Mitchell Water Business Development Manager Ross Bennett said the company’s proprietary Swiftpipe technology represents a massive leap forward in comparison to other pipe ploughing methods.
“The most compelling case for Swiftpipe is that it can currently plough up to 200mm diameter pipe to depth and grade requirement in just one rapid pass, and do so with minimal ground disturbance.”
Mr Bennett said that the speed of installation is only limited by the speed of the welding and preparation of the pipe for ploughing.
“There is no drag on the machine or shear force on the pipe itself, as the innovative “˜bullet’ head on the Swiftpipe ripper boot creates an ideal, friction-free tunnel on which the pipe travels, allowing us to install very long lengths of pipe,” he said.
A low-tolerance shear bolt that fixes the pipe to the ploughing head further ensures the pipe will not experience shear or other stress damage.
According to Mr Bennett, Swiftpipe maintains accuracy regardless of the length of the pipe installation or ground conditions.
“The plough attachment is connected to the dozer by stabilising hydraulics and everything is automated by GPS machine control technology, which means we can plough to grade,” he said. “Along with that, “˜as built’ records are automatically produced, recording the final level and location of the pipe.”
“The Swiftpipe will plough polyethylene (PE) pipe with complete accuracy up to depths of around 1.4 m, and because of the accuracy of the GPS guidance, grades as flat as 1 in 750 can be achieved allowing a reduction in the number of gas relief valves and low point drains required on a pipeline,” Mr Bennett explained.
Key to the success of the technology is the “˜tunnel’ created by the innovative Swiftpipe bullet head, which protects the pipe during laying.
“Creating a premium bed allows us to plough large diameter pipe over significant distances but it also reduces the impact or squeeze forces on the pipe, which can occur with other ploughing methods, when the plough strip is compacted,” Mr Bennett said.
Moving at a fast walking pace, Swiftpipe is able to quickly traverse agricultural land, grassland reserves or other sensitive areas without the need for typical a right-of-way and usual clear and grade requirements. Topsoil compaction is reduced as the Swiftpipe method requires just one pass for the 35 mm wide ripper blade to lay the pipe to depth and grade and one pass each side of the rip line to complete a section. Alternative pipe ploughing methods often require multiple ripping passes just to prepare the route.
“As the pipe route is back rolled – typically by a backhoe or loader tyre pass – fine soils will fall into the rip line and encase the pipe, creating a firm bedding,” Mr Bennett said. “This ensures there will be little chance of surface subsistence or erosion occurring.”
Minimal disturbance to the environment
While the ploughing technology is creating significant interest in the fast emerging coal seam gas (CSG) sector, Swiftpipe’s environmental credentials have likewise received acclaim.
“We have used this technology extensively through some highly sensitive areas with terrific results – there is minimal ground disturbance, and the soil profile is not mixed, bringing clays to the surface and the original organic matter layer is preserved,” Mr Bennett said.
“In grasslands it can be difficult to actually see where we have passed, save for the pipeline marker signs and minimal disturbances at joint holes.
“Swiftpipe has now been used on more than 2,000 km of PE pipe installation in a wide range of soil types and we have also received very favourable results in trials of PE pipe larger than 200 mm in diameter,” Mr Bennett noted.
“It can also install marker tape, trace wire and sand surround if required, and is even equipped with a plan to tackle rocky areas. Twin barrel installations are simply put in with two passes,” he said.
“Trials are currently underway ploughing in 315 mm PE pipe which we believe is achievable, but which is probably more expensive than our conventional trenching options.”
Mr Bennett said “All the same, if the proposed route is through sensitive areas, it may still be worth using the Swiftpipe in these instances.”
“At any demonstration of the Mitchell Swiftpipe technology, we have received very positive feedback from asset owners, environmental bodies and clients – the scope of this technology is astounding,” Mr Bennett said.