Faster roading cuts into wasteful transit

Farmers spend up to 15 percent of their day field-hopping equipment during seeding and harvest. This unavoidable time waster is the obvious result of bigger farms with more distant fields.

That information comes from research conducted by Quebec manufacturer Camso, according to product manager Jeff Staab.

“Growers are increasingly working ground that’s spread out from the main farm. We’re seeing 10 percent and up to 15 percent of their time during planting and harvest periods spent on the road, bringing equipment to and from the fields,” said Staab.

One partial solution is faster road speeds, which is precisely what Camso is now offering to farmers who tow trailers and other implements equipped with tracks. The new road-speed tracks are designed for sprayers, seeding equipment, fertilizer carts, grain carts and any other towed implement.

The new roading component gives a 30 percent speed boost to TTS 35, 40 and 45 tracks, allowing them to travel at 20 m.p.h. for two continuous hours. In January Camso will include the same 20 m.p.h. roading speed and extended transit duration capability for the 70, 80, 100 and 110 series tracks. Twelve of its 16 trail track system (TTS) models for agriculture will have the high-speed long-duration feature by early 2021.

Staab conceded that rubber tracks at 20 m.p.h. on a gravel road for two hours are going to experience a heat problem. Heat was the main challenge Camso engineers faced.

“We have two solutions to manage heat. The TTS already has oscillating axles, which help the track conform to the surface of the road. We’ve had that for a while,” Staab said, adding that this feature helps distribute the weight more uniformly on the rubber belts.

Heat was a major deterrent in meeting the twin goals of speed and duration for Camso rubber track systems. The project to fix the issues required a ground-up re-design, focusing on preventing heat rather than getting rid of it. On the left is the previous design, on the right, the new high-speed configuration. | Camso photo

The design emphasis was not to make heat dissipate. It was more on preventing the heat from building up in the first place. Staab said the process was proactive rather than reactive:

The compression of rubber against the road surface creates heat. The more evenly the weight of the trailer is distributed, the less heat generated by the tracks. That’s a job the oscillating axles were already performing.

The new technology dealing with heat is found in the tracks themselves. Camso has changed the belt carcass and the tread pattern. Engineers spent a lot of time finding the correct angle of the treads and the best profile to reduce rubbing and scrubbing at the higher speeds.

He said higher speeds definitely transfer more heat into the hubs, but like the oscillating axles, that concern had already been addressed by making hub upgrades before the new TTS were ready. The only real change was a different seal for the oil baths. The hubs require no greasing or repacking.

Staab said the active track tensioner is a pretty simple design. It uses a mechanical spring rather than a hydraulic system. He said it provides a very fine balance between track tension and ease of pulling.

“People instinctively feel a hydraulic tensioner reacts more quickly and accurately than a mechanical spring. Not true. We run some very light tensions to make these tracks easier to pull. The more tension you put into any track, the harder it is to pull. Any parasitic loss from a rubber trailer track is going to be big. The tractor will feel it.

“Our springs create just enough tension to keep the rubber belt running correctly on the undercarriage. It has a big lever arm that we adjust at the factory. This is a ‘set it and forget it’ system. The increased recoil movement improves debris management. Optimal track tension makes for longer life of the belt and components. Plus, we decided against hydraulics because of the higher level of required maintenance.

“There’s sort of a compliment from the industry on our spring tensioner. Most of the other track manufacturers have adopted our system. We first installed it on our trailer tracks systems in 2013.”

The roading TTS employs double oscillating bogie wheels to improve ground contact. The mechanical spring tensioner is adjusted once at the factory, and needs no service after that. | Camso image

“(The new TTS feature is) a specially designed track for less berming when turning on headlands and lower rolling resistance for greater ease of pulling in the field and on the road.”

Staab said it’s well accepted that operator behaviour is a big factor in headland berming when pulling an implement on rubber tracks. Gradual turns at lower speeds are the key to reducing berming.

However, people are people and people don’t like to slow down when turning. That being the case, Staab said there are actually some tread design factors that can reduce berming. After all, these are not power tracks, so there’s no need for traction or big lugs.

“We developed these tracks for very low ground disturbance while going straight or turning. The tread pattern is designed to minimize ground engagement and displace very little soil. It’s a very shallow tread with a very wide contact area, so it doesn’t penetrate a lot into the soil surface.”

He said the pivoting, double oscillating, bogie wheels improve belt stability and flexibility for better weight distribution and reduced point loading.

“Our TTS reduces ground pressure up to 70 percent compared to round rubber tires. On a big grain cart, for instance, tracks will have up to three times the footprint of a comparably equipped cart with tires. Our two large systems are for carts at 80,000 pounds or 110,000 lb. Compare that to a cart with two 12.50x50R32 tires.

“The cart with tracks obviously weighs more, simply because the undercarriage is heavier. But we gain triple the footprint. So you can pencil out a 60 to 70 percent reduction in ground pressure. As we know, that results in less soil compaction, better soil health and potential to maximize yields.”

Tractors and combines are a different story. Camso designs and produces power tracks for many combine and tractor applications. Those power tracks already have roading speed capability for continuous 25 m.p.h.

“Power tracks experience a different load condition when roading compared to trailer tracks. Designing for trailer tracks, we often do not have the physical space to do exactly what we want to do. Tractors have the luxury of more space for us to work with. That’s why we can’t make the trail systems go 25 m.p.h. like the tractors do.”

He said the other reason Camso won’t build TTS that go above 20 m.p.h. is the legal implication of ignoring tractor specifications. There are guidelines regarding what you can and cannot do when pulling a farm implement with a tractor.

“The guideline says 20 m.p.h. max unless the trailer is equipped with brakes. So we match the performance of the rubber track to the guideline specification for road speed. We are working on brakes systems for TTS, and we have some new brake technology that we’ll be introducing in the future.”

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