Glass replacement manhole cover

Plastics can be used for break glass replacement where real glass would be too dangerous or too strong.

To be used for break glass, the plastic needs to be modified so that it is weaker in places to allow it to be broken.

Project Background:
The client’s yard has a number of man holes leading to chemical equipment. Each one has a lever to open it in an emergency. This lever needs to be covered to protect it and to ensure there is a flush surface.

The Brief
The client wanted a glass replacement break glass that would withstand heavy vehicles driving over it and have the ability to be broken in an emergency. In addition, it had to be clear so that the lever could be seen beneath the break glass.

The Solution
The client had already tried toughened glass but this was incapable of being broken in an emergency. Real glass was far too dangerous. Safeglass® would be too weak. The solution was to provide a thick plastic with scores cut into the panel to weaken it. Trial and error work was required to find the right depth of the grooves and the right strength of material. Finally a solution was found which involved 10cm thick plastic.

The Result
The customer can now break the glass in an emergency. The material stands up well to the vehicles that drive over it.

Please contact us to discuss your project.