MACHINERY manufacturers rarely get a design brief that starts: "It has to stall my 500 horsepower tractor without pulling the back end of it out".

But that's exactly what Smale Farm Equipment had to work with when a Wimmera farmer came to them with a concept for an oversized deep ripper that could be used to mix clay with sand.

A little more than six weeks after the briefing - just in time for the recent Wimmera Machinery Field Days - Smale Farm Equipment rolled out the monster ripper, which weighs in at about 13 tonnes.

Smale Farm Equipment's Mick Loats worked on the machine, which he calls a clay delver.

"It will be used to lift clay up from beneath the soil surface into the more sandy ground, which will enable the ground to hold more water and hence be more productive," Mick said.

"It's a one-off build for the customer, who has made several of his own versions, but he has to spend too much time repairing them.

"Hopefully this is strong enough to do the job."

Strength in the build quality of the clay delver is apparent from the first time you see the massive machine, which has four huge tines at the front and two main rippers at the rear.

Mick said the steel for the frame was the same as the steel used to build modern truck chassis.

"The thinnest piece of steel on the whole thing is 12mm thick," Mick said.

"We needed a crane to lift pretty much every bit of it, so it's very heavy duty."

Mick said one of the heavier parts was the main shaft at the rear of the delver, which is 125mm in diameter.

"When people saw the shaft, which is just shorter than the 5.2m width of the delver, they thought it was ridiculously big.

"But now it's in place on the machine, it looks quite small."

Six weeks seems like a short turnaround time to build the delver from scratch, but Mick said keeping the design simple was a key factor.

"And the computer-aided design programs we use in the factory are a huge help. We would not have had a hope of building it without CAD," he said.

"It can generate detailed drawings and we can simply email those to steel suppliers, to ensure that we get the material fabricated to exacting specifications."