The Challenge
We are often asked to design lifting and handling solutions for facilities where debris needs to be controlled for quality or safety reasons. Clean rooms, nuclear decommissioning, defence facilities, and aerospace manufacturing plants all need to avoid the risk of contamination, while food manufacturers strive to minimise formation of microorganisms.
The primary objective of these designs is to control debris from overhead lifting and handling systems, or to mitigate the risk of falling objects during operation and maintenance.
The Solution
Our engineers carefully consider the equipment’s construction and usage to identify potential causes of debris and how to implement effective Loose Article Control features.
The full working life of the machinery is assessed, with thought given to its through life maintenance with specific reference to lubricants, fluid drips, and mitigation against dropped objects. Our innovative solutions eliminate common causes of debris, designing out long-term contaminators such as flaking paint, swarf and oxidisation.
Technical Details
- The most direct and effective defence against loose articles, drips and other internal particulates is an integrated drip tray
- Custom-made for each crab, hoist, and hook, the trays help to minimise falling debris from the crane’s own machinery
- This also protects from debris originating from the wider surroundings that can accumulate on the crane over time
- Demands of the clean room necessitate subjecting the bridge, gantry rails, wiring, and all electrical connections to the same loose article analysis
- Reducing the total number of objects on the crane is key, and ancillary items that cannot be permanently affixed are carefully planned, positioned, and held securely in place
- This all assists in reducing surfaces and openings in equipment that can produce and harbour contaminants
- Even large bespoke machines like this 125t crane incorporate many Loose Article Control features
- Our standard approach to ensuring no paint or surface coatings flake off is to utilise plain stainless steel wherever possible, such as walkways and electrical enclosures
- Full perimeter kickplates and smart placement of infill panels prevent larger items from accidental displacement
- For less demanding Loose Article Control, commercial-off-the-shelf hoists can be modified with debris shielding
- This particular hoist also has a -MotoSuiveur load arrest device, preventing dropped loads in the event of a hoist brake or gearbox failure
- Radio pendants allow operators to control the cranes while situated outside of clean zones
- Control of the crane plays an equally important part in clean room systems
- Variable speed drives ensure that the bridge, crab and hoist accelerate and decelerate smoothly, minimising shock loads that could loosen debris
- Slow-down and ultimate limit switches protect the crane from over-travelling and over-hoisting
- SCX can also upgrade existing lifting equipment with Loose Article Control
- This crane, used to build Astute-class submarines, was given a full EC&I upgrade, in addition to a range of loose article control features
- Overall safety is improved too, following a detailed review of the lifting system and implementation of physical debris control barriers