International Dredging Review

International Dredging Review

With tilting rear stabilizers and the excavator arm the dredge can walk independently from land to water.

A Watermaster amphibious multipurpose dredge from Aquamec Ltd. worked in the Magdalena River in Barranquilla Colombia to clean a water inlet to the river that serves the local water supplies.

To serve the varying needs of its owner the dredge can walk independently from land to water launching without cranes; can cruise without tugboats; and operates without winches wire or cables or assisting vessels.

The dredge was purchased by Sociedad de Acueducto Alcantarillado y Aseo de Barranquilla S.A. E.S.P. (Triple A) which operates the water facilities in the city of Barranquilla with water from the Magdalena River taken from a water inlet on the shore of the river.


The Watermaster dredge’s excavator arm works with different attachments for pumping raking or digging and round detachable floats on the sides of the dredge provide extra stability while cruising and are used for anchoring when the dredge is working.

The 1528-kilometer (about 948-mile) long Magdalena River flows through the western half of Colombia and supports large populations near the waterfront. Along with sediment and vegetation the river carries trash and debris from the waterfront communities. However the river supplies water for two million people in the city and 15 other municipalities in Colombia’s Atlantic Department located in the northern part of the country with the Caribbean Sea to the north.

To clean the inlet Triple A put the Watermaster dredge to work in September 2013 and by May 2014 it had dredged 1200 hours and cleaned the entire 22000 square meters (about 26300 square yards) in the water inlet to a depth of four meters (about 13 feet).

Previously Triple A owned a cutter suction dredge and rented additional machinery like barge mounted excavators to remove vegetation or other excavation work the dredge couldn’t do. The Watermaster amphibious multipurpose dredge can do the work of all that equipment Johannes Karvonen marketing manager for Aquamec Ltd. said.

In 2012 Triple A conducted a study to test different technology for keeping the water inlet open. “They compared many different machines and work concepts did thorough calculations and in the end came to the conclusion that Watermaster is the best option” Karvonen said.


The dredge working in the Magdalena River cleaned a water inlet that supplies water to the city of Barranquilla Colombia.


The amphibious dredge is self-propelled and can walk independently from land to water even steep riverbanks without crane assistance moving between jobs along the river in short time.

The dredge moves on dry ground and in very shallow water with two rear tilting stabilizers and an excavator arm. When it is working the four stabilizer arms anchor the dredge. It can cover a large area in shallow water from zero to six meters (about 20 feet) deep. The two front stabilizers have a maximum depth of five meters (about 16 feet) and the two rear tilting stabilizers have a maximum depth of 6.7 meters (about 22 feet).

The six-cylinder diesel Caterpillar C7 engine is air-water radiator cooled so it does not need deep water to operate like water-cooled engines.

“To reposition the dredge raises its four stabilizers and drags itself forward or backward using the suction arm then lowers the stabilizers again” Karvonen said.

The steel round detachable floats on the  sides of the dredge provide extra stability while cruising and are used for anchoring when the dredge is working.

The versatile dredge has several heavy duty attachments for to the excavator arm to work as a backhoe dredge or suction dredging pile driving hammering or raking.

With the submersible cutter pump attached to the arm the dredge can operate 180 degrees without winches wires or cables or extra anchors. The flexible suction arm can cover a large area as opposed to the narrow band that a stiff suction pipe can reach. The Watermaster comes with two different cutter crowns – the universal cutter crown with teeth and the soft soil cutter crown with vegetation cutter. The universal crown has a flat bottom piece for a smooth bottom cut or a conical bottom piece for deeper penetration in the sediment.

A spray pipe can discharge from the cutter pump to an area up to 30 meters (about 98 feet) away. If the dredge is working farther away from the discharge area the Watermaster can pump via pipeline up to 1.5 kilometers (about .93 miles).

If the sediment is not suitable for pumping the Watermaster can work as a backhoe dredge to excavate hard soils. If there are rocks or very hard soils the hydraulic hammer can break up the bottom underwater first before excavation.

A clamshell bucket can also load sediment to a barge or the 2.75-meter rake can remove reeds roots and other vegetation or clean the bottom for trash.

The Watermaster dredge in Barranquilla will be used to clean water treatment settlement ponds at different locations. The city can also assist other small municipalities who face similar siltation problems in water inlets. This is especially a problem during the dry season when the low water level prevents many dredges from operating.

The Watermaster amphibious multipurpose dredge concept was developed in 1986 and are manufactured in Finland. The fourth generation machine was introduced in 2011.