OO- Works - Provan Gas Holder Refurbishment - 0326

Description

There is a requirement to carry out some repairs to the two frames of the column guided gasholders located off Blochairn Road in Glasgow. The gasholder frames at Provan are nationally listed, grade B. A detailed structural survey and a Hardness test of sample members has been undertaken on both gasholder frames. The purpose of carrying out the survey and tests was to inform SGN of the structural condition of the gasholder frames but also determine the possible repair and refurbishment strategy for the gasholder frames. The survey has established the structural performance requirements of the individual elements of the gas holder frame. The survey has identified defects which have been categorised as A required to be remediated within 1 year B require to be remediated within 2 years. There are 9 identified A defects on holder 1 and 15 on holder 2. The A listed defects have not included staircases, hand-rails and walkways which have been assumed they would be removed as part of the early phase of works, subject to Local Authority and/or Historic Environment Scotland (HES) approval. The A listed have been classified as showing severe defects such as large amounts of holing, thinning into deterioration, significant section loss (5.1% to 20%). The B listed items have been classified as moderate defects such as minor to moderate amount of holing, thinning/warping/major pitting, small section loss (2.1% to 5.1%). To note, it is likely that any scaffolding or similar structure provided would take lateral and vertical support from the gasholder frame, and as such the wind loading exerted on the frame by the scaffold enclosures is likely to become a critical load case in terms of the structural assessment. The structural assessment has identified the likely restrictions that may be placed on the extent of the gasholder that can be enclosed at any one time. Lot 1: There is a requirement to refurbish the two frames of the column guided gasholders located off Blochairn Road in Glasgow. The gasholder frames at Provan are nationally listed, grade B. A detailed structural survey and a Hardness test of sample members has been undertaken on both gasholder frames. The purpose of carrying out the survey and tests was to inform SGN of the structural condition of the gasholder frames but also determine the possible refurbishment strategy for the gasholder frames. The survey has established the structural performance requirements of the individual elements of the gas holder frame. The survey has identified defects and shown permissible section loss and this information will inform the refurbishment process. The report identifies the elements that require repair and indicates the levels of corrosion and justifies the levels of corrosion encountered without the need to repair. To note it is likely that any scaffolding or similar structure provided would take lateral and vertical support from the gasholder frame, and as such the wind loading exerted on the frame by the scaffold enclosures is likely to become a critical load case in terms of the structural assessment. The structural assessment has identified the likely restrictions that may be placed on the extent of the gasholder that can be enclosed at any one time. It must be noted that the structure is painted in a lead-based paint and as such will be required to have an enclosed structure to capture any airborne contaminants escaping to the local environment.