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Down-the-hole drilling
DTH hammer drilling
In down-the-hole drilling a drill rod is fitted with a hammer at its lower end. The hammer, which is mounted on the drill bit, is activated through the addition of compressed air and driven into the ground – simultaneously rotating and impacting. A flushing current collects the loosened drill cuttings and conveys them upwards. This method is mainly applied for hard to very hard rock and/or for penetrating large boulders.
Process principle of cased DTH hammer drilling
1. Setting the DTH hammer with drill rod and casing on the drilling point.
2. Rotary and percussive drilling of the drill string under compressed air supply.
3. After reaching the final depth, unlocking of the drill rod with DTH hammer and pilot bit.
4. Withdrawal of the drill rod, DTH hammer and pilot bit out of the casing.
5. Completed cased borehole.
Video: Down-the-hole drilling
The video shows the down-the-hole drilling method for very hard soil or rock.
This YouTube video is provided by Google*. If you load the video, your data - including your IP address - is transmitted to Google and may be stored and processed by Google inter alia in the USA. We have no influence over further data processing by Google.By clicking on "Accept", you consent to the transmission of data to Google for this video in accordance with Art. 6 (1) (a) GDPR and at the same time explicitly consent to the transfer of data to the USA in accordance with Art. 49 (1) (a) GDPR. If you no longer wish to consent to each YouTube video individually in the future and wish to be able to load the videos without this blocker, you can also select "Always accept YouTube videos" and thereby consent to the associated data transmissions and transfers to Google and to the USA for all other YouTube videos which you open on our website in the future. Please note that, in the opinion of the European Court of Justice, there does not currently exist an adequate level of data protection in line with EU standards in the USA, and at present we cannot provide appropriate safeguards to protect your data and offset this shortcoming.Possible risks to you of data transfer to the USA are that access by state authorities cannot be excluded and that your data could be processed for reasons of national security, law enforcement or for other purposes in the public interest of the USA, possibly without you being informed separately and without enforceable rights and effective legal remedies being available to you.You can withdraw consent that you have given at any time with future effect via the settings. For further information, please see our Data Protection Declaration and Google's Privacy Policy.*Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland; parent company: Google LLC, 1600 Amphitheatre Parkway, Mountain View, CA 94043, USA
Cased down-the-hole drilling
A rotary drilling rig, type LB 20, working with down-the-hole hammer inside a casing.
Discharge of drill cuttings
A flushing current conveys the loosened drill cuttings upwards and exits at the upper end of the casing.
Video: LB 16 unplugged DTH drilling
This YouTube video is provided by Google*. If you load the video, your data - including your IP address - is transmitted to Google and may be stored and processed by Google inter alia in the USA. We have no influence over further data processing by Google.By clicking on "Accept", you consent to the transmission of data to Google for this video in accordance with Art. 6 (1) (a) GDPR and at the same time explicitly consent to the transfer of data to the USA in accordance with Art. 49 (1) (a) GDPR. If you no longer wish to consent to each YouTube video individually in the future and wish to be able to load the videos without this blocker, you can also select "Always accept YouTube videos" and thereby consent to the associated data transmissions and transfers to Google and to the USA for all other YouTube videos which you open on our website in the future. Please note that, in the opinion of the European Court of Justice, there does not currently exist an adequate level of data protection in line with EU standards in the USA, and at present we cannot provide appropriate safeguards to protect your data and offset this shortcoming.Possible risks to you of data transfer to the USA are that access by state authorities cannot be excluded and that your data could be processed for reasons of national security, law enforcement or for other purposes in the public interest of the USA, possibly without you being informed separately and without enforceable rights and effective legal remedies being available to you.You can withdraw consent that you have given at any time with future effect via the settings. For further information, please see our Data Protection Declaration and Google's Privacy Policy.*Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland; parent company: Google LLC, 1600 Amphitheatre Parkway, Mountain View, CA 94043, USA
