built up custom unit in this example a drum hoist 240 is used that is located under the platform line 230 may be securely attached to the top of the structure to be traversed line 230 is further guided at the top of the hoisting device 200 by a restraint assembly 210 such a restraint assembly guides the line 230 from the drum 240 to the top of the platform by preventing the line or cable from moving laterally and otherwise prevent the line or cable from snagging the restraint assembly 230 also prevents the line 230 from vibrating or rubbing on other surfaces as illustrated in fig3 restraint device 210 typically comprises a fairlead 302 which is a member such as a ring or a block that has a guide opening and a tension holder the tension holder as described more fully herein is a device that keeps tension in the line 230 when the hoisting device 200 is in a position that would cause the line 230 to go slack the restraint assembly 210 operates to restrain movement of a line 230 passing through an opening 306 of the restraint assembly the line 230 may be any type of rigging operable to elevate or lower a platform to be controlled by the hoisting device and is typically a wire rope or cable an embodiment of tension holder 303 is further illustrated in fig4 the tension holder comprises substantially identical.