Maarakennus

Dimensions and measurements for the test machines

Arto Turpeinen
The tractive force was measured with a balance with strain gauges. The other machines were used as counterweight, in the case shown in the picture, three machines were needed.

A whole series of performance efficiency measurements was carried out on the test machines. Eurofins Expert Services Oy (formerly ATT Expert Services Oy), which performs various certification and audit services, measured the lift capacities and tipping loads. In addition, Eurofins measured the size of the lines-of-sight and the performance of the air-conditioning systems of the machines. With our own machines from Koneviesti, for example, we measured the dipper stick power and swing power of the revolving superstructure. We also performed the sound level and fuel consumption measurements ourselves.

Scattering at operating weight

All machines that took part in the test are in the KKH 08 class of the Finnish classification system, which means that the weight in this group should have been less than nine tonnes. When completely fitted out and ready for operation, however, only three of the machines remained below this weight limit when weighed.

The Komatsu machine was the lightest, at an operating weight of 8,595 kilos, closely followed by the Kubota machine at 8,795 kilos and the Wacker Neuson machine at 8,910 kilos.

The other extreme is the ECM machine, which, with its rubber padded steel tracks, weighted over 10 tonnes. The Bobcat, CAT and JCB machines also had an operating weight of over 9,500 kilos. The operating weight of the Takeuchi engine only exceeded the 9,000-kilo limit due to the operator sitting in the cabin weighing 70 kilos.

The tail swing was also taken into account in the awarding of points, because the test invitation expressly asked for reduced tail excavators. From the edge of the chain to the side, two machines had a genuine "zero tail" - only the ECM and the JCB could turn without protruding beyond the track width. The tail swing of the Caterpillar was as much as 41 cm due to the additional counterweight and that of the Kubota was 36 cm. The differences were pretty big.

In a small space, it is important to be able to turn forward as well. Due to the original lateral displaceability of the boom, you can fold the excavator arm into a small size next to the operator's cab. The outermost point of the excavator arm protruded just 68 cm beyond the track width in the turn. The result for the ECM, which has a conventional boom attachment, was 81 cm. Together with the zero tail, this ensures that the ECM can even turn in very small spaces.

The differences were also remarkable in this measurement, since the CAT needs as much as 213 cm of room. This, however, was affected by how the dipper stick was attached to the cylinder, as the bolt can be attached to two different brackets. On the test machine, the cylinder was attached in the rear position, meaning that it was not possible to move the dipper stick very close to the machine, for example, the bucket did not approach the dozer blade. With a change in the bolt position, the situation would have been different.

Lift capacities and tipping loads

Eurofins Expert Services was responsible for measuring the lift capacities and tipping loads. Due to differences in reach and dipper stick, the measuring distance was measured at 4.5 metres both laterally and longitudinally from the centre of the machine. The ECM had the best lift capacity with a result of 28.7 kN, which corresponds to a result of approximately 2,927 kg. The Kubota came second with a result of 27.4 and the Wacker Neuson came third with 26.6 kN. The weakest machine was the Takeuchi, which, with a lift capacity of 17.8 kN, was the only one under the 20 kN mark. The difference between the best and the worst result was as much as 10.9 kN, about 1,111.50 kilos.

The ECM proved to be the machine with the best stability, as its tipping load was the best in both lateral and longitudinal direction. In addition to the high operating weight, the steel tracks and the traditional fixed boom also had an impact. With a raised plate, the longitudinal tipping load was 22.2 kN, which was 1.5 kN more than the second-placed CAT. The weakest result by far was achieved by the lightest machine in the test, namely the Komatsu, whose track edge lifted off at a force of just 12.4 kN.

The ECM began to tilt laterally at a force of 21.8 kN. The CAT, with its very long tail swing, and the Bobcat took second and third respectively. The most tipping-prone was the Wacker Neuson, which was beaten by the most stable machines by 10 kN, or about 1,020 kilos, which is a significant difference.

Shovel arm and turn

The tractive force of the dipper stick was measured by placing the boom upright and lifting the tilt rotator bolt to a height of 60 cm from the ground. The two machines with the shortest reach, the ECM and the Komatsu, took the top positions in the measurements.

However, the comparatively short working range of the ECM can be explained by the fact that the boom is fixed next to the cab in a conventional manner. The values of the top duo were 5,740 and 5,630 kg. The Kubota also achieved a force of over five tonnes. The weakest was the Takeuchi, whose power was measured at 4,180 kilos.

The swivel powers of the revolving superstructure are comparatively modest in this size category. Even the largest value, achieved by the Wacker Neuson, was only 580 kilos. Second was the Kubota with just 20 kilos less. The ECM was 30 kilos weaker than this. The top trio were therefore within a range of 50 kilos. When considering hydraulic force measurements, however, it must always be borne in mind that several movements are always carried out simultaneously during smooth digging work. However, measuring the forces of simultaneous movements with the test methods available is extremely difficult, if not impossible. Nevertheless, the measurement of individual movements gives a general indication of the performance efficiency of a machine.

Tractive forces and speed

The highest speeds were measured with a Vbox Sport unit, which can measure speeds to a tenth of a second. The fastest was the ECM, which can cover a distance of 5.5 kilometres in one hour. The secondplaced Takeuchi was only one tenth slower. The differences were quite large, as the slowest two, the Wacker Neuson and the Komatsu, only had a measured speed of 4.5 kilometres per hour. In the tractive force measurements, three machines, the Bobcat, the JCB and the Takeuchi, achieved the same result of 7,350 kilos. The ECM proved to be the machine with the highest tractive force, with a result of 8,100 kilos. Somewhat surprisingly, the Wacker Neuson also came last in the tractive force category, as the scale showed only 6,900 kilos.

Big differences in noise

The machine sound levels were measured with a Rion NL-52 sound level meter. Overall, the Wacker Neuson was the quietest machine by some distance, its average measured values were below 70 decibels. The Komatsu was only 0.5 decibels behind in its averaged values. There were amazing differences in the sound levels. The sound level of the loudest engine by far, the Kubota, at 68 decibels when idling, was similar to that of the quietest machine, the Wacker Neuson, while working. Overall, the Wacker Neuson was clearly the quietest machine, even though the sound levels were no longer peak values when the fan was at maximum power.

The values of the third-placed Komatsu were slightly affected by the very high volume carried to the outside. All in all, however, it can be said that, with the exception of the Kubota, the operator's cab of modern machines is slowly becoming quieter, even in this size category.

Fuel consumption

Fuel consumption was measured using the traditional "full tank" method. After careful ventilation, the tank was topped up to the top, and the machine was used to dig an 80 cmdeep cable trench in a loamy field. All machines worked with the same bucket. After digging, the venting process was performed again. To ensure reliability, this section was repeated twice. However, the differences between the individual test runs were very small. The consumption measurement was carried out at full throttle but without power mode. The measurement was carried out at full throttle to ensure the most productive work possible.

Equipped with the smallest engine in the test, the Wacker Neuson came out on top in this comparison, with fuel consumption of about 8.4 litres per hour during work.

The Wacker Neuson was followed closely by the ECM and the Takeuchi, which consumed only 2 decilitres more. The CAT, with the most powerful engine, was last; it consumed 1.1 litres more fuel than the least thirsty engine. At the same time, however, the trench was a bit longer, which indicates precisely functioning hydraulics.

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