The only gold medal awarded in the 2021 DLG Innovation Awards went to a relatively obscure German company by the name of Nexat for its reiteration of gantry farming.

This company was formed in 2013 with the sole purpose of developing what it describes as an 'all-in-one-system-tractor', which is a bang-up-to-date take on the gantry tractor concept that has been around since the mid-19th century.

Pioneered in Kensington

A gentleman by the name of Alexander Halkett built what we would now call a bed system at Kensington before it became part of the larger conurbation.

In effect, it was a very broad gauge railway with the steam engine located at one side of the machine while collecting or supply boxes were mounted at the other, the two connected by a frame or gantry.

Alexander Halkett railway
Alexander Halkett's system relied on permanent rails being traversed by a steam powered gantry 'tractor'

Running on rails, it was termed by its inventor 'Guideway Agriculture' and appears to have been used successfully in an area where vegetable produce would have commanded a premium price.

Its fate is uncertain but the rapid growth in rail transport was likely to have brought in produce from further afield, while the expansion of the city saw the borough develop rapidly with a corresponding increase in land values.

Gone but not totally forgotten

It appears that little more was done with the idea until the 1970s when David Dowler, a farmer from Chipping Norton, Oxfordshire, started developing his own machine based on a Hesston swather.

David Dowler gantry tractor
David Dowler's machine relied on the the implements being hung from the frame

David's main concern was the damage done through soil compaction in tillage farming, an anxiety that was shared by the Silsoe Research Institute which eventually acquired a machine of his design with which it carried out its own research.

The benefits of gantry systems soon became evident with both a marked increase in soil condition and great savings in pesticide usage.

Keeping traffic to well defined areas of the field, now referred to as Controlled Traffic Farming (CTF), paid dividends all round with the range of tasks that the gantry was capable of performing expanding as the soil condition improved.

Back in 1996, a report in New Scientist noted that the "Dowler 'gantry' tractor’s developers say it could raise crop yields by as much as 25%, halve farmers’ fuel use, lower fertiliser bills and reduce applications of herbicide by up to 70%".

Silsoe highlighted advantages of gantry farming

A great deal of the development work undertaken at Silsoe research station, which, incidentally, now lies under a housing estate, was done by Tim Chamen who is still very much a champion of the concept.

Dowler gantry tractor
The final proposal for the Dowler gantry system never made it into production

Talking exclusively to Agriland, Tim noted that the major advantage of Gantry systems is that they confine soil compaction to a dedicated area of the field, both throughout the growing season and over the years.

With the Dowler machines, this area was around 10% of the land, yet with the much larger Nexat unit, spanning 14m, this is reduced to just 5%. Conventional systems may drive on 80% or more of the field.

One reason why gantries require less ground is that for every two adjacent passes only three, rather than four, tracks are required as the one end will use the same track going back as it did coming up.

A different approach to field work

He also notes that for best effect, these wheel tracks need to become semi-permanent with the same lines being used annually.

Eventually, a hardened 'foundation' of soil builds up which remains uncultivated but better able to support the weight of the machine during wetter periods.

field harvesting gantry
The semi-permanent tracks of the gantry system can be seen in the crop running parallel to the harvester

Another observation he passes on is that the great advantage of the Nexat machine is that rather than implements hanging from the gantry, the machine docks with them from the side.

Building the machine in a 'U' shape allows for attachment to the working modules from their flanks rather than the top. This speeds up the process and better allows for its automation.

Unfortunately, neither the Dowler machine nor the work carried out on gantry systems at Silsoe enjoyed commercial success, although the focus on the importance of avoiding soil damage and the development of CTF is perhaps the greatest legacy of both.

Various other attempts have been made throughout the world, including Japan, Russia and California, but still no widely accepted or mass produced machine is currently on the market.

Enter Nexat

This situation may well be set to change with the Nexat (a shortened form of Next Agricultural Technology) gantry system announced in December of last year.

The company behind the machine is Kalverkamp Maschinenbau GmbH of Germany, an engineering consultation business that specialises in helping companies create and manufacture machinery, mainly in the agricultural sector.

Nexat unit docks with modules
The Nexat may be considered a powered frame that docks with working modules rather than carrying them under a connecting span

In 2013 it formed Nexat to develop the gantry in partnership with several other companies and organisations who contributed their particular skills and knowledge to the project.

Ready for autonomous operation

Past attempts to commercialise gantry-based farming would appear to have foundered upon the rock of competition from conventional manufacturers taking heed of the damage done by soil compaction and adapting their products to minimise it.

This, coupled with the ever increasing width of tramlines, eroded the clear benefits that gantry farming offered. Yet one clear advantage it does offer is its adaptability to autonomous farming.

Designed from the ground up to run autonomously, the Nexat machine will be able to take advantage of the latest developments in digital farming as well as any new ones which come along.

Nexat Gantry farming
Although it presently requires manual operation, the Nexat unit is built to eventually run autonomously

It is claimed that the system will take care of every working step, from cultivation to sowing, plant protection and harvesting; all will be possible without the need for an operator.

Every field operation will have a dedicated unit that fits on to the gantry. This includes a cereal harvesting unit with a 5.8m long axial flow separator.

It would appear that the displacement of the combine harvester may become another scalp it carries.

The modular approach means that each implement, in effect, becomes self propelled which further erodes the ancient pairing of a draught unit with a working implement, be the former an ox or a tractor.

Operator road transport
A driver's station is retained for road transport and observation of the work in progress

Road transport, often cited as a major stumbling block for autonomous tractors, is accomplished by retaining a driving station so that it can be driven manually between fields.

Power is presently supplied by two 550hp diesel engines with electrical drive to the tracks. It is planned to use hydrogen fuel cell technology in the future.

Partnership driving innovation

One of the problems that earlier attempts at commercialising theses machines ran into is the lack of support and investment from other companies.

Nexat has circumnavigated this hurdle by bringing several companies on board during the early phases of development.

The major partner is Vaderstad which has produced a modular series of implements and drills which are easily attached to the gantry and are designed specifically for use with it.

The company notes that it has "played a significant role in the development and adaptation of the respective module solutions and will offer our machines as modules in the new crop production system".

Other partners include Herbert Dammann GmbH, fluid application specialists, Geringhoff GmbH, which is involved in the harvesting equipment and the two German universities of Osnabruck and Bremen.