Combination Finnpusku

pusher rautaruukki barge botnia outside raahe, finland, raahe steel works in background.

a finnpusku pusher-barge combination consists of 1 pusher vessel , 1 barge. overall length of combination 166.6 metres (546.6 ft) , breadth , draft @ summer load line of barge, 27.2 metres (89.2 ft) , 6.7 metres (22.0 ft), respectively. however, in brackish water of baltic sea can loaded maximum draught of 6.85 metres (22.5 ft). during ballast legs pusher maintains normal draught while barge ballasted draught of 5.6 metres (18.4 ft) reduce displacement 20,930 tons 17,630 tons. in such loading condition main deck of barge @ same level pusher s gunwale. tonnage of combination of pusher , barge combined, 10,620 gt, 3,184 nt , 14,447 dwt.

the combination classified det norske veritas class notation of +1a1, pusher/barge unit, ice ia+. has highest finnish-swedish ice class, 1a super, means designed operate in difficult ice conditions without icebreaker assistance. icebreaker bow , sloping sides, combination operate independently in level ice. when finnpusku system entered service in mid-1980s, icegoing capability superior conventional bulk carriers.

finnpusku uses unique rigid coupling system, wärtsilä marine locomotive, consists of 2 hydraulic locking pins, 1 on each side of pusher, , 1 fixed pin in bow. when connected, hydraulic pins exert transverse force of 450 tons sockets, forcing jaws of barge apart 45 millimetres (1.8 in), , angled faces of coupling pins push pusher forwards, resulting in longitudinal force, of 450 tons, @ bow pin. three-point connection removes degrees of freedom , results in combination behaving hydrodynamically single ship, allowing unrestricted service , independent operation in severe ice conditions of gulf of bothnia. pusher can connected barge @ 3 different levels, removing need ballast barge same draught pusher when not carrying cargo. in addition mechanical coupling pusher connected barge several electrical cables on starboard side , flexible pipes on port side. latter allow pusher s fuel , freshwater tanks topped larger storage tanks of barge.

the combination of pusher , barge referred using names of both vessels, e.g. rautaruukki-board.