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Manhole Cover Lifters
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Whilst manhole cover lifters come in all sizes, shapes and lifting capacities, they invariably share a common feature, that is, they attach to the manhole cover using a form of key. These manhole lifting keys slot into holes in the manhole cover. The one exception to this rule is the Manhole Buddy, a magnetic attached manhole cover lifter. Most significantly, no cover lifting keys are needed with the Manhole Buddy. Before considering the attributes of the magnetic attached manhole cover lifter, it is worth reviewing the general methods and issues associated with lifting manhole covers.
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The subject has been divided into relevant sections and you can skip to any using the links below:
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Lifting Manhole Covers by Hand .... best advice “DON’T”
Doubtless there are situations where people attempt to lift manhole covers using levers to pry the cover out of the frame and then by applying their hands directly onto the cover. By any measure, this is an extreme foolhardy activity. Just like the manhole cover lifters, manhole covers come in all shapes, sizes and weights. Amongst the multitude of dangers present when trying to directly handle manhole covers, the greatest is the risk of trapping hands or feet between the cover and the frame or the ground. Thereafter, the significance of size, shape, thickness and weight of a cover are amongst the variables that may only become apparent whilst lifting is in progress. And the local environment in which the manhole cover is situated is also likely to contribute directly to the challenge of lifting it – if the manhole cover is in a raised position, bordered by a nearby structure, surrounded by an uneven, broken or slippery surface or temporarily obstructed by a vehicle, it becomes more difficult to adopt any form of safe lifting posture. And of course the vast majority of manhole covers weigh significantly more than the personal manual handling limits advised by the Health & Safety Executive – back injuries are synonomous with manual handling of manhole covers. Put simply, manhole covers should never be handled manually!
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Lifting Manhole Covers with Handheld Lifting Keys
More commonly, persons who persist in manually handling covers do so through the use of manhole cover lifting keys. These themselves come in all shapes and sizes, because of course there is no common size and shape of key slot. Therefore drainage engineers needs to equip themselves with an array of manhole lifting keys to cover the wide range of manhole covers they are likely to encounter. Immediately you can see one of the inherent drawbacks of a manhole cover lifting system that relies upon cover lifting keys – with such an array of manhole lifting keys required, there is a temptation to improvise when the correct key is not available. An ill fitting key increases the risk it will not be retained in the manhole cover slot and the manhole cover will become detached.
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However, assuming the correct manhole lifting key is available, the operative now faces the challenge of trying to adopt a good lifting posture. Consider for the moment that a typical manhole cover will be at least 600 mm wide, many much wider. The operative therefore must straddle the cover, feet at least 700 mm apart, and attempt a lift with straight back and bent knees (see HSE Manual Handling Guidance). Many 600 mm square drainge chambers are covered by two triangulars manhole covers, fitted with inter-connecting bolts. When lifting such an arrangement, the natural movement between the two parts creates an ungainly load, which increases the dangers for the operative as they stand astride the drainage chamber. Even if two operatives share the load, each having one manhole lifting key, they need to achieve good co-ordination of movement and be able to react in unison to any unexpected event. Of course, the potential risks associated with refitting a manhole cover over an open chamber are significantly greater, than when removing it.
And once again, there is the issue of weight. Most covers will exceed the advisable lifting limit for one person, many will be more than double the limit, hence beyond the range for a two-person lift.
The dangers inherent in manually handling any manhole cover, whether by direct application of hands, or through hand-held manhole cover lifting keys, are clearly considerable and reinforce the previous statement that manhole covers should never be handled manually!
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There are a myriad of manhole cover lifters on the market, reflecting the requirements of different sizes, shapes and designs of manhole cover systems. The majority of manhole cover systems require the cover to be lifted vertically to clear the frame. A minority of designs try to minimise the lifting requirement and instead facilitate sliding of the cover out of the frame. This approach has the potential to minimise lifting risks but the inherent installation constraints imposed by the design (usually only being able to withdraw in one direction) result in only a very small proportion of such covers being deployed. And even with these, it is still necessary to find some means of unseating the cover …..
Unseating or freeing a manhole cover from its frame is a significant part of the overall cover lifting activity. The manhole cover will invariably be well embedded in the frame as a result of passing traffic (foot or vehicular), dirt that has been deposited into the gap between the cover and the frame (whether naturally or otherwise) or perhaps just the effect of corrosion if the manhole cover has not been lifted for some time. The traditional (and highly inadvisable method) is to thump the manhole cover with a sledge hammer. Yes, it can often achieve the required result, but at what cost:
- Damaged or broken covers
- Strain or impact injuries to the sledge hammer ‘operator’
- Flesh or eye injuries from detached pieces of metal
- Risks to other persons in the vicinity
Similarly, wedges, pry bars and crowbars can be used to force the cover out of the frame. These methods often involve hammering such tools into the gap between the manhole cover and the frame, so the same risks of physical injury, broken covers and flying metal particles apply.
With the notable exception of the magnetic attached manhole cover lifter (the Manhole Buddy), virtually all manhole lifting systems use the key slots to connect with the manhole cover. Whilst these fixed positions might ensure a cover is lifted evenly and uniformly, they create the need for undue force when trying to unseat the manhole cover – or put another way, they do not permit an unseating effort to be applied right at the edge of the cover, which is precisely where it is needed. That said, a commonly used method with this fixed position design of lifter is to apply the lifting force and then use some ‘shock tactics’ on the edge of the manhole cover, repeating the process until the seal is eventually broken. Such a method is an improvement on the ‘sledge hammer only’ approach but still introduces undesirable risks to people and equipment. There is a better way ......
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Manhole Buddy - Magnetic Manhole Lifter
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The Manhole Buddy is amazingly effective on a wide range of metallic covers and is generally unmatched in its speed of deployment and use. Inherent in its design are a number of significant advantages:
- Firstly, it requires no form of manhole lifting key. Instead, you place the magnet on the manhole cover and operate the On-Off lever. Permanent magnets are used, so no external power or recharging is ever needed. Ask any drainage engineer how much time is spent cleaning out key slots in manhole covers and locating the correct type of lifting key and you’ll quickly appreciate the simplicity and attractiveness of the magnet.
- Secondly, it requires no physical lifting effort. The human input required is a downward action and the mechanical advantage inherent in the design reduces that by a factor of 2.5:1, relative to the weight of the cover. So it’s easy to lift and move heavy loads.
- The most effective method of unseating a jammed cover is to apply force nearest possible to the edge. With the Manhole Buddy, you can place the magnet wherever you choose, so you can apply localised force where most appropriate on the manhole cover. And better still, the Manhole Buddy trolley has a secondary lifting position, delivering a mechanical advantage greater than 5:1 - this makes unseating the majority of covers a doddle!
- Portability and speed of deployment are unrivalled. The lifting trolley (whether the Steel or Aluminium version) can be comfortably carried in one hand and unfolded within 15 seconds. You then hook the trolley into one of three positions on the magnet lifting frame and start work. Up and running within 30 seconds at the most. Refolding the trolley at the end of the job is merely a reversal of the deployment method – 15 seconds is more than enough, whereupon it can be stored neatly in the boot of a car!
There are numerous alternative manhole cover lifters on the market. All are capable to varying degrees of lifting drainage covers. Many fall out of favour due to their size and complexity, including the need to assemble multiple parts. Invariably the user then reverts to the faster, albeit more risky, approach – using handheld manhole lifting keys. By contrast, the Manhole Buddy is a highly versatile cover lifter, having the capability to quickly and safely handle the widest range of manhole covers. In this respect, it is undoubtedly the manhole lifter most likely to deter operatives from reaching for the handheld lifting keys. And that will undoubtedly save backs from injury!
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