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A MODERN SWISS LOCO on the St Gothard run. The overhead catenary supply is 15kVAC at 16.6Hz but the traction motors are 3-phase, driven by solid state inverters. For a description of this drive system, see the previous episode in this series. THE EVOLUTION OF ELECTRIC RAILWAYS Swiss railways have always been innovative, both in their use of tunnels and electrification and in their electric locomotive technology. They were also among the first to employ rack railways, for use in their mountainous terrain. By BRYAN MAHER For 140 years, Switzerland led the field in hard rock railway tunneling. While other countries were still contemplating railways, Swiss trains were running through long mountain tunnels. Swiss engineers build the world's best railways in terrain which would daunt a mountain goat. Their complex structures allow an electrified main line to gain 100 metres of height in a ground distance of 500 metres, without overly steep gradients. Saint Gothard Tunnel For at least 800 years travellers have crossed the southern Swiss Alps by the Saint Gothard Pass, a 2134m high saddle-back depression in the icy mountains, to reach Italy. The modern steep winding road through the pass leads from Zurich and the Swiss plateau to the Po valley in Italy. To avoid the difficult road many international travellers take the train, burrowing through the mountain via the Saint Gothard railway tunnel. PT.23: SWISS TUNNELS AND RACKS 102 SILICON CHIP 1882 a Locomotive vapeur D 4/4 puissance 950 CV remorque 170-200 t 17 km/h ~ ····•..a-M a 1917 ········... a Locomotive vapeur C 5/6 puissance 1580 CV remorque 335 t 18 km/h ~ a 1920 Locomotive electrique Ce 6/8 puissance 2200 CV remorque 450 I 35 km/h a ,.. 1955 Locomotive electrique Ae 6/6 puissance 6000 CV remorque 650 t 75 km/h ················- a 1975 Locomotive electrique Re 6/6 puissance 10 600 CV remorque 800 t a 80 km/h ·-----. ~~;:;-; < THIS DIAGRAM SHOWS how increasingly powerful locomotives have been able to pull trains at progressively higher speeds on the steep approaches to the St Gothard tunnel over the years. The power designation CV for the various locos refers to Cheval-Vapeur, the metric equivalent to horsepower, equal to 935.5 watts. Tunnel construction First proposed by engineer Gottlieb Koller in 1852, the St Gothard tunnel was initially referred to a 9-state committee formed on 19 August, 1853. Discussions over tunnel construction raged for 20 years. On 6th December, 1871 the company 'Compagnie du Chemin de fer du Saint Gothard' was formed to bore the tunnel and build the railway. Work started in 1872. Conditions were terrible. The continuous uplifting of the Alps causes high temperatures, water rushes and rock splintering deep within the mountain. The difficult tunnel construction caused the illness and death of many workers. Of the 2500 workers employed, mostly Italian, 177 were killed and 400 were hospitalised due to the atrocious working conditions. On 29th February, 1880 the northern and southern working parties met in the middle of the mountain. Where they met, the centrelines of the tunnel bores differed by only 50mm vertically and 330mm transversely; an incredibly good result for the engineering standards of the time. The first run through the tunnel was on Christmas Eve 1881 by a AN INTERNATIONAL EXPRESS train pulled by a 10,400 horsepower Swiss Re 6/6 locomotive negotiates the helical tunnels on the St Gothard route. 0-8-0 steam locomotive weighing 55 tonnes. Full service between the towns of Goschenen at the tunnel's northern portal and Airola at the southern exit commenced the next year. How long would an equivalent railway project take today? Much longer, we suspect. Completing the approach ramps up to the main tunnel are 64 avalanche galleries and smaller tunnels. To gain height in a short distance, seven of them are helixes (or spirals). These complex constructions keep the ruling grade down to 2.8% and protect the track from avalanches and rockslides. Though double track working through the main tunnel was achieved in 1883, the difficult access ramps worked single track until June 1893. The first Zurich-Milan steam SEPTEMBER1989 103 es which are the most powerful single unit locos in the world. These race their BOO-tonne trains up the ramps at 80km/h, then at 125km/h through the tunnel. Of the 713 mainline electric locomotives owned today by CFF, the largest are used on the Saint Gothard section. Modern freight trains of 1600 tonnes use two Re6/6 locos, one at the head and a second about one third of the way down the train length. Trains are marshalled with 470 tonnes of freight wagons between the two locomotives, and 1130 tonnes of wagons following the second loco. With so much power available, Swiss freight trains are scheduled to run at passenger express speeds. Communications THE SWISS HAVE SOME of the most spectacular railways in the world, both for their scenery and their steep gradients. This is the Zermatt to Gornergrat rack railway, with the Matterhorn in the background. The electric supply is 3-phase AC via twin catenary wires which feed divided pantographs. trains weighing 170 tonnes ran at a stately 17km/h up the steep ramps. On the easier grade approaching the 1151-metre high summit in midtunnel, 44km/h was possible. Electrification As far back as 1904 the Swiss were experimenting with a variety of electric locomotives. One AC loco was driven by DC motors supplied by an onboard AC/DC rotary converter. Eventually, the St Gothard tunnel 104 SILICON CHIP was electrified in September 1920 using single phase 7.5kV AC at 16.6Hz. Articulated ''crocodile'' electric locos were tops in those days. Rated at 1.6 megawatts, they could haul 450-tonne trains at 35km/h while ascending the ramps and achieve 75km/h in the tunnel. Today, with the St Gothard system absorbed into the Swiss Federal Railways, CFF, international expresses are pulled by the 120-tonne 7.BMW Re6/6 locomotiv- By 1964 the original telephone system had been replaced by radio telephone and teletype. This maintains communication between ground controllers and drivers of moving trains throughout the tunnel section. Enormous problems are incurred in such radio links. Transmission and reception is difficult in a tunnel anyway and is compounded by the interference generated by the high voltage overhead wiring and the large commutated traction motors. After further upgrading of the radio system in 1981, controllers at Goschenen and Airola can independently identify running trains within the tunnel. In an emergency the ground controller can bring any designated train to a halt without driver response. Results In the first three months of 1882, 27,500 passengers and 3000 tonnes of freight were carried through the tunnel, assuring the project's success. Annual passenger patronage has grown from 250,000 in 1883 to 7,000,000 a century later. Nett freight consigned has increased from 1.5 million tonnes in 1883 to 28 million tonnes in 1980. A 1-day record attained on 25 July, 1979 was 109,950 tonnes. The number of trains passing through the tunnel per day has increased from 20 in June 1882 to 310 JUNGFRAUJOCH, INSIDE THE SUMMIT of a mountain, is the highest railway station in Europe, at 3454 metres above sea level. Note the rack between the rails. Rack and pinion drive is the only way to ensure traction on really steep gradients. ENORMOUS AMOUNTS OF HEAVY freight moves along the mountainous St Gothard route. This train is devoted to heavy trucks. Why can't we have the same system in Australia, for freight between capital cities? today. Sometimes only two minutes separates following trains. At any time up to four trains will be racing through the tunnel. Simplon tunnel The next very large engineering project undertaken in Switzerland was the Simplon tunnel to provide a short route from France and western Switzerland to Italy. The first Simplon tunnel was begun in 1898 and opened for traffic on 25 January, 1906. (This subsequently prompted the building of the ambitious Bern-Lotschberg-Simplon system which was described in the May 1988 issue of SILICON CHIP). At the time it was the world's longest railway tunnel. High above is the freezing mountain pass over which Hannibal marched his troops, elephants and horses in 218 BC. For expediency the 19.8km tunnel was bored single track. The contractors, Brandt and Brandau of Hamburg, Germany added a parallel smaller pilot tunnel for ventilation and spoil transport. Interconnecting the main and pilot tunnels are transverse galleries spaced at 200 metre intervals. The 4000 workers had to endure terrible conditions, not the least being air temperatures of up to 53°C, caused by hot springs. After completion of the Simplon tunnel, traffic problems were compounded by heavy grades on the approach ramps and by the tunnel being single track. With the opening of the Lotschberg tunnel in 1913, more trains came direct from the Swiss capital Bern and western Germany. In effect, the Simplon tunnel became a bottleneck. SEPTEMBER 1989 105 WHILE SWISS LOCOMOTIVES probably would not win prizes for beauty, they are right up among the winners when it comes to sheer power. This 20 year old Re4/4 weighs only 80 tonnes but is rated at 4.7MW (6320hp). It has a top speed of 140km/h. To provide double track running, enlargement of the original parallel pilot tunnel, to be called Simplon II, was begun in 1912. This was interrupted by the 1914-18 war and was not completed until 1923. Electrification was not completed until 1930. Since then, many improvements have been made to the tunnel wiring to allow faster running. Now, trains race through the tunnel at 140km/h, with speeds of 160km/h planned for the near future. Tourist tunnels In Switzerland there are many privately owned and operated railways. These companies cater for the thousands of tourists and ski buffs wanting transport to otherwise very inaccessible places. 106 SILICON CHIP Adjacent to the 4166m high Jungfrau mountain in the Bernese Alps was a centuries-old hospice on the peak of Jungfraujoch. When fire destroyed the ancient building in 1972, the construction of a new modern tourist hotel was hampered by the severe climate. During the day, temperatures vary between + 7°C and - 30°C. In addition, blizzards at 250km/h are common, with 15 metres of snow falling annually. The rebuilding, transport of materials and influx of tourists carried on despite the weather, using the Jungfrau private railway. This unique line has few problems with snow and ice because most of its track is in tunnels inside the Eiger mountain. One of the railway stations halfway up inside that infamous mountain was featured in the movie "The Eiger Sanction". Built in 1910, the Jungfrau line connects with the CFF system at Interlaken, then heads for the high country, to Jungfraujoch, 3454 metres above sea level, the highest railway station in Europe. This station is hewn from solid rock, inside and almost at the summit of Jungfraujoch Mountain. The highest 9.3km of this railway includes 7km of tunnels and the track gradient on the steepest slope is 1 in 4. Rack and pinion drive Since normal wheel adhesion is impossible on such grades, the Jungfrau line uses a rack-andpinion drive. Interestingly, the Jungfraujoch railway is one of the remaining five in the world still using a 3-phase supply. It was built that way right from the start and uses 650V AC at 40Hz. This was the local industrial supply. Twin overhead catenary wires THIS VIEW IS OF another privately run rack railway in the Swiss mountain countryside. How is this train powered, since the pantographs are down? Did they stop for lunch? Note that narrow gauge track and rack drive. and divided pantographs are used to feed the train, with the third phase connection being via the wheels and rails. When trains are negotiating track intersections, one section of the pantograph must not meet the wrong overhead wire for fear of short circuits. Should both pantograph sections touch wrong overhead wires, the train would be instantly reversed. Overhead wiring construction at track points and crossovers must prevent any possibility of such accidents. The designs used to fulfill this condition are truly ingenious. Branches of this line take tourists to Murren, on the western side of Jungfrau mountain. Also served is Grindewalde, near the Wetterhorn and the 4030m high Mount Schreckhorn. Zermatt Gornergrat railway Since 1898 there has been a railway system taking sightseers to the top of Mt Gornergrat in the Pen- nine Alps. It attracts tourists from all over the world, eager for a closeup view of the breathtaking scenery. From the lookout on Mt Gornergrat, at over 4000 metres elevation, visitors have a breathtaking view of the roof of Europe. Only 5.4km to the south is the 4633m high Dufourspitze de Monte Rosa, the highest point in Switzerland. Just 13km to the west is The Matterhorn, 4477m high, regarded by many as the wonder of the world. To the north, a mere 7km distant, are 4203m Mt Rimpfischhorn and 4207m Mt Alphubel. The Zermatt to Mt Gornergrat railway has been continually upgraded and modernised to provide safe and comfortable transport. Hugging the cliffs or bridging the ravines, this 9.35km line ascends the mountain to the terminal station 3089 metres above sea level. Again on grades of 20% or more, adhesion traction is an impossibili- ty and so an ABT type rack-andpinion drive is used. Two-car trainsets are employed, driven by eight motors each rated at 300kW. The overhead supply is again 40Hz 3-phase at 550VAC. On such heavy grades brake design is critical. Dynamic braking is standard and available at all speeds, even during power supply failures. Disk brakes are also provided for emergencies. Passengers come to Brig via the CFF or BLS main lines, then take the narrow gauge train up the Nikolai Valley. Passing close to the 4512m high Mt Weisshorn, the train climbs the foothills to Zermatt where the rack railway is joined. From Zermatt to the top of Gornergrat mountain, the demand is such that on this rack railway trains run every 12 minutes. Acknowledgement The author thanks CFF for information, photos, drawings and permission to publish. ~ SEPTEMBER 1989 107