What is a deck barge (zolderbak)?

A deck barge, in Dutch zolderbak or zolderschuit, is a simple, box-shaped hull with a flat cargo deck running the full length and width. It is used in dredging, marine construction and ports as a floating work platform or to carry materials. The flat deck is called the zolder (loft) in Dutch, hence the name.

Construction

• Hull shape: a rectangular box with a flat bow and stern, without a pointed bow. This makes it easy to build and very stable.
• Cargo deck: steel, often covered with timbers laid crosswise that absorb impacts from the load and protect the steel.
• Internal support: rows of stanchions under the deck support it so it can carry heavy loads.
• Propulsion: originally a deck barge had no engine of its own. It was towed or pushed to the site by a tug and anchored there, for example with anchors or spud poles.

Uses

• Work platform for cranes, piling rigs or plant when working on banks, quays and bridges.
• Transport of building materials, soil, rock and dredged material.
• Transhipment in ports: such barges were once used as lighters to unload goods from larger ships.

Tilting barge

A special variant is the tilting barge. Water is let into side tanks so the barge heels over and the load, such as rock armour, slides off the deck. The tanks are then emptied and the barge rights itself.

Practical points

A deck barge has no high side walls like a cargo hold. The load therefore has to be well distributed and secured where necessary, to prevent capsizing or shifting cargo. Working on water is subject to strict safety rules and is a job for specialist marine contractors.

Related terms

• Spud pole
• Pontoon bridge
• Canal lock
• Bascule bridge

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