Under the rainbow


A Dutch dike strengthening project is home for a special version of the Cat 336 writes Steven Vale.

FINISHED in the distinctive yellow and grey colours of Dutch earthworks giant Boskalis, the one-of-a kind excavator is playing a vital role sand works role on the edge of the Markermeer (Marker lake).

Laying down the base of what when finished will be a wider and stronger dike than the present one, the 33km section, which heads north along the shore of the lake from the village of Durgerdam on the outskirts of Amsterdam to the town of Hoorn, will protect more than one million people should the dike break.

Each year the Dutch spend hundreds of €millions pumping unimaginable volumes of sand along the North Sea coast to shore up the beaches to protect the country from rising seas levels.

Normally, coastal defence work is a job for huge trailing suction hopper dredgers (TSHD). These rainbow the contents into the shallows or, when the height of the beaches needs raising, pump sand through a rigid pipe (typically from 80cm to 1.0m-diameter) to an outlet on the beach. The water drains and the sand is levelled by a dozer.