A Crane Is A Tower Or Derrick That Is Equipped Withcables And Pulleys That Are Used To Lift And Lowermaterial. They Are Commonly Used In The Constructionindustry And In The Manufacturing Of Heavy Equipment.Cranes For Construction Are Normally Temporary Structures, Either Fixed To The Ground Or Mounted On A Purpose Built Vehicle. They Can Either Be Controlled From An Operator Ina Cab That Travels Along With The Crane, By A Pushbutton Pendant Control Station, Or By Radio Typecontrols. The Crane Operator Is Ultimately Responsiblefor The Safety Of The Crews And The Crane.Medieval CranesCranes Of The Middle Ages Were Used To Build Thecathedrals Of Europe. The Crane Was Fixed On Topof A Wall As It Was Being Constructed And Was Powered By Men That Ran Inside Of Two Large Wheelson Each Side. Cranes Were Also Used In Medieval Portsand In Shipyards.Mobile CranesThe Most Basic Type Of Crane Consists Of A Steeltruss Or Telescopic Boom Mounted On A Mobile Platform,which Could Be A Rail, Wheeled, Or Even On A Cattruck. The Boom Is Hinged At The Bottom And Can Be Either Raised Or Lowered By Cables Or Hydrauliccylinders. Telescopic CraneThis Type Of Crane Offers A Boom That Consists Ofa Number Of Tubes Fitted One Inside Of The Other.A Hydraulic Mechanism Extends Or Retracts Thetubes To Increase Or Decrease The Length Of Theboom.Tower CraneThe Tower Crane Is A Modern Form Of A Balancecrane. When Fixed To The Ground, Tower Craneswill Often Give The Best Combination Of Height Andlifting Capacity And Are Also Used When Constructingtall Buildings.Truck Mounted CraneCranes Mounted On A Rubber Tire Truck Will Providegreat Mobility. Outriggers That Extend Verticallyor Horizontally Are Used To Level And Stabilizethe Crane During Hoisting.Rough Terrain CraneA Crane That Is Mounted On An Undercarriage Withfour Rubber Tires, Designed For Operations Offroad. The Outriggers Extend Vertically Andhorizontally To Level And Stabilize The Crane Whenhoisting. These Types Of Cranes Are Single Enginemachines Where The Same Engine Is Used For Poweringthe Undercarriage As It Is For Powering Thecrane. In These Types Of Cranes, The Engine Isnormally Mounted In The Undercarriage Rather Thanin The Upper Portion.Loader CraneA Loader Crane Is A Hydraulically Powered Articulatedarm Fitted To A Trailer, Used To Load Equipmentonto A Trailer. The Numerous Sections Can Be Folded Into A Small Space When The Crane Isn't Inuse. Overhead CraneAlso Refered To As A Suspended Crane, This Typeis Normally Used In A Factory, With Some Of Thembeing Able To Lift Very Heavy Loads. The Hoist Isset On A Trolley Which Will Move In One Directionalong One Or Two Beams, Which Move At Angles To That Direction Along Elevated Or Ground Leveltracks, Often Mounted Along The Side Of An Assemblyarea.In The Excavation World, Cranes Are Used To Moveequipment Or Machinery. Cranes Can Quickly Andeasily Move Machinery Into Trenches Or Down Steephills, Or Even Pipe. There Are Many Types Ofcranes Available, Serving Everything From Excavation To Road Work.Cranes Are Also Beneficial To Building Bridges Orconstruction. For Many Years, Cranes Have Provento Be An Asset To The Industry Of Constructionand Excavating. Crane Operators Make Really Goodmoney, No Matter What Type Of Crane They Areoperating.PPPPP(word Count 581)
