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• BRISBANE'S EXPO 88 MONORAIL was very successful. In 6 months each train travelled 39,000 kilometres and provided a total of 32 million passenger journeys. Note the current busbars on the side of the box beam. THE EVOLUTION OF ELECTRIC RAILWAYS Monorails are often touted as the solution to mass transit problems but they do have considerable drawbacks. In this episode we take a close look at two new monorail systems in Australia. Many myths (mostly false) circulate in any public discussion on monorail systems. Do they really carry many people? Are they about to replace railways? Are they an asset or a liability in any citv? In the author's opinion monorails should not be compared with railways. These two types of people movers should be seen as complementary. Both are in the business of moving people. For long distance travel or commuting to outlying suburbs of a busy metropolis, no-one denies the effectiveness of high speed electric trains. For example, what other mode of transport can shift 2120 passengers at a time from Sydney's Town Hall station to Bondi Junction so quickly? But for a delightful tour of Brisbane's Expo 88 what could have been more enjoyable than to travel by any of their four monorail trains? If we must make comparisons, PT.24: AUSTRALIAN MONORAILS 104 SILICON CHIP why not pit monorails against buses; those diesel monsters that clog the city's traffic more completely than trams ever did? And pollute the air with diesel fumes! Let's look at the successes enjoyed by monorail systems in their short but popular history. Australia's first Australia's first monorail system, at Sea world .on Queensland's Gold Coast, was commissioned during August 1986. Installed at a cost of $4 million, the two monorail trains follow a 2km oval circuit around the amusement park, giving passengers an excellent elevated view of dolphins, whales and other attractions. At one point the monorail passes over the "corkscrew" roller coaster; at another, passengers are delighted by views of kilometres of coastline, yachts and blue water. The 9-car trains travel at 27km/h, stopping at two stations, one on an upper level of the Seaworld Nara Hotel. Each aluminium bodied car seats 12 passengers with provision for handicapped persons. The doors are electrically operated by the driver. Drivers are in continuous radio contact with the control station and operate from a streamlined control console in the front car. The 40-metre long trains, weighing 23 tonnes loaded, are driven by eight incredibly quiet DC motors. AC power comes from 3-phase 415VAC covered busbars mounted on the sides of the box section track. Sliding contacts on the train bogies collect this supply, one phase being grounded. On each train, thyristor bridges rectify the 3-phase AC to drive the DC traction motors. Gate trigger circuits control the thyristors for motor control and regenerative braking. The system incorporates a backup power supply. Each train runs on 20 pneumatic steel-belted radial tyres which provide traction and braking. In addition, 60 other rubber tyred wheels provide location in the horizontal and vertical dimensions. The track box section is of welded steel, 750mm wide and 600mm deep, erected in spans 24 metres long and supported on concrete columns. AUSTRALIA'S FIRST MONORAIL was at Seaworld on the Queensland Gold Coast. It is definitely a tourist attraction. What other monorail passes over a corkscrew roller coaster? The system was supplied by Von Roll Habegger of Thun, Switzerland and installed by the Gold Coast McMasters construction company. Expo monorail The popularity of monorails was confirmed by the millions of delighted visitors to Brisbane's Expo 88. Four trains each of nine cars circled the 2.3km loop track at speeds up to 24km/h. Installed at a cost of $12 million, these trains were also operated from a 415V 3-phase 50Hz supply, with on-board rectification and DC motors. The Expo monorail was installed and serviced during the six months Expo period by the Von Roll Habegger company. The reliability of the system allowed more than 32 million passenger journeys, day and night. The total downtime of the four trains was approximately 3 minutes per train over 6 months, a remarkable achievement. Expo was an example of a monorail installation adding significantly to the environment created. With nearly 18 million visitors to the site, no criticism was heard on aesthetic or other grounds against the monorail system. Rather, it was enjoyed to the full. Monorail design All Australian monorails have many common features, though size, power, voltage, suspension and other details vary in the difOCT0BER 1989 105 monorail was proposed and construction began. True, the Sydney installation was more difficult with most of the track necessarily fitted around finished buildings and overcrowded streets. This is far from the ideal of integrating the monorail into city building architecture. Though the temporary station in Pitt Street generated little applause, the mirror-faced steel pylons are an excellent step towards hiding trackwork. Credit must be given to Sydney's monorail for its clean, efficient and reasonably quiet operation. Automatic operation THIS PHOTO SHOWS A CLOSEUP view of the current collectors on the Expo 88 monorail. You can also see the rubber types which take lateral forces and those that provide downward thrust, preventing derailments. The Sydney system is designed for continuous running of 6 to 8 trains under completely automatic control. Control officers watch the operation directly and on video screens in the Darling Harbour control room. Normal train control relies on a computer system centred in Darling Harbour, with train position and speed information relayed via a fourth busbar installed throughout the system. By this means, starting and stopping at stations can be automatic, with halt times regulated by the boarding and alighting of passengers. At stations, doors open and close automatically then lock before the train departs the station. Automatic operation gives the system an average 3.5km round trip time of 12 minutes, with 6 trains capable of carrying 5000 passengers per hour. Power system THIS SPECTACULAR CURVED SPAN on the Broadbeach monorail is the largest in Australia and weighs 135 tonnes. ferent installations. The articulated cars are mounted on motor driven bogies, each bogie carrying one end of two adjoining cars. Rubber tyred wheels take the downward weight and left and right sideways thrust, with extra wheels restraining the cars against any upward movement. In principle, derailments are impossible. Power for monorail trains of this design is supplied by busbars 106 SILICON CHIP mounted on the track girder sides. Each aluminium busbar has a stainless steel facing along which the train current pickup contacts slide. Contact pressure is maintained by steel tension springs, with duplicate pickup arms for reliability. Darling Harbour Much criticism arose when Sydney's City-to-Darling Harbour Power for the Sydney monorail is derived from 1lkV 3-phase city mains, stepped down by 11kV/500V 700kVA transformers installed at 8 sites around the city. Within the nose-cone ends of the train, the 500V 3-phase supply is rectified and controlled by thyristor bridge circuits to drive the 35kW DC traction motors. A 7-car train has one traction motor driving each bogie except for the end bogies which are not powered. Thus each Sydney monorail train is driven by 6 motors. At starting each motor can deliver 75kW for a short duration to accelerate the train at a rate of 0.9m/s2, SYDNEY'S MONORAIL HAS A NOVEL arrangement whereby the Pyrmont horizontal swing bridge can swivel independently of the monorail above it, to let small boats pass through. To let larger boats pass, the bridge and the monorail swing together. The maximum speed of 35km/h is attained on the Pitt Street and Pyrmont Bridge sections. With optimum traffic control, the interval between trains can be as close as 90 seconds. In the event of a city power failure, a 400kVA diesel driven alternator at Darling Harbour provides enough power to move all trains to the stations. Pyrmont Bridge This bridge is interesting, being a rejuvenated horizontal swing bridge with the monorail track supported on a swivel pillar on the bridge central axis. To allow passage of small boats up to 15-metre mast height into inner Darling Harbour the bridge deck swings horizontally 90° on a vertical axis, leaving the monorail track above intact. In this mode trains can still cross. But to allow larger ships to pass, the bridge deck and the monorail track swing together, giving clearance for ship's masts of any height. This open-track mode is used only after all trains on the system are brought to a stop at a station, monorail track busbars isolated and the bridge track section unlocked by the system computer. Track curvature is 20-metres minimum radius, the gradients being limited to 4.4% uphill and 6.6% downhill. On test a fully laden train is required to successfully negotiate the whole track circuit in reverse. The heaviest Sydney grade occurs on the east side Pyrmont Bridge approach from the city. Certain support columns are fitted with sensors to detect any track misalignment. Dimensions Suspension Each of the mid-train cars of the Sydney monorail is 4.12m long, 2.06m wide and 2.6m high and weighs 4.5 tonnes. This short car length allows trains to negotiate sharp curves. Because of their nose cones, the end cars are longer, at 5.55m each. A complete train is 32.5m in length, weighing 31 tonnes empty. Each train is capable of seating 56 passengers and a maximum of 114 standing. The box section steel tracks are 700mm wide and 832mm deep, with a 940mm wide top flange plate. Average track span length is 30 metres on straights and 23 metres on curves. Unlike the Seaworld and Expo systems, the Sydney monorail trains are supported on air bag suspensions and pneumatic rubber tyred wheels. The wheel rims have special flat-tyre protection. In common with other Australian monorails the suspension system used in Sydney incorporates side thrust wheels. In addition, vertical restraining wheels running on the track flange underside prevent any possibility of derailment of the train. The traverser The monorail systems are designed for continuous forward operaOCT0BER 1989 107 45 tonnes, nearly three times the weight of the train which traverses it. Having crossed the river the Broadbeach monorail gains 8 metres elevation in the next two spans on a 6.5% slope. This is to give sufficient vertical height to enable it to cross both the Gold Coast Highway and the proposed Gold Coast North-South monorail tracks. The two trains each consist of four cars, the middle cars being 3.7 metres long and the complete train 21.4 metres long. It weighs 16 tonnes when empty. Power THIS PHOTO SHOWS THE HEAVY braced construction of a box beam for a monorail. MONORAIL POINTS ARE LARGE, expensive and cumbersome. This assembly rotates to change tracks. tion around the loop track, without points, track crossovers or direction reversal. However every system must allow for train maintenance. The storage and maintenance yard is at Ultimo on the Sydney system. It consists of a horizontal traverser feeding parallel yard tracks, each capable of accommodating a complete train. The traverser itself is a short section of the main line which can be moved sideways, carrying one whole stationary train with it. Sideways movement brings the traverser track in line with one of four parallel storage/maintenance tracks onto which the train is driven. Meanwhile, a second traverser track section moves to fill in the gap in the main line to allow other trains to continue operating. Comprehensive interlocks safeguard 108 SILICON CHIP running trains while traversing manoeuvres are proceeding. Broadbeach monorail Australia's newest monorail, in operation since August 1989, connects Jupiter's Casino, Conrad Hotel, Pan Pacific Hotel/Oasis shopping plaza and Broadbeach. Situated on Queensland's Gold Coast, this monorail crosses the Gold Coast Highway and a tributary of the Nerang River. Some of the track spans in this river crossing are fine examples of engineering. One span in particular is unique. From Jupiter's station the track immediately crosses the river on a 52-metre span girder which turns through 135° before the next support column. This, the heaviest span on the system, consists of a box girder 940mm wide at the top and 1.6m deep. This girder weighs Because of the heavy facing grades, the 4-car trains are equipped with five 35kW traction motors, one in every bogie. Under normal conditions only four of these motors are used, the leading bogie motor idling unpowered. The four motors, each exerting 75-B0kW for a short time, are capable of full acceleration (0.9m/s2) up the 6.5 % grade with a fully loaded train. The power supplied from the track mounted busbars is 500V 3-phase, with one phase grounded. The current pickup, thyristor bridges and control systems are similar to those used in Sydney, however the Broadbeach trains each carry a driver. Another difference is the emergency power arrangement. To cope with a mains power failure, a large diesel driven alternator starts up within the Oasis/Pan Pacific complex, giving the monorail emergency supply. But should this supply also fail the monorail train driver starts up a diesel-alternator carried in the nosecone of the leading car. This provides lights for the train as well as power to the normally unpowered bogie motor. The architectural design of the Broadbeach monorail, like the Expo system, is a model for monorails everywhere. At the Broadbeach Pan Pacific Hotel, the monorail train, tracks and station are fully integrated into the building design rather than being an add-on. The North-South monorail Soon to come is the Gold Coast SYDNEY'S MONORAIL HAS SOME quite steep slopes. This section is near the old Paddy's Markets. The beauty of a monorail is that it takes very little space, does not pollute and makes little noise. THIS IS THE SYDNEY MONORAIL traverser at the Ultimo storage yard. It looks quite different from a conventional railway shunting yard doesn't it? North-South monorail system. At present in the design stage, this extensive monorail system will connect Southport, Seaworld, Surfers Paradise, Broadbeach, Pacific Fair and suburbs in between. With a total track length of about 24km and a mainline junction near Main Beach, this will be the largest monorail system in Australia when completed. It will cost about $200 million, with construction to begin about the end of 1990 and scheduled for completion by 1993. Monorail points Will monorails eventually take over the role of railways? Probably not but they do have advantages in that they do not take up anywhere near as much space or cost as much to build as conventional light railways. Until now though, they have been mainly used as a tourist attraction and usually operate fairly slowly. One big problem inhibiting the monorail concept mushrooming into complex systems (as railways have) is the difficult construction of track points. Regular railway tracks were conceived to allow easy switching of trains from one track to another as well as providing for diamond and multiple track intersections. Facing points in some cases can be negotiated at 125km/h. Trailing points can be designed for safe runthrough from the wrong track. To date none of these facilities have been incorporated into monorail systems. Though it is difficult to conceive how they could be implemented, we would be foolish indeed to say they 'never' could! Who knows what the future will bring concerning this interesting mode of transportation. Acknowledgements Our thanks to Seaworld and Von Roll Habegger companies and their engineers for photos, information and permission to publish. ~ OCT0BER1989 109