We have always known that the various trenchless methods of construction resulted in reduced excavation and other added advantages but nobody ever developed this thought further. For years we sold trenchless as a preferred method to reduce things like traffic concession, pavement patching and cutting dangerous open excavations. However, we never concerned ourselves with the concept that while installing utilities, from a domestic water connection to a traffic tunnel, the main difference between trenchless and open cut is the large differential in energy used to remove and replace the material above the utility.

In the case of trenchless techniques the only area we work in is the area immediately surrounding the utility. Thus, at most we excavate an area 150 per cent of the surface area of the utility.

However, in open cut we have to start from the ground surface and remove all the material above the utility zone, waste it and replace it, rebuild that material to solid ground over the pipe and reinstate the ground surface.

Open cut techniques use a lot of energy. When you start to look at most utilities, the proportional cross section of the utility to the cross section of the required trench can be smaller by orders of magnitude of 60 times.

The difference in material, to be removed between trenchless and open cut, to allow the installation of the pipe, is 53 times or 5,300 per cent.

As the trenchless systems develop and mature, we will become more efficient and get closer to achieving these enormous savings.

So, even if you do not buy into the reduced carbon concept, and think it is a government conspiracy, I think we all agree that we need to reduce our energy use. If we can use a number of methods of construction that can achieve these kinds of energy reductions and yet maintain our standard of living then we need to change.

A 200 mm pipe installed in a 2.5 m deep trench

Trenchless option

If we use a HDD to install the pipe we require a hole, 300 mm in diameter, or a surface area of 0.07 metres square, 7 cubic metres of material removed per 100 metres of pipe installed.

Open cut option

To excavate to that depth we would require a trench 1.5 metres wide to allow a trench shield to be installed and with a depth of 2.5 metres the resulting trench area would be 3.75 metres square, 375 cubic metres per 100 metres of trench installed.

The environment, economic downtown and No-Dig

The impending change of government in the US has been welcomed, it seems, by most of the world. It now looks much more likely that a carbon trading system will be in place for the western world very soon.

As the US did not sign on to the Kyoto Protocol, the agreement lacked credibility. However, the new US government direction will change that and it will become universally accepted very soon. It should be noted that 39 US states, as well as all of the Canadian provinces and six Mexican states are already in some form of carbon trading agreement. There is already a lot of support within the US to reduce carbon output.

Though most other western governments did sign on to Kyoto, many did not follow through when it came to reducing their carbon outputs. In fact, most countries have increased their carbon output since the signing of Kyoto. I believe they were afraid to put their own economies at risk for the sake of an idea and so they paid lip service to the concept of carbon reduction but continued to expand their economies using the old methods of energy production.

If all western governments agreed to lower the use of energy output then a Kyoto type agreement can and will work. Carbon output may be reducing at the moment, however I believe this is because of the economic downturn. When the economy turns around, if we do not change how we use energy, the pollution of the world’s atmosphere will continue.

A recession should be a time to reinvent ourselves and thus we should utilise this opportunity and move away from our dependence on fossil fuels. We are starting to see more of the hydro electric, wind and solar power plants, but we also see a lot of coal and natural gas power plants being built.

Trenchless Technology allows us to install utilities in a much more efficient manner.