Cable drums, cable reels and safety issues

Cable, as sold by electrical distributors and as used by contractors, is almost always supplied in bulk. As such, it is wound on to cable drums at the manufacturers' premises and transported to electrical wholesalers or specialist cable distributors that way, later to be stored and dispensed, often in measured lengths, at depots or on site.

At first (and second) thoughts, it may seem to most people that there's not a lot that can be said about cable drums and reels. After all, they are just drums around which electrical cable is wrapped, aren't they? Then, you simply unwind the required cable, don't I?

Well, yes and no. This is certainly true on the face of it, but there are definitely safety issues, especially for large drums, which frequently weigh many tonnes loaded (even, sometimes, unloaded), but also for smaller motorised cable dispensing equipment.

Types of cable drum or reel:

Firstly, it is important to emphasise the differences between the various types of cable drum and reel, and their applications. For the purposes of this VoltiBULLETIN, we are covering the following:

Large cable drums - The carry cable (often heavy-duty) from manufacturer to wholesaler, or by contractor to site. These are traditionally of wood, by many now are made of steel (or occasionally aluminium).

Smaller cable drums (more typically cable reels) - These carry generally lighter cable for use on site by electrical contractors and installers. They are normally made of plastic or even cardboard. Some are available in cardboard box dispensing packages.

Cable dispensing and cutting machines - These, found usually in electrical wholesalers' warehouses, are used to measure, dispense and cut cable to contactor's required lengths. The technology used to carry this out is often very basic - such as self-welded racks to store the cable drums, fork lifts to move them, and the floor or a bench to measure and cut it into discrete lengths. The machines may, however, be motorised - and more modern and safer equipment is now becoming available.

Cable racking systems - These store cable on the drums, as delivered by the cable manufacturer, ready to supply the cable dispensing and cutting machines.

Then there is a whole host of related ancillary equipment, such as equipment for lifting heavy drums.

Handling cable drums can be dangerous:

There are many stories of injuries to staff received while manhandling cable drums and cable. Most injuries occur because of the generally unsophisticated equipment used, although better staff training would help. HSE investigations are ongoing for some of the incidents, with employers potentially liable for large fines if found lacking in their provision of the correct work equipment. For example, one fatal accident occurred when an operator was operating a measuring and reeling machine with his back towards the racking. Cable snagged on a drum and pulled the racking over on top of him.

New Code of practice for wooden cable drums:

Partly as a result accidents, a new Code of Practice for wooden cable drums and reels has been published. Though this primarily concerns wooden cable-carrying drums, rather than dispensing machines with steel drums, some of the recommendations would be relevant to both.

BS 8512:2008 Electric cables, therefore, is the new Code of Practice that covers the storage, handling, installation and disposal of cables on wooden drums. Topics covered in the new Code of Practise, therefore, include wooden cable drums, materials handling equipment (for cables), as well as the storage, installation, waste disposal, lifting and related safety measures for wooden cable drums.

Published in March 2008, the new Code of Practise, is believed to have been drafted by the British Cable Association (BCA) and seen by the Electrical Contractors' Association (ECA) and the Electrical Distributors' Association (EDA).

It is available from BSI as hardcopy, priced £80.00 (£40.00 for members) - ISBN: 978 0 580 59979 8. It is also available as a 229kB file size download from www.bsi-global.com

Cross references to BS 8512:2008 include the following: BS 5308, BS 5467, BS 6004, BS 6007, BS 6195, BS 6231, BS 6346, BS 6500, BS 6724, BS 6883, BS 7211, BS 7629, BS 7846, BS 7889, BS 7919, BS 8436, IEC 60050-461, Management of Health and Safety at Work Regulations 1999, Personal Protective Equipment at Work Regulations 1992, and the Manual Handling Regulations 1992.

Note that there is not, it is believed, a proper standard for the design and manufacture of wooden cable drums. These have been made the same way for many decades, but because of the lack of a standard (BS 8512:2008 is only a Code of practise, not a standard), Voltimum UK has learned that some cable drum manufacturers have been making drums more lightly recently, to save money, and this has led to drums having, in some cases, a much shorter life than was previously the case. Worse, some have been known to fail dangerously when being picked up by a fork-lift, for example. Perhaps it is time such a standard was formulated.

Some general cable drum handling precautions:

Incorrect or careless handling any rotating equipment, such as a cable reel or drum, can cause accidents, such as damaged hands, but when the cable drum is large and heavy, and possibly motorised as well, the potential risks are substantial. A number of accidents have occurred - often where cable drums are stored on racking systems from which cable is drawn off for supply. The example was given above, but there have been many more - though not usually fatal.

Apart from always following any related H & S advice, and manufacturers' recommendations, operators should ALWAYS wear protective gloves or gauntlets, or rigger gloves for hand protection, as well as safety footwear to BS EN 345 for toe protection. Bearing in mind the fatality mentioned above, wearing a hard hat would be a sensible precaution too, and indeed should be compulsory on site. However, having visited many electrical wholesaling companies and branches, I know that such precautions are often not taken, and it may be a little unrealistic to expect warehouse staff - who usually are not dedicated to cable - to keep putting on and removing items of protective clothing. Never-the-less, wearing such clothing is what they should be doing.

In terms of the cable racking, as well as the dispensing and cutting equipment, always ensure the load is properly balanced. Some recommend using tag lines to control rotation. Where vertical lifting is concerned, use only equipment designed for such work, and position or suspend equipment from a safe point to safely take the weight of load and equipment. Operators should also ensure that all other personnel stay clear, and the equipment should never be left un-attended when in use or ready for use.

The overlapping and tangling of cables on a cable reel is a long-standing problem with winding cable reels. When rewinding cable reels of any length, they have an irritating and time-wasting habit of overlapping and getting tangled on the frame. There is also a health and safety issue. Users may be advised to completely unwind the cable before use but, because of the cable tangling and overlapping, many contractors have found it better only unwind sufficient cable for the particular job. Unfortunately, this can cause a build up of electricity within the cable left on the reel (acting as a coil). These can cause premature cable failure and even dangerous overheating, which, in extreme cases can result in fire. There is also electrical shock risk.

A fully unwound cable reduces the risk of it overheating, so minimising the risks of fire or electric shock.

Storage racks for cable drums:

The following information summarises HSE advice on the hazards of storage racks for cable drums and precautions that should be taken. Accidents, including a fatality, have occurred where cable drums are stored on racking systems from which cable is drawn off for supply.

Rack storage is commonly found in warehouses and wholesale outlets. Drums may be up to one metre in diameter and weigh more than a tonne. Drums are supported on solid steel bars running through drum centres; trunnion brackets bolted to the front uprights of the racking system support the bars.

Cable is drawn off and rewound using measuring and reeling machines, which are often electrically powered, portable ad foot-pedal operated.

Other precautions:

Racking systems should be designed, soundly constructed and rated for the maximum loads anticipated during normal use. Good stability is essential, and it is important that no more than three tiers of drums is considered. The addition of cross-bracing at the racking ends does much to improve stability and rigidity. The stability of a line of cable drum racks can be improved by bolting them together. Note that all cable drum racking should be regularly inspected and maintained, because damage from fork-lift trucks is common.

Racking systems should be mounted on firm, level ground and securely fixed to it using anchorages strong enough to withstand forces generated by snagged cables, so that if they do snag, the measuring and reeling machine motor stalls and disengages the clutch, rather than the dangerous occurrence of the racking being pulled over. For this reason, even if the racking is securely fastened to the floor, cable drums should be checked to identify potential snags. These include the inner end of the cable protruding through a drum flange.

For maximum safety, measuring and reeling machines should be fitted with suitable load-limiting devices such as slipping clutches, and machine operators should be able to clearly see both the racking and the meter on the measuring and reeling machine from their normal seating or standing positions.

Cable drum handling equipment types:

Cable handling products include cable reeling drums (including spring-operated, sprocket-driven, motorised and stall torque motor operated types). Related equipment for cable reels, especially motorised ones, include cable drag chains, thrust or-operated brake or AC/DC brakes, as well as control items such as limit switches.

Where large and heavy cable drums are concerned, lifting the cable (which may itself be very heavy and stiff) off can be hard work. In such circumstances, rollers provide a safe and effective method of reeling cable off heavy drums. Available in a range of sizes, cable rollers can also be turned on their sides, using skid rollers to steer cables around corners.

Supporting very heavy cable drums may require use of a heavy-duty drum jack. These may use a rack and pinion mechanism to allow the raising of 900 to 3200 inch diameter drums up to 20 tonnes in weight. Axle heights are usually fully adjustable, and these jacks may have integral wheels for easy positioning.

Large cable drums also have to lifted. This can be carried out be crane or by forked lift truck, but both have their inconveniences and dangers. Another way is to use a hydraulic drum lifter. Such equipment can lift cable drums weighing 10 tonnes or more. The drum lifter hydraulically lifts the drum clear of the ground for drum rotation and operations. Locking collars secure the drum on to the shaft to prevent floating.

Cable drums also have to be transported. Small reels are no problem and just fit in the back of a contractor's van, but big reels and drums may be another matter. Here, a cable drum trailer may the answer. Such trailers allow large cable drums to be transported from one job or site to another. The cable drums themselves are typically secured on a central suspended spindle, while integral hydraulics allow easy positioning and lifting of drums. Cable/conductor stringing is carried out when the trailer's parking brake is engaged.

Such equipment is available from www.hss.com, among other companies.