Norfolk engineer builds speedy hemp harvester


West Norfolk engineer Stephen Eyles has developed a high-capacity multi-bladed hemp harvester capable of cutting at high speeds.
His machine has three blades, which cut the crop into three lengths, which makes it easier to handle for baling.
Mr Eyles, who has more than 30 years’ experience as a practical engineer, was encouraged by his farming brothers to tackle the challenge of designing an effective machine.
And, the three-stage cutter bar is powered by a 135hp Massey-Ferguson tractor, which is far more economical than a heavy-duty forage harvester, weighing about 16 tonnes, fitted with a 500hp engine.
Mr Eyles, of Hall Farm, Northwold, has been involved in hemp harvesting for about 12 years. His efforts were given a major funding boost with the enthusiastic support of the InCrops Enterprise Hub at the University of East Anglia.
He has used his practical experience and also his farming background to design and modify machinery to tackle the challenge of harvesting hemp.
Once the crop has been cut, it has to “ret” or start to break down for several weeks in the field before it has to be baled, dry, for delivery for processing at the Hemp Technology factory at Halesworth.
In the current season, Mr Eyles, who is driving the harvester, expects to complete about 200 hectares of hemp, which is being grown by farmers in west Norfolk and across the county at Quidenham and at Easton College.
His machine is able to operate at high speed and in a long working day might be able to cut as much as 20 hectares. “I’m using 100 litres of fuel and on average I’m cutting 2.5 hectares an hour. In a working day, I’m using 100 litres to 120 litres of fuel. A forage harvester would be using 400 litres of fuel and would do half the work.
“A 100hp tractor would operate the cutter because it only needs about 40KW to drive. It is very low in power consumption but enough tractor power is needed to travel at speeds of 16 to 20kph in places, if conditions suit.”
Mr Eyles has fitted hydraulic valves to keep the power constant to the reciprocating knives. “A forage harvester needs continuous power for the chopping effort and then two more operations are needed. Firstly, the crop has to be spread across the field to allow it to ‘ret’ more effectively and then it has to be brought together.
And with short lengths, crop can be lost. “There are disadvantages of this approach both to the grower and to the final product at the factory.”
The prototype hemp harvester was demonstrated to growers earlier this month at Northwold, where his brothers, Roger and David Eyles run the family farm.
It was commissioned by InCrops Enterprise Hub with funding support from East of England Development Agency (EEDA).
The harvester’s cutting bars are designed for quick folding and unfolding for easier transport. And the adjustable bottom bar can more easily follow the ground contour and leave a lower stubble height.
Preliminary trials were carried out on his brothers’ farm.
The project was initiated by InCrops Enterprise Hub, which is a knowledge-transfer project supporting business growth in alternative and non food crops.
Dr John French, managing director, said: “As a result of our field based activity in 2009 and increasing familiarity with the supply chain it has become clear that a major impediment to the utilisation of hemp is the available harvesting technology.
“InCrops is actively engaged in promoting the development and increased uptake of hemp, both as a crop and also as biomaterial in numerous downstream applications.
“We commissioned the prototype hemp harvester to help promote the production and commercialisation of hemp products.’
A low input, fast growing crop, which can be grown on a range of soil types, the fibres are used in industrial applications such as the automotive and construction industries. The harvested crop will be processed by Hemp Technology, of Halesworth.
Mike Duckett, of Hemp Technology, said: “I’m very impressed with the quality of the machine that Stephen Eyles has built. For a prototype machine almost starting from nothing this is a great achievement!
BLOB A demonstration will be held at Easton College on Friday, September 3, starting at 9.30am and finishing about 11.15am. After a briefing, the harvester will be put through its paces. To attend, please contact Julia on 01603 591765 or email