CRANE CRITIQUE
Synthetic Hoist Rope on Cranes? A monthly crane and rigging informative column for all personnel directly or indirectly involved with crane safety. Each month we will attempt to explain a different technical issue pertaining to crane operations here on Guam, addressing the sometimes over-looked or misunderstood topics by management and operators alike. By Dave Barnhouse
This month’s topic: Samson rope manufacturer and Manitowoc Cranes have teamed up to introduce the first synthetic hoist wire for mobile cranes, called the KZ™100.
The advantages are many while the disadvantages are few, biggest of which is initial cost. But this is debatable and only time will tell if the benefits outweigh the costs. Let’s look at the Pros and Cons: Weight savings of 80%. This equates to safe and easy handling, reeving, and installation, plus a few hundred extra pounds on the load chart. Torque neutral. This eliminates load spin and cabling, a major reason for wire rope damage. Operators appreciate this. Corrosion resistant, and no lubrication required. A big plus especially on winch drums used infrequently. Practically no wear on sheaves. Whether using nylon or steel sheaves, noticeable wear on block and boom sheaves will disappear with synthetic rope. No diving on winch drum. The unique construction eliminates kinking, bird caging, and damage caused by diving on the winch drum. This greatly reduces frequency of change outs. Close to same breaking strength. The synthetic rope is sized slightly larger than the wire rope it replaces with close to same breaking strength enabling 5:1 safety factor and delivering same line pull. Cost. The lone negative of this synthetic rope is the cost, approximately 2.5 to 3 times the cost of a high quality rotation resistant wire rope. But as with other new products, surely the rope will be improved on and the price will be lowered.
14 | NOVEMBER2014
CONSTRUCTION NEWS BULLETIN
Grove RT770E 65 ton crane configured with 16 part Samson Synthetic KZ™100
www.guamcontractors.org