Tomorrow's tractors

These machines have advanced rapidly over recent years but what does the future hold? Sally Drury looks ahead.

SESAM: battery tractor features two 150kW electric motors in a JD 6R Series chassis - image: John Deere
SESAM: battery tractor features two 150kW electric motors in a JD 6R Series chassis - image: John Deere

Tractors have developed substantially over the past decade, with cleaner, more fuel-efficient engines, models that run on natural gas or biogas and even GPS-equipped machinery. But what will the tractor of the future look like and how will it be used? Let us first consider fuels.

Last year New Holland Agriculture delivered its prototype biomethane-powered tractor, heralding it as the model set to make energy-independent farming a reality. Behind the concept is the fact that methane-powered tractors emit 80% fewer pollutants and could achieve fuel cost savings of 25-45%, while offering energy independence for users with access to biomethane derived from waste and produced by on-farm biogas plants (anaerobic digesters).

Somerset Cheddar producer Wyke Farms, based near Bruton, has tested the new tractor. Wyke Farms farm director Roger Clothier reports: "On first impression it looks and feels just like a normal tractor when you jump in the cab. It easily managed to tow a full slurry tanker up and down the hills here — with a combined tractor and tanker weight of 27 tonnes."

Clothier believes a future possibility could be sharing gas power, with local filling points for neighbouring users. With the number of UK on-farm biogas plants continuing to increase, there could be a fuel supply on the doorstep.

Iseki tractor used without a human entering the field - image: Ransomes Jacobsen

Compressed natural gas

New Holland’s methane tractor borrows from commercial vehicle technology already used by its sister brand, Iveco. The use of compressed natural gas in vans, trucks and buses is well developed and limited only by storage capacity on the vehicle. The company has managed to squeeze 300 litres (52kg) of compressed methane into nine tanks around the T6.180 179hp tractor — enough for around six hours of work depending on the type of activity. Refuelling is quick, taking around the same time to fill as with diesel.

Adapting existing engine technology, fitting a small three-way catalytic converter and housing it in a standard tractor chassis and cab mean that the methane tractor looks and drives just like a diesel-powered one, and the price should be about the same.

Biogas does not immediately spring to mind when considering equipment for grounds maintenance, particularly in urban areas. But battery power certainly does. The growth in lithium-ion powered kit shows users in parks and gardens are keen to take advantage of no emissions, low noise and reduced vibration benefits.

We already have day-long use of battery mowers — check out our review of the Mean Green ride-on mowers (HW, 9 June 2017). So is the battery powered tractor just pie-in-the-sky thinking? Perhaps not. It is one concept being looked at by John Deere and one that received a Special Mention Award at SIMA 2017, held in Paris in February.

Major steps in the development of the SESAM (sustainable energy supply for agricultural machinery) concept tractor were taken in a joint research project in co-operation with the Technical University of Kaiserslautern and BAUM.Consult, Munich, with financial support from the German Federal Ministry for Economic Affairs & Energy within the funding programme ICT for electromobility projects.

As part of John Deere’s vision of the future of farming, the tractor is a further step by the company towards CO2-neutral farming and follows the Multifuel tractor, which uses pure vegetable oil instead of diesel fuel (SIMA Innovation Award 2013) and the Battery Boost tractor, a hybrid machine featuring an alternative battery concept (SIMA Innovation Award 2015).

SESAM is aimed at the agriculture market, although the technology could have applications in other sectors. It is the industry’s first fully battery powered tractor and, as a concept machine, produces 130kW of continuous power. It involves two 150kW electric motors, with a 24-speed DirectDrive transmission carried in the mid-size frame of a JD 6R Series chassis and supplied by a 130kWh, 670V Li-ion battery system, which fills the space normally used for the diesel engine, the exhaust gas treatment system and the fuel tank. Further components of the tractor include a battery management system and the power electronics.

It has a speed range from 3kph to 50kph at full power and develops high torque at low speeds as well as a maximum output of around 400hp, with no energy losses when idling.

In standard operating mode, one motor is used for the drivetrain and the other for lubrication, the hydraulic pumps and the power take-off. In extended mode, the electric motors can be linked to temporarily increase the power of the drivetrain up to 300kW (400hp). Brake energy is recovered with more than 90% efficiency, while power losses are completely eliminated when the tractor is in idling mode.

Controlling the Iseki hands free tractor - image: Ransomes Jacobsen

Low noise levels

SESAM operates at the lowest possible noise levels — clearly an advantage when operating close to residential areas or when working at night. Currently, one battery charge lasts for up to four operating hours in typical mixed mode operations or for around 34 miles of road transport work, while charging time is about three hours. The battery is designed to last for 3,100 charging cycles.

A representative from John Deere’s European Technology & Innovation Centre research and development base in Kaiserslautern, Germany, says: "JD sees electrification and electromobility as a key technology for the future application of ‘green’ power.

"Nevertheless, on the road to fully electric mobile agricultural machines, several challenges will have to be met. Today, for example, the operational periods without recharging as well as battery costs are not fully sufficient. We are working on these issues and we expect that we will be able to deliver improved new technological solutions in the next couple of years. A time schedule for market launch cannot be given at the moment. Thus, we still see the SESAM tractor as a vision, but as a vision that will come true."

The SESAM tractor paves the way for other vehicle and mobile machinery sectors, notably commercial vehicles. Market studies show that the capacity of commercially available Li-ion batteries will significantly increase while costs will continue falling considerably until the end of this decade. At the same time, battery technology is making rapid progress.

But the question to which everyone wants the answer is: will there still be an operator in the future? In the UK, driverless cars are being trialled, as are three-convoy driverless trucks. Last year we saw the Fendt tractor driving itself around an orchard. That was a "show and copy system" whereby whatever the tractor was shown, it was able to copy in the future — headland turns and sprayer control included. Now, at Harper Adams University, attempts are being made to grow and harvest a hectare of cereal crops using an Iseki tractor but without a human entering the field.

The tractor entrusted to deliver this revolutionary project is the 38hp Iseki TLE3400. The research team adapted the tractor to transform it into a fully autonomous machine, which was then used to cultivate, sow, spray and harvest a crop of spring barley.

Commenting on the choice of tractor for the project, Kit Franklin, agricultural engineering lecturer at Harper Adams and one of three project engineers, says: "The smaller, lighter machines don’t damage the soil to the degree that modern full-size tractors do. Over the years, tractors have grown larger to counter the tight working window that farmers have to navigate with a small labour force, but soil compaction has been a side effect. Healthier soil and more precise, targeted inputs lead to higher yields. Because the small machines are autonomous, one person can take charge of three or four."

Martin Abell from Precision Decisions, the project’s industry partner, adds: "The tractor is able to navigate the hectare using an autopilot system for drones. This allows it to follow a predetermined path in the field. It runs entirely on GPS and follows the requested route making its way between waypoints.

"The waypoints are digital GPS markers created using our software that we have positioned at the ends of the field for the tractor to navigate to — like a more advanced version of dot-to-dot. Our waypoints for the drilling also incorporated lifting and lowering signals that picked the drill up at one end and placed it back down once it had turned around." From drilling to mowing — it is not such a big step, surely.

Kubota M5001 Series - image: Kubota UK

Sustainability, functionality and efficiency

Featuring Kubota’s unique diesel technology, the two-model M5001 Series is recognised for sustainability, functionality and efficiency.

At the heart of the 95hp and 113hp units is a four-cylinder, 16-valve V3800 Kubota engine designed to meet strict emissions control requirements and featuring new engine characteristics for improved performance.

Looking under the bonnet, we find Kubota is the first manufacturer to incorporate a common rail system equipped with a urea catalyst, a water-cooled system to recirculate exhaust gases, a diesel particulate filter and a diesel oxidation catalyst. This combination of technologies optimises the individual operation of each, reducing consumption and emissions.

Smoother operation comes as standard thanks to a new fingertip electro-hydraulic shuttle that provides greater performance and easier handling.

In addition, the 40-ECO transmission with six synchronised gears and dual-speed High-Lo technology allows users to change gear directly, gently and quickly. The electro-hydraulic reverser, which avoids using the clutch, provides a fast and gradual change in direction that reduces emissions as well as increasing user comfort and control.


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