Little Mermaid

The Suttle family name has been part of the stone industry in Dorset in the south west of England for some 70 years. Today the quarry owners and stone merchants company runs a large fleet of modern tipper and crane offload vehicles, and is the premier provider of crushed stone, aggregates, recycled crushed concrete and natural stone products in the Poole, Bournemouth and neighbouring areas of Dorset.

The company undertakes a range of civil engineering and piling projects – including sheet, driven and CFA piling – together with some more general construction work around rivers and railways.

As part of its site objectives, the company needed a means of moving material in hazardous, confined spaces such as tunnelled waterways using an unmanned, remotely controlled excavator. The answer was a fully submersible unit christened the “Little Mermaid”.

The machine – a modified Kubota mini excavator – was developed jointly by J Suttles and the local centre of hydraulic hose specialist Pirtek.

Working alongside the Suttle’s workshop vehicle technician Jimmy James and under the direction of managing rirector Joe Paine, Pirtek designed the conversion hydraulic circuits for the traction, steering, shovel and blade operations. He also reconfigured the electrical ignition circuit as the cab along with cab control systems were removed.

The engine was removed and then skid-mounted for easy transportation. The engine/hydraulic power pack was connected to the digger unit via 20 metres of supply and return umbilical hoses. Manifold blocks were commissioned from local engineering companies and Hydac Technology Ltd attended on site to provide the pivotal wireless operated control valve system.

But the ambitious project was not without its challenges.

The major problem was setting up the wireless controller to the correct command functions. This took approximately two weeks of methodical diagnostics and modifications. There was also a solution required to achieve a balance between engine power and hydraulic power circuit requirements. Circuit relief valves had to be fine tuned to prevent engine stalling.

Initial commissioning of the system was carried out at the Pirtek Poole Centre. Once the control circuits were operating correctly, the vehicle was taken back to the local Suttle’s quarry for power handling tests.

The month of May saw the “Little Mermaid” carry out her first paying. After initial operations, there are plans to develop a hose deployment and recovery reel synchronised with the traction command functions on the wireless panel. In the interim, floatation buoys are going to be fitted along the hose run to make recovery easier. The next assisted project is already in the planning stage, once again converting a piece of plant for remote operation.