We recently took delivery of another high-power quad fan suction excavator to join our existing specialist fleet. Having recently posted this fact on LinkedIn we received questions as to why we invest in these larger machines, were they necessary when carrying out standard excavations and what type of works we used them on.

So, let me answer these questions and share a few examples of the types of projects these machines are utilised on.

Our standard twin fan machines are suited to what I would describe as traditional excavations i.e., when working within the reach of the intake arm which is normally a 2 to 5 metre radius. They can also extend their intake arm by connecting longer nozzles (for depth) or extension pipes to give a greater horizontal reach. However, effectiveness will be dependent on the material type being excavated/extracted plus the overall depth and distance involved.

Our investment in the large high-power triple and quad fan machines is to remove performance uncertainty and ensure that we can move a greater range of soil conditions and material from greater depths, heights and distances.

Two examples of project types recently undertaken with these machines were the iconic Thames Barrier as well as a project at Bournemouth sea front.

Both projects involved the removal of material using extension hosing connected to our machines. Material would be extracted over distance, depth and height.

The Thames Barrier site required a build up of a wet, silty/muddy material containing stones and small rocks, to be extracted rapidly from around the shore side section of barrier itself.

Speed of operation was vital as there were limited working hours due to tidal constraints.

Although the distance and depth involved in this project were not great, the project sensitivity called for assurances in the machine performance. Our high-power machines met this requirement. Works were completed as necessary and within time constraints.

The second project at Bournemouth, required stabilisation works to a sandy bank overlooking the beach area and access ways. These works were to clear and expose an existing stabilisation system, allowing for replacement or repair.

The material involved was a mix of heavy soil that was compacted in some areas, sandy/silty soil plus some root material. This was built up around and between metal stabilisation structures within the bank.