A common practice in larger plants is to mount bases wherever hoists are needed and use only one or two portable davit cranes to do the lifting, moving them from station to station as needed.
While this is an excellent space- and cost-saving measure, some plants have discovered it creates an additional problem.
At lift stations where the cranes are not in use, extra wire rope is left with nowhere to be tied off or stored, creating a hazard to operators and equipment.
When left near the lift stations, the mess of excess wire rope creates a potentially dangerous obstacle for operators working around aeration tanks. If not tied off correctly, the wire rope can easily slip into wet wells where it can cause significant damage to mixers.
Tightening extra wire rope
At plants such as the new Eagles Point Wastewater Treatment Plant in Cottage Grove, Minn., the problem is more common because more than 24 wall and floor bases are installed at various lift stations, and only two portable davit cranes are in use at any given time.
The result is a lot of extra wire rope around the biological aeration areas.
Tim Miller of Electric Pump, a supplier for the new plant, recognized the potential hazard immediately.
Miller suggested to the owners, as well as their engineering firm, that there be a provision to eliminate the problem. Miller contended that the operators don’t have time to tie off the loose wire ropes appropriately, so any solution would have to be quick and simple.
As it happened, Thern’s newly developed RW50 Cable Spool was an ideal solution for the Eagles Point Wastewater Treatment Plant. The stainless steel reel winds up excess wire rope when it is detached from the crane, thus eliminating the mess and danger created by the loose cables.
From an operations and maintenance standpoint, Miller believes the cable spools the plant installed at each lift station are the best solution to eliminate any potential problems associated with unattended wire that may be present in the biological aeration areas. The cable spools help keep the cables tight, secure and out of the way, and they are simple to use, according to Eagles Point Wastewater Plant operators.
Additionally, Thern’s RW50 Cable Spools are constructed of durable stainless steel with an electro-polished finish for superior corrosion resistance.