Introduction: National Grid in the past has looked at the problem of screening from a very local viewpoint, and tended to rely on screening systems that are not capable of being easily transported, manoeuvred and put into the HV environment without outages, lifting equipment and substantial cost.

The screening material under investigation is designed to primarily be completely effective in preventing all fragments of porcelain from a catastrophic failure at a distance of less than 10m. The system is designed to be modular, which means entire walls can be quickly assembled. The materials are to be extremely cost effective, relatively lightweight and will be designed to be easily fabricated to address several roles such as relay room protection, outer perimeter fence guards (for third party protection), window guards, safety pathways through substations, wheeled screens for ASAP coverage and emergency refuge shelters for those working within the substation, where travelling to a point of exit represents a danger in itself.

The materials employed will be able to be 80% recycled (post use) on our substations as trench covers, with the lightweight transparent armour plate being recycled through normal recycling channels. It is thought that only the main stay frame will be the only component that will require disposal or return to the manufacturer.

The entire system will be completed from non-conductive components, and assembled by Redman Composites, who currently are building blast protection screens for the enhanced security projects at many London substations.

Objectives: This project is to deliver a cheap, effective and easily deployed ballistic screening module that is easily capable of withstanding the resulting debris from a typical catastrophic failure of porcelain clad High Voltage (HV) transmission assets such as those seen in FMJL, FMVGs, SP2 breakers, bushings etc. It will be modular to cope with as small, or as large a deployment screen as required. Fully non-metal, it can be used within a live substation.