Gwynedd residents are calling for measures to mitigate the potential screams of ‘terror and thrill’ by Zip World visitors if plans for a new ride at its Bethesda quarry site goes ahead.

Locals in the village, particularly around the Rhes Jams, Braichmelyn area, nearby, are worried over the potential for “anti-social noise” if the attraction succeeds in a planning bid.

They are asking Gwynedd Council to raise the matter with the company.

A full application has been submitted to Cyngor Gwynedd and will be considered at a planning meeting on Monday, 20 October.

The recommendation is to approve with conditions.

The proposal relates to a giant, six seater ‘Swing’ ride, and includes development of a swing platform structure, ramp, landing structure, associated cables and anchor structures, with associated works at Penrhyn Quarry.

A notice was posted at the site, in the press, and the neighbours were informed, a report said.

Locals had responded by saying “the proposed giant swing will be designed to create a ‘terror’ and ‘thrill’ experience for those who ride, leading to inevitable loud, anti-social screaming to be suffered by the residents of Rhes Jams and the nearby community on a daily basis.

“If the proposed plan is approved, we ask Cyngor Gwynedd to discuss the above matter with Zip World, to ensure that the company takes appropriate steps to mitigate our concerns.”

A council report stated that a noise assessment was submitted with the application, and a baseline noise survey undertaken in two locations that represented the closest dwellings. A noise model of the proposed ride was also developed.

“The noise model’s results were used to provide “a comparative assessment against the existing noise levels,” the report said.

Predicted noise levels of the swing ride were “far below the overall residual noise levels of 10 dB or higher, suggesting that the noise would not be noticeable under normal conditions and that there would be no detrimental noise impact,” it had stated,

Consultants also undertook a BS 4142 assessment with results showing that “the predicted Specific Sound Levels are far below the Background Sound Levels and only note a ‘low’ impact” it said.

Although the Public Protection Service had “largely accepted” the conclusions in relation to noise deriving directly from the machinery, it had expressed “some concern regarding the lack of attention given to the noise from customers screaming while using the swing”.

It stated “as this is the first of its type, it is very difficult to assess whether the swing will have a noise impact on the area.

“If the authority approves the application, the service would recommend that conditions are imposed on any permission in relation to the operational hours and the noise threshold as outlined in the noise report to ensure that local residents are not affected by noise.

“We have concern about noise from customers screaming while they are on the Swing, and how this can be managed”.

The application site includes land within Penrhyn Quarry, to the south west of the existing Zip World site, extending across the quarry lake towards the south east, towards the gallery, on a higher level on the southern side of the quarry pit.

The site is partially located within the Slate Landscape of North West Wales World Heritage Site and the Dyffryn Ogwen Landscape of Outstanding Historic Interest, with the monuments of Penrhyn Quarry, the quarry hospital, underground levels and relict areas nearby.

The development would include creation of a lower anchor point (northern), a ramp, landing area, cart, swing and platform, higher anchor point (southern), connected by two tensioned cables traversing the quarry between both anchorage points.

These would be fixed in place by pairs of upright steel columns on concrete pad footings.

Cadw had raised some concerns over the impact on the World Heritage Site and monuments but which it said would be reduced, providing mitigation measures were taken.

Among them were “removal of detracting structures” including storage containers and timber-clad shed to “remove visual clutter,” dedicated viewing spots, including a heritage viewing area, interpretation panels, vegetation management, landscaping, screening, a Princess Mary head frame report and team training.