The glorious simplicity and versatility of impeller-type side-spreaders that has made them popular over countless years hasn’t been lost on manufacturers looking to develop new and bigger-capacity machines.

With an easily-filled, open-topped body, one or two augers to move material to the discharge mechanism and the ability to spread yard manure and slurry in a controlled, even manner, impeller spreaders make an attractive option for stock farmers and contractors alike.

In the field, they also have the advantage over rear-discharge machines of pulling the load forward rather than pushing it to the back. So weight distribution (which is also helped by the location of the spreading rotor) is always biased towards the drawbar and the tractor’s rear wheels.

One or two slowly-rotating augers with a combination of flighting and paddles – including spring-steel feed-out paddles on the Abbey All-Purpose spreader – get bulky material to the rotor.

On the Harry West Dual Spreader and Kuhn ProTwin Slinger, this is positioned hard against the front bulkhead.

All the other designs follow Econ’s original idea of positioning the rotor further back, which requires an auger drawing from the front and the rear of the machine.

Manufacturers with this layout say it creates a tumbling action that helps break up material and discourages bridging, although the Hunton Legg Multispreader and Shelbourne’s Powerspread can be fitted with hydraulically-operated devices to discourage this potential problem.

The Dual Spreader has steep body sides and a built-in agitator to deal with this issue while the Slinger, sourced from Kuhn’s North American factory, has two augers – one set a little higher than the other and running to the rear to create a circulating action said to help break up dry, bulky material.

The 14t model in the built-to-order Multispreader range, which used to be a Dowdeswell product, also has two augers in its wide-bottomed body – but they rotate in the same direction, albeit at different speeds to achieve the same effect.

A guillotine door to regulate the flow of material to the discharge impeller is a common feature but rotor designs differ.

Most have replaceable serrated blades between reinforcing plates. But the West Dual Spreader continues to dispense its load using a finger rotor with replaceable weld-in tips and Kuhn’s Slinger has free-swinging flails which, apart from anything else, gives a degree of damage-limitation when they encounter a solid piece of debris.

The high-throughput 1.5m-wide rotor on Richard Western’s Side Delivery Spreader is matched on Shelbourne Reynolds’ new Pro 2400 and Pro 3200 machines to meet contractor demand for bigger workrates, especially with relatively dry material.

Being able to lower the rotor on hydraulic cylinders and having a higher-lifting guillotine door makes it easier to remove concrete blocks and other debris, says Shelbourne Reynolds.

The higher-torque chain and sprocket drive, together with a larger diameter auger of different pitch, has eliminated the need for the three-speed set-up of the Contractor models.

Another feature that the two newcomers share with the Richard Western SDS 2400 is the option of sprung tandem axles for contractors with long road hauls on their books.