| dc.description.abstract | Indonesia has a very large land area of about 1.905.00 km2 with about 63% covered by forest. However, due to the logging activities and increasing population, the forests area are decreasing year by year. People aware about this situation and they started a campaign for reforestation activity. The government also realized it, so there are more rules to control the deforestation and promote reforestation. Albizia (Albizia Falcataria L) or sengon is the one of common trees for reforestation. Sengon has a lot of potential for industrial forests. it grows fast enough as a tree, it can be 45 meters only in 25 years with 100 cm diameters, sengon usually called the miracle tree. Sengon’s seeds usually has 15-20 cm diameters for their roots. They don’t need any special treatment, because they can grow in almost any condition in tropical areas as long as their roots are not broken. In Indonesia, sengon planted traditionally by using hoe. It takes longer time, but effective because the planted areas are usually remote and difficult to be passed by tractor. Portable hole digger machines are one of solution for this kind of problem. Nowadays, there are a lot of hole digger machine can be found in the market. But most of them are using liquid fuel as power source. It is making holes in shorter time, and made work easier. In order to that, it needs more money for the fuel and it is not clean because the pollution. This research is to test the performance of machine that can help farmers to make holes for planting sengon’s seeds. This hole digger machine with DC motor, 0.125 HP with less pollution and cheaper than the other one. This machine can make up to 68 holes with each holes ranges are 2.5 x 2.5 meters and then each 15 cm diameters and depth. With only 2 batteries 12 v – 5 Ah, it can be used for 21.13 minutes until the power goes down and reaches the minimum point. So the capacity is 3.2 holes/minutes. Work load can be measure by using IRHR, which is test the heart rate when working with this machine. There are 2 types activities when working with this machine, the hole making process and the moving activities. IRHR for hole making process is 1.45, so it can be classified by average work load. And IRHR for moving activities, which is include stepping and lifting the machine, is 2.17 that classified by extra heavy workload. But, each activities are done awhile, they only take 15 seconds and 5 seconds. | en |
