Crane Technology
Equilibrium Cranes let Gravity do the Work
29.10.2009 | Author / Deskman: B. Tolhuizen / Marcel Dröttboom
Reducing equipment energy consumption decreases the CO2 footprint of an operation – and its costs. Equilibrium cranes can not only help to achieve this goal. Due to their special design, that works without steel cables and winches, they are also easy to operate and maintain.
Unless science will some day master the art of nuclear fusion – which seems quite unlikely at the moment – energy consumption will always be a major issue. Not only the resources currently used are limited, also the negative effect on the environment of burning fossil fuels is tremendous. Any system that promises a reduction of 50% in power consumption would, therefore, be appreciated by the respective market.
Nuclear fusion, of course, is an extremely complex matter, sometimes efficient solutions for problems such as energy consumption can be much easier than that. A good example for this is the ‘equilibrium’ or ‘balance’ crane developed by E-Crane.
Basic Mode of Operation
The design of this equilibrium crane is based on a parallelogram style boom that provides a direct mechanical connection between the counterweight and the load. This counterweight pivots on its axis actuated by a hydraulic cylinder. The movement of the counterweight is transferred to the stick by rigid connection road. When the stick moves out, the counterweight moves back. As a result, the crane is almost always in balance throughout its working cycle.
Compared to conventional cranes that may require up to 80% of their available energy just to move the boom, stick, and grab, the E-Crane makes gravity work for the job instead, reducing horsepower requirements and power consumption by up to 50% and significantly reducing maintenance and operating costs.
Another eye-catching characteristic of this crane is the absence of steel cables. Consequently, this type of crane is not plagued by problems commonly associated with cable based system, such as cable wear, bucket sway and low bucket fill.
The hydraulics are controlled by an electronic management system and CAN BUS electronics. This allows the operator to programme certain operation parameters like height and reach to avoid collision with obstacles or other equipment, e.g. a hopper.
Versatility and Flexibility
A capacity of 50 tonnes per duty cycle, up to 45 metres horizontal reach and up to 20 metres reach below grade, and modular design that allows tailoring to specific needs and requirements of the user allow for a wide range of applications and commodities.
For example, 10 years ago E-Crane delivered the first barge and ship mounted cranes to offload barges and small ships. This concept has also been adapted for the offloading of ships up to Panamax class and today there are more than 15 units successfully operating world-wide.
A floating terminal also proved to be the best solution for Seaboard’s Midema grain handling terminal in Matadi, Democratic Republic of Congo, Africa. Matadi is the farthest inland harbor on the Congo River, and as many African ports it was facing some problems such as lack of reliable dockside equipment and port congestion. Therefore, the client opted for its own floating transloading station. The floating terminal named “Mama Mobokoli” is equipped with a 1500 Series E-Crane model 9359 and is specially designed to unload up to Handymax vessels ship-to-quay or to transload them ship-to-ship. The Mama Mobokoli is a self sustaining platform complete with electric genset. However, the system can also easily be attached to shore power through built in switch gear. The balanced crane results in very low tipping moments which means less barge movement and a more stable work platform.
The barge is also equipped with a winching system that allows the platform to shuttle alongside the ship for full access to each of the ship’s holds. Installation of the system on site at the port was quick and easy as the entire platform was erected and tested at the port of Zeebrugge, Belgium. From there, a dedicated tow transported the platform to its final destination in the DRC where unloading could begin immediately; a big advantage for Seaboard since the logistics of marine construction locally would have been very difficult and costly.
Dredging Applications
The equilibrium principle is also highly suitable for dredging and related operations. Clients can be found in several water related sectors, specialized in piling, ship salvaging, heavy demolition with dynamiting, classic dyke works, construction of breakwaters, quay construction and beach and embankment preservation jobs.
Recently, an E-Dredger was installed onto a self-propelled spud barge for Herbosch-Kiere (part of the group Eiffage) in Kallo, Belgium. The 1500B Series, model 10290 E-Dredger has a horizontal reach of 29 meters, a lift capacity of 15 tons and a dredging depth of more than 18 meters, and will be mainly used for port and river maintenance dredging jobs.
E-Crane Worldwide
This article is protected by copyright. You want to use it for your own purpose? Infos can be found under www.mycontentfactory.de (ID: 324855)