Lower fuel consumption and fewer vibrations
Lower fuel consumption and a better working environment with fewer vibrations go hand in hand. This has been shown by tests using Hydrema backhoe loaders at Byggetek in Ulfborg Kjærgaard.
Working environment and fuel consumption can both be improved if operators are given brief instructions in optimal operation with fewer engine revs. The quality of the work also improves, though productivity drops a little – but not so much that it cancels out the efficiency improvements.
This was demonstrated by a test carried out by Hydrema in cooperation with Byggetek in Ulfborg Kjærgaard, which is part of Mercantec. Four experienced operators took part in the test of a Hydrema 926D and a Hydrema 906D.
The operators performed precisely measured and timed tasks. Fuel consumption and full-body vibrations were measured. The operators were first asked to do the tasks as they usually do them. They were observed by specialist teachers from Byggetek. After this the operators were given individual instructions and a brief general introduction to economical operation. They then carried out the same tasks again. A 30-metre trench was dug in an area of approximately 60m2, and five dump loads were loaded.
On average, 16% and 19% of the fuel was saved on the two machines respectively during the digging, and 6% was saved during the loading work. The level of full-body vibrations fell by 21-24% during the various work functions. On average the operators spent 12% more time digging the trench and 18% more on excavation, but only 4% more on the loading work.
Specialist teacher Niels Kristian Andersen from Byggetek has instructed machine operators and others in economical driving for many years, and he is surprised that fuel consumption can be reduced so much through such small changes in operation.
”These results will influence our teaching in future. Reducing the revolutions and fuel consumption that significantly has several positive effects. Of course it’s about saving money, but it’s also about improving the working environment and reducing CO2 and general wear on the machines. Also, the test shows a significant reduction in full-body vibrations”, says Andersen.
Contractor Kim Hedegaard from Mors took part in the test. He operates a Hydrema 926D on a daily basis. He feels he normally drives very economically, but there were still savings to be made in his operation.
”I reduced the revs from 1600-1700 revs to 1200-1300 revs during the digging. It took longer, but it was a nicer piece of work that would have saved some time for the manual worker. Apart from the lower revs I also got a couple of tips about how to drive more smoothly and not shaking the shovel. The second time I dug the trench I saved 13.4% in fuel consumption and reduced the vibrations by 27.1%, and only spent 5% more time. I have to say those very small changes made a big difference. As a self-employed operator I’m obviously very focused on the financial aspect, but the vibrations are important too. I’m only 33 and want to be able to do this for many more years”, said Hedegaard after the test.
One of the reasons why it is possible to achieve such marked improvements is the construction of Hydrema’s hydraulics system, which can maintain a large flow even at very low revolutions. Hydrema has worked hard on improving comfort and working environments for many years, and to this end has hired engineer Thomas Langer as an industrial PhD student from Aalborg University. He focuses on reducing full-body vibrations for operators of Hydrema machines.
”We work with computer simulations of the machines’ movements and the relation between operator and machine. By simulating the machine’s movements in a 3D computer programme we can vary and combine different constructions, components and processes to get the fewest possible full-body vibrations. We can also simulate the types of movements and speeds that produce the most strain on the operators and use this to give them advice on how to minimise vibrations in the daily work”, says Langer.
Hydrema’s cooperation with Aalborg University has also provided the basis for the brand-new suspension systems in Hydrema’s dump trucks 912DS and 912HM, which have recently been presented to the public.
The Danish construction industry consumes a total of around 170,000 cubic metres of diesel oil each year. If 10% of this consumption can be saved through instruction in economical operation, it will contribute to an annual reduction of CO2 emissions of 45 thousand tonnes. The level of full-body vibrations felt by the operators will be reduced and the reduction in wear and tear on the machines will mean lower service costs.
Ulfborg-Kjærgaard is near Holstebro and has many years’ experience of training contractors and gardeners.
Today Ulfborg-Kjærgaard is part of Mercantec, an educational institution with over 450 employees and over 3,000 students annually. Ulfborg-Kjærgaard offers a wide range of courses in the operation of many different kinds of contracting equipment.