23.09.2024

When rain threatens cranes

Hundreds of people were evacuated from schools and homes in Munich last week when several tower cranes lost stability in the face of torrential rain, with one of them going over while it was being secured.

Last Wednesday saw two incidents. In the morning construction workers arriving on a site in Munich's old town discovered that the ground under a 30 metre high crane’s counterweighted base had been partially washed away causing it to become unstable. The emergency services decided that it had be dismantled immediately and evacuated around 300 people from the immediate area.
Firefighters study the crane’s base
All photos courtesy of the Berufsfeuerwehr München - Munich Fire department
The skies were at least clear for part of the recovery

The Munich fire service's high altitude rescue team worked with crane company employees to bring the stricken crane down, completing the task by around 19:00 that evening.
The fire department worked with the crane company to bring it down - with the crane unstable and time of the essence, riding the hook was considered the best option

At around 16:00 that day the alarm was raised on a second tower crane with a hook height of 20 metres, which had already started leaning. Firefighters managed to secure it, while the crane’s owners prepared to dismantle it. With more than 50 homes in the fall zone, around 200 people were evacuated to a bus depot and restaurant. The eight hour operation ended at around 22:00 when the affected residents were able to return to their homes.
The second incident not far away from the first - the slowly leaning crane caught the attention of local residents who raised the alarm

The removal went well into the evening

The Friday before these two incidents, a third crane actually went over, landing on two apartment blocks in the upscale Bogenhausen district of the city, causing substantial damage, but fortunately nobody was injured. Local residents had called the emergency services as it started to lean, but it went over not long after they began their efforts to secure it.
This one landed and caused considerable damage - but no injuries

The crane’s eight tonnes of counterweight blocks broke through the roof into the attic apartments, causing two people to be treated by the emergency services but they escaped uninjured.
The removal went well into the night

The crane company brought two All Terrain cranes in, including a 230 tonner, to remove the concrete counterweight blocks and the rest of the debris.

Vertikal Comment

Three unstable tower cranes over a few days in one city is highly unusual of course. Questions are being asked as part of the ongoing investigations, such as how much attention was paid to the foundations and whether anything more could have been done to prevent such incidents. While the details of each incident may vary, one thing is certain the unprecedented and exceptionally heavy rain played an important factor in all three and given the changing weather patterns this might trigger changes to some tower crane installations?

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