Review nr 1. 2003 - TTS Group ASA

14 TTS Review June 2003
Specialised cranes for Jan de Nul
dredgers building in Spain
Currently under construction in Spain at Izar’s Sestao Shipyard are two
11,300m2 trailing suction hopper dredgers for leading Belgian dredging
operator Jan de Nul (Hull Nos. 324 and 325).
B
Both 138.94m long dredgers feature
two TTS designed and supplied
electro-hydraulic deck cranes for the
repair and replacement of the vessel’s
dragheads and other elements that
form part of each dredgers suction line.
A 1,200mm bore draghead, with an adjustable
visor and a swell compensator, is fitted to the end
of the dredger’s suction arm.This swell compensator
allows for a 6m movement of the draghead
with respect to the vessel.The suction pipe is
hoisted by three gantries placed at the draghead,
at the intermediate cardan joint and the trunnion
connection of the arm to the hull.
Each gantry is provided with an hydraulicallydriven
winch with nominal pulls of 1,005kN in the
draghead, 960kN in the intermediate for a nominal
hauling speed of the suction pipe of 8m/min.The
draghead winch is arranged for single part hoisting,
trunnion and intermediate winches for double part
hoisting.
Of the two TTS cranes being supplied to these
dredgers, one is a low profile cargo crane, type
CCL, with an SWL of 45 tons at 22m outreach.
This crane has an auxiliary hoist rated at 5 ton at
22m outreach.The second crane is a service crane
with a hoisting capacity of 14 tons at a maximum
outreach of 22m.