Farmers Guide was the first UK magazine to try out at an exclusive Case IH demonstration event.
In the past most half-track tractors have been the result of conversions of standard wheeled tractors by specialist suppliers, but the increasing power of modern conventional tractors combined with the need to maintain a width practical for road use has resulted in Case IH developing its Magnum Rowtrac. Farmers Guide was the first UK magazine to try it out at an exclusive demonstration event.
Agricultural tyre development in recent years has resulted in the availability of tyres capable of running at lower pressures, carrying higher loads, running at higher road speeds and transmitting more power to the ground than ever before. However, with the requirement from users for higher work rates, tractors with more power have become popular and during heavy draft work, it is often the ability to gain adequate grip, which limits performance. Tracked tractors have become a popular alternative, spreading the load over a larger area reducing compaction, and often providing better traction but the twin-track design, used by most manufacturers, is not ideal according to Case IH product marketing manager for the Quadtrac, Magnum and Rowtrac, Paul Freeman.
Case IH includes some of the most powerful conventional tractors available in its popular Magnum range including the 380CVX, boasting up to 435hp in its power boost mode, and which was awarded the coveted Tractor of the Year title for 2015. “The Magnum range has been a great success since it was introduced in 1987,” explained Paul, “and constant improvements and performance upgrades mean it remains the first choice for many larger farms and contractors. Correctly set-up and ballasted it is capable of high work rates and superb traction, but for the most demanding applications the new Rowtrac option will increase its abilities significantly.”
Case IH has considerable experience of track drive systems, its Quadtrac articulated tractors having four separate tracks instead of wheels and offering up to 682hp and its Axial-Flow combines available with tracks as an option for the past few seasons.
Not just a tracked Magnum
The Magnum Rowtrac is very different to its standard wheeled sibling, and although the front axle, engine, CVT transmission and cab are almost identical, the complete rear end has been specially designed to put up with the extra stresses created by the improved grip, and to maximise the performance of the track assemblies. From the rear crown and pinion, a shaft transmits power to a massive cast reduction gear housing, from which a large driven drive wheel engages with the track lugs transmitting the power.
Below the drive wheel is the track assembly, with a large idler wheel at each end and three track rollers between. Track tension is provided by a hydraulic ram between the idlers, automatically adjusting to provide correct tension every time any hydraulic service is activated on the tractor.
The track assembly is very cleverly designed, capable of pivoting front and rear and to the sides to ensure constant full ground contact by the tracks. A large fulcrum point, just below the centre of the drive wheel, provides the movement fore and aft.
The front and rear end idlers are 15mm above the three centre rollers which, the manufacturer explained, reduces wear on the road when ground contact by the full length of the tracks isn’t needed.
Track width options for the UK market will include 24 and 30in, and track centres of 72, 80 and 88in can be specified.
Lift capacity is the same as for the wheeled equivalents, but the lower lift arms are slightly extended, providing extra clearance for implements during headland turns. The PTO and hydraulic services are also as the wheeled machines.
For the UK market, three versions of the Rowtrac will be available; the Magnum 310, 340 and 380. Transmission options include an 18-speed powershift or CVT for the smaller models but the 380 flagship is available only with CVT. All UK machines will have a 40kph maximum travel speed as standard.
The Rowtrac is considerably heavier than the wheeled tractors, the 380 weighing in at approximately 19t unladen. Paul Freeman explained that, unlike a conventional 4wd wheeled tractor on which the rear wheels transmit some 70 per cent of the power, on the Rowtrac almost all the traction is provided by the tracks with the front wheels, on their suspended axle, used mainly for steering. When pulling hard in the field there is a natural tendency for the weight to transfer to the rear and this means most weight is on the tracks, helping provide the tractive effort.
A consequence of the heavier unladen weight is that the cab frame has been strengthened, to provide the protection needed in a rollover situation, although from the outside there is nothing to suggest a difference.
Because the tracks don’t provide the steering function, they have a standard differential, which can be locked for maximum traction if needed. The differential lock can be set to disengage automatically when the steering wheels exceed a preset angle, which means that when small corrections are needed during work the tracks can be left locked together for maximum efficiency.
Paul explained that the system results in a further significant benefit for users. “Most farms purchasing this sort of tractor will be operating using guidance systems, and a problem encountered often with twin-track crawlers is that when crossing uneven ground, there is a tendency for the tractor to twitch left and right, as the draft forces on each side vary. Because the automatic steering tries to correct this movement through the tracks, the result is a constant movement left and right which is uncomfortable for the operator. This isn’t the case with the Rowtrac, as the conventional front wheel steering allows minor corrections to be made as required, which are no more noticeable to the operator than they would be on a wheeled tractor.”
The steering front wheels provide an additional significant advantage over twin-track machines as, when carrying out tight headland turns, the land is left relatively flat and undisturbed whereas tracked machines, which rely on varying the speed of one track compared to the other, often have a tendency to push earth into ridges as the tracks slide. “This is a huge advantage,” added Paul, “particularly when carrying out light cultivations or drilling as the absence of ridges and troughs resulting from the four points of contact means the Rowtrac creates no more surface damage than a conventional wheeled machine.”
The Rowtrac 380CVX driven by Farmers Guide had been in the UK for dealer training, ahead of the autumn demonstration season when a number of machines will be available for potential customers to see at work. Following the dealer training the machine was due to travel almost immediately to Spain, but a 2-day gap meant there was an opportunity for the Case IH UK team to gauge customer reaction with a small demonstration event on a farm in Cambridgeshire, close to where the training had taken place, and this magazine was invited to attend.
The land was heavy and dry on top, but much wetter and more slippery underneath and some heavy rain showers during the day made conditions for the demonstration almost ideal, allowing the benefits of the track system to be clearly seen. Behind the Rowtrac was a Great Plains 4.2m SLD tine and disc cultivator, which took plenty of pulling in the working conditions.
The cab is immediately familiar to anyone used to the wheeled Magnum, and the CVT transmission made it easy to get the best from the machine. The engine speed was set at 1,800rpm at a working speed of approximately 8kph, providing flexibility as the draft requirement varied with the engine’s flat torque curve and constantly variable transmission ratio compensating easily.
Driving across the tramlines, the ride is smoother than on a wheeled tractor due to the long track sections in contact with the ground, and the operator’s suspension seat soaked up any vibrations easily. A ride on the passenger seat, without suspension, meant the tracks were more noticeable, the ride harsher than would have been the case on large tyres, but never uncomfortable.
In work, the tracks provided noticeably better traction than would have been possible with tyres and the engagement of the tracks with the top surface meant there was no noticeable slip during acceleration, even with the tines of the SLD deep in the ground. Looking out of the rear window, the small amount of slip was visible from the broken top surface behind each track, and the disturbance increased when accelerating hard from standstill or when cultivating heavier areas of the field.
Perfect match with RTK
Paul had explained clearly the benefits of the front wheels over twin-tracks when operating with automatic steering in conjunction with RTK, and cultivating diagonally across the tramlines clearly demonstrated the argument. Watching the front wheels as first one track, then the other crossed the tramline and then as the SLD’s tines met the compacted soil on one side and then the other, the steering was constantly correcting but the front wheels twitched just a few degrees from centre, keeping the tractor on track with no noticeable variation from the operator’s seat.
The headland turns were also interesting, with the front wheels setting the direction of travel and the turns completed with the same precision as would be the case with a wheeled tractor. Keen to test the theory regarding reduced ridging of the land, tight turns were executed, but although it was easy to see where the machine had manoeuvred, the disturbance was just a few inches deep and would cause no problems for following field operations or crops.
Some uneven areas in the field, including the path of an old farm track where some large lumps of rubble were ‘excavated’, gave the SLD and the Rowtrac a challenge, as the subsoil legs disappeared almost down to the cultivator frame. At this point the travel speed reduced as the CVT transmission adjusted and the engine growl increased and while it was possible to see increased track slip, there was no problem maintaining enough traction at any time.
Case IH is excited about the potential for the new tractor, believing its flexibility will be its main appeal. “It will probably replace some of our smaller Quadtrac sales,” said Paul, “but we expect most demand to be from farmers who want to replace conventional high horsepower wheeled tractors as well as some twin-track crawlers. The Rowtrac is quite at home on the road, no wider than a conventional wheeled tractor, but with more ground contact than a tractor on dual wheels, and much easier to move around than a twin-track crawler.
It needn’t be just for cultivations either; if an extra tractor is needed on a grain trailer, then this is a practical alternative, and it will be equally at home carrying out grassland harvesting activities such as mowing – the tracks providing a stable platform for the implement and reducing the possibility of soil contamination through ground contact. For drilling arable crops, the tracks will provide stability and accurate depth control, and there is no reason why it can’t carry out spraying and fertiliser applications.”
All Rowtracs sold in the UK will have front linkage fitted as standard and a higher specification cab than the European version tested, including a plush leather seat with pneumatic suspension.
The Rowtrac will be displayed at Cereals, and a demonstration tour will commence in late summer. Prices are yet to be confirmed.
The new Rowtrac was demonstrated on a Cambridgeshire farm, its owner a customer of Case IH main dealer Collings Bros. Dealer sales director Tony Fincham was delighted to be able to invite potential customers to take an early test-drive; Our sales staff at the event reported an excellent day resulting in many enquiries and requests for demonstrations during the autumn. Many visitors had seen details about the Rowtrac in the farming press and were intrigued, but wanted to see the machine in action to see how it performed in the field, and conditions on the day were very good, presenting a challenge for the machine.
We invited customers who are users of large wheeled tractors, twin-track crawlers and Quadtracs, including several users of older lower-horsepower Quadtracs which are of similar power to the Rowtrac being demonstrated and they were impressed with its size and versatility. Feedback was very positive and we had one farmer who expressed regret that he had recently ordered a new twin-track machine, once he had had an opportunity to work a couple of bouts in the field. There was a lot of good, open interest and we believe the Rowtrac will be ideally suited to our customer base, and farms in this area, he added. (l-r) Case IH area sales manage David Redman, Paul Freeman and Tony Fincham.