Abstract: In 2004 IHC Engineering & Renovation delivered multi purpose pontoon Imtiaz to Drapor in Morocco. The pontoon is primarily used for dredging by means of a heavy duty 80 tons dredge crane. However Imtiaz can also be used for offshore construction works, heavy lifting operations up to 70 tons or transport of goods.

Imtiaz is equipped with two rock breaking hammers. These hammers are used in combination with the (semi) free fall function of the crane. In practice these hammers can be used to remove small hard spots during dredging operations.

A more sophisticated approach to remove rock under water would be to use a hydrohammer on such a pontoon. The hydrohammer can be handled by an excavator crane or by a leader guide hinged to the pontoon. Pro’s and con’s are discussed of both methods as well as operational constraints.

Key words:

rock breaking, hydrohammer