On the 14th of September 2011 Uljanik Shipyard delivered the fourth Self-Propelled Cutter Suction Dredger, named “Niccolò Machiavelli”, to the Luxembourg company Jan De Nul S.A. G. D. Luxembourg that forms part of the Jan De Nul Group. As a reminder,the first dredger “Ibn Battuta” was delivered to the same buyer at the end of May while the second one, “Zeng He”, was delivered in October of last year.
The delivery documents were signed by Walter Dietens, Project Leader at JDN Group Technical Department and Mr. Petar Car, Sales, Project and Calculation Manager at Uljanik Shipyard.
It is worthwhile noting that apart from the already mentioned four dredgers, Uljanik has contracted with Jan De Nul the construction of two Trailing Suction Hopper Dredgers. These are very complex floating objects for carrying out work on the sea bottom, i.e. cleaning and transporting material from the sea bottom. The contracting of ‘hoppers’ represents the continuation of Uljanik’s orientation towards the construction in shipbuilding niches of more complex ships with greater added value.
“Niccolò Machiavelli” is a Self-Propelled Cutter Suction Dredger, a technically extremly complex ship used for dredging water ways, building wharfs, artificial islands or dredging the coastline, which is able to reach a dredging depth of 36.6 meters. The ship is capable of dredging (cutting and simultaneous suction) compacted sand, stiff clay, stones and similar sediments of the sea floor . The excavated material is unloaded by the port or starboard side spuds into barges or through a swivel to a floating pipeline to the shore at a distance of about 10 kilometers.
The fact that in the world today only six similar ships exist and that, to date, there has never been the construction of four dredgers in the same shipyard, mainly one or two at most, speaks volumes about this project. This unique shipbuilding achievement surpasses general shipbuilding in the wider region, since by building and delivering such ship-machines, Uljanik has become a member of a small group of global shipyards which are offering the construction of, or have already built, such a type of floating unit.
The ship has three engines of type MAN Diesel A.G. – 6L48/60 7,200 kW/500rpm which are running three main alternating generators, each having a power of 7,200 kW at a voltage of 6.6kV. The ship length is 138.50 m, beadth 26 m and height ranging from 8.80 to 12.20 m, with a deadweight of 2,200 tons and a draught of 5.75 m. The enormous power of 21 MW, sufficient to provide electric current for a small town of 25,000 people, is being used for the operation of the dredging equipment. The major consumption of power is by three huge dredge pumps, each having a power of 5 MW. The ship develops a speed of 13 knots with diesel electric propulsion, driven by two electric motors of 3.5 MW each.
The project solution of electrical distribution and automation is the achievement of Uljanik’s designers. To put this into perspective, on a dredger of length 138 m, 330 kilometers of cables are installed while on a standard tanker or bulk tanker 100 km of cables are laid.
From the slipway the cutter, weighing 1,200 tonnes, was launched such that the ship entered the sea by the bow unlike the customary way of launching ships by the stern.
During the construction the ship steel plates, which are considerably thicker for dredgers than for other ships such as tankers or car carriers, were heated before welding to over 100 degrees followed by controlled cooling. The ship has an automated engine room and is suitable for unattended operation according to the requirements of both Bureau Veritas AUT-UMS and the National Authorities. Control of dredging, propulsion, steering and navigation is from the wheelhouse, namely the captain’s bridge. An air-conditioned accomodation space above the tweendeck level in the aftship and above the main deck level is suitable for accomodating 46 persons.
On the open deck there is one hydraulic travelling deck crane with a capacity of 2 x 350 kN and one 10 kN hydraulic store crane is installed. The ship’s added value is a number of times higher of that of a classical tanker.
It must be said that in the construction, Uljanik has succeded in achieving exceptional harmony and a good organization of all those who have participated and been included in the construction of the ship, meaning also those who are not part of the Uljanik Group.
The Shipbuilding Contract for “Niccolò Machiavelli” was signed on the 21st of December 2007, with the keel laying taking place in January followed by launching on the 23rd December 2010.
After the delivery “Niccolò Machiavelli”, as all the other ships from the serie,s will be sailing under the flag of Luxembourg. The construction of the ship is supervised by the classification society Bureau Veritas in cooperation with the shipowner and Uljanik Shipyard.
Source: uljanik, September 16, 2011;