Recommendations on applying various rope designs
Areas of application and service conditions of rope are very wide what does not allow giving concrete instructions on applying various rope designs. All areas of application in the catalogue are only recommendatory. The usage peculiarities of various steel rope constructions are listed bellow.
Every type and construction of a steel rope is peculiar what must be taken into account when choosing a rope for special service conditions. At that one must keep up all the recommended rations between diameters of coiling bodies and ropes (see table1), and observe necessary margin of safety what provides accident-free operation of rope. Safety and durability of rope mainly depend on the material of the core; ropes applied in hostile environment are safe due to protective metal covering and usage of anticorrosive lubricant.
Unary lay ropes of round wires possess the increased rigidity, therefore they are recommended to be applied in the conditions when stretching loadings prevail (lightning protector of transmission facilities, etc.).
Double lay ropes with a linear wire contact possess rather big efficiency and have sufficient number of various constructions. It allows to choose ropes for work at the big end loadings, at significant abrasive wear , at minimally allowable ratio of diameter of coiling body to rope diameter.
Ropes of ЛК-Р type should be applied in hostile environments, when exposed to the influence of intensive reversed bendings at work in the open air. The big structural toughness of these ropes permits using them in many rather intense operating conditions: on building and metallurgical cranes, mine elevating installations, escalators and scrapers, aerial tramways, cables-cranes, etc.
Ropes of ЛК-0 type steadily work under conditions of intensive abrasion due to the increased wire diameter in the top layer. These ropes have received a wide application as elevating ones on marine vessels and lifts, as breaking ones - on mine elevating installations, as traction ones - on ropeways, etc. But normal operation of these ropes needs an increased diameter of blocks and drums.
Ropes of ЛК-3 type are used almost in all industries as they possess higher flexibility, but should not be exposed to influence of hostile environment because of thin wires, easily corroded.
Ropes of ЛК-РО type have rather big number of wires in strands and consequently possess increased flexibility. Thick wires in the external layer of these ropes ensure their successful usage under the conditions of abrasive wear and hostile environment.
Double lay ropes of ТЛК type should be applied when usage of ropes with a linear wire contact in strands is impossible because of violation of the established minimally allowable ratio between diameters of coiling bodies and rope wire diameters or when it is impossible to maintain the recommended safety margin.
Double lay ropes of ТК type are not recommended for intensively working installations as they are of low technical resource. Application of ropes such as DC is allowable for not intense conditions of operation where reversed bendings and pulsating loadings are insignificant or absent completely (braced ropes, temporal floating fastenings, etc.).
Trihedral-strand ropes are characterized by the increased structural stability, the big factor of filling and the big supporting base. Application of these ropes are appropriate with big end loadings and strong abrasive wear. Trihedral-strand ropes should be applied on the mounts with friction pulley and in case of multi-layer drum coiling. Imperfections of trihedral-strand ropes are sharp wire bending over the verge of strands, the increased rigidity of a rope, labor input of strands manufacturing.
Ropes of the closed construction are used as carrying ropes for aerial rope ways and cables-cranes. The big factor of metal filling of rope cross-section, the maximal supporting base, the minimal elastic and residual elongation at operation, ability of profiled wires to keep the position in a rope at their breakage - all this presupposes the application of these ropes on heavy loaded installations working in hostile environment with bid changing frequency of working loadings.
The ropes of the closed construction made of galvanized wires, are widely applied as bearing elements at building of various technical constructions (sustention bridges, overpasses, etc.).
