PEGGY FISHER: Plowing through the development of ag tires

The Feb. 4 special section of Tire Business focused on OTR and farm tires. I was asked to tailor my column to this subject as well.

Now, I have to tell you that I don't know much about farming, but I did grow up in the Garden State (New Jersey), which is home to a lot of truck farms. (No, they don't grow trucks. They grow vegetables for the market.)

While my family lived in suburbia, I did see a lot of farms that my parents pointed out during car excursions around the state and also visited some dairy farms that sold ice cream during these formative adventures.

However, my eldest sister, Jean, graduated from Rutgers University with a degree in nursing in 1958. Her first job was as a visiting nurse to farmers in southern New Jersey. She provided health care to these farmers and the migrant workers who lived and worked for them temporarily on their farms.

I shall never forget the day she brought home a piglet that a farmer had given her as thanks for the care she had given his family and workers. She promptly gave the baby pig to me (age 8) and my next elder sister, Linda, who was 10.

If you didn't know this already, pigs smell really bad, so my mother told us we could not bring the pig into the house until it had a bath and smelled a whole lot better.

So we gave the pig a bath in the garage and raided the bathroom medicine cabinet for every bottle of perfume, cologne, aftershave and toilette water it had and dumped it all on the pig after scrubbing it with lots of soap and water.

Have you heard the expression, "You can put lipstick on a pig, but it's still a pig"?

Well, there's another truism I discovered: "You can put perfume on a pig, but it still smells like a pig."

We named that pig, kept it in the garage, walked it up and down the street on a leash and gave it loads of love and attention, but by the end of the week Jean had to return it to the farmer.

We also had a rooster sometime later. We named it, kept it in the garage, walked it up and down the street on a leash, and gave it loads of love and attention but by the end of week, it too was returned to the farmer. And that is as close as I have ever been to being a farmer.

So I thought what would be interesting is to learn something about farming and specifically farm tires and share that information with you.

Early lessons

Farming is hard work (don't I know it). It takes a lot of power to force a plow through tough soil and turn it over, to push a seed into the ground and make it grow, to water the crops when it doesn't rain, to chop down the weeds that grow with the crops, harvest the crops and separate the wheat from the chaff and the corn from the husk.

In the olden days, all this work was done by farmers, their families and their horses and/or mules. but in the early part of the 20th century, machines began replacing animals.

In fact, by the 1930s, machines were being developed for every step of the growing process. Plows were mounted directly to tractors so they could be lifted out at the end of a row; grain drills and corn planters got better at distributing seed accurately and quickly; the tricycle tractor was invented that enabled farmers to drive cultivators through closely spaced rows, and in 1935 the first wheat combine that could be operated by just one man was invented.

Advances in steel manufacturing resulted in stronger and cheaper steel so many implements like harrows, used to break up dirt clods and root up weeds, that were made primarily out of wood with steel teeth mounted in them, were replaced with machines built completely from steel.

Early tractors were relatively simple machines that had no battery so you had to crank them to get them started. Over the course of the decade, tractors went from two cylinders to four and then six cylinders with electric starters and lights.

Harvey Firestone grew up on a farm and even as president of Firestone Tire & Rubber in the early 1900s continued to work on his farm outside of Akron, in Columbiana, Ohio, with his father and then his children. He understood the needs of farmers and in 1918 worked with International Harvester to outfit a tractor with solid rubber front tires and rears that had solid rubber blocks molded to steel wheels.

However, Firestone's pneumatic balloon tire, which was first built for automobiles in 1923, was a revolutionary development in the tire industry. The secret behind it was to lower the inflation pressure by changing the shape of the tire from a circle to an ellipse, which was the shape of large balloons at that time.

Firestone invented a method to impregnate every fiber of every cord in every ply with rubber to increase flexing life. This technology provided a soft ride that counteracted vibration and enabled tires to be run at greater speeds. The softness yielded to sharp obstacles, which prevented punctures and resulted in a longer tire lifespan as well.

The balloon tire was radically better than the previous generation of tires. Not only that, but it was one of the most important inventions in the automotive and tire industries, since it improved tire durability by two to three times, improved fuel economy and reduced the number of punctures dramatically, which then made the car a reliable means of transportation and spurred the sale of automobiles.

In 1932, Firestone introduced the first balloon farm tire, and pneumatic rubber tires began replacing the steel lugged wheels that had been used on tractors before. These steel wheels had good traction in the field but they rode roughly and put divots into paved roads.

The pneumatic balloon tire, which provided superior performance, driver comfort and better fuel economy, was quickly in demand down on the farm. In 1935 about 14 percent of tractors in the U.S. were sold with pneumatic tires. By 1937 that number had risen to around 43 percent and by 1950 nearly all tractors came equipped with these tires.

Less is more

All this innovation changed farming forever since tractors allowed a farmer to farm up to five times as much ground as he could with horses.

However, to afford a tractor, a farmer had to produce much more, which meant he had to farm more land. So farmers were forced to get bigger or get out. By the end of the 1930s, there were fewer farmers but those who were left were farming more acreage.

World War II brought a big change to farming. Thousands of people left farms for the cities to work in factories that supported the war effort or to join the military, and a tractor was the only way to get things done back on the farm.

New technology produced to support the war effort revolutionized agriculture after the war by increasing productivity for farmers, who could do much more work in fewer hours.

The development of more powerful tractors reached its sales zenith in 1951 when 564,000 tractors were sold to fill pent-up demand during the war years. After that production dropped back to about half that and stayed there.

As the number of farms continued to shrink and the remaining ones got larger, agricultural machinery manufacturers built larger and more sophisticated machines with more horsepower and more labor-saving features like combines for harvesting wheat, corn, cotton, soybeans, rice and other major crops, which enabled two workers to replace a huge threshing crew, seed planters with fertilizer attachments that planted crops closer together for dramatically higher yields, and center pivot irrigation systems.

Agricultural research resulted in better crops through new hybrid seed varieties and better insecticides that increased crop production. All this resulted in fewer but much larger farms that could afford this machinery and operated more efficiently with great productivity.

As farming machinery got bigger and heavier, tires evolved as well. The original balloon tire gave way to the conventional bias tire, which became the mainstay of the agricultural market.

After a couple of decades, radial farm tires came in to carry heavier loads and the increased amount of road travel some farm machinery does. (Today radials make up 42 percent of the replacement rear farm tire segment and 37 percent of the OE rear farm tire segment.)

But the larger, heavier equipment also came with the disadvantage of increased soil compaction, which proved to hamper crop growth and yield performance.

Studies have shown that by reducing the inflation pressure in tires, the contact pressure on the soil surface is reduced. The problem with this, however, is when the inflation pressure in a conventional tire is dropped, it loses load-carrying capacity.

Pressure vs. load

The conundrum that farming presents is: "How do you drop the inflation pressure to protect the soil but increase the load-carrying capacity in order to support equipment that is increasing dramatically in size, power and weight?"

To give you an idea of the weights farm tires are dealing with, a high clearance sprayer with 120-foot booms and 1,200 gallons of liquid requires each tire to carry 12,000 to 14,000 pounds. Class 8 and 9 combines' front-axle weight can exceed 65,000 pounds with a 40-foot draper platform used for harvesting grain or a 16-row corn head with 400 bushels of crop in the bin.

When implements that are 50 to 60 feet wide in the field are folded narrower for road transport, the load placed on the equipment's four tires is exorbitant. A bias tire is not built to withstand these loads.

Further, how do you make farm tires that must carry more weight, fend off rubber and steel-belt piercing by genetically modified organism (GMO) crop stalks, and perform well on the roads at higher speeds for longer distances than ever before?

The answer came in the early 2000s when Michelin invented ground-breaking technology that is now widely known as increased flexion (IF) tires. The company introduced this technology in North America as its AxioBib tire.

IF tires have flexible sidewalls and are designed to carry the same load as a standard tire at 20-percent lower inflation pressure or carry 20-percent higher loads at the same air pressure.

Tires with lower inflation pressure have a larger footprint, which distributes the weight over a larger area and reduces compaction.

IF technology also provides enhanced traction in the fields that can improve fuel economy by reducing slippage, which occurs when the tires are turning faster than the ground speed of the tractor and translates into wasted horsepower and more wear and tear on the machine.

A few years later IF technology evolved to create very high flexion (VF) tires, which can carry the same load at 40-percent lower air pressure or carry 40-percent more load at identical pressure as conventional radial farm tires in the same size.

VF tires are a higher-load version of the IF technology and also reduce the cost of farm production by improving traction and fuel economy, while reducing slip and soil compaction.

When IF and VF tires were first developed, they required wider rims, which made them expensive as replacements on existing equipment. Since then specifications in many cases have changed to allow these tires to use standard rims.

Today all the major manufacturers are building IF and VF tires for various implement applications such as tractors, combines, self-propelled sprayers, air seeders, planters, carts, tillage equipment, and manure tanks. (Yes, the proliferation of SKUs is a problem in this agricultural tire market.)

All types of implements on a farm must be equipped with IF or VF tires, since it makes no sense to minimize the compaction caused by tractors, combines and grain carts and then go back out on the field with an air seeder that weighs 20,000 pounds or more with highly inflated tires and cause the same problem you've been trying to avoid.

However, these tires are very sensitive to inflation pressure and rely heavily on farmers to actively adjust air pressure based on the weight of the load being carried, which can be a time-intensive process that reduces equipment productivity and costs farmers time and money.

Just like consumers, truck drivers and commercial fleets, farmers pay little, if any, attention to inflation pressure once the tire is on the machine.

Shortly after IF and VF tires were introduced to the market, Titan International developed its low-sidewall (LSW) technology, which was another technological evolution in farm tires. (Titan also manufactures and sells the Goodyear farm tire brand.)

Like VF tires, LSW tires can carry the same load as standard tires at 40-percent lower inflation pressures or carry 40-percent more load at identical pressures. Instead of more flexibility in the sidewalls, however, LSW tires have larger wheel rims and lower sidewalls.

They were developed not only to reduce soil compaction but to address some of the drawbacks of IF and VF tire sidewall flexibility experienced on the road, which are power hop and road lope. Power hop is the bouncing effect a tractor sometimes experiences when pulling a high draw-bar load in the field. Road lope is the swaying and bouncing of a machine during road transport that can result in rider discomfort and can decrease productivity between fields.

Titan also developed super-single tires that use both LSW and VF technologies to replace dual tires on farm equipment. The company's most popular sizes are the LSW1250/35R46 and LSW1400/30R46, which, according to Titan, is the world's largest farm tire.

By replacing two tires with one really big tire provides a lot more surface area, a greater contact patch, a lot better flotation and less compaction.

New technologies

Adoption of LSW tires has been slow. OEMs usually drive the use of new types of tires but are dragging their feet on LSW technology since Titan is the only company that produces both the tires and the wheels.

So what's in the future for farm tires? Well, since equipment manufacturers like Deere & Co., Case IH and CNH Industrial's New Holland brand continue to build large, more powerful and heavier equipment, tire makers are devoting more R&D resources to IF, VF and/or LSW technologies.

It is expected that the big three areas of tire design, tire construction, tread design and compounding (farm tires have more than 30 compounds) will all be worked on to improve weight-carrying capabilities. Also since recent advances in crop science have resulted in GMO crops that are heartier and tougher than previous generations of plants, tire developers are working on compounds and constructions that improve both puncture resistance from crop stubble and decrease the tendency for tire sidewall cracks to grow.

To address the chronic inflation-pressure-maintenance problem that IF and VF tires are sensitive to and optimize the performance of these tires, several tire companies are looking at combining their advanced tire technology with central tire inflation systems (CTIS).

CTIS enables a tractor operator to change tire pressures on the go to minimize compaction and increase traction, fuel economy and tire performance when moving from road conditions to field operations. Tire pressures are adjusted with a touch of a button on the tractor's control panel.

CTIS has been widely used in logging for years. To prevent wash-boarding of forest roads, tractor-trailers loaded with logs travel slowly (about 25 mph) with 25 psi in their tires, but when they get to the paved road, the drivers push a button, inflate the tires to 100 psi and drive at whatever the road speed is.

OTR construction and military equipment also have used central tire inflation systems for years. So why not farmers?

Farm tires certainly have come a long way since the days of solid rubber fronts and rears with steel wheels and molded rubber lugs. Today's farm tires are highly engineered marvels that carry incredible loads while treading lightly to keep soil optimum for healthy crop growth.

Farmers certainly have a lot to think about when trying to improve the efficiency of every aspect of their operations. Not only do they have to make decisions about the equipment they buy, the seed, fertilizer, and chemicals they use that affect crop yields and productivity, but they also have to choose their tires and the inflation pressures to protect their soil and improve their fuel economy and productivity.

This is a lot more complicated than giving a pig or a rooster names, keeping them in the garage, taking them for a walk on a leash and giving them loads of love and attention. No wonder the best place for them was back on the farm.

Peggy can be reached via e-mail at [email protected].