Usability

• Simple components, consisting of a single lift cylinder and two small latch actuators controlled by an off-the-shelf control valve

• Straight-line lifting: No highly loaded winch drums or sheaves and no bending loaded lift element, as there is with wire rope 
• Superior corrosion resistance and easy inspection
• Increased safety: Two chains at each lift station for a redundant lifting design 

• Each chain is designed for the full capacity, with a 1.5:1 safety factor per chain, or a total safety factor of 3:1 with two chains

• Chains under load do not wrap around a sheave or drum and, thus, do not incur the wear and fatigue associated with wire-rope storage 
• No spiral strands twisting under load

Usability

• Corrodes from the inside out, requiring destructive testing or expensive inspection equipment
• Wire rope is sized for 12.5% of the winch load, not the full load

• If any part of the 8-part line fails, the whole system fails
• Known wire rope failures occur at an approximate rate of one per year globally, with at least one incident occurring during final testing of a new system

• Wire ropes stretch 15x more than chains
• Typical cranes using wire ropes do not submerge the wire ropes in seawater; comparing that use case with wire rope shiplifts is like comparing apples and oranges
• Winches used with wire ropes have poor load-monitoring accuracy due to their many wraps around sheaves, wire rope fleet angle, and bearing friction; aggregate error is over 15%
• Wire rope systems have no redundancy

Parts & Maintenance

• Chain jacks do not use pulley sheaves
• Simple maintenance
• Bardex offers options to stock spare parts in or near your facility; most parts are also readily available from local suppliers

Lloyd’s Code Inspection

Connection to Platform

• No Lloyd’s inspection required

Chain Jack

• No Lloyd’s inspection required

Insulation Resistance

• No Lloyd’s inspection required

Chain Maintenance and Inspection

• Any length of chain so worn that its mean diameter at its most worn part is reduced by 4% or more from its nominal diameter is to be renewed. This is an easy visual inspection/measurement with no need to do any disassembly.

Lloyd’s Code Inspection

Connection to Platform

• Must conduct inspections at all levels
• 20% of all sheaves, bearings, axles, and housings are to be examined yearly, with at least two complete sets of sheaves disassembled for examination
• All sheaves are to be disassembled at least once in the 5-yearly survey cycle

Wire Rope Hoist – Annual Periodical Surveys

• Tooth alignment for gears
• Main shaft pillow block bearings opened
• Re-torque screws securing final spur wheels to the drum
• Primary gears, shafts, and bearings 
• Hoist frame and bolting

Electrical Systems Test

• Electric motor insulation resistance test 
• Breakers, relays, and all mechanical electrical gear examined
• 20% of electric motors including bearings and magnetic brakes examined
• All circuit breakers tested for overload tripping
• Air compressors for hoist ratchet and air tank examined
• Demonstration of all safety devices

Rope Maintenance and Inspection

• Annual visual examination for signs of corrosion, wear, or broken wires
• Wire ropes are to be renewed when 5% or more of wires in any length of 10 rope diameters is broken, worn, or corroded; for small installations, this will result in a replacement cycle of about 5 years

Longevity

• Two 4-person crews can replace 92 chains in one week (46 chain jacks with two chains each); replaced every 12-15 years
• 5 days x 8 persons = 40 person-days over 24 to 30 years

The fatigue life of chains far exceeds their duty life in this application, so is not a concern

Longevity

• Crew of 4 for 3-5 days to replace two wire ropes; for a 46-hoist system, 10 ropes must be replaced annually
• 5 days x 4 persons x 5 rope pairs = 100 person-days = 3000 person-days over 30 years

Environmental Considerations

• Chain jack systems do not submerge any greased or lubricated parts
• Extreme measures are taken to ensure no leaks of hydraulic fluid, which is also readily biodegradable for added environmental safety
• Drip trays and curbs offer further protection from accidental spills
•  Carefully selected safety factors provide a high level of security against component failure

Environmental Considerations

• Deliberately submerge heavily greased rope and pulley sheaves into the water with every operation
• Grease must be re-applied once per month at a minimum
• Grease is not allowed in some jurisdictions

Operation

• PLC controlled for automatic operation
• Adjustable lift/lower speed depending on vessel weight equal to speeds of wire rope systems
• No active adjustments needed for vessel transfer on and off the shiplift platform
• Weight-distribution measurement capability
• Ultra-precise synchronization: A level platform is achieved after every stroke; lift cylinders are synchronized within +/-1mm throughout cycle
• Mechanically locked at all times: No positional adjustments for transfer required
• No operating depth limit because chain does not require storage drums
• Smooth and quiet operation: No sudden movements or shock loading

Operation

• Annual removal and destructive test of a minimum of 2 ropes; more ropes required if wire breaks at less than 90% MBL
• It is the intention that all ropes be replaced in sequence at a rate determined by wear, chemical attack, corrosion, or other forms of deterioration associated with the particular installation