The Health, Safety and Environmental Impacts of Gas Holder Demolition

Rob Hopper
Britain's energy mix is changing and the way our gas and electricity networks operate needs to change too.

The Revenue Incentives Innovation Outputs (RIIO) model - is designed to encourage energy network companies to make positive changes by:

  • playing a full role in delivery of a sustainable energy sector
  • delivering value-for-money network services for existing and future consumers. 

These changes have meant that gas holders, which have historically stored coal gas (town gas) and natural gas, have become almost obsolete. The combination of improved above ground installations (AGI) and governor stations contribute to the improved distribution network and have resulted in the decommissioning of these dominant structures of the industrial age. Faithful+Gould delivers solutions in support of AGI, governor station upgrades and on the decommissioning and demolition of gas holders.

What is a Gas Holder?

A gas holder (commonly known as a gasometer) is a large container in which natural gas or town gas is stored near atmospheric pressure at ambient temperatures. The volume of the container follows the quantity of stored gas, with pressure coming from the weight of a movable cap.

...many gas holders have become redundant and therefore need to go through the decommissioning and demolition process. 

Due to the installation of state-of-the-art equipment in AGI and governor stations, to deliver a more sustainable energy sector, gas can now be delivered to the network without the severe drop in pressure, which the gas holders used to compensate for. As a result, many gas holders have become redundant and therefore need to go through the decommissioning and demolition process. This has substantial health, safety and environmental impacts.

Health and Safety

Gas holders are traditionally either above or below ground installations and the challenges can include:

Cutting and Dismantling Operations
Changing the method of cutting from hot to cold eliminates the risk of sparks entering the holder. Oxy-fuel cutting (hot) uses fuel gases and oxygen to cut through the holder; changing the technique to cold can mean minimal burr production, fewer sparks and no dust. Using a specifically designed 'cold saw', the revolutions of the saw are slowed down so the blade chips the metal away rather than rotates at high speed.

Working in Confined Spaces
This involves the risks of gas build up, flooding and access issues. To overcome these challenges, atmospheric monitoring – ensuring site personnel aren't exposed to hazardous substances or significant flooding – is a must, with site personnel being equipped with personal gas monitors.

Cranes/Lifting Operations
Load testing on the site ground should be carried out in order to ensure the stability of machinery is maintained.

Contaminated Land
The ground on sites where town gas was previously manufactured can be heavily contaminated with a substance commonly known as 'Blue Billy', spent lime that becomes fouled with sulphur and sometimes cyanogens, noticeable by its distinctive blue colour. These areas should be covered with protective membranes and cordoned off to prevent access during the demolition process and removed by a specialist contractor during land remediation.


The dismantling of gas holders leaves a massive issue around land remediation and the need to fill large holes in the ground.

The key to environmentally friendly demolition practices revolve around the proper, licensed removal and disposal of liquids and sludges from the vessels.

Dismantling below-ground holders leaves a huge hole in the ground, sometimes in residential areas where children could potentially access the site. Full security on these sites need to be utilised to avoid injury and utilising waste excavated material from other projects i.e. from road infrastructure or local streetworks can be used as a backfill. This is a key environmental win as the spoil would otherwise go to landfill.

Subgrade vessels may be compromised by disturbance during demolition or subsequent site activity, settling or penetrating piping which could have corroded or been cut without plugging. This can allow the contaminated waters or sludges to leak into the environment, causing both soil and groundwater contamination.

The key to environmentally friendly demolition practices revolve around the proper, licensed removal and disposal of liquids and sludges from the vessels.

In Summary

Gas holders are a testament to Britain's role in creating the industrial revolution, but as the distribution network becomes larger and more effective, they are becoming obsolete.

Faithful+Gould are providing construction design and management (CDM) and health and safety services in support of the programme to remove gas holders and improve AGI and governor stations, including:

  • supporting the drafting of pre-construction information (PCI)
  • safety inspections
  • guidance/support to contractor/client supervisor
  • utilising a comprehensive suite of inspections templates/documents
  • support during complex lifting operations

These metal giants of the past, which marked a transition in our towns and cities, are now getting the chance to contribute to our communities again, by giving back the land to create a more modern and sustainable Britain.