Like many German crane service providers, Colonia is faced with the challenge of obtaining transport permits for its mobile cranes – some weighing significantly more than 60t – due to many roads and bridges in North Rhine-Westphalia not permitting heavy vehicles, often resulting in detours during transport to construction sites (time delays and costs).
To tackle this issue, Colonia has worked with Manitowoc to create a new transport system, the first tests of which have already been completed.
The new crane configuration is based on the six-axle Grove GMK6300L-1. With its 80m main boom and at a radius of 28m, the crane offers a lifting capacity of 14t.
In addition to an overall reduction in operating weight, Colonia’s requirements included a hydraulic boom removal system on the mobile crane for rapid assembly and disassembly of the main boom and lift cylinder. It also required the construction of a transport system that didn’t require an assist crane for assembly and disassembly.
In response, Manitowoc produced a crane that matched Colonia’s requirements. The base unit can be equipped with an easily removeable rear outrigger box, while hydraulic rigging cylinders on the chassis can be operated from the carrier, and hydraulic and electrical quick couplings enable rapid installation and removal of the outrigger box in less than 10 minutes.
The assembly and transport unit for the main boom and lift cylinder was redesigned to eliminate lift cylinder overhang while transporting the crane on the road. Using this design configuration, the boom and lift cylinder are moved directly from the crane to a separate transport trailer on a set of sliding rails. The boom and cylinder are removed and reinstalled precisely without the need of a separate assist crane.
The first tests with the modified crane have already been carried out. The main boom and lift cylinder move out of the upper structure of the crane with the semi-trailer's sliding frame, avoiding overhang during road transport. The total weight of the semi-trailer loaded with the main boom and lift cylinder is less than 59t. By removing the boom and lift cylinder, the crane’s gross vehicle weight is reduced to under 40t, with axle weights below 7t per axle. This is also beneficial in other countries with road restrictions, such as Norway, Canada and the USA.
Says Colonia chief executive officer Frank Schönges: “Together with Manitowoc, we have configured a crane that fulfills all our requirements for an especially high-performance mobile crane that is simultaneously easily handled, and well suited to roads and everyday situations.
“We have now obtained transport permits for a six-axle mobile crane in North Rhine-Westphalia and are happy with the results.”