Race Rock

The ideal material for farm races and tracks – Atiamuri Gold Race Rock mined at Atiamuri is an amorphous blend of mainly silicon and aluminium oxide and low levels of other metal oxides.

Pumice is a light siliceous vesicular volcanic rock that is suitable for use in construction, industrial applications, agriculture and also horticulture and hydroponics. The primary attraction of Atiamuri Gold Race Rock is that whilst it is extremely porous ensuring free drainage of water it is strong enough that, when compacted, it still retains all its properties and provides the perfect surface.

Benefits include:

• Less time and money spent on repairs
• More efficiency through better cow flow
• Fewer incidences of lameness

What makes a perfect track – six attributes your track should have. The perfect track is:

• Wide enough
• As short as possible
• Distraction-free
• Well fenced
• Has good paddock access
• Has a good surface

Here are some basic race construction principles to follow:

• Remove all grass and topsoil
• Construct a sound base with strong foundation material
• Provide adequate compaction
• Provide a suitable walking surface
• Crown the race
• Construct an efficient drainage system
• Fence cows out of the drain but ensure access for cleaning
• Include a maintenance programme in the budget

Track surfacing and formation. Ensure the camber is between 3-8%, and that the paddock side is fenced off if there are drains beside the track.

A good track is constructed in layers. A foundation, or base layer, is formed with a surface, or wearing layer, placed on top.

The base layer provides the structural support for the surface layer – if it is weak the surface layer may break up and collapse. If water can penetrate into the base layer it may lose its strength resulting in potholes.

The surface layer has two functions: to provide a comfortable surface for cows to walk on and to shed water to protect the structural integrity of the track.

Each layer should be thoroughly mechanically compacted using vibrating rollers. Loose, open layers have much less strength than well-consolidated ones. Cow traffic does not provide an adequate substitute for mechanical compaction.

Foundation (base) layer:

Topsoil and grass are not suitable for use in the base layer and should be removed before beginning construction.

The base should be made up of layers, each up to 150 mm deep. After each 150mm layer is laid, it should be firmly compacted before the next is added.

Consider the following when selecting materials:

The creation of a satisfactory track surface requires compaction into a hard, smooth, wear resistant layer, with a minimum of particles that can cut or bruise feet.

• It should be 100 – 150 mm thick.
• Crushed pumice (5-6 mm). This need to be verified by trial farm
• Sand alone does not make an ideal surface – it is abrasive on cows’ feet and washes away too readily.
• Well rounded pumice, less than 25 mm in diameter, is preferable to large stones. Large stones can be kicked aside, leaving the surface susceptible to water penetration and damage.
• Fine particles of clay will fill the gaps between larger particles, binding it together. It also gives the surface a long wearing and smooth finish.

To check if a material is appropriate for a top surface, a small sample rock should shatter under the heel of your gumboot when ground against a concrete surface. Trialling small loads of proposed materials will show which are going to work and which are not.