Our Teams Pioneer A First In Underground Construction

EA Hire in-conjunction with sister company, SU Underground has been awarded the contract to perform the box jacking works on Airport Link. These works carried out for Thiess John Holland as part of its Airport Link project will be the largest box jacking works ever undertaken in the Southern Hemisphere.

This operation is one of the most complex engineering aspects of the projects construction and is the largest of its type in Australia. Two crews of highly skilled operators will perform the works in around the clock shifts.

A total of 8 "jack in the boxes" each containing a 5 tonne excavator has been lowered into the tunnel at the Turnbull section of the link and placed in a configuration 2 rows of 3 boxes across and finishing with 2 boxes at the top. Each excavator operates within the framework of the box working in sequence to remove the ground in front and then continue on pushing forward until the tunnel is completed.

As they are jacked into position the soil is removed using a secondary fleet of excavators and skid steers.

Each of the concrete boxes measures 12.5 metres high, 65 metres long and have a span of approximately 38 metres. By the end of the project, our operators will have pushed the boxes 55 metres to position them beneath the railway embankment.

It is estimated that the 8 "jack in the boxes"will take our team 3 months to remove the few hundred metres of soil, dirt and rock in this section of the link.