Conversion to jetty pontoon

On behalf of the Dutch dredging contractor Royal Boskalis Westminster, Vuyk modified the stone pontoon 'Jamuna VIII' into a jetty pontoon. The pontoon was used for a harbour extension project at Ras Laffan in Qatar.

 

Principal dimensions   
Length moulded 230' = 70,104 m
Breadth moulded 60'  = 18,288 m
Depth moulded 14'  = 4,267 m
   

Description of system

The pontoon was equipped with two heavy spuds, ramps, winches etc. The spud system enables the pontoon to be moored alongside breakwaters. To enable loading of heavy ump trucks, the pontoon is fitted with two land ramps at one side of the pontoon while at the other side a ramp to the stone barge is installed.

To guide the spuds, large spud wells were created inside the pontoon in such a way that most of the construction work could be carried out beforehand. The spud wells could be installed afterwards as soon as the 'Jamuna VIII' became available. The spuds are equipped with sheaves at the lower side enabling them to be hoisted and lowered. Once the spuds are lowered, the hoisting wire is slackened to enable the pontoon to move freely with the tide. Counterweights are installed in the fixed part of the spud wires, which keep the wires tight and prevent them from running out of the sheaves.

Large land ramps with hoisting posts are installed, where large dump trucks can drive across onto the jetty pontoon or via the third ramp straight onto a stone barge. Furthermore, the pontoon is equipped with the necessary winches for hoisting and lowering the spuds and the land ramps, mooring winches and dust sprinkling towers to moisten the delivered stones to prevent too much dust and containers to serve as office, day-room and machinery spaces.

 

Follow-up orders

After the modification of 'Jamuna VIII' barge, three other barges were outfitted in the same way to serve as jetty pontoons.

Length moulded  100,584 m 91,50 m  85,344 m 
Breadth moulded 30,480 m 27,46 m 24,384 m
Depth moulded 6,096 m 5,49 m 5,486 m

 

Vuyk scope of work

On behalf of Boskalis, Vuyk performed the concept and detail design of the complete modification, including:

Construction of:

  • Spud keeper fore and aft
  • Upper part spud keeper
  • Counterweight tower
  • Hinge points ramps
  • Ramps

Arrangement of:

  • General Arrangement Plan pontoon
  • Hoisting points ramps

 

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