Pianotondo railway accident

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Pianotondo and Travi roundabout tunnel between Lavorgo and Giornico. The scene of the accident was shortly after 115 km from the entrance to the Pianotondo tunnel.

When railway accident Pianotondo derailed the Pianotondo- on July 29, 1941 shortly after 15 pm in front of the entrance circle helical tunnels between Lavorgo and Giornico the freight cars of a runaway freight train of the SBB . The locomotive , which was detached during the derailment , hit a stationary freight train four kilometers further.

Starting position

View of the tunnel portal and the Pianotondo caretaker's house. The chaos of the iron parts pushed into one another and the broken and bent wheel axle illustrate the force of the impact on the tunnel portal.

On the southern ramp of the Gotthard Railway between Airolo and Biasca , the trains overcome a height difference of 813 meters. To ensure that the gradient does not exceed 26 to 27 per thousand, the route was extended to 39 kilometers with the help of four circular tunnels.

The freight train traveling downhill in the accident was relatively light at around 300 tons. It consisted of 21 wagons of Swiss, Italian and a few Czech origins and was equipped with a continuous air brake. At the end there were two manually operated brake trucks. The locomotive Ce 6/8 III 14304 had a Westinghouse brake , a handbrake and an electric recuperation brake .

the accident

Up to Rodi-Fiesso , around 12 kilometers after Airolo, the engine driver was still able to control the speed. Then the freight train got out of control. After another 17 kilometers he derailed on the Pianotondo viaduct in a curve with a 300 meter radius. A number of cars crashed into the portal of the Pianotondo spiral tunnel, others tumbled down the mountainside. As a result of the journey, the wheels were so heated that a stationer's house and a military barracks stationed at the tunnel entrance caught fire.

In the derailment, the locomotive had the train severed and raced four kilometers through the Pianotondo- and Travi-loop tunnel on. According to the speedometer strip, she drove up to 120 km / h. At the former Giornico station , she hit a freight train that had come to a standstill due to a short circuit caused by the derailment . The rearmost wagons of this train were compressed and thrown off the rails . The final brakes recognized the danger in time and managed to save themselves. The burnt-out locomotive rolled over to the left and came to rest at the foot of the embankment .

consequences

Burnt-out guard house Pianotondo next to the tunnel entrance
Wheelset with tight-fitting brake pads

The accident claimed seven lives at the entrance to the Pianotondo tunnel. The train driver and the brakeman who were in the two brake cars at the end of the train perished . Thanks to the continuous air pressure brake, the freight train was manned by few personnel: the two railroad workers who died in the brake car and the locomotive driver, who was not injured except for a scratch on his scalp. Five soldiers from a Ticino territorial unit were killed in the burned-out barrack next to the guard's house . The military affiliated guarded the railway facilities of the Gotthard line, an important link between during World War II Axis powers Germany formed and Italy.

The material damage was considerable. 13 freight wagons were completely destroyed at the entrance to the Pianotondo tunnel. At the former Giornico station, nine freight wagons were ready for scrap. The locomotive Ce 6/8 III 14304 could be rebuilt in the main workshop in Bellinzona .

The accident demonstrated the solid design of the Ce 6/8 III locomotive. The frame halves together with the wheel sets were comparatively little deformed. Although the two drive frames twisted about 90 ° against each other in the longitudinal direction, the dome held tenons . The rod drive and the drive motors of the crocodile locomotive, designed for a top speed of 65 km / h, withstood 120 km / h. The drive and coupling rods did not fall off until they fell. The electrical equipment of the locomotive also remained almost intact.

Cause of accident

Underframe of the overturned locomotive
View from the tunnel portal up the valley. The track on the mountain side, marked with an arrow, has already been cleared.

The search for the cause of the accident turned out to be difficult because of the great destruction of the rolling stock and the locomotive. There was no evidence of sabotage . The freight cars were in normal maintenance.

The Swiss wagons were equipped with the Drolshammer freight train brake. Her brake pads had apparently worked because they were almost worn out. Others were worn out or fallen off. The investigating authorities found that the braking ratio was not quite sufficient for the speed specified in the driving regulations . The evaluation of the registration strip led to the assumption that a technical malfunction had also occurred while driving through Rodi-Fiesso, which led to the braking failure. During test drives with the same train composition, the train could only be brought to a stop at any point on the ramp with the locomotive and the two handbrake cars at the end of the train - without the help of the continuous compressed air brake.

The accident is very similar to that between Iselle and Domodossola , which occurred two years earlier. In both cases, a train burned down a steep ramp with a gradient of 27 per mil and hit stationary cars.

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