Mar 2014
Gas Distribution
Cotter Plate Identification and Remediation (Stage 1)
Mar 2014
Jun 2014
Oliver Machan, Innovation Project Manager
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Network Innovation Allowance
GD - Repair
Gas Distribution Networks
The scope of this project is to work in partnership with specialist GIS data suppliers, who will use their own resources in combination with network maps provided by SGN to identify five trial areas (expected to be 2km x 2km) in SGN’s Scotland and/or Southern license areas where mains are likely to have been sealed using Cotter plates. These areas will then be used during the Stage 2 project to confirm the location of Cotter Plates. This will involve refining a methodology (2 months) and producing an output of trial areas that are highly likely to contain Cotter Plates (1 month). Once complete we will be able to assess the benefits of using the information generated throughout the trial.


The proposed methodology is to utilise photo maps compiled from war time aerial imagery and bomb maps where available to identify bomb damaged buildings throughout SGN’s Scotland and Southern licence areas. Where the photo maps are inadequate to identify bomb damaged buildings, a combination of the summary bomb maps and individual reconnaissance photos will be used. A GIS polygon map will be created, with polygons covering blocks of buildings that have the same bomb damage severity classification. The existence of bomb damage will be collected as an attribute code to the polygons. Trial areas will be identified based on the coincidence of bomb damage and gas mains.

The objectives of this project are to:

•         Develop and refine a method to identify likely Cotter Plate locations

•         Create a shape file (GIS) output of trial areas in support of Stage 2

The key success criteria will be:

  • Part 1: Polygon map created covering blocks of buildings that have the same classification - existence of bomb damage collected as an attribute code to the polygons.

  • Part 2: Five trial areas of 2km x 2km agreed by both parties selected for Stage 2.