Working indoor with machine control guided by two total stations from Leica Geosystems

Case Study

Working with two total stations and machine control in Bålsta

Author & Photographer: Arne Forsell

 

Impressive…very impressive…!

This is the first word that enters your mind when you see the enormous building emerging from behind the forest. The Swedish wholesale company Dagab’s new logistic centre for groceries in the city of Bålsta 50 kilometers northwest of Stockholm, will become one of North Europe’s largest buildings. With a length of 575 m and a floor area of 100,000 m2, which is the equivalent of 15 football stadiums and a ceiling height of 15 meters, storage rooms with different temperature zones, the building is constructed with a strong focus environment.

Dagab can close down six existing facilities and move their activities to Bålsta when the project is completed in 2023.

Using machine control for creating one of North of Europe’s largest buildings 
Using machine control for creating one of North of Europe’s largest buildings

The construction company Kanonaden is responsible for the earthmoving works – a project that involves ground stabilisation and piling. Kanonaden has gathered a well-oiled clockwork of subcontractors to ensure smooth and timely execution of the workflow. Two of these indispensable, sharp, and distinct gears of the clockwork are Dennis Larsson and Simon Sundkvist. Dennis drives a skid steer machine and levels the final layer in a forest of pegs on one side of one of the storage rooms. 33-year old Dennis works as the third generation in the family-owned Sanna Gräv AB. His green-yellow safety vest and his black T-shirt reveal that he works for Sanna Gräv – if anybody should ever doubt that!

Soil sanitation, sewage systems, surface geothermal heat and even archaeological excavations, adjustment of asphalt and concrete are some of the activities that the company has focused on since the beginning of 1973. The customers are mainly larger companies in the area of Mälardalen. The machine fleet includes, besides the skid steer, tire tractors, excavators, and dumpers.

 

Using skid steer for fine grading

Dennis' career in the heavy construction industry started with a summer job at the age of 13, so it is a very experienced machine operator that operates the CAT299D2 for fine grading of the final surface layer of the future warehouse.

This hybrid of a machine that some people would call strange and find difficult to describe is maneuvered safely by Dennis in the narrow spaces between the concrete foundations. The blade underneath the machine drags the filling material that is transformed into the final layer used for the foundation for the subsequent floor and deposits it with unfailing precision. Dennis demonstrates that behind the joysticks inside the machine, he is a true artist.

Dennis is assisted by his machine control solution from Leica Geosystems.

- We have machine control from Leica Geosystems on all of our machines, says Dennis.
- We only want to work with the best, so we use the MC1 software on the MCP80 panel. Our customers and we are very satisfied with it, and I wouldn’t want any other system!

The work under the massive roof and between the obstructing piles has created new challenges for Dennis and the handling of his machine.

- When I work under a roof, it is advantageous to use dual TPS because the surface has so many different heights, and it is essential to know exactly what the height differences are. Thanks to the two iCR80 total stations, I never have to think about moving the machine because they track the machine all the time. That makes a big difference compared to using just one TPS and cross slope function. I can’t use the total station all the time because of all the blocking things. Then I switch to the laser solution instead, he says.

Dennis switches easily from dual TPS to a dual laser solution
Dennis switches easily from dual TPS to a dual laser solution


- But it doesn’t matter. The result is almost the same as long as the height is constant. I drive with a margin of 5mm, up or down, without any problems. I can do everything myself! I place the total stations and do the job myself! The total stations give me a sense of security, when I work. As long as the model is correct, the job will be performed correctly.

Dennis Larsson claims that he sometimes finds it hard to learn new technology, but he immediately realises:

- I have learned to use GPS, and it has become a lot more fun to work when you can see the heights. It might be that younger people, who have always used GPS on their machines, don’t feel the same joy as I do, but I have been in this business for a long time… To learn MC1 has definitely not been a problem!

 

Machine control is used for high precision excavation

In another part of the giant warehouse, Simon Sundkvist works in his Volvo EW160E signed Granlunds Grävmaskiner. The company started in 2001 when Andreas Granlund bought an excavator for his one-person company and stating that “the rest is history” is a bit of a cliché, but also true underlined by the fact that the company today has 45 employees and machines for construction work, earthmoving, and transportation.

Simon Sundkvist worked initially as a truck driver, but his uncle had worked as an excavator operator for about 50 years and inspired him to switch career 8 years ago.

- I took a GNSS course offered by Leica Geosystems and thought that machine control was cool and interesting, and that was that he says and laughs through the beard. I have continued with it, adjusted it a little, and learned more and more, and the Leica systems are easy to use.

The almost cathedral-like environment that Simon and his excavator work in with the smooth, bright concrete walls that lead the gaze upwards towards the ceiling creates almost total radio shadow. In his work with floor area Simon is guided by the two total stations that catch the prisms on his machine with unfailing accuracy and help him place the bucket with the exact tilt and correct height.

On one of the short sides of the area that he is working on, he has dug several holes to give room for future installations in the room. Beautiful, sharp-cut edges, holes with millimeter tolerances, and razor-sharp angles are a silent testimony about the accuracy of the machine control solution – when it is performed by a competent machine operator.

High precision excavating with MC1

 

The solution allows Simon to work independently. He rarely needs help from surveying engineers for stake-out, and the job is a lot more efficient and cost-effective.

- I start every day by positioning the two iCR80 total stations. I did it very thoroughly in the beginning, but that didn’t work. It was too accurate for the machine control solution. Vibrations and even the air pressure level in the machine’s tires were enough to influence the machine control, and it didn’t function. Now, I only use two decimals, and it works a lot better.

Simon thinks that it saves a lot of time because he now works independently.

- It is a question of hours, he says. And it is nice to work autonomously as well.

He has only praise when it comes to describing his relations with Leica Geosystems.

- If I need something, I have a direct phone number of people at Leica. It works really well!

 

Surveying manager Jerker Wretman fully trusts the accuracy of the machine control solutions

Jerker Wretman works as surveying manager in the company Kanonaden Mälardalen, which is the department that takes over the project from the mother company Kanonaden. He has been with the company since 2017 and is one of 80 employees. Jerker says that Dagab logistics center is the largest project that the company has worked on until now. Still, he feels safe in the role despite the size of the project and specific challenges with the height differences on the site and the very tight deadlines.

Surveying manager Jerker Wretman
Surveying manager Jerker Wretman

- Having the machine control solution from Leica Geosystems is of great value to us. I trust it fully, and the fact that we don’t need to call for surveying engineers makes the process a lot faster and more efficient. The result is highly accurate regardless of using total stations or lasers.

The Dagab project in Bålsta is a project built for the future. From here, groceries will be delivered to several grocery store chains. The storage space is also built for the handling of e-business in the future distribution of groceries.

It is an impressive location, and machine control from Leica Geosystems has played an essential role in its construction!

 

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