Comparison of Productivity and Cost Estimate of Two Roundwood Loading Machines (Case Study: of G.M.S and Loader-Grapple)

For roundwood loading in the northern ern forests of Iran, different kinds of machines are used namely G.M.S, loader- grapple, revolving crane and so on. Work study and time measurement were used to compare two roundwood loading machines of G.M.S and loader grapple. Collection of the needed data to estimate the production rate and cost for every cubic meter in loading operations in Golband station was done by harmonizing the work stages (load-free going time, taking and lifting, return time, putting and arranging) of these two machines, then the time measurement of two machines was handled in four components and the obtained results are as follows: Pure spent times for each one-time loading component of G.M.S and loader- grapple show that the total pure spent time in G.M.S is 5.28 times as much as that of loader-grapple. The production rate of loader-grapple machine using pure time without including delay time is 69.29 meter cube per hour (mcph) and using total time with including delay time is 43.43 mcph while the former of G.M.S is 11.55 mcph and the latter of G.M.S is 9.65 mcph in a way that the amount of production of loadergrapple without including delay time is 5.99 times as much as that of G.M.S and with including delay time it is 4.50 times as much as that of G.M.S. The results also show that in G.M.S loading system despite the higher cost per hour, there was lower hour production than loading system of loader-grapple .Therefore, loading system of loader-grapple not only shows higher hour production, but also shows lower cost per hour than G.M.S loading system.