Things are going uphill

TIGAS-Erdgas Tirol GmbH (TIGAS for short) operates a gas network with a total length of currently approx. 3;700 km in around 170 Tyrolean communities and supplies customers throughout Austria and Germany with natural gas. The company plans to measure 1,300 house connections with NAVA this year. We spoke to Rainer Fischer and Florian Schirmer from the network planning department.

R. Fischer: On the one hand, we were dissatisfied with the situation on the construction sites. Today it is neither up to date nor reasonable for a pipe fitter or welder to measure house connections with a tape measure or a laser distance measuring device. The delivered measurement results were mostly only of sufficient quality. On the other hand, we saw Augmented Reality as a chance to introduce an innovation on construction sites and to optimise the area of house connections. There was no comparable product on the market, so the decision was made to use NAVA.

R. Fischer: Network construction at TIGAS is carried out by external pipe construction companies. That’s why it has always been our basic idea not to measure ourselves but to commission our service providers to do it. So, with NAVA, our specialist department has given the welder a tool that is easy to use and has a certain coolness factor. Currently, about 30 assembly teams use the app and deliver the captured data to our network information system in real time. We consider this a very elegant solution. We also regularly receive positive feedback from the construction site.

F. Schirmer: In the first step, we advise our customers on site and conclude a network access contract with them. In the network planning department, a construction contract is created from the network access contract and sent to the construction supervision, pipe construction and civil engineering departments. After the foreman has received the construction contract, he defines two reference points in the immediate vicinity of the house connection in coordination with the local construction supervisor, which will later be required for the surveying. At the same time, we enter the construction together with the order number and address order into the NAVA Manager. For data protection reasons, we do not enter any personal data at this point.
An employee of the construction company then takes over the further proceeding and forwards the order via the NAVA Manager to the smartphone of the responsible pipe fitter. At this point, we have a special feature at TIGAS: Before the construction begins, a surveyor drives to the construction sites in Tyrol and captures the two reference points “A“ and “B“ in the correct position with GPS support.

In addition to these reference points, the pipe fitter later captures the building contour with NAVA, defines the reference line with zero point as well as the alignment and captures the complete course of the pipe with all essential components and the photo evidence in the shortest possible time. We have deliberately reduced the components catalogue to a few positions to keep the process as construction site friendly and user-friendly as possible. This includes the fittings, the house entrance, and the connection point on the area supply line. We can then call up the finished order in the office using the NAVA Manager and convert the captured pipe route into absolute coordinates using Helmert Transformation.

F. Schirmer: Correct. We receive the relative data as CSV file from the NAVA Manager and transform it. We import the resulting absolute coordinates into the NIS and trace the points. At this point, we can already see whether there is a deviation from the reference points that were previously measured by GPS. Another quality indicator is whether the pressure tapping fitting is located on the existing pipe and whether the house connection point is situated at the building. If this is the case, the rest of the pipeline usually also fits. During the process, we then document the dimension of the gas pipe and the house connection type, i.e., whether it is an underground or above-ground house connection. At the same time, we use the pipe book to check whether the entire house connection is shown correctly. In the future, we plan an automated transfer of the data into the NIS so that the line and point capturing no longer needs to be done manually.

R. Fischer: The photo evidence has proven to be very helpful and is now also an explicit part of the order to the pipe manufacturer. With the NAVA photos, we can establish the connection to the pipe book and maintain the overview when we enter the sketches with the attributes of the house connection into the network information system. We are thus able to additionally ensure the quality of the network documentation.

Overall, the system is very easy to handle. We receive similar feedback from the employees of the construction companies on the construction sites. The accuracy is also very high in the construction fields where we use NAVA. Of course, there are always exceptions where NAVA measurements are not feasible due to special local conditions. With NAVA, we do not have any accuracy problems. If errors occur, the source of error is usually the GPS-supported measurement of the reference points done by the construction companies in advance, for example due to unrecognised shadowing, but also due to the assignment to changing coordinate systems. A significant advantage of using NAVA in our processes is the time aspect because the various specialist departments (professionals) involved in the house connection now work in a temporally decoupled manner. For example, there is no need to wait for the surveyor as the survey can be carried out directly at the open trench by the welder and his smartphone. Of course, this was initially also a change for the professional group of welders. Fortunately, however, we are dealing here with a flexible team that has quickly learned how to use NAVA. The fact that from now on manual drawings have no longer to be made was very well received by everyone involved.

The bottom line is that NAVA is much better than the system we had before, and we will certainly continue this path. Mettenmeier has also turned out to be a pleasant partner during the cooperation, who is responsive to our wishes. We are therefore happy to continue to contribute our ideas to the partnership.