Commissioned by Eisele AG Crane and Engineering Group, Holmatro supplied an extremely low and lightweight Skidding System that is easy to handle and install, without the use of a forklift or additional tools.
Commissioned by: Eisele AG Crane & Engineering Group
Location: Frankfurt am Main, Germany
Eisele AG Crane & Engineering Group, founded in 1988 as a towing and crane service, is now a professional service provider in the field of mobile crane work, heavy transport, company relocations and industrial assemblies.
For one of their customers they have to install several emergency power transformers (aggregates) in a steel construction.
Dimensions of 15 meters long, 3.5 m wide, 5.5 m high, a weight of 61 tons and an asymmetrical center of gravity (39 t at the front, 22 t at the rear) makes it impossible to install the transformers using cranes. The transformers have to be slide into a drawer system in the side of a steel construction. The individual storey heights sometimes leave only 10 cm free for placing (sliding in) the transformers.
Another challenge is the load-bearing capacity of the steel structure. When installing the transformers, the 2.5 m long intermediate beams are temporarily loaded with forces of up to 20 tons. These intermediate beams are not designed for this.
Holmatro's Skidding systems are suitable for moving industrial objects and installations with exceptional sizes and weights to locations, where using a crane is not an option. Due to the user-friendly modular composition of the both systems, they are easy to adapt to each load size and project.
The extremely lightweight Skidding System is fast and easy to set up and designed to be easily carried, handled and positioned by one or two people without the need for a forklift or the use of extra tools. The system has a capacity of 200 tons, based on 2 skid tracks. The total construction height is just 56 mm (2.20 inches).
The essence of a Skidding System is that a relatively little force is required to move a heavy load horizontally. The tracks are easy to connect to each other by a click system. With a handle on the push-pull unit, the push or pull direction of the lightweight Skidding System can be switched in a split second. The return line of the push-pull cylinders (each with a capacity of 10 tons) is internal, which significantly reduces the chances of this being damaged.
Procedure for installing transformers:
To protect the intermediate beams, the transformers are placed on a frame (2.7 x 3.7 m). This frame is then placed on the skid tracks. This to avoid a point load and to bridge the overloaded support beams.
In a tandem lift, the transformer with frame is lifted to the entrance opening in the steel construction. Crane 1 places the front part with approx. 2 m overhang on the Holmatro skidding system in the construction. Crane 2 keeps the transformer in balance and moves it synchronously with the input speed of the Skidding System.
In similar projects, these activities are carried out with heavily armored transport rollers. However, the disadvantage of this method is the high point loads on the rollers and the external forces that occur when they are retracted with winches.
Due to the load-bearing capacity of the steel structure, such loads on the intermediate beams must be avoided in this project. The intermediate beams are not designed for these high point loads and there is also a risk that the steel structure will swing if the transformer is pulled in with winches.
The Holmatro lightweight Skidding system offers the possibility to distribute the occurring point loads over a larger area. These could even be bridged by using an intermediate frame. Another advantage is the "independent power distribution". Outside the skid tracks, there are no forces acting on the steel structure as the push-pull units are anchored on their own rails.