High power and comfort in one stylish package
As well as massive pulling
power, the big STX440
tractor from Case IH also
scores high marks for driver
comfort, as Mike Williams
discovered when he talked
to one of the first UK owners
WITH 440hp under its bonnet the STX440 became Britains most powerful production tractor when it was launched last year and it was this power output which attracted Duncan and Andrew West of the C A West & Son farming company on the Norfolk/Suffolk border.
The STX tractor series built at the Case companys Steiger factory in America comprises four models. All feature pivot steering and are available with four-wheel-drive or as the now familiar Quadtrac version with its four rubber tracks. The West family chose the Quadtrac build for their 1600ha (4000 acres).
The farms, run as a family partnership at Pulham St Mary and Oakley near Diss, are all arable with 1200ha (3000 acres) of cereals and other combinable crops plus sugar beet, peas and beans on soils ranging from medium-light to heavy clays.
When the new STX440 was announced last autumn the Quadtrac version was an obvious choice for the Wests, who have been using crawler tractors with rubber tracks since the early 1990s.
They started with a Caterpillar Challenger which was replaced four years ago by what was then the most powerful Quadtrac with a 360hp engine. When the new 440hp tractor was ordered 12 months ago it was decided to keep their existing Quadtrac to allow cultivations and drilling to continue while using wide equipment.
"We need plenty of power and we can easily justify running the two high horsepower tractors like the Quadtracs because they give a big improvement in work rate and output per man," says Duncan West. "We also need to keep the ground pressure low and when the 36in wide tracks are available they will bring a further improvement."
As well as the compaction factor, the Wests also like rubber tracks because they can be used on the road including the seven-mile journey between their two main farms, plus some contract work.
"We were using big wheeled tractors before we bought the Challenger, and I think our soils have benefited from changing to tracks, particularly in the wet years we have had recently," says Mr West. "One of the advantages of the Quadtracs is that we can use them for top work and drilling as well as heavy cultivations, even in adverse conditions. We do a lot of spring work with the Quadtracs and about 35% of our wheat is spring sown after late harvested crops, including s ome double cropping. Our ploughing, cultivations and drilling in the spring and summer total about 650ha.
"I like the layout of the Quadtrac because I think the four separate tracks give better traction than full-length tracks. Both Quadtracs have performed well, but they have not been completely trouble-free."
The biggest problem with the first Quadtrac was that the tracks needed replacing sooner than expected because of cracking. The front pair was changed at 2522 hours and a new rear set was fitted at 2890 hours, according to the detailed records kept by Chris Jude.
Mr Jude drove the previous Quadtrac, but took over the new STX440 when it arrived at the end of February.
Since then, the new tractor has clocked up about 750 hours and at this stage the tracks are showing no signs of the problems experienced on the previous Quadtrac. Mr West thinks this is partly because Goodyear is using a different compound to make the latest tracks and also because the diameter of the drive wheels has been increased.
The only problem so far on the new 440hp tractor has been a bearing failure in one of the track rollers and because of this all the other roller bearings were replaced at the same time.
The list of equipment pulled by the Quadtracs includes a Kverneland 12-furrow plough, a Tim Howard seven-leg soil loosener, a Simba 6m Solo cultivator, a 10m wide Vaderstad cultivator and an 8m Vaderstad drill plus a 6m Simba Solo cultivator complete with a press roller. The Wests also recently tried a Michael Moore three-leg mole plough, which was pulled at 24in.
Field sizes average 17ha and actual work rates depend on the size and shape of the fields, but typical rates with the 12-furrow plough are 25ha a day and about 50ha a day with the drill.
Although the obvious advantage of the new tractor is the ability to handle big equipment with pulling power to spare, there is much more to the STX440 than just a big engine, says Mr Jude.
"Case redesigned the cab for the new models and this is easily the most comfortable tractor I have ever driven." *
The Quadtrac makes light work of a 12-furrow Kverneland plough.
An extended dipstick allows engine oil to be checked from ground level.