4 June 1999

Rubber tracks tough enough for road and field

By Mike Williams

RUBBER tracks, introduced more than 10 years ago, allowed crawler tractors to drive on the road for the first time, but it also raised concerns about track wear and replacement costs.

Steel reinforced rubber tracks first arrived on the Caterpillar Challenger and have been adopted by other makes including Case IH and John Deere. They are one of the tractor industry success stories and have given a big boost to tracklayer sales.

When the first Challengers arrived, they quickly showed they had inherited most of the virtues of the traditional steel-tracked crawler tractors, such as reduced ground pressure and positive pulling power, but proving that the new tracks could stand up to the wear and tear of field work and travelling at speeds up to 19mph on the road has taken longer.

The evidence on track wear comes from Challengers, and this is because other leading makes of rubber-tracked crawler tractor have not been available on UK farms long enough to build up a record of track replacement data.

Few farmers have more experience of rubber tracks than John Harrison. When the first batch of Challenger 65s arrived in the UK in 1989 he bought one of them, which he is still using, and this was followed two years ago by a Challenger 85D. The two Challengers deal with the ploughing, cultivating and drilling on 960ha (2400 acres), including Mr Harrisons Garlands Farm at Steeple Bumpstead on the Essex/Suffolk border plus farms he runs on a contract basis.

Because the farms are spread over an area measuring 42 miles from end to end, road travel forms an important part of the work routine for the Challengers. The steel tracked crawlers they replaced were moved about on a low loader, which was inconvenient, but the big problem was transporting the implements on the road.

"We had our own low loader for moving the tractors on the road, which worked reasonably well, but having to use another tractor to move the implements made things really complicated," says Mr Harrison. "I was planning to buy a new crawler tractor when I heard a rumour that the Challenger was coming, so I decided to wait, and I bought one as soon as they were available.

"Being able to drive on the road is a tremendous advantage, and it means a lot more flexibility and efficiency. I was not sure what to expect in terms of track costs when I bought my first Challenger, but the wear rate has certainly not been a problem."

Mr Harrison has just fitted new tracks to his Challenger 65. The old ones were still adequate for top work, but he wanted the new tracks ready to start this years ploughing season. This is the fourth set in 10 years, with the hour meter reading 10,800, which means the previous three sets averaged 3.3 years or 3600 hours each. The price quoted by Claas UK for a pair of tracks for the big 300hp plus Challengers with a track frame with four intermediate idlers is £8000.

There is usually a fitting charge as well, but Mr Harrison avoids this by doing the job himself. Removing the old tracks and fitting new ones is a two-person job and takes half a day, he says, but it is essential to have suitable equipment.

The maximum road journey for the two rubber-tracked Challengers on the Bartlow Estate is 15 miles. The two Challengers deal with most of the cultivations and top work on the 1320 ha (3300-acre) arable farming operation based at Bartlow, near Cambridge. It is spread over three farms, and most of the land is Hanslope series boulder clay, but there is also some chalky soil with flints.

The oldest of the Challengers is a 45 model with tracks on the shorter frame with three intermediate rollers. It has completed four seasons and is ready for its first track change with the hourmeter reading 4400.

John Goodchild, the farm manager at Bartlow, says the tracks still have enough tread to cope with top work, but he was arranging to have them replaced ready for autumn work. The cost will be about £6000 for a pair of standard 25in wide tracks plus nearly £600 for fitting, which suggests track wear has cost about £1.45p an hour.

"We were using a Caterpillar D5 before we bought the Challengers, and I think it was costing more to maintain the steel tracks," he says. "But the big advantage of the Challenger is being able to travel on the road, and it is also a lot easier than having to escort a large tractor on dual wheels. We do a fair amount of road work with the Challengers, but it is probably no more than average.

"Getting 4400 hours out of a set of tracks seems very reasonable compared with using steel tracks, and I dont suppose we would get as much work out of a set of tyres on a front-line tractor.

"Our second Challenger is a 55 model which has done two seasons, and at this stage it looks as if track wear is about the same as on the older Challenger, so they should do more than 4000 hours," says Mr Goodchild. "As far as I am concerned track wear really is not an issue with these tractors."

David Webb, who drives one of the Bartlow Estate Challengers, is also a rubber track enthusiast. Compared with the traditional steel tracked Caterpillars he has driven previously, the rubber tracks are much quieter and they allow faster travel speeds and a bigger output, he says.

According to Claas UK the typical working life for the shorter tracks for frames with three intermediate rollers is 4000 hours plus, but less than 4000 for the longer frame tracks because of increased wear when the tractor is turning. This compares with about 3000 hours for a set of tyres on a tractor of 250hp plus on arable work according to Claas.

The Challengers Mobil-trac rubber tracks are made by Caterpillar, but tracks for Case Quadtrac and John Deere 8000T tracklayers are made by Goodyear. The price of John Deere tracks is about £6000 for a pair, but Case IH could not quote a track price as the only replacement tracks they have supplied so far in the UK were under warranty. &#42