A 30-YEAR-OLD, home-made tractor, like its 79-year-old owners, is still going strong in the Mallee, reports MARK SAUNDERS

George and Albert Oliver's home-made 30-year-old tractor is not only still running strong, it now has the latest GPS precision equipment.

The 224kW articulated tractor, built by twins George and Albert in 1977, can now be operated with two centimetre accuracy and driven hands-free.

The Olivers crop about 2840ha on their family property at Manangatang with their sons Peter and Kevin.

For the twins, who both still drive the tractor, the addition of GPS is simply another step towards more efficient farming.

Albert said they have been cropping on 300mm row spacings for four years and now they have GPS capabilities, the next change could be to controlled traffic farming.

"We got into the GPS because of the increased accuracy and reduced input costs," Albert said.

"We sowed all this year's crop using the GPS system and it's proved a winner. We can also spray with the GPS and we will be using it on the harvesters for the first time this year."

Peter added that another benefit was the reduction in stress on the driver.

"In the past we had used a foam marker, but that could blow away in the wind or be dissolved by the time you completed a lap of the paddock.

"With the GPS, we can spray at night or in the mornings which is great for summer weed control and the dust is no longer a problem," Peter said.

"The real benefit is what you save by avoiding overlap. In one paddock of 640 acres (260ha), we saved 20 acres (8ha).

"It's costing us about $80 an acre (0.40ha) so that really adds up. Just in that one paddock we were $1600 ahead."

And the twins are living proof that age is no barrier when it comes to technology.

Albert said the GPS was quite simple to use, once he had spent a little time getting familiar with the programming.

"Once you have it set up right, it is very easy and just a matter of following the processes. You just need to sit down and take your time and follow it through."

Jim Castles from GPS-Ag at Ouyen installed the GPS equipment that is an A5 Autofarm RTK 2cm system using base stations that are located at either end of the Oliver property. Jim said both stations are available to other farmers in the area using GPS-Ag gear.

"We're creating a network right across the Mallee," Jim said.

The twins' "can do" attitude has been a part of their farming for decades.

In the 1960s they built their own self-propelled harvester by joining two PTO-driven harvesters.

Generally, they prefer to innovate, where possible, rather than buy new equipment. Neither George nor Albert has formal qualifications in fabrication or engineering. It was no different with the articulated tractor.

Albert said they felt they could not justify the expense of buying a new tractor in the 1970s for the amount of land they were farming then, so they decided to build their own.

"We really only had a sketch to go on and we had seen an articulated tractor and thought that was the way to go.

"We are quite mechanically minded and we thought it should not be too hard a task."

Twelve months later, Albert and George had built the tractor, complete with a GM 71 Series diesel that, in its day, was standard in Kenworth trucks and the differentials are from a Sherman tank.

The front and rear differentials weigh close to five tonnes each and have 75mm thick steel casings.

It has never been weighed, but the twins reckon the tractor would tip the scales somewhere between 15 and 20 tonnes.

"There are no issues with ballast, that's for sure," Albert said.

He added there have never been any major breakdowns with the tractor, known simply as "AGO" that stands for Albert and George Oliver. The twins built everything on the tractor, except for the cabin, which was pre-fabricated in Ballarat.

In more than 30 years, the tractor has racked up about 14,000 engine hours and is still on its original tyres, although Albert conceded he ordered a new set just the other week.

The tractor sowed about half of the Olivers' crop this year and is used in cultivation work.

Albert said it was also one of the first tractors to have closed centre hydraulics, that enables most of the hydraulic functions such as steering and implement control to be run from the one pump.

Gearing is courtesy of a 13-speed Roadranger gearbox.

Albert laughed when he recalled the day they attempted to find the tractor's top speed.

"We had it up to about 80km/h and the car was struggling to keep up. We weren't game to go any faster."

He also remembered when the tractor was to first be registered.

"We had to provide a chassis number and as we built it, we just put the date on it - 12071977."