More information needed on lighthouse beam switch

More information needed on lighthouse beam switch

1 October 2025

THE Commissioner of Irish Lights has been accused of not providing enough evidence to justify its controversial plan to downgrade the iconic sweeping beam at St John’s Point Lighthouse in Killough.

The Dublin-based Commissioner (CIL) is seeking approval to reduce the scale of the lighthouse beam and replace a mercury bath— on which the lighthouse’s giant lamp rotates — with a rotating ball bearing mechanism.

A formal bid to implement the changes was lodged with local planners last December, with the Listed Building Consent application currently being scrutinised.

Billed as an “engineering upgrade”, CIL insists the work, which includes replacing a 1000 watt high energy lamp with a 90 watt LED bulb, is necessary with the emphasis on improving the reliable and safe operation of the lighthouse.

CIL insists the existing high energy lamp will soon become unavailable due to energy efficiency regulation changes which will make it impossible to source, arguing the planned programme of work is necessary to ensure the “safe and reliable operation” of an aid to navigation in a sustainable way.

The lighthouse’s rotating Fresnel lamp and unique flash character of the light will be retained, with the Killough proposal similar to CIL projects which have already been completed at Tory Island, Rathlin West and Rathlin East lighthouses.

CIL is also planning to reduce the range of the light down to 18 miles, provide full emergency lanterns, remove an existing diesel generator and provide a battery back-up.

There are also plans to remove the existing wall lining to expose the original masonry on the lighthouse tower, with the work aimed at reducing cost and maintenance requirements.

CIL has described the Fresnel lens as an “exceptional work of engineering” but says current UK regulations require organisations to put processes in place to protect human health and the environment from the adverse effects of mercury, including phasing out of its use where alternatives are available.

The Lecale Lightkeepers campaign group, which is opposed to the planned changes, wants politicians who have insisted there must be no change at St John’s Point, to stick to their position.

DUP councillors Callum Bowsie and Alan Lewis have reaffirmed their support for the lighthouse to reman as it is.

Cllr Bowsie claimed the character of the light source was not being given enough historical value and cited a “lack of evidence” from CIL to justify the need to change the current bulb and the rotating mechanism.

“Retention of any old industrial asset always carries a degree of some risk and a Listed Building Consent application should prove the need for mechanical alteration based on the actual level of risk, supported by evidence of the harm mercury causes at this site or other similar sites,” he said.

“The lighthouse’s primary function is not a museum piece but as an operational lighthouse. This is an important distinction that must be respected by historical enthusiasts.”

“The heritage impact assessment states that ‘the light’s character will remain unchanged’ yet

in other documents the old and new light source is described as ‘almost identical’, therefore there is a change and to what extent is unclear and debatable,” said Cllr  .

“To the thousands who have watched the sweeping beam of light for many years, any slight change will be distinguishable. The light in its current emanation remains unchanged since 1910 and that itself is a historical quality that must be protected at all costs.”

Cllr Bowsie continued: “While adaptations to an operational listed building are often acceptable, they must be justified. Based on the documentation provided, I do not believe this to be the case.

“The benefits of an LED light source, if any, do not seem to outweigh the impact on this most intrinsic part of this historical asset, the character of the light, which there is uncertainty as to its extent of change.”

He added that outstanding evidence justifying the replacement of the current rotational mechanism and light source should be provided by the applicant to allow the Historic Environment Division to re-evaluate the Listed Building Consent application.