TRACTO INSIDER
IN FOCUS PROJECT: CONNECTION BORE FOR BACKBONE LINKAGE

 

469 Meters in 11 hours

HDD Record for
broadband expansion

A trenchless HDD project in Handewitt in Germany demonstrated just how quick and painless it is to expand a broadband network. In difficult ground conditions the infrastructure to connect around 1000 houses to the fibre optic network was established in just 11 hours. 

 
 

 
Handewitt, a community located in Northern Germany near the city of Flensburg, had, up to that point, no access to fast internet. To solve the problem, the "fibre optic expansion project" was launched in 2017 and in February 2020 the tender for the construction of an FTTB/H network (Fibre-to-the-Building/Home) was finally published. The expansion area included 1,000 households in eight districts of the community covering an area of around 7,800 hectares.

The framework of the tender also included a plan to install a pipe bundle to connect sub-networks directly to the main arterial line (Backbone). What seemed to be an ordinary job to the average person was actually a first class result for planners, executers and the machine itself. The almost 470 m long route ran from the village of Gottrupel into open countryside to the east, before crossing the four-lane A7 north-south motorway and continuing back on into the open countryside. It was vital not to affect or damage either the motorway or the open agricultural areas during the process and was therefore a clear case for installing the pipes using a trenchless HDD method. The tender contract was duly awarded to Bahnsen Tiefbau from nearby Brenstedt, who owned the appropriate equipment and the necessary know-how to undertake this demanding job using their GRUNDODRILL 15XP.


 
 
The bore team successfully completed a 430 m pilot bore with the GRUNDODRILL 15XP; setting up the jobsite for the 469-metre underground bore task. This included surveying and marking the bore path which was quick, precise and simple. The pilot bore began unhindered with a bore speed of 42,6 m per hour. The difficult section was drilling underneath the A7 motorway without shutting down any part of the road and a ‘blind bore’ was necessary for this element of the project.

“Blind drilling” is the term used when it is not possible to locate the underground bore path using a locating device from the surface. In addition to the professional skills of the operator, it requires a powerful and precise bore rig with the right drilling tools. The GRUNDODRILL 15XP is the perfect machine for the job. Known for its reliability and productivity, it is equipped with a particularly easy-to-steer MDH (medium Drill Head). The flush bore rig, with a thrust and tractive force of 150 KN, completed the blind bore at a single depth of 7 m with record-breaking precision. Just 1cm deviation in height was achieved between the starting and final measuring points on the A7. 

The pipes to be drawn in

After 469 m, the drill head reached the target pit without any obstacles - a record for the Bahnsen team and this HDD rig. The expansion of the pilot bore and the simultaneous pulling in of the pipe bundle went smoothly. It took the team and the GRUNDODRILL 15XP just 11 hours to install the pipe; laying the foundations for 1,000 fibre optic house connections in Handewitt, saving time and resources in the process.

Bahnsen boss Paul Baumann was delighted with the job: “I would have loved to continue drilling. Undertaking this project with my team and our TRACTO machine was great fun and we could easily have done another 50 m.” Thanks to the performance of the Bahnsen team, the foresight of the community to use trenchless technology and the use of the GRUNDODRILL 15XP, the residents of the Handewitt community can now enjoy fast internet via fibre optics with speeds of up to 1.000 Mbit/sec.


 
The GRUNDODRILL 15XP during pilot drilling.


 
Project Data
 
CUSTOMER:
Datacenter Flensburg Handewitt GmbH

PLANNING OFFICE:
MRK Media AG

CONTRACTOR:
Bahnsen Tiefbau GmbH & Co. KG

LOCATION:
Community of  Handewitt

TASK:
Connection bore for Backbone-connection

BORE RIG:
GRUNDODRILL 15XP

BORE LENGTH:
469 m

NEW PIPES:
- 1 x HDPE OD 50 & Multipipe
- 1 x OD 50 (24 x 5)

DURATION:
11 h pure bore time



The 469 m long bore path running from west to east under the A7 and in open terrain.
 


 
 
 
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