Case Study

Rail: Geotechnical Investigations (UK)

SLR was retained to complete detailed intrusive geotechnical and geo-technical site investigations on the sites of three proposed rail depots in south east England.

All three sites are on Network Rail land and exploratory hole locations lay within the active rail network. SLR was able to mobilise PTS qualified staff to supervise the works and carry out all works in accordance with Network Rail requirements.

The contact included a very short mobilisation period between contract award and the start date on site required by the client. However, SLR was able to complete all necessary pre-mobilisation planning and liaison in order to be on site by the required date.


Hornsey, Tonbridge and Crawley, South East England


Department for Transport



Project Objectives:

The Department for Transport required a dual purpose intrusive investigation assessment of ground conditions at the three potential depot sites, in order to:

  • support applications for Planning Consent and anticipated environmental planning conditions
  • to enable the selected bidders for the rolling stock contract to prepare their bids for the construction of these facilities.

Our Role

SLR undertook the following works

  • detailed liaison with Network Rail regarding project planning and site access
  • completion of 50 deep rotary auger boreholes and 118 shallow window sample boreholes
  • completion of four rounds of post investigation gas and groundwater monitoring
  • laboratory analysis of soil and groundwater samples
  • preparation of factual and interpretive combined geotechnical and geo-environmental reports including recommendations for foundation design and assessment of risks to Controlled Waters and human health.