The fact that the surface is broken generates noise but this can be more or less depending on other factors.
The shape and spacing of the bars is a crucial issue. The BS defines the permitted size and ranges of spaces for bars. This is to ensure effectiveness and to protect animals who become stuck in a grid.
Circular Bars with maximum permitted spaces are the noisiest.
Square or rectangular bars with minimum, permitted, spacing are the quietest solution to this particular aspect.
but there are further relevant factors….
The steel unit needs to be a good fit with the concrete sleeper walls or base. Steel banging on concrete does not aid sleep! This is best dealt with by ensuring high quality concrete forming to ensure a snug fit with the flat steel structure.
It is increasingly difficult to secure the services of Contractors with the necessary skills. This is a driver for the switch to the Pitless Units also known as Drop-in Units . These units if correctly fitted are very quiet.
These Pitless or Drop-in units avoid sleeper walls by providing a steel base for the grids to sit on. It is vital that these are well made so the removable grids do not bang against the base creating another source of noise.
Sadly this installation has left a strip of concrete (on the right hand edge) a sheep would find both enticing and easy to use to thwart the grid.
The main aim is to improve the users experience by avoiding repeatedly dis mounting to open and close gates. They also help to lower the extraordinary high blood pressure experienced by farmers when their stock escape.
Ongie Cattle Grids are the brainwave of “laughing” Scott Roberts. An inventive soul with a cruel sense of humour . It is not true that he hates cyclists – allegedly
These useful smaller Cattle Grids do not need to carry the same loads as a vehicle grid. They do need to conform as closely as possible to BS spacing and grid bar ranges. Correct pit depth is vital if stock control is to be effective.
There are some designs which are frankly deadly! One used around Cambridge made from small diameter ridged rods is particularly unattractive.
There is a very important distinction between a Cattle Grid and a Catch Pit.
Cattle Grids are designed to contain stock and so to miniseries the harm if an animal become trapped in it
Catch Pits look like cattle grids but are designed to capture flood water, running along a road or drive. They should never be used to contain stock as animals could be injured, potentially fatally, by becoming trapped with their legs in the pit.
Catch Pits are usually shorter in length along the road but much deeper to contain the maximum flows. Depths can exceed the length of an amimal’s leg !