RR1216: Review of progress of the Iron Mains Risk Reduction Programme (IMRRP) 2013 to 2023
The Iron Mains Replacement Programme (IMRP) was introduced in 2002 to address 'societal concern' regarding the potential for failure of cast iron gas mains with the risk of injuries, fatalities, and property damage. A review of the IMRP was carried out in 2011 and published as HSE Research Report 888. Following the review, the IMRP was renamed the Iron Mains Risk Reduction Programme (IMRRP) and the HSE Iron Mains Enforcement Policy governing the IMRRP was revised taking into account the review findings.
This report describes research commissioned in 2023 to review the progress of the IMRRP since 2013 to:
- determine whether over the period 2013-2023 the Iron Mains Enforcement Policy has secured the decommissioning of the highest risk iron mains; and
- consider if there should be changes to how the programme is structured as it enters the final six years of the 30-year programme (2026-2032).
The review found that the number of pipe failures recorded each year per kilometre of remaining iron mains is increasing slightly and identified concerns with the methodology used to prioritise larger diameter pipes for decommissioning. The review also suggests an alternative approach to address weaknesses in the Condition (integrity) Monitoring practices currently used by the Gas Distribution Networks. Based on the findings of our review, we present a number of options for revising HSE’s Iron Mains Enforcement Policy as it enters the final six years of the 30-year programme (2026-2032), to ensure that it remains fit for purpose.
This report and the work it describes were funded by the Health and Safety Executive. Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.
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