Background
During the late 1940’s in South Africa, a young civil engineer by the name of Aubrey Berrangé, was watching a fleet of equipment build an embankment on a remote road building project. The soil was being placed in thin layers and compacted with multiple passes of a vibratory roller. As he watched, he was struck by the fact that, of all the processes happening on the site, the compaction of the newly placed soil was both the most critical to the success of the project and at the same time, the least efficient. He began to wonder what it would take to enable soil to be compacted in much thicker layers. Little did he know at the time that his thinking was about to lead him into a study that would last a lifetime and lead to the only real revolutionary advance in soil compaction since the invention of the steam roller…..
Between the years of 1949 and 1953, Aubrey Berrangé worked on the development of a “square wheel” roller. The principle was to provide a large compactive force on a large contact area similar to a “stamper” or a “rammer” but on a continuous basis. There were many development challenges as the forces were enormous and it wasn’t as simple as one might imagine at first. Nonetheless he persevered and through the development of a series of trial machines, he was able to produce a machine that effectively compacted soil to far greater depths than was possible using the conventional vibratory equipment. Despite the effectiveness of the “square rollers” the idea seemed to be a little “ahead of it’s time” since the real need for deep compaction was not clearly apparent to most people in the industry.
Some 20 years later, during the 1970’s, conditions for the use of “deep compaction equipment” became more favourable. Roads were having to withstand the strain of carrying larger truck loads, airports were having to cater for much larger aircraft [747’s etc] and many places around the world were looking at reclaiming land from the sea. With a renewed interest in the requirement for deep compaction becoming apparent, Aubrey Berrangé dug his old machine out of mothballs and went in search of industrial development partners. What followed was a twenty year development story that was filled with much intrigue and interesting developments. Many collaborations were undertaken including a lot of work done under the auspices of the South African Council for Scientific and Industrial Research [CSIR]. During this twenty year development period, the impact compactor became widely accepted in Southern Africa and Australia.
As the design was refined, a twin mass [split-mass] configuration was adopted. This proved to overcome some of the constraints of the single mass machines. Different shapes of masses were also developed within the twin mass range of equipment to better suit different applications.
In the early 1990’s, Landpac purchased the patent rights to many of Aubrey Berrangé’s designs and they embarked on a programme to produce improved models of some of his equipment as well as the development of new products based on his original developments. Initially, Aubrey Berrangé continued to provide some technical consulting services, but later he moved on and now lives in retirement in the United Kingdom.
Landpac has however continued at an ever increasing pace to develop Impact Compaction technology and various other allied technologies and products in an effort to truly innovate the ways in which compaction and ground improvement can be effectively achieved. One recent development was the introduction of Continuous Impact Response [CIR] measurement to enable the effective control and “certification” of the compaction performed by Landpac Impact Compactors. This system is now being used as a quality control tool and further development is taking place to enhance the capabilities of this new technology. Work is also being performed by Landpac on the development of two new Ground Improvement Products that will introduce further innovations in the field of compaction and ground improvement.
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