Third-party work

On-site orientation

Before work begins, Gaznat provides the contractor in charge of the project with specific information about its underground pipeline installations (high-pressure gas pipeline, telecommunications cable, etc.), and warns of the dangers and consequences of potential damage. The general conditions for carrying out the work, as well as the requirements of the Swiss Federal Pipeline Inspectorate (IFP), are discussed between the two parties.

Determining the position of the high-pressure gas pipeline

Before starting work, Gaznat determines the exact position of the high-pressure pipeline axis and marks it accordingly. The pipe axis must be marked in all construction phases and may only be removed or relocated with Gaznat's consent. The marked pipe axis must be checked against the planning documents.

In general, the pipe axis is determined using a pipe finder or by internal exploratory operations (e.g. pistoning). If, due to excessive overlapping or for other reasons, it is not possible to determine the pipe axis with the necessary precision, the coordinates must be determined by a qualified surveyor. If there is any uncertainty as to the exact location, boreholes must be drilled.

Determining the position of telecommunication cables and other conduits

Gaznat's telecommunications cable and fiber optic bundles run alongside the high-pressure gas pipeline. During excavation work, particular care must be taken when exposing the telecoms cable and any other pipes.

Excavation work

The first 30 cm layer (road surface, humus, etc.) can be removed by machine if the pipe has a minimum overlap of 1 m.

Further excavation work by machine within a 2 m strip on either side of the pipe is permitted only under the following conditions:

- Pre-probing the excavation by hand. When excavations are fairly long or close to curves, the excavation area must be pre-probed in at least two places.

- Hand-digging only from an overlap of less than 30 cm, with 50 cm clearance on both sides of the pipe.

- The above distances may be reduced according to the situation and in agreement with Gaznat. Gaznat must be notified immediately if the pipe covering or third-party work does not correspond to the plans.

- Machine excavation with a backhoe bucket without teeth, and only to a manually probed depth. Use of the lightest excavator possible.

Protection of the pipeline system

If the high-pressure gas pipeline and/or the telecommunication cable are cleared, these parts of the installations must be protected, in agreement with Gaznat, by massive mechanical protection against the influence of third parties. Before reclosing, the cleared parts of the installations must be inspected by Gaznat.

Damage to the pipeline system

If the high-pressure gas pipeline, pipe insulation or telecommunication cable is damaged, Gaznat must be notified immediately.

Monitoring

Gaznat supervises work in the area of the high-pressure gas pipeline.
If Gaznat is unable to carry out this task, qualified personnel, previously instructed by a competent Gaznat employee, will be called in. The personnel in charge of supervision must be informed in particular of the construction project, the safety regulations and the provisions of the Federal Pipeline Inspectorate for third-party construction projects.

Excavation work within a 2 m strip (horizontal clear width) on either side of a high-pressure gas pipeline must be supervised at all times by a competent Gaznat employee.

For excavation work outside a 2 m strip (horizontal clear width) on both sides of a high-pressure gas pipeline, all necessary measures must be taken at all times to ensure that any danger to the pipeline system can be excluded. If the work has been planned and discussed in advance with Gaznat, no permanent supervision is required by the competent Gaznat personnel.

Special protection measures

Special precautions must be taken if mining, drilling or pile-driving is to be carried out in the area of a high-pressure gas pipeline, or if the pipeline is to be crossed by vehicles or heavy machinery. Such projects must be specifically mentioned in building permit applications, and may only be carried out after prior authorization from the Swiss Federal Pipeline Inspectorate. The necessary protective measures are to be agreed in advance with Gaznat.
Before drilling or pile-driving work in the vicinity of a high-pressure gas pipeline, it is generally necessary to test the pipe by means of a borehole. Seismic measurements may also be required for mining or pile-driving operations.

Subcontractor

Gaznat shall be notified immediately of any subcontracting, so that it can inform the subcontractor of these requirements before the subcontractor starts work.

Fees

The costs of the authorization procedure shall be borne by Gaznat, except in exceptional cases. Gaznat reserves the right to invoice travel and other expenses if it has not been informed of a postponement of work requiring its supervision on site.

Getting to know you

The representative of the executing company or the subcontractor of the executing company must undertake to ensure that work in the area of the high-pressure gas pipeline is carried out in full compliance with the aforementioned safety regulations.