Gallagher Ltd was approached by J&J Franks Ltd to work on the Mercers South Quarry on the Old Reigate Road in Betchworth, Surrey. Gallagher would not have been able to complete the project without the excellent Leica Geosystems kit and solutions. Leica Captivate software was used to reduce unnecessary costs and delays and was fundamental in setting out.

Gallagher was awarded the contract for the construction of a new site entrance to the quarry and works were undertaken over a two month period. Ken Maillinson, Technical Contracts Manager at Gallagher said, ‘We always choose Leica Geosystems solutions for our surveying jobs as we can rely on the high quality of the instrument, the accuracy of the measurements. Furthermore, the support and excellent aftercare received from their Technical Support and Technical Service teams are second to none’.

Gallagher is Kent’s premier building, civil engineering, quarrying, and property business. A long-term customer of Leica Geosystems, when the new Captivate range was launched in 2015, Gallagher wanted to invest in the technology. Gallagher is currently equipped with 17 Captivate one person kits and a GNSS unit.

Challenges

Mercers South Quarry had challenges. Ensuring the existing statutory services were deep enough not to be damaged was critical. The Leica Geosystems Captivate kit ensured the setting out and allocation of these services was quick and easy. Without Leica Geosystems equipment if the services were damaged in any way, it could have set the project back six months or more. Other obstacles included a footpath which needed to be removed. Trees and shrubbery also needed to be removed with minimum disruption to local pedestrians and residents. The contract was completed within a tight programme to minimise disruption.

Project Details

Gallagher had to construct a cut and cover tunnel to form the site entrance. To do this, it was first necessary to check for existing statutory services such as water, gas and telephone lines. Trial holes were dug to check the depth of the site, making sure the site entrance was deep enough to put in the bell mouth (site entrance). Using Leica Captivate solutions meant better measurement accuracy, efficiently providing even the smallest of details. Leica Geosystems’ products and solutions were used in order to complete the project within budget and on time.

When setting out, positional accuracy was paramount, it was crucial to understand exactly where the new works might clash with any statutory services so as not to cause any unnecessary disruption. The Leica Viva TS16 and Leica Viva GS14 were chosen for this; with the Leica Viva GS14 also being used for the basic cut and fill operations at the start of the project. The Leica Viva GS14 was perfect for this scenario, as it is purposefully made for demanding environments such as quarries site entrances and it provides real endurance in extreme temperatures and weather conditions. Robust and lightweight, it made it easy to transport around the quarry site. Simple, accurate and easy to use, the Leica Viva GS14 was partnered with the new CS35 Tablet which ran the Captivate software and was connected to SmartNet for accurate GNSS RTK corrections.

The Leica Viva TS16 ‘self learning’ one person total station was chosen because of its versatility to adapt to any environmental condition, boding well for a quarry site. Running the Leica Captivate onboard software, the most comprehensive onboard capability available, the exact conditions of the quarry site could be surveyed and recorded. This provided an understanding of any potential clashes or pinch points with the utilities. The Leica Captivate software allows for a great user experience.

Using this survey data from Captivate, a 3D model was produced of the site and the design was determined for the work. The survey data helped Gallagher to decide on the best alignment of the road, making sure that the existing contours of the field were followed. Then with the new design and services, data was loaded onto the Leica CS35 tablet and available on site in the 3D environment within Captivate. All elements of the site could be staked out with a ‘live’ understanding of any potential clashes or pinch points with the utilities.

Benefits

The Leica CS35 tablets offer more than a conventional total station controller, being a full Windows 8.1 Computer, the capabilities it offers for onsite use are almost limitless. The Leica CS35 tablets can be used for everything from setting out and surveying, to filling in check sheets, documenting and photographing as-builts, exchanging important data, and doing email.