On Tuesday morning, a tram derailed and crashed into a shop in central Oslo. – It is not often that trams derail, but it is not rare either, says Albert Lau. He is an associate professor at the Department of Construction and Environmental Engineering at NTNU, and researches, among other things, on railways. – Trams often have to navigate through many tight curves, so it is not unusual for them to derail, says Lau. The tram drove into the Eplehuset store after derailing. Photo: NTB The researcher emphasizes that he is only relying on the information that has come to light in the media, and must therefore take reservations. But he points to three possible causes: Too high speed – The speed may have been too high, so that the outer wheel simply climbed over the track and derailed, says Lau. He points out that the curves on the tram track where the accident happened are quite narrow. The probability of a derailment is therefore higher if you drive too fast. Many people took the trip to see the tram after the accident. Photo: Tips When tram drivers have to drive over switches, they must not drive faster than 15 kilometers per hour. This is confirmed by the club leader for tram drivers in the Oslo tramway workers’ association, Thomas Stave. – The higher the speed you drive, the more exposed you are, he says. Based on the video of the accident, Stave thinks the speed seems high. – But I can’t say anything about how fast it goes, he says. Witnesses to the accident have also described that the tram was traveling at high speed. Both the police and the Accident Investigation Board are investigating the accident. They have not revealed what kind of speed the tram had. The wheel climbed over – The other reason could be that the wheel flange came into contact with the track junction, so that the wheel climbed over, says Lau. Four people, including the driver, were injured in the accident. Photo: Terje Pedersen / NTB A wheel flange acts as a safety mechanism to keep the train set on the track. When a tram runs on the rails, the wheel flange will prevent the wheel from climbing over the rails, he explains. Lau also points out that one or more wheels on the tram may have driven onto the wrong track and thus come into contact with a switch tip. NTNU researcher Albert Lau. Photo: NTNU – This could be due to a fault at the switch or a defective wheel, says Lau. At the same time, he explains that the speed of the tram itself can be a factor that led to the wheel running onto the wrong track in the interchange. – The speed may have been too high, so that the outer wheel simply climbed over the track and derailed, says Lau. Faults or damage – It could be that the wheel had faults or damage, says Lau. He points out that such a mistake may have gotten worse over time. – Something that may have ultimately led to the tram climbing over the track and derailing, says Lau. The accident happened at the intersection in Storgata. Photo: Fredrik Varfjell / Fredrik Varfjell / NTB He also points out that there may have been objects in the track that caused the train to derail. – In addition, trams often have to share the infrastructure with cars and other road users. This means that other road users can damage the tram’s infrastructure, which can lead to problems for the trams, says Lau. – Absolutely horrible to look at The model that derailed and crashed into the shop is called SL18. It is a newer model that has replaced the older trams in Oslo. – It is loved by some and hated by others. But it has been relatively well received by the driver community, says club leader for tram drivers, Thomas Stave. The SL 18 tram was ordered in 2018 and capacity for more passengers and a lower floor. The SL95 trams were ordered in 1995 and have a driver’s seat at both ends and are equipped with four two-axle bogies. He thinks that the accident on Tuesday was terrible. – You see how big the consequences our profession can have for others. It’s really horrible to watch, says Stave. – Now we’ve had three or four ugly derailments. Then we have to get this checked and turn over all stones, says Stave. Facts about the SL 18 tram: The SL18 tram is the newest tram model in Oslo, and was ordered in 2018. Today there are 87 SL 18 trams on the city’s streets. Length: 34.16 m Seats: 56 Width: 2.65 m Places in total: 220 Height: 3.65 m Floor height above rail top: 35 cm Max speed: 70 km/h Weight without passengers: 42.7 tonnes Weight with passengers, fully loaded wagon: 94.9 tonnes Wagon body material: Aluminum Supplier: Spanish company CAF. Source: Sporveien.no – Does not understand what could have happened He does not know what could have caused the accident today. – I have looked at the videos, and I don’t understand what could have happened, he says. Many people took the trip to see the tram after the accident. Photo: Tipser SL18 differs from the previous models in several ways. Among other things, the floor is lower. – It makes you feel the surface much better. There is less suspension, says Stave. – It has a very large overhang at the front, so you notice curves quite easily, compared to the old ones, he adds. But according to him, it is no more difficult to drive through tight turns with the SL18. – I don’t want to say that. It’s a matter of getting used to it, he says. Published 29/10/2024, at 21.31 Updated 29.10.2024, at 21.40
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This may have been the cause of the tram accident – news Norway – Overview of news from various parts of the country
