Punched by the Earth: The 2014 Tiefencastel Landslide Derailment

Background

The location of Tiefencastel in Europe.

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 site of the accident seen from above, located on a hillside between two tunnels.

The train involved

RhB Ge 4/4 III number 651, the locomotive involved in the accident, photographed in October 2008.

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.

A series IV first class passenger car identical to the one included in the train involved in the accident photographed in 2017.

The accident

The train involved in the accident, caught by a webcam at the Landwasser Viaduct minutes before the accident.

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

Passengers walking towards Tiefencastel station (left) and a survivor arriving at the evaluation site by helicopter (right).

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.

A translated photo from the record, pointing out the path of the landslide.

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.

The locomotive (left) and leading car (right) in the aftermath of the accident.
Car 2 (left) and 3 (right) in the aftermath of the accident.

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.

The loose/fallen ceiling tiles, photographed in the leading car after its recovery.
The leading car photographed in 2015, awaiting recycling.

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.

RhB Ge 4/4 III number 651, still wearing the chrome livery, pulling a regional train in October 2016.

Video

A video filmed a few hours after the accident, interviewing RhB-employees and showing the aftermath.

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