DCA Europe

Technical Information

Recommendation – Education – Networking

Technical Information

In order to a better structure of the publications of the DCA, the Board has introduced the series “Technical Information” in addition to the Technical Guidelines, which are currently being revised again. In the future, the results of task groups, committees etc. on technical issues will be published under this series.

Are you interested in the “Technical Information”?

Use the following order forms in the individual sections.

The publications are free of charge for members.

Quality Assurance – Guidelines to better quality, August 2005 edition

Horizontal Directional Drilling (HDD) was developed in the late seventies in deep drilling technology and has been used for more than four decades at a high quality level for the trenchless installation of pipelines and cable strings. As the trade association of the European HDD industry, the DCA documented the technical status of the HDD process in a guideline in the mid-1990s, which is now in its 4th edition.

With the present elaboration, another guideline is presented, which has the title “Quality Assurance” and contains more extensive recommendations for the quality assurance of HDD projects. The guideline provides recommendations for the areas of planning, construction and monitoring of HDD projects and was compiled with special consideration of construction site-specific aspects. The present recommendations are aimed equally at clients and contractors and should be applied in addition to the Technical Guidelines.

Order Form Technical Info No. 1

Model Bill of Quantities for HDD Measures with drilling rigs <40t and >40t pull-in force, January 2012 edition

The horizontal directional drilling method (HDD) is an emerging technique that has been successfully used for years for the trenchless installation of gas and water pipelines and telecommunications cables. Due to the high technical and professional requirements, careful planning of all project phases, starting from the bidding phase to work preparation, execution and final documentation, is essential.
The present DCA elaboration, entitled “Model Bill of Quantities for HDD measures with drilling rigs > 40 t or < 40 t pull-in force “, aims to provide the industry with a model specification for HDD drilling work. In the industry, clients, engineering offices and contractors have specifications with significantly different contents and scopes. As a result, misinterpretations often occur during the tendering process, e.g. certain services are tendered as ancillary services within a main item in one tender, but as a separate item in another tender.

In the case of lump-sum requests without specified service items, a client may receive offers that are difficult or impossible to compare with each other in terms of their form and pricing. Large price differences often result from differing scopes of services, since, for example, necessary auxiliary or preliminary services are included by one bidder and assumed by the other as on-site services.
In order to make offers for HDD measures more comparable, but above all to provide planners and building owners with support for a qualified enquiry, this sample contract has been created, which provides basic service items and various additional service items.
At this point, it should be mentioned that the DCA still recommends the client to engage a specialist planner with proven experience in the HDD sector despite the use of this model specifications.

Order Form Technical Info No. 2

Shaping Recommendation of Technical and Legal Contract Conditions, February 2016 edition

This DCA document, entitled „Shaping Recommendation of Technical and Legal Contract Conditions“ aims to provide partners operating in the HDD industry with largely uniform recommendations for the drafting of contracts, both in technical terms and on legal issues. These recommendations are therefore aimed equally at clients and contractors and, together with the Technical Guidelines, form a guideline for the drafting of contracts for the execution of HDD construction measures. Due to the European orientation of the association and the transnational activities of our member companies, this recommendation has been prepared and published in English, German and French in cooperation between clients and contractors.

Order Form Technical Info No. 3

Recovery and disposal of drilling cuttings and fluids from HDD operations, current legislation and recommended procedures, November 2019 edition

In Germany the HDD industry faced serious problems, when in 2015 the federal state Lower-Saxony passed a decree stating very clearly that cuttings and drilling muds will be classify as waste and they would be subject to the „Kreislaufwirtschaftsgesetz“.

Other federal states, for instance, Baden-Württemberg, have meanwhile followed this initiative. Drill cuttings and drilling mud are hence to be recovered and disposed properly and safely as mineral waste. According to the current legal opinion, cuttings or drilling mud from horizontal directional drillings may only be disposed on agricultural land, as was common practice on many locations and projects in the past, if certain exceptional preconditions are fulfilled (the decree by Baden-Württemberg goes as far as to categorically ban it). It should be noted that the Lower-Saxon decree does not produce any new legislation, but repeats and clarifies legislation already in force.

The consequences of the decree for the HDD industry are:

  • immediate uncertainty with respect the legally compliant recovery and disposal of cuttings and drilling mud;
  • Great uncertainty with respect to the calculation of recovery costs, given that the definite point of disposal / recovery may usually be determined only after specific laboratory analyses
  • Increased waste treatment costs due to long transport routes and limited number of disposal locations;
  • Creation of “regional or company-specific local solutions” instead of global ones.

It was against this backdrop that the DCA founded Task Group 1: Recovery and disposal of drilling cuttings and fluids from HDD operations in the spring of 2016. The aim was to study the challenges for the industry with regard to the recovery and disposal of cuttings and drilling mud arising from the decree and to develop suitable recommendations for action or universal guidelines / minimum standards.

The report points out the most important facts about waste legislation that need to be taken into account. It includes comments on the responsibilities of the project partners, information on sampling and transportation, indications on possible and legally compliant recovery and disposal routes as well as recommendations on organisational and contractual waste treatment provisions both contractors and clients.

Order Form Technical Info No. 4

DCA Technical Guidelines – Information and Recommendations for the Planning, Construction and documentation of HDD-Projects, 4th edition 2015

New version chapter 4.1.4 Tolerances, Juni 2019

With the publication of DIN VOB 18324, tolerances for the execution of horizontal drilling work were introduced for the first time and adopted mutatis mutandis in the subsequently published 4th edition of the DCA Guideline as tolerances for pilot drilling. These tolerances describe the permissible deviations between the delivered work and the construction target in the form of the contractually agreed geometric properties of the structure. In addition, the publication of the tolerances serves as an orientation for all parties involved for the fundamental deviations caused by the procedure. In practice, however, the introduction of generally valid tolerances has often resulted in long disputes, especially with regard to the required accuracy of boreholes and the observance of bending radii of the pipelines.

Especially in the case of boreholes for large pipelines and in difficult or changing geologies, the required tolerance could often not be met. The discussions were aggravated by misunderstandings or differing views of the parties on how the construction target should be defined and the concept of tolerances should be interpreted – especially due to the different requirements from VOB DIN 18324 (geometry of the pipeline) and DCA regulations (geometry of the pilot bore). In order to prevent future discussions and to eliminate contradictory requirements to VOB DIN 18324, a proposed amendment to chapter 4.1.4 was prepared as part of the revision of the regulations and published as a supplement to the 4th edition.

You’ll get the supplement to the 4th edition by order of the Technical Guidelines.

Technical Information No. 6 – Pipe casing and coating in HDD

1st edition – March 2023

The working group established by the board in 2019 initially aimed to analyse the current situation regarding the materials used for HDD technology, testing procedures, and related regulations. Furthermore, measures/recommendations should be developed that ensure the quality of the coatings on behalf of the client and help horizontal drilling companies to identify and indicate sources of error and risks before taking over the pipeline (often provided by the client or third parties).

The present Technical Information No. 6 “Pipe casing and coating in HDD” of the DCA bundles the results of the working group and provides information on all parameters, processes, and interactions that have an influence on coating quality. In addition, the Technical Information helps in selecting the most suitable coating system for specific drilling and soil conditions.

All information and recommendations in this document apply to standard HDD drilling but can be similarly applied to related trenchless applications such as pipe jacking, direct pipe, HDD installation of pipes in micro-tunnels and protective pipes, etc. if their individual characteristics are considered.

The explanations in the present Technical Information No. 6 complement the information in the DVGW worksheet GW 340 or the information in DIN 30340-1 and DIN 30340-2.

The board of the association would like to thank all those involved in the working group who partici-pated in the creation of Technical Information No. 6 “Pipe casing and coating in HDD” of the DCA.

The English-language edition of Technical Information No. 6 is already available for download in the members’ area. A printed version is expected to be available for non-members at the end of June.

Order Form Technical Info No. 6