Hard Rock Trenching

Tesmec Chain Trenchers

Trenching Systems Australia's fleet includes 3 Tesmec trenchers. The Largest of their type in Western Australia, these machines are purpose built in the USA and designed for extreme soil and rock conditions. The cutting chain uses tungsten carbide tipped digging teeth to "grind" the ground as it moves along. The action of cutting excavates the soil, or spoils, from the trench at the same time, bringing it up to the top of the digging face where it is dropped on to a conveyor. The conveyer can be moved to the left or right and discharges the 'spoils' into rows at a predetermined distance from the trench. As the rows are set away from the trench edge, access by machinery and personnel is less restricted and allows for a better ;working environment.

TESMEC TRS 1300 Trencher

This machine is capable of digging a trench 1100mm wide by 2400mm deep. Powered by a 500HP Caterpillar 8 cylinder diesel engine, the TRS1300 is the largest machine in the fleet. Mobilised on large tracks and weighing around 75 tonne, this trencher is set up for the hardest of soils and the larger type projects.

TESMEC TRS 1200 Trencher
This machine is capable of digging a trench 800-950mm wide by 2400mm deep. Powered by a 480HP Caterpillar 6 cylinder diesel engine, the TRS1200 is the same physical size as the larger machine but with less Horsepower. Also mobilised on large tracks, the TRS 1200 weighs in around 68 tonne but is also set up for the hardest of soils and the larger type projects.

TESMEC TRS 1000 Trencher

This machine is capable of digging a trench 700mm wide by 2100mm deep. Powered by a 350HP Caterpillar 6 cylinder diesel engine, the TRS1000 is smaller in size and is typically used for smaller projects such as subdivisions and lateral pipework where a narrower trench is all that is required. The TRS1000 runs on lugged tracks and weighs in around 35 tonne.

» Click here to view a PHOTO GALLERY of these machines in action.


Trench Bedding Machine


Typically, pipelines used for oil, gas and water, as well as large electrical and communication cables for major infrastructure projects, can cover distances from half a kilometre to hundreds of kilometres. The route taken by these pipelines and cables inevitably transverses all types of country, conditions and soil types. In most cases, these pipes and cables must be placed below the surface to minimize exposure to the natural elements and protect the environment.

Current technology uses large machines such as Trenching Systems Australia's Tesmec chain types to dig the trench. The trench is cut up to 1100mm wide and up to 2400mm deep through all types of soil and rock. These trenching machines excavate the soil and rock from the trench whilst cutting it. In some cases, when the earth is rocky, the trench base can be left rough and uneven. It then becomes necessary to 'bed' the trench base with a layer of sand up to 150mm deep prior to laying any pipe or cable. This creates a soft, even bed for the pipe or cable to lay on and ensures longevity and stability of that product.

Existing Practices

Currently, the process of bedding a trench is carried out using either skid steer loaders (or large articulated type loaders) or excavators to bucket imported material into the bottom of the trench. All these machines require an operator to dump the imported product from the bucket. The machines are continually stopping to refill and stopping to move further along the trench. The dumping action means the material is inevitably inconsistent in nature and requires a labourer in the bottom of the trench to level the material to the required thickness. Skilled skid steer operators with a labourer to level the product can bed around 100m of trench with 100mm of sand in around 2 hours.

The Safety Issue

A trench by definition is a narrow (and sometimes deep) chasm in the earth. In certail soil types, the labourer is placed in a high risk environment that may lead to injury or death if the trench wall collapses. This may be caused by machines working overhead or, even if the machines are not currently in use, caused by the machine running close to the trench edge whilst filling. It is very difficult to see into a narrow trench so visibility also becomes an issue on construction sites where staff and vehicle movements are frequent.
The protection of the labourer is currently achieved by having safety regulations in place that require additional observers, safety platforms, trench support frames and procedures designed to offer the best practices of protection.

Added to this is the fact that the job of the labourer is to level the material using hand tools. He/she will be invariably bending over and pushing or pulling heavy material that could cause severe back strain and injury of not properly executed. Back Pain or Spinal Injury is one of the largest causes of lost time due to injury in the construction industry.

» Click here to view a PHOTO GALLERY of these machines in action.