Background
Soure is a city of 19245 people (as of 2011) in western Portugal, located 155km/96mi north of Lisbon and 121km/75mi south of Porto near the Atlantic coast (both measurements in linear distance).
Passing through the western edge of the city is the “Linha do Norte” (“Northern main line”), a 336km/209mi electrified main line connecting Portugals two largest cities, Lisbon and Porto. Opening in sections between 1853 and 1877 the line carries everything from regional commuter trains to long distance high speed trains on two to four tracks at speeds of up to 220kph/137mph. The whole line is built in 1668mm/66.5in “Iberian Gauge” wide gauge track, with early sections actually having the 1435mm regular gauge before being adapted to make it compatible with neighboring Spain.
The trains involved
Train number 4005 was a high speed passenger service from Lisbon to Braga provided by Alfa Pendular train number 4005. Built by Fiat, ADtranz and Siemens the Alfa Pendular is a six-car electric multiple unit introduced in 1999 based on the Italian ETR 480 with the suspension design adapted to the Iberian gauge. Each of the 10 units made measures 158.9m/521ft in length at a weight of 298 metric tons and can carry 301 passengers in a two-class configuration. The trains are driven by eight motors located in the four outer cars of each train, with a combined power output of 4500kW/5400hp allowing a regular top speed of 220kph/140mph (245kph/152mph have been achieved in testing). The “Pendolino” name refers to the tilting-ability of the trains, leaning the body into turns at up to 8 degrees to allow higher speeds on curvy sections of track without the centrifugal forces inflicted on the passengers becoming too high. The trains were initially delivered in a red-white livery, but by 2017 the CP (Portugiese national railway) started an extensive refurbishment-program giving the trains new interiors and a more modern silver-black livery.
On the day of the accident the IP (Infraestruturas de Portugal), the state-owned company tasked with maintaining Portugals railway and road network, was shuttling a maintenance-vehicle from Entroncamento to Mangualde. The vehicle, VCC number 105 (VCC stands for “Veículo de Conservação de Catenária”) is a small diesel-powered railcar used to inspect and repair the overhead catenary. The two-axle vehicle weights just 32 metric tons and isn’t even as long as a single car of the Pendular trains.
The accident
On the 31st of July 2020 at around 3pm Alfa Pendular 4005 is on its northbound way towards Braga with 212 passengers and two crew members on board. It was to pass right through Soure station without stopping as part of the Pendular trains’ concept is a low number of stops to cut down on travel time. Just north of the station VCC number 105 was sitting in a siding with two crew members on board, who were taking the vehicle to its next job site. They had stopped in the siding at 3:12pm, being told to wait for the Pendular to pass before continuing. For unknown reasons the crew soon disregarded the order and, despite no train having passed them and their signal still being red, set the vehicle in motion again at 3:25pm just as Alfa Pendular 4005 was approaching their location at approximately 200kph/124mph. The VCC left the siding and entered the main line at low speed, being recognized by the main line’s signaling system as having breached the block section of the high speed train. This switched the nearest signal to the south to red (which happened too late for the high speed train’s driver to see) and automatically triggered an emergency stop on the high speed train. However, by the time the high speed train started to slow it was hopelessly too late.
At 3:26pm, 20 seconds after the VCC had breached the main line, Alfa Pendular 4005 struck the slow moving vehicle at 190kph/118mph. The force of the impact derailed the leading two cars of the high speed train and separated the leading car from the rest of the train. The leading car proceeded to drag the destroyed VCC along for over 500m/1640ft before coming to a stop somewhat aligned with the tracks, next to the second car. The impact was violent enough to largely rip the VCC’s body off its frame, leaving no chance of survival for the two people on board. Everyone aboard the high speed train survived the collision despite severe damage inflicted on the train, especially the leading car, with 43 people being injured, 7 of which seriously (other sources claim 3 seriously injured survivors). The driver of the high speed train had started to retreat from his seat once a collision was imminent, saving his life as the collision obliterated the driver’s cabin.
Aftermath
Within minutes of the accident only 160 responders were dispatched to the site of the accident, including 2 helicopters, five ambulances and two psychological support crews. A field hospital was set up near the wreckage allowing the passengers to be treated, evaluated and either released or distributed to hospitals. Within a few hours all the passengers were off the train, with the driver being the last to be rescued after requiring to be cut free.
Even if the VCC’s crew couldn’t be interrogated about their actions it was soon quite clear what had happened, as, obviously, they hadn’t waited for the high speed train to pass. If they had forgotten about the instruction or maybe thought that the train had passed while they were distracted cannot be determined. The head of the train driver’s union sharply criticized the Portugiese railway after the accident, pointing out the lackluster safety equipment. The Alfa train was fitted with Convel, an automatic train control system that monitored the surrounding signals and could trigger an automatic stop if the train was passing or departing under a red signal. However, the VCC had not been fitted with the system meaning it could pass its own signal and breach the other track just fine. The signaling-system could then detect it in the occupied block section, turn the signals red and thus cause Convel to stop the other train, but as the accident showed that took too long. Had the VCC been fitted with Convel the system would’ve kept it from entering the main line in the first place.
Back in 2018 IP had announced that they would install the system on all their railway maintenance vehicles, but by the time of the accident this hadn’t happened yet. When asked about the delay the explanation was that there were problems in acquiring the needed equipment from Bombardier, generally assumed to mean they couldn’t or wouldn’t afford it. They had given the original announcement after an incident in 2016 where a VCC had run a red signal and entered the main line, as it soon came to light one of fifteen times this had happened in just a few years.
The day after the accident work already started on removing the wreckage from the tracks, the next day at 1:45am traffic on the southbound line resumed under a strict speed limit as repairs were still being carried out on the northbound track. By 9am the northbound track opened for traffic as well. IP was urged to expedite the installation of Convel on their railway vehicles to stop them from continuing to be time-bombs on wheels. Along with that IP was urged to improve training of their employees who would drive the vehicles.
The VCC and the high speed train were written off and scrapped after the accident, making train 4005 the first Alfa Pendular to be removed from service. The remaining 9 units have finished the refurbishment-program and continue regular service going back and forth between Braga and Faro via Porto and Lisbon.
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