Background
Tiefencastel is a town of 247 people (as of December 2014) in eastern Switzerland, located in the Canton Graubünden/Grisons 21km/13mi south of Church and 29km/18mi northwest of St. Moritz (both measurements in linear distance).
The town lies on the Albula Railway, a 61.67km/38.32mi narrow gauge (1000mm/Meter gauge) single track electrified rail line owned and operated by the Rhaetian Railway (RhB), a private Swiss railway company. Opened in July 1904 the railway connects Thusis (at 697m/2287ft above sea level) with St. Moritz (at 1775m/5823ft above sea level). To handle the mountainous terrain without the need for a cogwheel-system the Albula Railway contains 144 bridges and 42 tunnels, some of the latter seeing the train turn around inside the mountain to gain height. Trains travel at an average speed of just 38kph/24mph, which gave the famous Glacier Express running on the line the slogan “the slowest express in the world”. The line is almost exclusively used for different passenger services, from standard regional passenger trains to more tourism-oriented trains like the Glacier Express, which use panoramic cars to show off the landscape. Freight traffic has dropped off in recent years, most freight cars are added to the back of passenger trains rather than setting up pure freight trains. Nonetheless the Albula Railway plays an important part in supplying the area with everything from wood and cement to food and mail. In July 2008 the Albula- and Bernina Railway were jointly added to the list of UNESCO World Heritage Sites on the basis of both their engineering and the landscape they go through.
The train involved
RE 1136 from St Moritz to Chur was a regional passenger train provided by the RhB, consisting of RhB Ge 4/4 III number 651 and seven passenger cars. The RhB Ge 4/4 III is a four-axle narrow gauge multipurpose electric locomotive made by Adtranz and SLM specifically for the RhB. Introduced in 1993 these locomotives weight 62 metric tons at 16m/52.6ft in length and can reach up to 100kph/62mph thanks to a power output of 3100kw/4160hp. Almost all the locomotives wear some sort of advertising as their livery, either for the RhB itself or various local companies. At the time of the accident locomotive number 651 wore a red-chrome livery advertising the Glacier Express.
The train consisted of five series II and IV passenger cars, each weighing 20 metric tons at 18.5m/61ft in length, a luggage/bycicle car (18 metric tons at 13.7m/45ft) and an older series I passenger car (18 metric tons at 14.9m/49ft). At the time of the accident the train carried 150 passengers along with the driver and a conductor. The leading passenger car was a series IV first class passenger car offering 36 seats that had been introduced in 1993.
The accident
In early August 2014 the Tiefencastel-area had seen a lot of rain, more than usual at that time of the year. In the morning hours of the 13th of August the section of the Albula Railway between Tiefencastel and Thusis was examined on foot by a track keeper, who found no signs of danger or damage. At 11:45am the regional express 1133 from Chur to St. Moritz passed the later site of the accident without incident, the driver later reported seeing nothing suspicious. In the meantime the 54 years old driver had taken command of RE 1136 from St. Moritz to Chur and made it to Tiefencastel station without incident. At the time the sky at the site was overcast and light rain had set in.
Leaving Tiefencastel station the train entered the valley of the Alora river, with the track winding along the wooded northern hillside. At 12:14pm the driver, leaving the Mistail-Tunnel, spots several branches on the track. He triggers an emergency stop while travelling at 50kph/31mph, calculations say the train would’ve needed 98m/321.5ft to stop. The train almost stops as it runs into the branches, at the same moment the driver spots soil on the hillside to his right breaking loose and moving towards the train. He feels a sideways jolt as the train comes to a stop, the same moment a short circuit cuts power to the train. The driver follows the procedure to secure a locomotive in case of a power outage before looking out the window to the rear of his train and spots a passenger car standing almost at 90° to the track. This was the second car of the train, the leading car has completely separated from the train and has fallen down the hillside towards the river before being stopped by some trees. The jolt the driver had felt had been the landslide hitting the leading car and tearing it out of the train, derailing both the rear axles of the locomotive and the second passenger car. The driver is completely uninjured, but in the leading cars of the train 16 people are injured, 8 of which severely.
Aftermath
Finding himself unable to radio dispatch or call the emergency services on his personal cellphone the driver leaves the locomotive and meets up with the conductor. The two agree that the conductor will tend to the passengers while the driver goes to get help. He runs along the track towards Thusis, going 150m/492ft and through the next tunnel before finally managing to call the emergency services who connect him with the RCC (Railway Control Center), where he reports the accident and ensures that the catenary is turned off. Seeing power in the catenary at the site drop the RCC had already cut power and alerted emergency services that something had happened. After the phone call the driver goes back to his stricken train and assists in the rescue of the passengers. Eight ambulances are dispatched to a road near the site along with 4 helicopters, responders specifically trained for mountain rescue climb into the leading passenger car and rescue the passengers trapped inside one by one. Due to the inaccessibility of the site several injured survivors are rescued by winching them up to a helicopter and flying them to the hospital or the nearby ambulances. Within three hours the train is empty, most of the passengers are taken to Tiefencastel station where they can continue their journey by bus. Helicopters can’t spot anyone on the hillside and none of the passengers miss anyone, so it is assumed that all passengers are accounted for. Professional responders later praise the calm and organized behavior of the passengers which eased the rescue operation, with some crediting this to the conductor’s ability to take control of the situation and give clear and simple orders.
With all passengers removed from the site and the train cars secured against further movement investigators descend on the site, trying to find out what happened and if it could’ve been prevented.Examining the surrounding hillside investigators figure out that the track was actually near the end of the land slide, which had started approximately 100m/328ft further up the hillside. Geologists included in the investigative team find that a natural gap in the trees due to low soil above the rock below had created a slight trench in which water had accumulated, eventually softening the soil enough to separate from the solid rock below and start moving down into the valley. Going through a particularly steep section approximately 45m/148ft up the hillside from the track the landslide picked up momentum allowing it to break loose more soil as the hillside flattened a bit. 300m³/10590 cubic feet of gravel and soil eventually reach the track, covering it up to 1.5m/5 feet deep. A small underpass under the track constructed because of the gap in the trees was simply overwhelmed, filling up in an instant and sending the remaining material over the track. The trench created in the hillside actually limited the consequences of the accident, as it reduced the width of the landslide so it wouldn’t hit more of the train. Had the landslide hit several cars consequences could have been far worse.
Examining the data logger from the locomotive shows that the driver reacted essentially as good as he could have, he wasn’t speeding and the location gave him no choice to spot the landslide before he did. The rear cars of the train were towed back to Tiefencastel on the day of the accident, cars 4–7 were essentially undamaged and car 3 had suffered minor damage from remaining connected to car 2, presumably keeping it from following car 1 down the hillside. Within car 2 passengers had quickly figured out their situation and huddled together in the rear of the car, hoping to move the center of gravity onto the track-side end of the car. By turning and tilting car 2 had short circuited the catenary with its roof, causing the power outage. Car 1 had fallen down the hillside until striking several trees, ripping off both car 2 and the locomotive in the process and suffering severe damage but remaining structurally intact. The locomotive saw its rear two axles lifted out of the track and suffered damage to the body, lights and rail guard. The locomotive was re-tracked and towed away the day after the accident while the leading and second car were unable to roll on their own anymore and were removed from the site with flatbed cars and special temporary wheelsets. The line reopened on the 16th of August.
While the investigation was still underway and news of the accident had reached around the world (due to the high amount of tourists using the RhB every year) the 22nd of August saw the accident claim a life after all when an 85 years old initial survivor succumbed to his injuries at the hospital. This made the accident the second fatal accident in the history of the RhB after a derailment in 1952 claimed two lives. The report concluded that the accident was the result of an unforeseeable event, there was no way to tell that a landslide was going to start before it did and due to the proximity of the origin to the track an alert when it started would’ve come too late to avoid what happened. After the accident the RhB reevaluated their structural engineering at similar sites, the location of the accident had previously been evaluated to have a low risk of landslides (level 2 of 5), only receiving the small underpass. Evaluating the side after the accident showed that the landslide had removed most of the loose soil and rock at the site, reducing the risk of another landslide in the near future to essentially zero. Larger rocks in the area were removed and the underpass and its immediate surroundings were completely cleared of soil. The RhB also modified the attachment of the interior ceiling tiles in the series IV passenger car as those had fallen down when car 1 went down the hillside, posing an additional risk of injury. Each tile consists of a rectangular, curved piece of aluminum weighing about 6kg/13 pounds and has sharp edges.
After the accident the leading car was scrapped while the rest of the train was repaired and returned to service. The financial damage to material was listed as 1 million CHF/913 thousand Euros/1.12 million USD. In 2016 the RhB started modernizing the Ge 4/4 III locomotive, giving them new brakes, bogies and a new signaling/train control system along with LED lights. The modernization is scheduled to finish at some point in 2021, after which the RhB will start replacing the locomotive’s electrical converters with newer/better systems. These two programs are meant to ensure service for another 20 to 30 years.
Video
This link gets you to a video filmed a few hours after the accident, interviewing RhB-employees and showing the aftermath. Unfortunately the uploaded doesn’t allow embedding in other sites.
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