Does your casting comply?

A clear explanation of which materials and procedures are needed to deliver the best possible performance of road chamber top and gully top installations in trunk roads and motorways is provided in a new technical guidance note produced by Wrekin Products.

Highways authorities and civil engineering contractors regularly ask leading UK access cover designer and manufacturer Wrekin for advice on how to check that covers they are considering comply with HA104/09, and the new document provides the answer.

 “We always advise that procurers and buyers ask their manhole cover supplier to provide them with their calculation, it is a quick and easy way to check if a casting complies with HA104/09″ 

The first point on the document states that the bearing pressure of the frame must not exceed 2.1N/mm2 and goes on to provide an easy to follow explanation of how to calculate this.

The equation to use is F/L = B {s2.1}. F = flange area in mm2. L=EN124 test load in kN. B= bearing pressure.

Wrekin Products Technical Director Simon Gibson says: “We always advise that procurers and buyers ask their manhole cover supplier to provide them with their calculation, it is a quick and easy way to check if a casting complies with HA104/09.”

Other details included in the document include flange width, gusset depth and advice on when balanced lifting must be allowed.

The advice note sets out procedures and denotes materials which Highway Authorities believe provide the best possible performance of road chamber top and gully top installations in trunk roads and motorways. Its recommendations in this respect are also adopted by Sewers for Adoption which applies to nearly all new housing developments.

Copies of the note are available on the Wrekin Products website at //www.wrekinproducts.com/ha10409-guidance/