eng Science and Education Publishing American Journal of Mechanical Engineering 2328-4110 2015-07-20 3 4 115 121 10.12691/ajme-3-4-2 AJME2015342 article Cătălin Iancu ciancu@utgjiu.ro 1 Florin Vîlceanu 2 Engineering Faculty, University “Constantin Brâncuşi” of Târgu-Jiu, Romania Popeci Heavy Equipment, Targu-Jiu subs., Romania In this paper a method of calculus is presented step-by-step in order to establishing the residual lifetime of a lifting crane, using non-destructive methods of study. First it must be establish the actual state of machine and also areas subject to study, and then by applying the method it can be drawn the conclusion that at 2/3 of initial load can be reached an extension up to 5 times of actual residual lifetime. http://pubs.sciepub.com/ajme/3/4/2/ajme-3-4-2.pdf methodology lifetime lifting installation non-destructive methods