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Standards of Best Practice for Arboricultural Crane Operations
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| As you read this article you will obviously reflect upon your own working practice and experience and undoubtedly you will have an opinion about how well you, your crew or your company works with cranes. It may be that you are thinking that you and your practice is perfectly safe and that yes, OK, things have not gone quite as planned once or twice but generally you are pretty good. These were my thoughts during the early summer of 2002. We were contracted to remove a 100 foot (30m) tall London Plane from Russell Square, a historical open space in the centre of London. As usual during such a high profile task, I was to run the job with the assistance of a colleague Alistair Farquharson and two, three person crews, each equipped with chip truck and chipper. The idea was that we would use a fifty five tonne crane to lift pieces to each crew alternatively. This system would reduce delay and hopefully allow us to complete the whole tree and clean up in our seven hour traffic closure window.
The climber made the cuts and I gave the hand signal to the driver to lift slowly. The crane engine took up the pressure and then the overload warning buzzer could be heard from the cab. Luckily the factor of safety built into the crane was massive and with an amount of careful manoeuvring, the driver was able to jib up and lay the piece safely on the ground. At the sound of the buzzer, my confidence in my own expertise was shattered. We got away with it by pure luck, had the piece been any bigger, would the driver still have agreed to lift it? Would the crane have coped or would our worst ever day have happened, an overturned crane in the centre of London and possibly a dead climber? The event took the shine from an otherwise polished job and during discussion later in the day, Alistair and I decided to stop our use of cranes until we were absolutely sure that we were able to completely prove our own competence to run such work. I made several enquiries to various agencies both in the UK and in the USA and whilst there is much that can be read on the use of cranes during construction, there was little available to guide arborists in our work. Following conversation with the Health and Safety Executive (HSE), the National Proficiency Tests Council (NPTC) and several other companies, we decided to develop guidance for arborists in how to integrate the use of cranes into arboricultural operations. A working group was put together which comprised of industry practitioners, safety experts and qualification development experts from both the UK and the USA in order that we could work through the use of cranes from initial hire right through to the end of the job. It was felt that although both countries had differing legislation and guidance, good advice could be drawn together and hopefully the guidance that would be ultimately produced would be applicable to all arborists whether British or American. It was decided to hold a three day standard setting event in Danvers just outside Boston, Massachusetts, USA, as a close friend of ours, Chris Cloutman, owner of Dodge Tree Service, Inc, specialises in the use of cranes and work platforms for take down operations and he had agreed to set up a demonstration for the working party to observe and use as a bench mark for the development of the guidelines. Salcey and Dodge have had a reciprocal training partnership for several years and Chris had often commented about the lack of guidance and training for arborists in the States.
As the old saying goes, ‘the sun shines on the righteous’, the demonstration was made even better by the beautiful sunshine and tropical temperature. Chris was operating the crane whilst Charlie Williams was the climber. Bob Gillespie and Tom Rezza were organising the systems on the ground. The Dodge crew dismantled a large Oak tree using a combination of crane and climber and crane and platform and then stressed that they had worked as they would normally work and had not just put on a show of best practice for the demonstration, the reasoning being that we needed to see reality if we were to set standards not only of best practice but also standards that would be industrially credible. The atmosphere during the takedown was very exciting and there was a lot of networking going on. We took the opportunity to pick the brains of Richard and Al from OSHA who had had many years of experience in crane safety and accident investigation and in turn they took a genuine interest in our explanations of our working systems. The mood was definitely about people and agencies coming together with a common desire to improve the safety of our industry. After the tree was reduced to a stump and we had all eaten a splendid lunch back at the Dodge yard we reconvened in the conference room of the Sheraton Ferncroft Hotel in Danvers to get down to business and discuss the minute details of crane integration and hopefully by using the experience of everyone concerned, come up with some best practice guidance that could be applied day to day and would make arboricultural work with cranes totally predictable, controlled, safe and efficient. For the remainder of Saturday afternoon and then all day on Sunday we shared stories, argued, discussed and argued some more until we had talked out the whole subject of using cranes as an aid in arboricultural operations. Some of the major points that we discussed were: Who needs guidance? The Crane Risk assessment
Transport of branch and stem material An interesting point to note is that when hiring or using a crane in any situation, you must employ what is known as a Crane Supervisor or as is sometimes referred to as the Appointed Person. The Crane Supervisor is responsible for the site and work procedure and acts as the controller of the entire operation. British Standard 7121 states that “The Crane Supervisor should direct and supervise the lifting operations, ensuring that these are carried out in accordance with the method statement. The Crane Supervisor should be competent and suitably trained and should have sufficient experience to carry out all relevant duties. The Crane Supervisor should have sufficient authority to stop the lifting operation if the supervisor considers it dangerous to proceed.” The Crane Supervisor forms the crucial link between all other members of the lifting team and as above should be qualified and experienced in the use of cranes and clearly should also be a qualified and experienced Arborist. If I had been a qualified Crane Supervisor during our London takedown, the situation would not have occurred. Knowing what I know now as a qualified Crane Supervisor, I can report with confidence that the warning buzzer would not have sounded that day and I can also honestly say that looking back, what I thought to be safe practice and site organisation, was simply an accident waiting to happen. By far the most argued issue was the use of the crane to transport a climber by attaching the climbing system to the ball of the crane. Let me clearly state that the HSE, OSHA and everyone on the working group advise that this practice is not recommended as it is thought to be potentially very dangerous. In fact, under most circumstances, OSHA would issue citations for this practice. Only by careful risk assessment and detailed method planning can certain practices become acceptable. You as the Crane Supervisor must have the confidence in your own decisions to prove absolutely that your chosen method was the safest option and that full consideration had been given to all of the alternatives. At this point let me introduce the working group: As well as a big thank you to each of the above, I would also like to thank the following people for their support of the project so far: Cynthia Mills NAA President. To conclude this article please let me give two important pieces of advice: 1. If you intend to use a crane to assist your operations, qualify yourself or one of your staff as a Crane Supervisor. In the UK it is a legal obligation. Whether you are qualified or not, should something go wrong, you as the crew leader on site that day, will be held responsible. Do yourself a favour, reduce the margin for error and get qualified. 2. Prior to your work, conduct a thorough written risk assessment, plan the proposed method and produce a written method statement and then ensure that every member of the lifting team and every other person on site is briefed and understands exactly what you are about to do. Notes from the author: Email info@salcey.co.uk |
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