free ends thereof, or both, to control the speed of operation or the propulsive force supplied by each module's propulsion means so as to arrange for the two modules 5 to come together at the appropriate time and at appropriate speeds.

6 C i in<ato'^&-ait!m't^*aiff Ba w^ijg'iKi>aete5*jfflaasf't*^'a^'S''«^°> For preference, the meeting ends 10 of the two moveable modules 5 are scarfed or inclined so as to provide for a positive abutment one against the other in the transverse direction of the bridge as they come together.

For safety's sake latching devices 11 are preferably j provided, preferably of a kind which automatically engage, to lock the two moveable modules together when they meet.

Those latching devices 11 may be electrically unlockable to enable the micro-processor to cause them to be unlocked when it is necessary to swing the modules to their bridge open position.

An electrical interlock associated with the latching devices 11 may be used as a safety measure to ensure that the traffic boom gates 9 may only be opened when the latching means are positively engaged.

Because of their excellent speed control characteristics, and because they are amenable to control by solid state switching devices which are in turn amenable to control by a micro-processor, the preferred electrical motors are switched reluctance motors.

The north bank 12 of Sydney Harbour near the Harbour Bridge is relatively steep, and there is therefore a fairly deep channel close to that bank. In the present exemplary embodiment of the invention it is intended that advantage of that situation be taken by providing a fixed high level approach span 13 at the northern end which, because it would be a short stationary structure, would still be relatively inexpensive, between the bank and the inclined "approach" deck 14 extending down to the first met floating module 4 to provide a navigable underpass at the northern end of the floating bridge sufficient for small commercial craft such as ferries, tugboate, barges and the like to continue using the waterway even when the bridge is closed and available for road traffic.

4_I Thus it can be seen that for a much smaller outlay,a feasible alternative to the proposed Sydney Harbour tunnel is provided by the invention.

Of course, in all embodiments there would preferably be i 5 provision for overriding manual control of the bridge if only to anable it to function in the event of a failure in the automatic control equipment. Indeed, in other less sophisticated applications, for example in still developing countries, manual control alone may be preferred. In such instances, especially at remote locations without electric i~ower, the marine propulsion means may be driven by internal combustion engines. In some cases those means may be no more than commercially available outboard motors.

It is emphasised that, although described abovE) with 4 15 reference to a particular situation, there is no intention to restrict the invention to bridges operating as an adjunct to existing high level crossings, still less, of course, to an adjunct for the Sydney Harbour Bridge.

Claims (8)

1. A floating bridge of the kind comprising a plurality of floating modules linked one to another end to end, characterised in that at least one floating module is moveable, being hinged at one corner to anchorage means defining a substantially stationary vertical hinge axis and in that propulsion means are provided on said moveable V module whereby it may be driven to turn about said axis between bridge open, as defined herein, and bridge closed, as defined herein, positions and in that said anrcorage means are such that the moveable module may rise a. fall with changes of water level.

2. A floating bridge according to claim 1 further characterised in that said anchorage means comprise a non- moveable module which may rise and fall with the water Slevel.

3. A floating bridge according to any one of the preceding I claims further characterised in that there are two said moveable modules, being adjacent modules moveable in opposite directions.

4. A floating bridge according to any one of the preceding claims wherein the free end of the or each moveable module is shaped to come into positive abutment with a mating component when the bridge is closed. A floating bridge according to any one of the preceding claims wherein said propulsion means are electrically driven under the control of a computer.

6. A floating bridge according to any one of the preceding claims wherein latching devices are provided to lock the or each moveable module in its closed position. 1

7. A floating bridge according to any one of the preceding claims including traffic control boom gates.

8. A floating -ridge a-,cording to any one of the preceding claims furnished with audible or other alarms for vehicular and/or boat traffic. V9. A floating bridge according to claim 6, insofar as it depends on claim 5 wherein said latching devices are V controlled by said computer. A floating bridge according to claim 7 insof,,-zr as it depends on claim 5 wherein said boom gates are controlled by said computer.

11. A floating bridge according to claim 8 insofar as it depends on claim 5 wherein said alarm or alarms are controlled by said computer. 1 12. A floating bridge substantially as described herein 4 with reference to the accompanying drawings. P Dated this sixth day of August 1990, NORMAN TONKIN 4 Attorney: ROBERT G. SHELSTON Fellow Institute of Patent Attorneys of Australia of SMI2TH SHiELSTON BEADLE n7Y.