Frequently Asked Questions

Qu .Can anyone offer FACTA graded covers ?

A. We would strongly advise end users or specifiers to insist that the supplier is a Member of the Fabricated Access Cover Trade Association. Our Membership ensures that we manufacture the covers ourselves and our Member selection process ensures adequate experience in its manufacture and design.

By insisting that the supplier is a FACTA Member then the additional costs associated with failed assemblies can be avoided.

Qu. What Is a grade A ?

A. Grade A was frequently referred to and is applicable to the old BS 497 Standard. This standard was superceded by BS EN 124. Unfortunately we also lost the distinction between fast moving carriageway and slower speeds of wheel loads.

Qu . Where are 11.5 T wheel loads permitted ?

A. There is a maximum wheel load allowed on a British road of 6.5T as a result of increases in freight axle loads from Europe .

Abnormal loads cannot impose a higher load unless by special arrangement and even then the abnormal load tends to be distributed over a large number of axles to keep the wheel load within acceptable limits of the pavement design.

Unusual wheel loads off the main carriageway can occur and advice should be sought from the access cover designer for the more unusual case.

Qu. Why do we need different test loads for steel ?

A. Actual test loads in the FACTA guide are based upon wheel load plus dynamics plus material safety factor. Obviously the wheel load is the same for irrespective of material but the behavioural characteristics of steel differ from other materials.

BS EN 124 includes material specific ultimate test loads which are used to sample test from large batches of standard product.

As FACTA Members we are constantly called upon to design large bespoke assemblies and it would be impossible to subject these to a test rig .

With this in mind we use analysis and calculation based upon the base wheel load to establish a calculated serviceability load. Once designed within the elastic limits of the steel we then add a further ultimate safety factor of 1.6 against failure.

Obviously our methodology is no different from design of steel elements generally and we have used various National and European standards to confirm our approach.

Qu. What is GLV and how does it relate to FACTA.?

A. GLV or Gross Laden Vehicle weight has largely grown around the merchant market. The loading classes vary from as little as 5T GLV through to 38T GLV rating.

Care should always be taken as is detailed within our guide, vehicles as light as 17T GLV can have a 5Tonne wheel load hence the recommendation to class B from the FACTA guide.

Qu. What Is The Difference between a class B and a class D ?

A. In truth the only difference is speed of the vehicle. We are of the opinion that if it is possible for emergency vehicle access then we should assume the worst case wheel loading. If we apply this to a carriageway then the same wheel load is travelling at a higher speed and as such the dynamics are greater.

Recent changes to EU regulations permit higher axle loadings. European freight can impose up to 6.5T base wheel loads and as a consequence it is highly likely that the access cover designer may recommend a minimum of class C from class B to account for this.

Obviously the same argument stands-one of speed and its effects.

Qu. Why are there so many load classes in the FACTA guide - does this not complicate the issue of selection ?

A. FACTA was formed to address the shortcomings within BS EN 124. We are conscious of the number of different GLV ratings within the highly competitive merchant market and hence created additional load classes to address this.

N.B. GLV rating is not a guarantee that the cover has been subject to the rigorous design routine of its equivalent FACTA class - Always insist that the supplier is a FACTA Member and that the load class quoted is a FACTA load class.

Qu. How do I ensure adequate corrosion protection ?

A. Steel by its ferrous composition is prone to corrosion.We tend to recommend that the product is post galvanised to BS EN 1461 1999.There are specific cases which require special consideration - chlorinated water is one of a number and advice should always be sought from the access cover supplier.

Austenitic stainless steels of various grades together with aluminium alloys tend not to require additional corrosion protection although advice should be sought as to the appropriate grade of alloy to be used.

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