MAPS Viewer

The data is for the distribution systems operated by National Grid (including the High Pressure Gas Transmission in the National Grid retained areas only) and Wales & West Utilities (WWU). Gas mains and plant records for these Networks are published quarterly on disc, which can be installed on any PC running Microsoft Windows 2000 or later.

What is MAPS Viewer?

The National Transmission System and Gas Distribution Network form the pipe network, which carries gas from the shore terminals around the coast to individual users' properties. The Network consists of several pressure tiers operating at pressures ranging from 21 mbar to 70 bar.

The plans show the location of mains, including information on size, material, pressure etc. but do not normally show individual services or standpipes, etc. (However, these should be anticipated and their possible position derived from the gas meter point. Proprietary pipe and cable locators will help in establishing the position of gas mains and services on site, when used in conjunction with the plans.)

Transmission Network

The National High Pressure (NHP) network is owned and operated by National Grid Transmission. This data is included on the discs supplied by National Grid, but it is no longer on the disc supplied by Wales & West Utilities.

Distribution Network

National Grid are responsible for the Gas Distribution network in East Anglia (EA), East Midlands (EM), London (LN), North West (NW) and West Midlands (WM). Wales & West Utilities are responsible for South West (SW) and Wales (WA). Scotia Gas Networks owns the Gas Distribution network in the South of England and Scotland. Scotia Gas Networks do not provide their asset data via the Mains and Plant discs. Northern Gas Networks owns the Gas Distribution network in the North of England and Yorkshire areas. Northern Gas Networks do not provide their asset data via the Mains and Plant discs.

Quarterly Issue

MAPS Viewer Mains and Plant discs are produced every 3 months using an extract taken from the Network Owner's graphical records system. This extract is taken approximately 3-4 weeks before the discs are dispatched to users. Consequently, the data displayed can be up to 4½ months old by the time the next quarter's discs arrive. It is, therefore, of critical importance that the relevant Network Owner's office is contacted before any work is carried out in the vicinity of any plant, to obtain copies of the latest plans. Details are shown in 'Dial Before You Dig'.

Background Geography: Ordnance Survey

The background geography for the maps is provided by Ordnance Survey's Landline range of mapping solutions. Maps are only purchased from Ordnance Survey for those areas which contain gas mains and plant - it is not a national coverage of maps. Subscribers to Maps Viewer undertake to obtain a licence from Ordnance Survey.

System Requirements

The MAPS Viewer software requires Windows NT, 2000 or XP to run. The minimum required disk space is 80Mb for a software-only installation. Running the MAPS Viewer software in a client-server configuration is not officially supported - the intended use of the MAPS Viewer data discs is to run from a local hard disk, with data optionally installed or read from a disc.