Around thirty engineers participated in the IMechE Railway Division’s recent Technical Tour (the tour) to northern Italy and southeastern Switzerland. The participants included experts from main line, metro, trams and metre gauge railways, as well as academics and a large contingent of younger engineers, close to the start of their careers. Companies represented were, Angel Trains, Arup Australia, Atkins, University of Birmingham, CPC Systems, East Midlands Trains, Eversholt Rail, Montreux Oberland Bernois SA, Network Rail, Rail Delivery Group, RSSB, SNC Lavalin, South Western Railway, Transport Scotland, Unipart Rail, and Waxwing Engineering.
The mix of people and visits led to a great deal of discussion with learning for all, both young and old. The tour is notable because it allows people to access facilities that would not normally be open to them as individuals. It has a great deal of prestige, allowing the members of the group to talk to senior people, both hosts and delegates.
Over eight days, the group enjoyed technical visits and a number of journeys on technically challenging or historically interesting railways, ranging from 10km/h funiculars to 300km/h high-speed trains. The table outlines the programme and the highlights are described below.
Deposito Rotabili Storici, in Pistoia, one of several establishments of the Fondazione FS, is a large facility for storing, maintaining and renovating heritage locomotives and rolling stock. The visitors were privileged to be guided around the facility and some of its more notable vehicles by one of the company’s experts, who had come specially from Venice.
The group learned about the history of Italian railway development in the region, especially the line through the mountains between Bologna, in the Po plain, and central Italy. There have been three lines – the original mountain railway line, a lower level line with more tunnels and, most recently, the high-speed line that is mostly in tunnel. The original line had gradients of up to 2.6 per cent (1 in 38.5). This was challenging for the steam locomotives of the day and, over 90 years ago, the advantages of electrification were identified.
The railways in northern Italy adopted the three-phase system, initially 3.3kV 15Hz and later 3.6kV 16²⁄³Hz. The so-called Porretana was electrified with this system in 1927. Although it required two overhead contact wires and the rails as the third conductor, it also allowed the use of AC machines and avoided the cost and inefficiency of large rotary AC/DC converters that were vehicle-mounted or installed lineside.
Control of the AC machines was far from trivial and included the use of pole switching and series/parallel connections to start the locomotives and to control the tractive effort. These schemes involved liquid rheostats (electrodes that are raised or lowered into brine to control the starting of slip ring motors), which sounded really scary to the modern audience of largely mechanical engineers!
Later on, the Italian railways adopted DC traction, operating at 3kV, delivered at first by rotary converters and later by mercury arc rectifiers, until modern diode rectifiers became available. The original mountain line was converted to DC operation in 1935, after the low level line was opened in 1934, but it was as recently as the mid-1970s that the last three-phase line was converted to DC.
A number of electric, steam and diesel locomotives were on show, the latter with electric and hydraulic transmission. Everyone learned something from the principles and features of the steam locomotives to the water rheostats.
Those delegates who work in the UK heritage sector were jealous that the Deposito has its own wheel lathe, capable of turning steam engine driving wheels.
The following day, the group visited Hitachi Pistoia, where senior executives kindly provided an introduction to Hitachi and the group’s Italian facilities before escorting the group around the factory. The Pistoia site specialises in the construction of aluminium carbodies and the assembly of complete vehicles using components manufactured at other sites in Italy or elsewhere.
Amongst the trains seen were some of the last bi-mode Class 802 units for Great Western Railway, Class 385 EMUs for ScotRail, driverless metro vehicles for Taipai and some very stylish double-deck Caravaggio EMUs for Italy.
Hitachi described the virtues of friction stir welding, which is currently carried out solely in Japan but which is due to be installed at Pistoia over the next 12 months.
Other activities seen included the renovation of the ex-Dutch/Belgian high speed Fyra V250 train for use in Italy, and the tour concluded with a visit to the climatic chamber and the structural test facility for carbodies and bogies. Again, this visit was truly fascinating for all, especially those who had never seen rail vehicles being built before.
Following the Hitachi visit, the group travelled on an Alstom Coradia Meridian EMU, which had to work really hard over the original mountainous line to Porretta Terme, where we changed to a Stadler FLIRT to Bologna Centrale.
Arriving at Bologna Centrale at ground level, one has no idea that there is a huge four-track high-speed station underneath, from which the group travelled on a 300km/h Frecciarossa train to the huge, 24-platform Milano Centrale.
ATM, Milano’s public transport operator, hosted a visit to one of the construction sites for metro line 4. ATM’s representatives were from its engineering company, which plans and manages the construction of metros, railways, LRT, airports, streets and tramways in Milano and also sells its services around the world.
The group was introduced to the public transport scene in Milano and Italy in general. Italians love their cars – the overall proportion of cars in Italy is about 70 cars per 100 inhabitants. 10 years ago, the proportion in Milano was lower, at 63 per cent, and this has been reduced still further, to 52 per cent today, through the active development and promotion of public transport.
The modal split is approximately 57 per cent by public transport in the city area, which is exceptional by Italian standards. Moreover, the number of new driving licences has dropped by 50%. Public transport use rose to a record level during the 2015 trade Expo, but this record was beaten in 2017 with a total of 750 million journeys; up nearly nine per cent from 2012.
There are currently four Metro lines – M1, M2, M3, M5 – with line M4 under construction. M1, M2 and M3 are conventional metro lines with 105-metre-long trains. M1 uses a third/fourth rail 750V DC system, similar to London, whereas lines M2 and M3 use overhead supply at the same voltage.
M5, and M4 once it is opened, are designed to operate on a somewhat different principle. Platforms and trains are shorter – approximately 50 metres – and the trains run at 90-second headways. M4 will also use 50-metre trains operating at 90-second headways, but with the ability to reduce to 75 seconds. This provides almost the same capacity as a conventional metro operating longer trains at 2-3 minute headways, but allows for smaller and easier to build stations, which are therefore much cheaper – a 30 per cent reduction in civil engineering costs was claimed. The lines are/will be driverless with platform screen doors.
The IMechE group was able to visit the site of the forthcoming Tricolore station and see two tunnel boring machines being assembled. It was explained that earth pressure balance machines are being used to cope with ground conditions.
Although shorter stations are a lot easier to build, there is still not much available space in central Milano. They will therefore be using two forms of construction for the stations, all of which will have island platforms with a central circulating area. In the suburbs, the excavation for the station box is the full width of the station whereas, in the central area, the excavation will be much narrower, confined to the central circulating area between the tracks. At tunnel level, cross passages are mined and the running tunnels enlarged to form platforms.
Alstom has a facility in Sestro, a suburb of Milano. This plant had been manufacturing electrical equipment for Alstom Italy, but is now running down manufacture and is becoming a component overhaul facility. The plant is also the maintenance control centre for some 600 Italian trains that Alstom maintains. The group watched as control technicians monitored the status of hourly downloads from their trains.
A journey to Bergamo enabled two visits. The first was hosted by the city’s public transport operator and included a visit to the tram depot.
The current tramway runs from the main railway station to the community of Albino using the track bed of a railway that closed in 1967. It is standard gauge, double track, 12.6km long and serves communities with 220,000 inhabitants in total. It uses 750V DC overhead, has 16 stops, seven of which are interchange stops with over 700 parking spaces, and has 32 level crossings. There are 14 trams, of which nine are used in peak service, and they are low floor throughout.
Unusually, the system uses red and green colour light signalling and it was mentioned that there has been some confusion between tram and car drivers.
The depot has a 12-track stabling shed and a four-track maintenance shed with a wheel lathe, lifting and workshop facilities. Trams were originally maintained by their supplier, AnsaldoBreda, but maintenance was brought in-house to gain better knowledge of the tram in order to improve the management of these expensive assets.
The trams are 32 metres long with five sections and three bogies, two of which are motored. For those engineers who had not seen under a tram before, the individual resilient wheels with no axles were a surprise. The Network Rail engineers were particularly interested in the depot track layout that includes some incredibly tight radius curves, below 20 metres, although the minimum on the main route was 25 metres. Considerable time was spent examining the long cast points fan, where only the “high rail” was equipped with switch rails, and the lubrication system.
“Riding the train or tram” is as important to the Railway Division as visiting control centres is to the IRSE and, following a tram ride, the group’s second visit was to the WEGH concrete sleeper factory to learn about their manufacture and the technology applied to the design of slab track. This included work to develop repair techniques for slab track damaged by derailments or other incidents.
The day ended with a visit to Bergamo’s Città Alta (High Town), appropriately on two funiculars, neither of which conform to the traditional system of two cars that counterbalance each other on the end of a single rope. The lower funicular uses two independent cars, each on a single track with a counterweight system below the machine room at the upper station, while the higher level funicular features a single car connected to a top-to-bottom cable loop.
The journey from Milano to Bergün in Switzerland was effectively another visit! The Italian part of the journey was through a very scenic part of Italy – substantially alongside Lake Como. At Tirano, the group joined a Swiss Rhätische Bahn (Rhaetian Railway, RhB) train for the scenic journey over the railway’s Bernina line.
The RhB is metre gauge and the Bernina line climbs just over 1, 800 metres from Tirano (430 metres) to Ospizio Bernina (2,253 metres) with gradients of up to six per cent using adhesion only.
The line, famous for the loops used to help gain height, the most impressive being on viaduct Brusio, is part of a UNESCO World Heritage Site.
The group travelled in a 40-50 year old coach in excellent condition, with large opening windows, much appreciated by the photographers. Indeed, even the newest air-conditioned coaches with panoramic windows have some areas equipped with opening windows for tourist photographers.
A typical train on this route is a Stadler dual-voltage (11kV 162/3Hz, 1000V DC) three-car unit with eight out of the 12 axles motored and a combined output of 2,600kW on AC and 2,400kW on DC, with a peak tractive effort of 260kN. These are known as Allegra sets and can usually be seen hauling four or five trailer coaches. Indeed, it is not unusual to see passenger trains with freight vehicles attached, most often tankers and open wagons loaded with big tree trunks.
Friday included a visit to RhB’s Albula museum, illustrating the challenges of building and operating railways in mountainous conditions, and a visit to the work site of the new Albula tunnel, which was extensively described in issue 166 (August 2018). Many of the group took a 90-minute walk from the tunnel workings to Bergün, with an opportunity to view the many bridges and spiral sections on the line, all in excellent short-sleeves weather. Just two weeks later there was deep snow (pictured above).
The final visit was to the RhB workshops at Landquart (16km from the railway’s headquarters in Chur). There was a fascinating talk about RhB’s approach to installing continuous train protection, using some of the principles and components of ETCS, but tailored to the particular needs of Swiss metre gauge railways.
RhB is the lead organisation for the specification of continuous train protection on Swiss narrow gauge railways, many of which run intensive services on single-track railways with passing places.
The timetable often depends on trains approaching the passing loops at the same time. However, in many of the passing loops, the signal protecting access to the single track is located quite close to the points and the loops are often not long enough to provide the length of signal overlap and flank protection that UK signal engineers would expect. Figures of 20 metres and, sometimes, zero metres, were mentioned.
The current RhB signalling system includes a system of train stops using track magnets, but these are located at signals and are clearly no help if a train passes at danger a signal with little or no overlap.
The continuous ATP uses Eurobalises, both with fixed data (speed limits) and variable data (signal aspects) to provide information about the route ahead, very similar to ETCS Level 1. The train driver inputs the type of train and its length. This basic approach provides a safe system, but RhB has identified timetable issues with the basic system.
For example, the system might inform the train that the next signal is at danger. As a result, the train driver would have to keep within an ATP braking curve as the train approaches that signal. In the meantime, the signal might have cleared, but the train would have to continue to brake until it passes the next balise, at the signal position.
To cater for this situation, RhB has added loops to extend the range of critical balises, so that the train may be released from the braking curve earlier. In addition, RhB told the visitors that it will be installing the system on the entire network (over 1,000 signals and 120 vehicles) for approximately 60 million Swiss Francs (£46 million) and plans to complete the deployment by 2022.
Both the novelty of the system and its relatively low-cost installation caused a great deal of interest from those of the group involved in signalling, especially the representative from Transport Scotland.
As a footnote, RhB mentioned the challenge of the sections of dual gauge track they share with the SBB (Swiss Federal Railway), which also has a legacy system and is installing ETCS. For a time, some sections of this track might have four ATP systems!
The visit then moved on to the rolling stock workshops that carry out routine and heavy maintenance on locomotives, multiple units and coaches. The group saw some vehicles that had recently arrived from the manufacturer, 40-year-old equipment and a serviceable heritage locomotive over 90 years old (already equipped to read ATP balises).
Many of the features of the works and the rolling stock within were unusual to UK eyes. For example, the works itself has been extended over the years to accommodate multiple units and the turntable that serves the works’ roundhouse has been modified to include a second, curved track to allow trains longer than the turntable to access their maintenance shed.
The team saw locomotives and carriages still in front line service that were over 50 years old and one of three restaurant cars dating from the 1920s that have been extensively modified to allow use in push-pull mode on the RhB’s prestigious Bernina Express.
In another part of the works, rotary snow blowers were being serviced ready for the winter, and there was a long line of exceptionally small-diameter wheels used on the wagons of the car-carrying trains that operate through the Vereina Tunnel (at just over 19km, it is the world’s longest metre-gauge tunnel). The wagons themselves cannot be transported to Landquart unless they have their roofs removed, as they would otherwise be out of gauge.
There were very many aspects of the RhB that were new for the visitors and illustrated to all participants that there are more ways to do things than might be allowed in the UK. Trains over 130 metres long running down the street in Tirano was one example, as was the final surprise of the trip – the Chur-Arosa line running though the streets of Chur powered from an 1 kV 162/3 Hz overhead supply.
Once the visit to the RhB was over, the last leg of the journey was on a German ICE1 train to Zurich Hauptbahnhof, followed by a well-earned beer on a Rundfahrt on the lake.
Participants in the IMechE Technical Tour would like to thank Felix Schmid and Bridget Eickhoff, who organised and led the tour; all the group’s hosts in Italy and Switzerland, the event’s sponsors: Angel Trains, Eversholt Rail, Manchester Engineering Consultancy and Unipart Rail, and Liz Turner at Ffestiniog Travel who organised the hotels and travel.