Cutting through the BS25 June 2012 by Will North
A new revision to the British Standard for cranes will clarify guidance on inspection, maintenance and thorough examination of overhead cranes, emphasise scheduling testing and inspection to crane usage, and lay the ground work for a dedicated overhead crane standard. Will North reports
BS 7121, published by the British Standards Institute (BSI), lays out standards for crane usage and inspection. The part of the standard dedicated to inspection is now being revised, and public comments are being invited.
Since its launch in the late 1980s, the standard has been split into a broad general introduction on crane usage, another general section on crane inspection, and parts looking at specific crane types.
The problem with this structure is that the very different needs of, say, crane inspectors on mobile cranes and those working on overhead cranes are addressed in the same part of the standard. Now, with the revision of BS 7121-2 (Inspection, maintenance and thorough examination) overhead crane inspectors and owners will finally get a section dedicated to their needs. The new BS 7121-2 will be split into a general introduction, a section on mobile crane inspection and a section on overhead crane inspection. Future parts will cover loader cranes, tower cranes and cargo handling cranes.
Derrick Bailes, a frequent columnist in this magazine and technical consultant to LEEA, the Lifting Equipment Engineers' Association, contributed to the development of the current revision of the standard. He says, "The current version has a bias towards mobile cranes. It asks inspectors to check things like coolant and tyres. This is totally irrelevant to overhead cranes.
"From the overhead crane industry's point-of-view, there is quite a lot of dross. We've cut that down; the revised version clears it all out. A lot of material in the general section has been moved into the separate sections for mobile cranes, tower cranes and overhead cranes. That means there is a certain amount of duplication, but it is more user friendly."
Ian Simpson, HM Principal Specialist Inspector, represented the UK's occupational health and safety regulator, the HSE, on the group developing the revision of the standard. He explains that the split between mobile cranes and overhead cranes introduced in Part 2 of the standard, will lay the foundations for future development of the standard.
Simpson says, "Ultimately, we want each part of the standard to give users a 'one-stop-shop', so they can just buy one part of the standard." In a future revision of the standard, rather than having a part for general usage and a part for inspection, along with the parts dedicated to specific crane types, the specific parts will cover both usage and inspection.
Simpson says that, for each crane-type, different parts won't be telling users and inspectors anything they don't need to know.
Bailes says that the current structure doesn't give the same guidance on use for overhead crane users as it does for users of other crane types like mobile or tower cranes. However, LEEA has been developing its own guidance on usage, which could then be used as the basis, along with the new overhead crane testing guidance in BS 7121-2, for a dedicated part on overhead crane use and inspection.
Over recent years, crane manufacturers have increasingly fitted data loggers as standard. For a lot of users, the information recorded by the data logger will only come into play when they make a warranty claim. For most users, that won't be a problem, but if a crane has been misused, the manufacturer will know and may reject the claim.
But data loggers shouldn't be viewed as the enemy. In fact, they can be a vital tool for planning a cost effective and efficient maintenance and thorough examination programme. One of the key concepts the HSE wanted to see included in the revision was scheduling of inspections to reflect crane usage.
A recent incident at a major manufacturer illustrates the problem with planning inspection schedules on a one-size-fits-all approach. The manufacturer has installed 40 cranes in a workshop, and planned the same inspection cycle for all of them. However, two cranes were working far more intensively than the rest. As the manufacturer geared up for the launch of a major new product, one of the two busy cranes dropped a vital press tool, landing the manufacturer with the bill for an expensive replacement and jeopardising the product launch.
Checking the dataloggers after the incident, it was found these two cranes had been used thousands of times more often than the others on the site, and we effectively at the end of their service life after just 18 months. By tracking their use, and increasing the maintenance schedule for the two busiest cranes, the incident may have been avoided.
Simpson says the new revision will help crane users avoid this sort of problem: "The standard recommends regular downloads from the datalogger, and look at the number of cycles performed and hours worked. Users can save money, as some cranes won't need to be maintained so frequently." At the same time, by spending a little more to maintain the most heavily used cranes when they need it, expensive accidents can be avoided.
The HSE also argued for another revision of how crane users plan their maintenance programmes, that tailors the checks conducted on each crane according to how, and how often, it is used.
In the past, crane users may have had an independent inspector on site. Today, inspectors work across a region, being assigned jobs as needed. The problem with that approach is that individual inspectors don't have the same knowledge of individual cranes.
So, the standard recommends creating a written defined scope of thorough examinations. Simpson says the process of developing a defined scope for thorough examinations should start when a crane user chooses an engineering surveyor contractor to undertake its thorough examinations.
The starting point for the defined scope will be the crane manufacturer's manual. The crane user and engineering consultant should use the manual and maintenance and inspection records, combined with their knowledge of how each crane will be used, to agree a defined scope for each crane: whether the frequency of thorough examinations should be increased, and what checks should be carried out.
Then, when the engineering surveyor assigned to perform the checks arrives on site, they will have a checklist for each crane, ensuring that the cranes that are used the most, or the most heavily, have all the checks they require. The result should be that, even if a surveyor doesn't know each crane on the site, each crane will have all the checks it needs made, tailored to its usage.
One of the big differences between mobile crane inspections and overhead crane inspections is the problem of access. On a mobile crane, access to all the key points is increasingly built into the crane design. On an overhead crane, inspectors may need to use work platform of other access equipment to reach the crane.
Bailes says, "Crane owners should be thinking of access ahead of need, particularly if a breakdown is going to be business critical.
"So, when they are contracting out maintenance, they should check who is responsible for access. They should make sure a plan is in place for the provision and use of access equipment."
Simpson says this should take place at the same time as defining the scope of thorough examinations: "Part of the discussion with the consultant engineer should be who provides access, so when the surveyor arrives, the right access equipment is available.
Have your say
The revision of BS 7121-2 is now open for public consultation. To submit your comments, please go here. The consultation process closes on 31 July 2012.