Wilbert's largest luffing jib tower crane
By Alex Dahm14 May 2009
Further to IC's announcement of 27 April that Wilbert in Germany launched Europe's largest luffing jib climbing tower crane, special correspondent Heinz-Gert Kessel reveals more details of the new crane.
Wilbert's new WT 1905L e.tronic luffing jib tower crane is claimed to be the largest luffing jib climbing tower crane built in Europe. It is the first model in the German manufacturer's "Heavy-Lifter" product line. The new model already surpasses its closest-competing climbing luffing jib tower, the new Wolff 1250B, by about 50% at medium to maximum operating radius, says Kessel.
Internationally, the new giant manufactured in the all new Wilbert factory in Waldlaubersheim, Germany, can easily compete with the Favelle Favco M1250D at more than 25 m radius, Kessel continues. At long reach the WT 1905L e.tronic even catches up with the popular Favelle Favco M1280D. Capacity of that crane is 23.5 tonnes at 72 m radius and 30 tonnes at 60 m.
Due to its modular design, customer requests for the Heavy-Lifter line can be quickly realized concerning the length of the counter jib, winch capacity and maximum load. Performance data for the WT 1905L e.tronic makes impressive reading: to 25 m radius 80 tonnes can be handled and capacity is still 19 tonnes at the 78 m maximum radius.
A new modular hoist winch arrangement gives high hook speed and large rope storage capacity, making the crane especially suitable for ultra-tall construction projects. Maximum hoisting speed is 185 m/min and 32 tonnes can be lifted up to 900 m or 64 tonnes to 460 m. Compared with the Wolff 1250B, 60 tonnes can be lifted more than 70% higher, Kessel says, which is an advantage for mega column erection on skyscraper projects.
At the moment, however, Wilbert's main target is the busy power generation construction market. In Asia and North America large tower cranes are already intensively used for boiler house construction while in Europe, crawler cranes are mainly used. Franz Rudolf Wilbert, Wilbert Tower Cranes managing director is convinced that his Heavy-Lifter tower crane series offers numerous advantages over lattice boom mobile cranes in the 500 to 800 tonne capacity class range:
1.) Space needed on the ground by a tower crane is much less than that necessary for a mobile crane, especially one rigged with superlift.
2.) No long erection corridor is needed by a tower crane for fitting the boom system, which reduces space requirements again by up to four times against comparable mobile cranes.
3.) Another system-integrated benefit is the minimum working radius. On a 100 to 140 m tall building a mobile crane has a three or four times larger minimum radius, leading to a larger usable working radius of the Wilbert tower crane.
4.) Aside from the rope weight there is no loss of capacity in the tower crane as the hook height increases.
5.) Maximum under hook height on the tower crane is not limited to around 220 m.
6.) The WT 1905L e.tronic is allowed to work at a wind speed twice as fast as a mobile crane and no ground space is needed to lower the boom in case of storm warning.
7.) Higher hoist speeds increase safety of heavy lift loads as does the operator's better view of the load.
8.) Splitting down the crane components into 15 tonne segments enables erection and de-rigging under special construction site conditions and is a benefit for worldwide transportation.
The new Wilbert Heavy-Lifter crane line is based on more than 20 years experience of the family owned business in tower crane rental and an always-open ear for customer suggestions and requirements. For quality control, steel work and fitting of the crane components is done at Wilbert's own new factory. Mechanical and electric components are supplied by well known suppliers, including Flender for gearboxes, Rothe Erde for slewing rings and Siemens for control technology.
Emphasis is laid on safety and reliability of the crane concept. The luffing winch, for example, has as standard four secondary brakes. Access platforms and integrated ladders offer safer working conditions for erection and maintenance. An auxiliary winch in the tower head speeds up hoisting, rope reeving and jib stay installation. During transport the jib connection pins remain in sleeves in front of their inserting position. The luffing rope is transported in reeved position.
An air-conditioned 20 foot container hanging under the counter jib protects the electrical control system from harsh environments. For the first time two load moment measuring systems provide redundant protection against exceeding the permissible load moment.
Due to the risk of over-booming and to increase the maximum free standing height, Wilbert developed a unique moving counterweight system it calls "pendular counterballast". Ballast plates hung up on their tip are connected by rope with the boom foot section, which leads to a semi-circular movement that corresponds with the boom's position. If the boom is raised, the ballast follows forward, while when lowering the boom it swings backwards.
All drives are frequency controlled and, for light loads up to 8 tonnes at 83 m radius, Wilbert offers a runner winch instead of needing the time-consuming process of changing the number of rope falls.
The prototype of Wilbert's Heavy-Lifter series will be installed at the Westfalen/Hamm power station construction site in Germany. Freestanding height will be 90 m on a 3.25 m wide tower system and 60 m boom.
Five more Heavy-Lifters are due to be delivered outside Germany for another power station site. Under hook height will be 190 m and another 10 Wilbert tower cranes of different size will also be delivered for the same project.
When the WT 1905L e.tronic was presented to Wilbert dealers on 4 April, another unit was ordered for a dockyard. According to Franz Rudolf Wilbert his Heavy-Lifter crane family opens up new markets outside the classic tall building construction industry.