20.11.2023
Dropping the boat
A five axle All Terrain nearly ended up in the dock on Thursday when it dropped a classic Amsterdam sightseeing boat in the Netherlands.
The crane - a 100 tonne Liebherr LTM 1100-5.2 owned and operated by C&P Kraanverhuur - was lifting the boat, the Eveline, out of the water at a quay in Amsterdam-Noord for dry dock maintenance over winter. The crane was lifting the boat over one of the rear outriggers when it punched through the concrete dock surface revealing a large underground void.
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The crane tilted but remained upright as the back end of the boat initially rested in the water, while the front hung up on the dock, with some weight still held by the crane. As everyone recovered from the shock, the web sling at the rear of the boat shifted along the boat relieving the crane of its load almost causing it to flip over rearwards. Once again however, it did manage to remain upright on the dockside.
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The void below the dock surface
There were several issues with this incident, but the most critical was the assumption that the surface and construction of the old dock was sufficiently strong enough to support the crane without the need for outrigger mats of any kind. Why anyone would ever set outriggers on a machine of this size without at least putting down the usual on-board mats, in order to at least spread the outrigger loads a little, is hard to fathom. Thankfully no on was seriously hurt and even the boat is repairable.
An overnight salvage operation using two other cranes managed to extract the boat from the water, when its drained and loaded onto the waiting trailer.
The video below shows most of the incident as it occurred.
Spikey
When you have a calculated point load from the manufacturer and a UDL from the site it would very rarely be any good to sit a lifting appliance directly on its rigger feet.
Port side you would only opt for sitting a crane on the ports crane rails with mats.
You can see these clearly in the video. Crazy..
Pemby
This. This is why I didn't sit my riggers that close, and ended up not being big enough to lift up a barge (they only wanted one end out the water, and the angle it'd sit to expose the props, hahaha -NO.
Always said that these boat lifts should also have a spreader for along the length, so there's no inward pull to result in this.
andrewfoster47
I see a lot of machines on my travels throughout Europe with no mats under them.
It never ceases to surprise me how 'relaxed' the industry is when it comes to things we in the U.K. see as absolute basic requirements for working on site.