Managing Director Wang Guohui and Deputy Director Bai Xiaohong chose the “blue” machine again due to satisfaction with the support and service provided by Australian-based TTG sister company TT Asia Pacific, McAllen (Tianjin) International and from the operating characteristics of the Grundoburst unit and the Quicklock rod system.

Although Beijing Chuanganya operators were well experienced in operating the Grundoburst 800G unit, staff from TT Asia Pacific and McAllen (Tianjin) were on site in Beijing for the commissioning of the unit and to carry out further training.

There were two projects scheduled to carry out the commissioning and training. Project one covered the Shun to Liu to Tiao Streets in the south of Beijing. The task was to burst and replace an old 400 mm concrete sewer with a new 450 mm PE pipe. The section that was to be replaced ran from manhole two to manhole eight, creating a total length of 209 m, and the machine pit was placed near the centre of manhole six at an approximate depth of four metres.

The first stage of project one involved pushing through Quicklock rods to a length of 95 m from manhole 8 to the machine pit. The process took less than an hour with the machine running at high speed. Once the expander/PE puller was attached, bursting commenced.

An initial obstruction was encountered and overcome 10 m into the process. It caused no disruption to the machine as it continued to operate at an average pulling force of 50 tonnes over an hour of bursting.

The second stage involved replacing a 114 m pipe running from manhole two to the machine pit. After turning the 1250G eastwards towards manhole two, Quicklock rods were pushed through the old concrete pipe. Again the process clocked in at just over an hour with the machine running at high speed. Bursting commenced once the expander/puller was attached.

The machine again registered comparatively low pulling pressures with soil changes and obstructions at the 51 m mark showing a pressure of 76 tonnes and this figure quickly dropped to 50 tonnes. Stage two took 70 minutes to install 114 m of pipe at an average speed of approximately 100 m/h.

Project two covered the Jinsong area in Beijing. An old 500 mm concrete sewer pipe was to be burst and replaced by a new 560 mm O.D. PE pipe that would run for 194.4 m at an average depth of 4.3 m.

However, due to logistical problems associated with access, project two had to be postponed to a later date.

Currently, planning is in order to locate the Grundoburst 1250G in the machine pit at the street intersection and manhole twelve, to then pull from east manhole fifteen, and then to turn the 1250G by 90 degrees before pulling from south manhole nine.

The 1250G’s capability of providing immense power is reassuring when unknown obstacles are encountered and cleared with ease. Furthermore, the ability for the operator to monitor and record pressure readings from either the control panel or the remote control unit during the process is a useful feature.

Yet another excellent feature of the Grundoburst machine is its ability to perform sewerage lining operations. The machine can be either be upgraded with a factory kit or supplied ready for operation with the variable speed and tonnage controls available.

The Chuanganya Trenchless crew was able to quickly adapt to the Grundoburst 1250G and their solid experience with the Grundoburst 800G machine and Quicklock rod system was evident as they smoothly operated the machine.

In light of the satisfactory results of the projects, TT Asia Pacific and McAllen (Tianjin) look forward to further cooperation with Chuanganya Trenchless in the future with the possibility of introducing a Grundoburst 2500G (250 tonne) unit in China.

More challenging projects are in the works for the Grundoburst 1250G unit by Beijing Chuanganya Trenchless, marking the company as a true pioneer in pipe bursting in China.