OG Status: Fully open
Author Unit/Section: Manufacturing Sector
Target Audience: All visiting staff including Local Authority Inspectors
Fall arrest systems have been installed in some steel stockholders for use when gaining access to stored stock. This SIM identifies the range of factors to be considered in a suitable risk assessment for their use in steel stockholders to indicate whether their use in this application is likely to be appropriate. This SIM does not apply to work activities in the loading/unloading of delivery vehicles.
1 Several examples have come to light of the provision of fall arrest systems for use by workers who have to gain access to the top of stored steel stock in steel stockholders to attach /detach lifting equipment. Often these workers climb up and walk along products including tube, bar, beams or sheet/plate steel stored above head height. The provision of fall arrest systems appears to be an attempt to comply with the Work at Height Regulations.
2 Concerns have been raised by some inspectors that this appears to undermine the existing guidance in HSG246 'Safety in the storage and handling of steel and other metal stock' which recommends that storage arrangements should avoid the need for climbing onto and walking over stock.
3 Investigations have been made with one manufacturer/supplier whose fall arrest equipment has been installed to provide fall protection in these circumstances. They confirm that their equipment are safety systems, not access systems, and that a suitable and adequate working surface should be available or provided for the worker to walk on.
4 Work at height in steel stockholders should follow the legal requirements and generic principles for access to height applicable to all industries, i.e. by following the hierarchy as specified in Regulation 6 of the Work at Height Regulations 2005.
5 HSG 246 (which was drawn up by HSE in consultation with the National Association of Steel Service Centres (NASS) (formerly known as the National Association of Steel Stockholders) and Wolverhampton City Council (as partners with HSE in the steel stockholders Lead Authority Partnership) identifies that:
Note - For existing premises a stock profiling exercise may identify slow moving product which could be rearranged and reduced to enable improved storage organisation so enabling alternate empty aisles to be provided and thereby negating work at height (as per recommendations in HSG246).
6 Fall arrest systems should be considered only as the last resort if fall prevention measures (including work restraint) are not reasonably practicable. Any system should be verified as being suitable for its intended application by a competent person, usually the system supplier. Particular care should be taken when different components of a fall arrest system are combined eg retractable fall arrester used in conjunction with a horizontal flexible anchor line. The supplier should be able to demonstrate by appropriate testing that the system functions as intended and that potential problems (see paragraphs 11 & 12) will not be present.
7 One system known to be installed in a steel stockholder operates by suspending a retractable type fall arrester from a permanently installed and tensioned overhead horizontal wire, with the retractable wire from the fall arrest block attached to a harness worn by the worker. The retractable fall arrester is connected to the horizontal wire by a gate latch traveller mechanism which allows free movement along the length of the wire, including across anchoring rings supporting the wire. In the event of a fall the retractable fall line locks after a short distance to arrest the fall. This along with the energy absorber fitted to the horizontal line are designed to limit the forces acting on the falling person and the building. [Alternatively, rigid anchor lines could be used to attach work restraint or fall arrest systems].
8 The specifications from the maker/supplier require a minimum freefall distance below where the user stands to guarantee effective operation of the combined retractable fall arrester and the overhead horizontal line. This includes the length of the wire paid out by the retractable fall arrester before locking, plus the deflection of the horizontal wire and an allowance for harness stretch (up to 30cm). The vertical minimum freefall distance is dependent on the distance between the supporting points of the overhead horizontal wire, but as a minimum is approximately 2m. This freefall distance for the installation should be confirmed by the manufacturer or installer. The positioning of the horizontal line should be directly above the working position if possible. Where a deviation from the vertical is allowed/necessary when using the retractable line, this will increase the required height to be provided. This is due to a swinging pendulum effect. [A standard lanyard fitted with energy absorption is unlikely to be suitable for falls under 2m].
9 It is understood that in at least one steel stockholder the horizontal overhead wire has been installed on the underside of an overhead travelling crane to allow full flexibility on the use of the system throughout the storage area. In this system the harness wearer has to attach and detach from the fall arrest block at a safe position before each time the crane moves to transfer a load. Alternatively, if the fall arrest block is attached to a horizontal wire installed near the roof above the crane the fall arrest system is limited in its application by the position of the wire. The installation of numerous such wires and fall arrest systems to cover all positions of work in a storage area is likely to be prohibitively expensive. The advantage of this system is that the harness wearer could remain attached to the fall arrest system before the crane was moved – provided the worker was in a safe position. However, if the crane is moved (inadvertently or deliberately) towards the worker, or a second crane is moved incorrectly, the fall arrest block retractable line is in danger of entanglement with the crane(s) with consequent risks to the person wearing the harness.
10 The installation and use of fall arrest systems may be attractive to some steel stockholders who are reluctant to revise their storage layout to allow access to stored stock for slinging without having to climb and walk on product/racking, as this would mean a loss of storage capacity. The cost of a single fall arrest system (for one user) including installation of an overhead horizontal wire, supply of a retractable fall arrester and harness, and basic training in its use may be around £2000.
11 However, there are a number of additional factors that need to be taken into account in any risk assessment for the safe access to height in steel stockholders:
12 Other issues that should be considered are the potential effects of combining the device with other anchor devices including horizontal lifelines, which may increase the risk of a worker hitting an obstruction or the ground, caused by:
13 The use of fall arrestors may have a part to play as an interim measure until more suitable stock storage arrangements are provided. However, it is likely the limitations outlined in paragraph 11 12 would outweigh the advantages in most circumstances for access to the top of stored stock as a permanent system of work. Fall arrestors may be considered for other working at height activities such as maintenance work.
14 NASS and Wolverhampton City Council have been consulted in the preparation of this guidance.
Further advice on the selection, use etc of fall arrest systems is available in the Technical Guidance Notes produced by The Work at Height Safety Association.
The NASS H&S Committee includes members with many years of practical experience in the steel stock holding industry. They have advised that they would be happy to provide advice to any steel stockholder (whether a member of NASS or not) on safe working, including safe access to height, safe (un)loading of steel stock and other issues. Contact should be made with NASS at First Floor, The Citadel, 190 Corporation Street, Birmingham B4 6QD Tel: 0121 200 2288.
The contacts on this issue are: