Based in Ardstraw, near Omagh, Co Tyrone, Jason Mitchell owns and runs Greenville Dairies Ltd, a 750-cow dairy herd and a large anaerobic digestion (AD) plant, believed to be the first built in Northern Ireland in 2012.

Since 2012, Greenville Energy Ltd has increased plant capacity from 500 kilowatt (kw) to 1.7 megawatts (Mw). In 2018, Greenville Energy became one of the world’s first AD plants to liquefy biogas to produce liquid biomethane and liquid bio-CO2.

Feeding the plant with up to 100t/day of feedstock is no small task. Almost two years ago, site manager at Greenville Energy Gary Logue scoured the market in search for an on-board system for the telehandler to weigh feedstock as it was fed into the plant. Depending on gas production and performance, as well as feedstocks available, the quantities of each input can vary only a daily basis.

Until this point, weights had to be recorded manually with pen and paper using the fixed weigh cells on the Trioliet intake mixer. This prolonged feeding times of the digester, but also meant all feed data had to be manually recorded for historic purposes.

Finding a solution

Gary came across the range of on-board weighing systems from RDS, a subsidiary company of the Topcon Positioning Group. He felt after some research they were the best on the market in terms of functionality and build quality.

“We bought the Loadmaster a100 system through Wel-Tech in Louth almost two years ago now. We required a system that could communicate with the office as well as weigh on-board.

“We decided on the a100 for the fact it was compatible with the iSOSYNC software over Wi-Fi or sim card. This allows the transfer of data between the loader and the office or vice versa.

“For example, we can formulate the required feedstocks or recipe you could call it, then send it to the system in-cab. As the feeding takes place, the operator works through the required ingredients and amounts. After each bucket, the relevant data, including weight and time, etc, is transmitted using the iSOSYNC software.

“It meant a more detailed record of inputs can be kept, so, for example, if the digester happens to react erratically, we can look back and see, for example, if too much of a particular feedstuff was loaded on a particular date,” Gary said.

The system was first fitted to a CAT telehandler before switching it over to a JCB 417 HT wheel loader last year.

How it works

All the RDS systems from the entry level Weighlog a10 right up to the higher specification Loadmaster a50 and a100 work using the same principle.

Both use transducers placed on the pressure and return side of the lift rams, as well as the compensation rams. Therefore, it is possible to fit the system to almost any machine with hydraulic rams, whether it be a tractor and front loader, wheel loader, telehandler or skidsteer loader, etc.

The unit is then calibrated to find its own weight as a reference point known as zero kg. This is the oil pressure required to lift its own weight and the implement fitted, ie shear grab or bucket to a set height.

When a grab of silage, for example, is then taken from the pit and lifted to the height set, the oil pressure is again recorded and converted into kg minus the reference weight. This gives the net weight of silage.

The height or position at which the measurement is taken during the lift cycle can be set depending on the application. Generally, a height just before the load is emptied to eliminate chances of operator error.

Up to 10 attachments can be recorded and selected from both the Weighlog a10 and Loadmaster a100. As many as 30 products, ie feedstocks (grass silage, meal, beet, maize, etc) can be recorded and stored on the unit, as well as 30 customers and five recipes (ie dry cow, heifer and fresh cow diets).

Gyro sensors are fitted to the a100 for guaranteed accuracy, measuring the angle of the machine’s chassis and boom independently.

These sensors can tell if the machine is on a slope or not, counteracting the difference in hydraulic pressure needed to lift the load. This feature is more suited to units fitted to quarry machines where surfaces constantly vary.


After almost two years of using the RDS Loadmaster a100, Gary and the team are pleased with how it fits their needs.

“It’s exactly the system we required. Once familiar with how it operates, it becomes easy to use. We installed Wi-Fi in the area that the loader works, so there is no need for a sim card. If the machine ends up working out of range, this load data is still recorded and transferred over iSOSYNC once within range again.

“Standard procedure here is to calibrate the system every morning before feeding starts, not that it is needed to be, but for guaranteed accuracy, this takes only seconds.

“The list of feedstocks and quantities is sent to the loader every morning. The display shows all we need it to, including weight in kg loaded so far, number of buckets and the target weight remaining.

“At any point, the job can be paused and resumed. Build quality can’t be faulted, It is well fitted, with little evidence of its presence apart from the control terminal.

“Feed data can be quickly exported into Excel using iSOSYNC. For us, the huge benefits are not having to manually record feed data, reduce feed times and guarantee feed accuracy. If only a small amount of product is needed, we can ensure the exact weight is in the bucket before leaving the store.”

Simple solution for livestock farmers

For farmers requiring a simple weigh system for loading diet feeders or similar, the Weighlog a10 should fit the gap. This is a slightly stripped-back version of the Loadmaster a100, only in a smaller 4.3in form. It also has a touchscreen with a colour display.

Although the a10 has the same memory functions (recipes, implements, etc) as mentioned earlier to its larger 7in counterpart, it is best suited to customers not wanting to gather feed data on a regular or live basis. However, it can still be done physically via SD card or USB stick.

Target load is a nice feature of the system. For example, an operator requires 2,000kg of silage loaded into his diet feeder. The load target on screen is set to 2,000kg. For every grab of silage taken from the pit, its weight is removed from the 2,000kg target until zero is displayed.

The option of a printer is available for all models. This might be useful for operators who are selling goods, for example, and they want to provide customers with a receipt of the particular weight sold.

The Weighlog a10 has a starting price of €2,600 plus VAT, while the larger more complex Loadmaster a100 is priced at €3,800 plus VAT.