From the 19th August 2013 all requests to Vector for service location plans will now be automatically provided removing any delays previously caused when strategic assets were within your proposed work zone. Plan validity will be increased from 14 to 28 days. Vector will no longer be providing a mark out service for the following assets:
High Voltage Electricity, (6.6kV, 11kV & 22kV distribution cables)
High Voltage Sub Transmission Cables (22kV, 33kV, 110kV cables)
Strategic Gas Mains (MP7, IP10, IP20)
Vector would like to remind you of your responsibilities under the Health and Safety in Employment Act 1992, whereby you must establish the location of underground services before commencing excavation. Vector will no longer be requiring a standover observer to be present when parties are working around strategic gas mains. Please note that for an interim period of time, Vector shall continue requiring a standover observer to be present when parties are working around Vector’s electricity sub-transmission cables. There are no changes to the asset location requirements and services provided for the Vector Gas Transmission high pressure pipelines. If you are unsure of how the changes affect you please call 0508 B4UWORK.
EMI (Electromagnetic induction) Locating gives the potential to locate any metallic utilities including steel pipes, power cables, copper communication cables or any plastic pipes with a copper tracer wire attached such as gas pipes and lines. Ground Penetrating Radar has the ability to detect and produce underground images of both metallic and non-metallic utilities including plastic, asbestos, cement, gas pipes (with out tracer wires), fibre optics, concrete pipes and any other identifiable unknown objects in the path of excavation. When combining the two methods, you will increase your chances of identifying all objects hidden underground. It is recommended (and in most circumstances a legal requirement) to have valid and current utilities plans onsite while excavating. These plans will give Sub Surface Detection Ltd the best chance of locating all hidden services and save you considerable time and risk. If required, Sub Surface Detection Ltd can assist by acquiring the utilities plans from "beforeudig". Please allow 1 week to ensure all plans are available. It is also recommended that any network service mark outs are carried out prior to our arriving on site. Network service mark outs have now become a more limited service provided from some of the network companies, however in cases of high voltage power, high pressure gas and bulk Watercare pipes (all transmission lines) these need to be marked out by the network companies. Also if required, Sub Surface Detection Ltd can apply for these mark outs to be made on your behalf. Results vary using GPR depending on a range of variables including; Ground conditions such as water content, soil density and make up (clay vs volcanic soil structures) and soils containing a high metallic content. The depth of the underground hidden object and it's materials of manufacture are also factors which can give quiet variable results when using ground penetrating radar alone as the tool for identifying underground objects. It is important to use all identification tools currently available to ensure you're obtaining the highest chance of correctly identifying and locating all hidden underground services.
While operating the Ground Penetrating Radar, we can't always determine exactly which utility it is we are viewing as we are only able to interpret the generated image. While applying EMI Locating it is very easy for the signal to transfer onto another nearby metallic service or structure. This is why it is import to have as many service plans as possible on site for us to use as guideline. We also may need to pot-hole when necessary to confirm correct locations.We're a service provider for Leighton Contractors whereby we mark out all underground services along council brems prior to drilling or trenching for the Ultra Fast Broadband project and motorway projects. Sub surface detection for Downer Roading helps protect services prior to road milling and channel trenching. Fletcher Construction -site surveys prior to excavation and building. Hawkins, Abernethy Civil (now Fulton Hogan/John Holland), surveying prior to civil works for the electrification of Auckland's rail network.
We also provide services for Transfield Services, Higgins, Hick Bros, McKenzie & Parma, Ross Reid, Contact Energy, Watercare Services and fuel installation companies prior to site excavations.