Berghavn (Dredger)

[john sefton]

BERGHAVN.
The SEADIP 75 Dipper Dredge is one of a range of non-propelled Dipper Dredgers in the Seadrec construction programme. '75' refers to the dig or bail pull at the bucket measured in Tonnes.
The BERGHAVN has special features to allow continuous operation in the extreme climatic and hard material conditions in the Norwegian northern coastline. It is used for the construction and maintenance of a very large number of fishing ports and harbours.
The Seadip 75 Diesel electric Dipper Dredge is built to comply with the requirments of Det Norske Veritas 'IA1 Dredger' and was delivered to its owners in 1980.
The robust monohull is of all welded steel construction specialy reinforced in high stress areas where the heavy dredging loads are transferred via the digging machinery to the hull structure.
The entire operation of BERGHAVN is controlled by one man from the well laid out control house located above the accommodation deck. Air conditioned accommodation is provided for a crew of eleven crewmen in single berth cabins and incorporates separate TV room, messroom, galley, and freezer storage for extended working provisions. All accomodation and machinery spaces are specially insulated and heated to extremely high standard to allow continuous working conditions prevailing in the Norwegian north. The BERGHAVN can truly work in conditions which no other dredge type can tackle.
All machinery is of well-tried and proven Seadrec design and constructed to readily withstand the heavy fluctuating stresses imposed by its rugged environment.
The bucket has a capacity of 4.60 cubic metres for normal dredging whilst a smaller capcity 3.0 cubic meter bucket is fitted for the heavy dredging of rocks and obstructions.
The dredge is fitted with two dipper arms, a long arm for 6.5-14 metres dredging depth and an alternative shorter arm for 2.5-10 metres depths. Two aft breast spuds and one centre line 'trailing' spud forward are fitted, designed to operate to depths down to 14 metres with an allowance of 2 metres for bottom penetration.
Power for the dredge is provided by a Mirrlees Blackstone ESL6MA marine diesel engine developing 700bhp. @ 750 rev/min. this engine drives the Ward Leonard generator for the main hoist winch together with, in tandem, the main AC alternator. An R.A. Lister JWS 6MA' diesel engine developing 140bhp @ 1.500 rev/min drives a 50kw auxilliary alternator and a clutch coupled to an emergency 33kw DC geneator for the spud hoist winch.
The dredging winches are supplied and controlled by a sophisticated yet minimum maintenance electrical installation with current provided by Ward Leonard generators.
During trials BERGHAVN produced a digging 'bail' pull in excess of 80 tonnes and comfortably exceeded all specification requirements. It is the most powerful dredge of its type built for the owners.

Log Book Sept 1990

Norway SG965

[aukepalmhof]

Built as a dipper dredger under yard No 195 by Ankerlokken Verft Glommen A/S, Frederikstad, Norway for the Norwegian Government.
08 February 1980 launched.
Tonnage 538 grt, 355 net, dim. Length overall including boom 52.50m., length of hull 33.00m., beam 12.50m., draught 2.00m.
12 February 1980 completed.

[D. v. Nieuwenhuijzen]

CONSTRUCTOR: Ankerløkken Glommen Shipyard in
Fredrikstad. Built in 1980. Rebuilt in 1996 as a backhoe dredger by Scheepswerf De Donge in The Netherlands.
CALL SIGN: LM 7128
NAVIGATION AREA: Small craft coastal shipping
MAIN DATA:
Overall Length: 49,5 m
Width: 12,5 m
Draught: 2 m
Depth Moulded Amidships: 3
Light Ship Weight: 900 tonnes
PRODUCTION CAPACITY:
Dredging Capacity: 100-400 m³/h
Max. Dredging Depth: 14,5 m
Max. Efficient Dredging Depth: 13 m
INTERIOR:
Mess room, 10 cabins, galley, living room and utility room.
BACK EXCAVATOR MOUNTED ON DECK:
Model: Liebherr P994
Own Weight: 173 tonn
Operating Engine: Cummins KTTA38-
C 1350 (840 kW/1800 rpm)
Control system: Electrohydraulic
Length of Boom: 14 m
Length of Arm: 4/5,6 m
Shovel Capacity: 5,7 m³/7,2 m³
OTHER MACHINERY ON DECK:
1 x Auxiliary power unit: DEUTZ BF4M1013FC
1 x Generator: Stamford UCM F130KWA
SMALL MACHINERY ON DECK:
2 x hauling winches
2 x anchor winches with yardarm
2 x capstan winches
DECK CRANES:
Palfinger MB 17500
Hydralift MVC 501-2-7.5
POSITIONING AND MONITORING EQUIPMENT:
PDS 2000 system is used for positioning.
A monitor that shows the position of the machine in the
dredging field (position, water level and dredging depth)
as well as the movement of the shovel underwater.