Crane vessel

A floating crane or crane vessel is a mobile, on waters floating crane and therefore belongs to the class of work boats.

It is generally used for lifting and implementation of particularly serious or extensive objects in, on or next to water. A common application is the salvage of sunken ships and other submerged objects in the water and the transport of structures for the port or offshore installations. Also the envelope or the installation of heavy goods or heavy-duty work in sea and inland ports are part of the application. The load being lifted is stored for longer journeys on their own or other floating pontoon and brought to the desired location.

Construction and Technology

The hull of the ships, which was previously mainly as monohull designed (English Monohull ) is designed in modern cranes usually as a multi-hull boat (catamaran ), with a floating body, similar to a pontoon, or semi-submersible to the ship quiet and stable in the water hold. Instead of anchorages or counterweights are working with changes in the ballast tanks.

If floating cranes have a private drive, this is for modern cranes for better maneuverability often a Voith-Schneider drive, Schottel rudder propeller or driven by propeller gondolas. These variable and flexible drives are often combined with systems for dynamic positioning ( DPS ), which hold the ships computer- controlled in position.

In the absence of self-propelled they are moved by tugs. Not self-propelled cranes are also referred to as jacks.

Among the different types there are pure jib cranes where the boom can only move up and down, and floating cranes, the boom is pivoted. A special design is the dual -link Wippdrehkran ( since about 1925), here the boom can be moved forwards and backwards, that the load always remains at the same height. Floating cranes without moving the boom, see sample picture of Anak are called Bock cranes, here the entire pontoon must be moved in order to enable the load forward or sideways. In the design of the static analysis is particularly challenging, as changed by the load center of gravity of the floating crane and thus the stability is at risk.

History

Floating cranes arrived in the 14th century in the medieval port operations, where they constituted a flexible addition to the stationary cranes on the quay. Modern Floating cranes have been built around 1880. The first German U- boat - lift ship was 1909, the SMS volcano, at the same time an early dock ship as a multihull.

The now powerful floating crane Thialf can lift loads up to 14,200 tons. The second largest floating crane, the Saipem 7000, allows the stroke a load torque of up to 560,000 metric tones (mt).

Large heavy-lift to be built since the 1980s, with their own cranes on board rich with up to 2000 t ( Sietas Type 183 since 2011 ) or 3000 t ( TBN from 2013 ) in tandem now to the lifting power of large floating cranes zoom. Some freighters ( usually with slightly reduced performance up to 2 × 1000 t) also work with dynamic positioning in which the offshore lifting power is less than in sheltered pools.

Overview of the largest floating cranes in the world

Image examples

Floating crane Anak in Bremerhaven

Taklift 7 during the construction of Rügen bridge in Stralsund

Thialf, the most powerful floating crane in the world

Asian Hercules II Cuxhaven

Floating crane on the Rhine before Achilles Cologne -Deutz

Floating crane HHLA III in Hamburg harbor

Floating crane Micoperi 30 off the island of Giglio