We sometimes get asked this question by clients who have heard that Australian Standards require chain hoists to be scrapped after 10 years in service.
The answer to the question is… “no”.
There is no standard in force that arbitrarily requires a hoist to be removed from service after 10 years use. There are however, standards and codes of practice that are in common use in Australia that describe the methodology to be used in determining the operational lifespan of a hoist, and depending on how heavily the hoist is loaded and how often it is used, that lifespan can range from weeks to centuries.
The Australian Standard that deals with the safe use of hoists designed to Australian Standards (usually to AS1418 – Cranes hoists and winches) is AS2550.1 – Cranes hoists and winches – Safe use.
The German Code of Practice that deals with the safe use of hoists designed to German Standards (BGV-D8, BGV-D8+ and BGV-C1) is VPLT.SR2.0 Codes of practice for event technology – Provision and use of electric chain hoists.
The British Standard that deals with the safe use of chain hoists designed to British Standards (BS7905.1 Specification for the design and manufacture of above stage equipment) is BS7906.1 Code of Practice for installation, use and removal of above stage equipment.
All of these standards and codes have one important feature in common – Hoist Classification.
The Hoist Classification determines the lifespan of the hoist in hours, dependent on how the hoist is loaded (The Load Spectrum).
Australian Standards require that the mechanical portions of a hoist be designed for 10 years use. When the hoist is designed, assumptions will be made as to the likely Load Spectrum and hours in use per year that the hoist will be subjected to, and the Hoist Classification that will result in 10 years of service life should then be selected as the basis of the hoist design.
The British and German Codes mandate a minimum Hoist Classification and that then determines the lifespan of the hoist in hours, depending on the Load Spectrum the hoist is subjected to.
The British and Australian standards use the same naming convention for Hoist Classification (M1 thru M10). The German codes use a different naming convention (1BM, 2BM, etc.) but the tables used to describe Hoist Classification are all but identical.
The German Codes specify a minimum Hoist Classification of 1BM. The British Standard specifies a minimum Hoist Classification of M3. In practice, most chain hoists built to Australian Standards use a “default” Hoist Classification of M3.
The following table describes the Load Spectrum and Lifespan Hours for a hoist designed to either Hoist Classification M3 (AS & BS) or 1BM (Germany).
The following examples illustrate a range of lifespans for chain hoists designed to Hoist Classification M3/1BM under either the British, German or Australian Standards & Codes of Practice.
Example One – False Proscenium in a Theatre
A theatre uses 2 x 500kg chain hoists to raise and lower a false proscenium weighing 400kg.
The hoist is subjected to Load Spectrum 3 (Light) so lifespan is 1,600 hours.
The hoist speed is 4m/min and the piece is moved up and down 1m, so a full cycle is 30 seconds.
Let’s say the false proscenium stays in place during the week, and is raised and lowered twice a day on weekends for matinees, so it is operated a total of 2 minutes per week = 1.73hrs per year.
Machine lifespan is 1,600 hours divided by 1.73 hours per year = 925 years.
Example Two – Truss Grid Chain Hoists in a Touring Music Show
4 x 1,000kg hoists raise and lower a lighting truss weighing 2,500kg.
Load Spectrum is 2 (Moderate) so lifespan is 800 hours
The hoist speed is 4m/min and the typical show sequence is:
- Run out chains 12m to attach the hooks to the venue steelwork
- Lift the truss 8m
- Lower the truss 8m after show
- Run in chains 12m for storage
Total cycle time is 10 minutes per bump in/out. 6 shows a week for 50 weeks a year = 50 hours a year
Machine lifespan is 800 hours divided by 50hrs/year = 16 years
Example Three – Hoists Used to Raise and Lower an Exhibit in a Museum
2 x 250kg hoists raise and lower a museum exhibit weighing 450kg.
Load Spectrum is 1 (Heavy) so lifespan is 400 hours
The hoist speed is 4m/min and the exhibit sequence is:
- Raise 4m
- Lower 4m
- Pause for 1 minute
- Repeat for 12 hours a day
Hoist is running 40 minutes/hour x 12 hours a day = 8 hrs/day
Machine lifespan is 400 hours divided by 8hrs/day = 50 days.
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