J D Neuhaus air and hydraulic operated chain hoists have been used to solve difficult underwater lifting and pulling operations for many years. Working in this dangerous and demanding environment puts additional strains on both the personnel and equipment, which are subject to conditions well outside conventional operating zones.
A typical subsea operation was recently shown on the National Geographic ‘World’s Toughest Fixes’ programme. This covered the removal, repair and eventual replacement of a damaged 50 ton rudder from a fully loaded bulk cargo vessel. After breaking down while hauling iron with a value of 3M US Dollars from Brazil to China, the vessel had been towed to a safe mooring in Caracas Bay, off the coast of Venezuela. The operation involved the underwater setting up and rigging of three air operated JDN Profi 25Ti hoists (offering 25 tonne lift capacity each) to provide the necessary pulling and lifting power. For subsea operations of this type, where standard JDN hoists have been used, they have also been subjected to full rebuild after the job completion.
Following their experience of underwater operations, J D Neuhaus invested in a research and development programme for the introduction of specialised handling products capable of undertaking subsea operations with the minimum of maintenance/repair afterwork. Two hoists, the Profi 3Ti and 6Ti offering 3.2 and 6.3 tonnes lift capacities respectively, have been introduced as specialised subsea products. These incorporate high performance sealing qualities and include a purposed designed hand valve for easy operation by gloved divers. These products have also been subjected to exhaustive testing and approval by UMC International, a specialist company in underwater maintenance and repairs.
Optional air or hydraulic operation is available for operation at depths of 70 metres, together with variable speed control and overload protection provided as standard. A top suspension hook mounting ensures versatility and maximum compatibility with horizontal or oblique pulling operations as well as standard vertical lifting. Both new units feature 3kW vane motors, with 3 metre chain lifts incorporated as standard and 2 metre cables supplied for control unit operation. Optional cable and chain lengths can be accommodated, together with uprated hoists for operation at even greater water depths if required.