PM300

Shotcrete were approached by the Main Contractor (BAM Nuttall and Taylor Woodrow) to assist them in overcoming the difficulties in constructing an SCL (Sprayed Concrete Lined) escalator tunnel.

We worked with manufacturer Putzmeister Iberia to produce a tracked spraying machine that could work on an inclined surface.

Most inclined tunnels are driven from the lower level in an uphill direction. The VSU project demanded that their 30 degree escalator tunnel had to be constructed downhill. This meant the machine had to be redesigned and modified to accommodate this change in construction.

The modification was completed at Shotcrete Services’ workshops and the machine was tested at their facility to check stability and functionality, prior to it being delivered to site in November 2013.

The machine successfully completed the works and was then used on a number of similar tunnels on the Crossrail project.

This project highlighted the fact that the machine should have the ability to complete tunnels in either an uphill or downhill gradient.

Shotcrete then started working with Putzmeister again to produce such a machine. The second generation machine incorporated a number of other elements that had resulted from operational feedback.

This revised machine was built and tested over a 6􀀀month period during the start of 2015; and in October 2015 the first of the revised machines was delivered to BBMV (Balfour Beatty Morgan Vinci) for the construction of the escalator tunnels for Liverpool Street London Underground Crossrail
connections.