When it bought an LR 11000, Sarens came to Liebherr with the idea of investigating whether SPMTs could be used as ballast trailers. The benefit for the global heavy haulage contractor is obvious – it has Kamag K24 SPMTs at almost all of its outlets.

Liebherr had already tried similar solutions with other crane models, however, the SPMTs were not controlled directly from the crane and additional personnel had to track the crane’s movements with the SPMTs.

Sarens supplied two Kamag K24 SPMTs for the development and testing work to find a solution which allowed the SPMTs to be controlled by the crane’s control system, just like a standard ballast trailer.

Kamag developed a control box which provided communication between the crane and SPMT and which enabled the crawler crane to control the movements of the heavy haulage vehicles.

Jens Könneker from Liebherr Lattice Boom Cranes Product Management demonstrated a fully functional solution at an internal presentation – circling, moving in parallel and towing. “Everybody involved here is delighted with the good collaboration with Kamag and Sarens and the result is sensational,” said Könneker.

“We are very satisfied with the results and the collaboration with Liebherr and Kamag. All our requirements have been met and we are confident that this will deliver significant added value for future projects as a result of the operative benefits and flexibility,” said Carl Sarens, technical director.

Trials were conducted with a standard ballast trailer without wheelsets and a specially designed test adapter. Sarens’ LR 11000 is supplied to the customer as planned with a suspended ballast pallet. This is then placed on the SPMTs for jobs which require a ballast trailer, using a special adapter. If the ballast trailer is not required, the crane operates using suspended ballast.