A Century Of Electric Operation Schynige Platte Bahn (SPB)
By Christopher Kyaw
Introduction
On 9 May 1914, the Schynige Platte Bahn opened its first season of electric traction. 14 and 15 Jun 2014, saw the centenary of this event celebrated with open days at the workshops in Wilderswil and a reception followed by a centenary special to Schynige Platte. Your correspondent contacted the Press Office of the Jungfraubahnen (the holding company for railways of the Berner Oberland) to request a copy of the press hand-out for the occasion and for permission to visit the Wilderswil workshops to photograph the innards of the venerable locomotives, very little changed from the time of building, with a view to writing an article for the Journal. Both requests were granted and, to my great surprise, I was invited to join the guests at the reception, on the centenary special and at lunch in the Berghaus at Schynige Platte. A most generous gesture! This article gives a brief history of the line, its route, operation, and rolling stock, with a more detailed look at the electric locomotives.
History
The mountain summit known as the Faulhorn (2,681 metres) lies on the south side of the Brienzersee in the Berner Oberland, Switzerland. A mountain hotel was opened there as early as 1830 with access on foot by the steep path from Wilderswil via Schynige Platte or by a more gentle but much longer route via Grindelwald. The less-athletic could get there on the back of a mule and I have also read (but can't remember where) that those with sufficiently deep pockets could be carried there in a four-man sedan chair! With the increasing ease of travel around Europe, tourism in the area developed, producing a demand for easier access to mountain viewpoints. A line as far as Schynige Platte, itself a remarkable viewpoint, would greatly ease access to the Faulhorn hotel.
Building started in 1893 and, despite surmounting a height difference of 1,383 metres in 7.3 kilometres, involving four tunnels and some very substantial retaining walls, both above and below the formation, the line was ready for opening on 9 May 1893. It was built to a gauge of 800 millimetre, using the Riggenbach rack to climb gradients as steep as 1-in-4. The motive power came in the form of four 0-4-2T tank locomotives from SLM in Winterthur. All coal had to be imported but hydroelectric power was abundantly available, thus the railways of the Berner Oberland were amongst the forerunners of Swiss electrification. A little behind the rest, the SPB changed to 1,500 VDC electric traction in 1914, taking its power from the Junfraubahn's generating station far below in the Schwarze Lütschinental at Lütschental.
Since then, the line has pursued a gentle existence, operating only through the months of June to October. Hardly a money-spinner, it has generated enough revenue to keep up with the times in terms of safety and of tourist facilities such as the splendid new Berghaus at Schynige Platte, opened in 2011. Equipment maintenance and renewal in compliance with Federal Regulations is an on-going process. However, care is taken to ensure that, as far as possible, century-old appearances are maintained. After all, the railway is within the perimeter of the UNESCO World Heritage Site of the Aletschgebiet.
The Route
The line starts at Wilderswil, the first stop on the Berner Oberland Bahn's line from Interlaken Ost to Grindelwald and Lauterbrunnen. The depot and workshops, where all maintenance is undertaken, is just across the tracks from the station buildings. At this point it is 584 metres above sea level. Leaving the station in a southerly direction, it meanders, parallel to the BOB, along the wide floor of the Lütschienental. After about half a kilometer, it crosses the river, swings left, and tips sharply upwards at 1-in-4. Emerging from a cutting, the line crosses over the road to Gsteigwiler, passes through woodland and over meadows to the crossing point of Rotenegg (Kilometre 1.87). It then starts the traverse of the mountainside above Wilderswil and the Brienzersee. Before a hurricane in 1999 felled many of the trees clinging to the mountainside, the view was very restricted. Now, although the trees are returning, there are many points where splendid views of Wilderswil, Interlaken, and the Brienzersee are to be seen. Levelling-out, the single intermediate station of Breitlauenen (Kilometre 4.6 and 1,542 metres above sea level) is reached. The station has a small buffet, is a crossing point, and is where the steam train, which operates around once a month, stops to take water.
Leaving Breitlauenen across alpine pastures, the gradients are a little easier as the line turns southwards to cross the ridge separating the Brienzersee from the Schwarze Lütschienental (in which Grindelwald lies). Another change of direction, this time eastwards, takes the line along the north side of the valley, high above its towering cliffs. The view over Männlichen to the Eiger, Mönch, and Jungfrau is simply stupendous. Finally the line levels out at the terminus of Schynige Platte (Kilometre 7.26 and 1,967 metres above sea level). This is the start of the walk to the Faulhorn, First, and Grindelwald, and also the location of the Alpine Botanical Garden, one of two in the World.
Operation
The SPB operates a 40 minute interval service as opposed to the 30 minute interval of the BOB and Interlaken-Wilderswil buses, so don't expect Swiss style 2 minute connections every half hour. Trains made up of two coaches pushed by a loco may leave the terminus either singly or in pairs as dictated by passenger numbers. The second train will follow about a minute after the first, running "on sight" in tramway fashion. The two-man crew consists of a conductor, who travels at the uphill end of the train, and the driver in the locomotive at the downhill end. Radio telephony (NOT mobile phones!) allows communication between crews, trains, and stations.
The crossing station of Rotenegg is unmanned but the points are hand operated. The lower points are left set for the line used by uphill trains and the upper points are left set for the line used by downhill trains. Once the downhill convoy has entered the loop, the conductor of the (first) uphill train must change the points before departure and re-set them after the uphill convoy has left the loop. A similar procedure is followed for downhill convoys but, as the conductor is at the uphill end of the convoy, a third person may travel uphill to Rotenegg to operates the points and return to Wilderswil with the downhill convoy.
Breitlauenen has a station master to operate the points for crossings and to supervise arrivals and departures.
Schynige Platte has two tracks, a siding and a neck-end, each of which can accommodate one train. Protocol requires that the first train disgorges its passengers from the track nearest the station buildings so that they are not in danger of being mown-down by the second arrival. Here, the station master operates the points, sells tickets, answers queries, and attends to the arrival and departure of trains. A reserve train may be stabled here during the day to accommodate peaks in patronage and to ensure that no-one is left behind because the last train of the day is full to overflowing.
Rolling Stock
Passenger Vehicles
There is an assortment of open and closed coaches, either on original SPB underframes and bogies or on chassies imported from the Wengernalpbahn, a nearby rack railway of the same vintage and gauge. Down the years, as the original bodies have suffered the ravages of time and passenger abuse, they have been replaced by new construction and borne a variety of liveries. These have varied from brown or the sedate Alpine Green of earlier years, through a flirtation with teddy bears to a red and cream, highly reminiscent of British Rail's early years.
Trains have no continuous automatic brake. Instead, the conductor at the front of the train has control of a mechanical brake which grips drums mounted on the axle of the rack pinion fitted to the uphill bogie of each coach. The driving shaft of this brake control is connected between coaches and to the bogies by universal couplings and drives the brake rigging through helical gears.
The conductor also has an emergency brake, operated by pulling on a long strap which passes under the coach body. This engages a ratchet clutch which transmits drive from the coach's wheels to the brake rigging, delivering a firm and abrupt brake application.
Other Vehicles
An assortment of 11 vehicles is available for non-passenger transport. Amongst these is a wedge snowplough which may see use at higher altitudes when preparing the line for its summer operation, an icicle-breaker with worker accommodation used to clear the overhead line, a tank wagon for conveying drinking water (no longer used) and a tower wagon for overhead line maintenance
Steam Locomotive
Number 5 is a standard SLM 0-4-2T rack engine (Swiss designation H2/3) built for the line's opening in 1894 and is very similar to those supplied to the Snowdon Mountain Railway. It has a service weight of 16.7 tonnes and a top speed of 9 Km/h. It sees service on summer steam specials and is used to power the works trains run after the winter shut-down to restore the line to operational condition.
Electric Locomotives
The SPB's four electric locomotives, Swiss designation He 2/2, numbers 11-14, were delivered in 1914 from SLM, with electrical equipment by Brown Boveri, and are still in daily use. They weigh 16.3 tonnes, have a top speed of 12 Km/h and two traction motors of 150 HP each.
These are supplemented by seven slightly more elderly (1910-1912) relatives, numbers 16, 18-20, 61-63, of the same characteristics but with the electrical equipment supplied by Alioth (Munich). Over the years, they were transferred from the Wengernalpbahn as they were replaced by rail cars. During their time on the SPB, they have been modified so that the railway now operates a fleet of standardised locomotives. The timetable allows 52 minutes to propel two loaded coaches the length of the line.
Resistance control of the motors was by the manual mechanical switching usual at the time of building. Unusually, the resistors are hidden in a housing which occupies most of the locomotive body. Despite forced ventilation by a substantial blower, much heat is dissipated into the interior, leading to difficulties in keeping both the motors and the driver sufficiently cool. This is particularly true on the descent, when the motors provide the braking. For this reason, the body side windows are always kept open.
The fitting of flange lubricators required the installation of a 24V power supply, taken from a battery kept charged by a generator driven from the uphill motor shaft. As the old mechanical control contactors became worn-out the 24V supply allowed them to be replaced by electro-mechanical contactors. At the same time, 24V electric lighting could be fitted throughout each train.
Mechanical design is based on their steam predecessors with only one driving position, at the lower end. The two carrying axles are un-powered, propulsion being through rack pinions mounted on their own shafts which also carry brake drums. There are two independent power trains, each consisting of a traction motor driving a clutch which, in turn, drives a gear train transferring power to the pinion shaft.
The clutch has the special function of disconnecting the motor from the rack pinion, should the pinion fail to engage properly with the rack. The clutch itself resembles a drum brake such as was once usual on cars but is, of course, much larger and far more robust. Its normal condition is engaged, a mechanical balance detects jarring in the gear train, automatically disconnecting and reconnecting the drive for just long enough to allow the pinion to settle into the rack.
He 2/2 Specifications
Locomotive numbers 11-14 Builders SLM/BBC In service since 9 May 1914 Length over buffers 5.76 metres Width 2.20 metres Wheelbase of rack pinions 1.15 metres Wheelbase of carrying wheels 2.60 metres Service weight 16.0 tonnes Number of traction motors 2 Motor voltage 1,500 Volts DC Trasmission gear ratio 1:11.6 Power rating 300 PS Tractive effort 118 kN Maximum speed 12 Km/h Purchase price CHF45,933.00 Seasonal average per locomotive 4,000 Kilometres Total average distance per locomotive to 2014 400,000 Kilometres
Acknowledgements
Information on the Faulhorn - from the hotel's own web site
Route data - Schienennetz Schweiz, SBB, 1980
Information about the Schynige Platte Bahn and its rolling stock came mainly from literature provided by the Jungfraubahnen and the staff in the depot at Wilderswil, to whom, many thanks.
On 9 May 1914, the Schynige Platte Bahn opened its first season of electric traction. 14 and 15 Jun 2014, saw the centenary of this event celebrated with open days at the workshops in Wilderswil and a reception followed by a centenary special to Schynige Platte. Your correspondent contacted the Press Office of the Jungfraubahnen (the holding company for railways of the Berner Oberland) to request a copy of the press hand-out for the occasion and for permission to visit the Wilderswil workshops to photograph the innards of the venerable locomotives, very little changed from the time of building, with a view to writing an article for the Journal. Both requests were granted and, to my great surprise, I was invited to join the guests at the reception, on the centenary special and at lunch in the Berghaus at Schynige Platte. A most generous gesture! This article gives a brief history of the line, its route, operation, and rolling stock, with a more detailed look at the electric locomotives.
