Digger Man

Digger Man Blog

by Nick Drew  |  Wed 10 Jul 2024

Underwater Excavation Japanese Style (Digger Man Blog on Holiday, Post Re-Visits)

Nick's on holiday, so we are looking back at some favourite blog posts from the archives over the coming days.

The Japanese do tend to do things a bit differently to us in the UK. In many cases because they are very technologically advanced and extremely capable of designing innovative solutions to problems.

Underwater Excavation Japanese Style (Digger Man Blog on Holiday, Post Re-Visits)

While trawling the internet recently I came across some videos featuring excavators that had been designed to work in and below the water level if needed. From some brief research I discovered that these machines are by converted Kyokuto Construction Co Ltd.

Details are sketchy but it would appear that some models are modified to work using conventional diesel engines with an extendable “breathing” pipe while other models use a submersible 440v motor and or a combination of the two in some cases. The operators sit in an open framed cabin area which can also be hydraulically raised if needed, when working completely underwater the operator would wear sub-aqua breathing apparatus.

It appears that two models are available the 20-tonne class TKM 200-9 and the 12-tonne class TKM 120-6. These machines can work at a depth of -50m but in many instances they are deployed on river dredging operations in rivers that meander through some of the big cities in Japan.


In the UK we would tend to use long reach excavators sat on the sides of the river, but I assume this is not always possible in the built-up areas in Japan. Either way, its interesting to see these extreme machines at work.

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