A rare breed of Lion28 February 2012
Former Wolffkran sales manager Claus Hartmann has developed a range of specialist tower cranes. Heinz-Gert Kessel reports.
Claus Hartmann decided to set up his own business under the trade name “Lion Cranes” in 1999 based on the reputation he earned as sales manager for Wolff maritime slewing cranes’ South Eastern market.
Driven by experience acquired through twenty five years in the industry, his simple philosophy suits a changing market.
Hartmann explains: “We are providing lifting solutions, no matter what kind of crane is under request and how comprehensive, as our customer wants our assistance—starting with different stages of engineering support, going over the supply of crane kits, ending with the quality control of fabrication through a plant selected by the customer and after-sales service.”
Hartmann highlights Lion Cranes' ability to arrange qualified local fabrication with contracted partners.
In his opinion it no longer makes sense to fabricate cranes in Europe only to ship them to a client based in Singapore, for example, due to the high cost of transportation adding significantly to the fabrication costs of the crane.
A second factor of growing importance can be found in the market restrictions of each country. For example in developing countries choosing a crane supplier is often a political decision, with preference given to those able to fabricate cranes locally in order to support that regional economy.
The lifetime of cranes is often reduced by law to reduce the number of horrible accidents caused by old equipment, sometimes imported from abroad.
However, as Hartmann explains, his clients will receive basic support in choosing the right lifting logistics and crane design. A client may have a fabrication shop on hand where they could produce the basic crane components, but may prefer to use core components like winches, electric steering and slewing rings from well-known overseas suppliers. In this case Hartmann and his team would aim to support construction of a bespoke crane through their knowledge of the market and collective crane design experience.
Using up-to-date software and a broad knowledge of the field, structural and mechanical engineering, system engineering and design engineering is provided by Lion Cranes in accordance with international standards and jobspecific client requirements.
For example, Hartmann has reviewed Lion Cranes’ designs for the machinery deck of its single-jib slewing cranes and adapted them to deal with the high humidity experienced when working at Asian wharfs. Hartman says: “We know very well the tropical conditions under which cranes are working in South Asian shipyards, therefore we respond with our own ideas based on our long-standing experience.”
In this scenario, installing the winch units in an enclosed machinery house would simply contain the heat of the working crane and add it to an already immense amount of internal wet heat generated by the humid climate. This would mean corrosion becomes a real threat, and an energy intensive cooling system would be needed, so Hartmann opted for an open machinery deck design. Besides the crane driver’s cabin just the electric cabinet must be weatherproofed.
Investigating the most economic crane design, Hartman is convinced that a single-jib wharf crane should be based on the main crane components of large luffing jib construction cranes. Today luffing jib tower cranes with more than 2000t capacity are being designed, so there are basic crane components which can also be used for fitting out shipyard cranes, such as the slewing ring support, machinery deck and rail bogies. These can be easily connected to a lightweight, long boom, column shaped tower with a portal fitting suitable for the requirements on each site. However that modular crane concept only works if the basic design features correspond to the regulations for shipyard cranes as well as for construction cranes.
Basic layout features, like the lightweight compact and easy-to-rig crane components, also reduce the installation costs for users of Lion shipyard cranes.
The universal Lion luffers can be classified as non-permanent equipment when working as wharf cranes. A leasing company can finance the shipyard crane in this case in the same way a construction tower crane.
By using the same crane components delivery time can also be reduced and engineering work saved.
The construction crane version of Lion luffing jib cranes can be fitted either with standard drum capacity and moderate speeds, a configuration mainly used for shipyard cranes, or with the high drum capacity and high speed motors often specially requested for ultra-high construction projects.
Following in the footsteps of the Wolff HDK series of single boom shipyard cranes, Lion Cranes optimises the crane design to produce an overall lightweight structure. Hartmann claims that the recently delivered Lion 1900LL crane, with a maximum capacity of 50t at 38m radius and 18t at 90m radius, is 30t lighter than a comparable competing single boom crane.
Due to the new lightweight design, bigger cranes can be installed on existing narrow tracks. In the case of the two Lion 1900LLs it copes with just a 6m-long and 7.6m-wide track. Equipped with a four fall rope, the level luffing function is dependent on the intelligent Lion electronic drive system. An alternative conventional triple-reeving system would lead to a storage of hoisting rope when luffing the boom, and closely approximate the true level luffing of the old gooseneck crane. However the rope stored between the A-frame and boom, as well as additional sheaves at the boom head, would add to the deadweight of the crane and is, according to Hartmann, no longer an upto-date crane design.
While the balanced boom concept achieves a comparable high luffing speed with low energy use, the moving ballast corresponds with the boom movement produces higher maintenance costs.
Due to his long experience in the shipyard crane business, Hartmann prefers practical features such as the ability to move a crane at the rail-going base with a safe cable remote control unit. This means the crane driver doesn’t have to climb the tower in order to drive the crane just for a relocation on the rail track. For pricing reasons the first Lion 1900LL is equipped with concrete ballast, however there is the option to choose steel ballast.
For climatic and safety reasons, the electric cabinet and driver cabin are separated, although both units are on the same side of the mounted platform. With the rising size of the vessels, requested capacity and outreach of the wharf cranes is also increasing. At Lion Cranes design studies are underway for luffing jib cranes with more than 100m outreach and a maximum lifting capacity of over 100t.
On the tower crane front Hartmann is following another idea to provide his customers with a very flexible crane system. For narrow site conditions, contractors normally use luffing jib climbing cranes are used for high rise construction. However this causes safety problems on sites with high wind speeds due to the steep position of the boom.
To address this, Hartman has updated the design principle, originally developed in the 1970s by Potain, tower cranes with retractable jibs. Instead of using a standard hammerhead crane as a base upper crane he opts for a flat-top version, called the Lion Vario. The crane can pass obstacles like nearby buildings and can easily fit into construction sites where the jib is not allowed to oversail neighbouring properties. Due to the flat-top design principle, a number of cranes can be installed at limited heights that still oversail the Lion Vario crane.
In the same manner a flexible saddle jib crane can be used at shipyards for outfit crane work, working under large heavy lift gantry cranes.
The first unit in this series on the drawing board is the Lion210/12-vario, designed on a 20m portal as a wharf crane. The saddle jib can be retracted from 70m to 40m by an integrated telescoping system.
The maximum capacity is 12t at a 25m radius, while at 40m 7,9t can be lifted. At its full radius the flat-top crane can lift 3t.
Following the business principle of providing lifting solutions, as Hartmann points out, Lion Cranes’ engineering staff is also working on special bridge cranes for the steel industry and waterway authorities.