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The series aims to assist all members, but younger members in particular, in understanding the background and issues relating to the management of health-and-safety risks in construction.
The series ran from 2012 to 2017.
This article focuses on the design and inspection of scaffolds. Based on UK practice and experience, the principles should be universally applicable.
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With care, engineers can reduce the risks to those who construct, maintain, use and demolish structures. Generally, we can presume that the strength and stability
of ﬁnished structures will be assured by compliance with design codes. The greatest hazards to design out are those encountered during construction or demolition, or ones inherent in structure use.
PPE is defined as 'all equipment (including clothing affording protection against the weather) which is intended to be worn or held by a person at work and which protects him against one or more risks to his health or safety'. This article provides an overview of employer obligations, the various types of PPE and the implications for ongoing PPE training and maintenance.
In a great deal of UK legislation and discussion on Health and Safety matters, the word ‘competence’ will arise (the principles will have parallels worldwide). This can refer to corporate competence or individual competence. This article is concerned with individual competence.
In the past accidents have been caused by cranes overturning due to overload or poor ground support. Cranes have collapsed when not properly assembled; loads have fallen (including counterweights) or swayed and impacted with people/buildings. This article highlights the different types of crane available (and the factors which determine their use), the process for introducing a crane onsite and the specific requirements when using tower cranes.
In 2009/10, there were 36 fatalities and more than 3000 major injuries in the UK resulting from falls from height. This article provides a brief overview of UK regulations and requirements, although the principles should be universal.
The principal reasons for the the increased risk of on site fires are highlighted, together with several high profile examples.
This article draws attention to such topical events as the publication of the Lofstedt report, the Health and Safety Executive's interpretation of "appropriate action" and firms prosectuted over the mis-handling of asbestos.
Schemes to promote health and safety knowledge and awareness
Employees are expected to have the appropriate knowledge, skills and experience for the tasks assigned to them, unless they are under competent supervision. This article focuses on the schmes for individuals.
No 6: The management of H&S risks during design development
Engineers involve themselves in many tasks in connection with civil and structural engineering projects, but above all else we manage risk. For the most part we can think of this in simple terms: how can we eliminate or manage the particular uncertainties and dangers that arise out of our projects?
No. 7: Legionnaires’ disease
The recent outbreak of Legionnaires' disease in Edinburgh (June 2012) resulted in 44 confirmed cases, including the desaths of three people, with a further 18 requiring hospital treatment (7 of these requiring intensive care). This makes it timely to remind engineers of the hazard and associated risks.
Common construction hazards
This article considers safety hazards in construction (as opposed to health hazards, e.g. noise, vibration etc). Hazards are ‘something with the potential to cause harm’ and the corresponding risk incorporates ‘the likelihood of occurrence and the severity of the consequences’.
When trying to understand whether a material is hazardous we need to understand what it can do to the health of humans and under what circumstances. This path of discovery will continue as we gain a greater understanding of developing innovative products.
We read about (and maybe unfortunately witness) people being hurt or killed; these events have an immediate effect on a company or project. Accidents may be recorded and analysed, often within a short time of their occurrence. It is no surprise therefore that traditionally, the industry has seen the improvement of accident statistics as representing a true measure of improvement in health and safety performance.
A number of Health and Safety Regulations are frequently encountered by structural engineers in Great Britain. Many of these address specific safety and/or health risks and can be used as a source of information for engineers during the design process.
An overview of the role of the designer in eliminating hazards and minimising risks associated with the fabrication and erection of structural steelwork.
Cement, a key constituent of concrete, is a chemical which has the ability to cause adverse health effects. This short article highlights the principal risks when working with the material and offers guidance on preventative measures.
This short article provides an overview of the formal, recorded process used to control work which is identified as potentially hazardous.
The majority of projects involve digging holes in the ground for basements, foundations or trenches. Obvious hazards are those of side collapse or water inundation — with potentially lethal consequences to people working at depth.
In developed countries, the space below ground is littered both with debris from past construction and with utility services — some active, some redundant. Risks from overhead services mostly relate to power lines, which may be fouled by crane jibs, scaffolding poles or plant. This short article discussed how the associated risks are best controlled.
Dangers of working in close proximity to water are ever present. Many engineering projects are constructed close to or directly over water, while others may involve the creation of containers for water. To ensure public safety, taking the precautions outlined in this article is of paramount importance.
Both criminal and civil law is relevant to the management of health and safety risks. The criminal law i.e. that made in Parliament (and much of which originates from the EU) is relevant to all workplaces and work related activities, but is specifically relevant because of the significant risks arising from construction activities.
The first in a series of articles aiming to present the basic demands and responsibilities of health and safety risk management in practice. The series will outline legal requirements, hazardous materials and occupational health hazards, as well as discuss health and safety matters that are relevant to all principal construction activities and materials.
It will often be safe to work alone. However, in some situations people can be exposed to additional health and safety risks when unaccompanied. Establishing a healthy and safe working environment for lone workers can be different from that required for other workers. This short article sets out the primary considerations.
During the design process, it is important to be aware of the possibility of vandalism and its potential consequences. This article gives an overview of the types of incident that need to be considered.
Traditionally, masonry was associated with stone and brick wall construction, but usage has widened to include blockwork, brick pavers, plus cladding and paving of various kinds. The standard hazards to consider are linked to manual handling and cutting. However, a particular safety issue is that of wall stability during construction.
After any accident or structural failure, investigators usually conclude that someone, somewhere got something wrong. Sometimes the error results from culpable negligence, more often it will have been caused by a simple mistake or by confusion at an individual or organisational level.
Unexploded ordnance (UXO) is explosive weaponry (bombs, shells, grenades, land mines, naval mines, cluster munitions, etc.) that did not explode when it was employed and still poses a risk of detonation, sometimes many decades after it was used or discarded. Such items are unearthed fairly regularly on building sites both in the UK and worldwide.
Periodically, there is a backlash against health and safety, with claims that much is unnecessary, that we are overregulated, risk averse and so on. Such comment is often uninformed. The reality is that creating the
built environment is full of uncertainty: there are uncertainties in the design parameters we use, uncertainty in the design process, issues with site execution and issues with performance in service.
Doubters need look no further than the regular CROSS newsletters or the terrible Grenfell Tower fire which occurred in London on 14 June. Was there ever a more graphic example of the continuing need for vigilance over ‘safety’?
The development of health and safety management
The history of health and safety management in construction is the history of adverse public reaction to events; a testament to the work of certain enlightened individuals and organisations, and a gradual promotion of increased standards by government. To counter this, there has been an equally long history of resistance: often framed as ojections to 'excessive paperwork' and to the perceived expense of protective measures.
Between 55,000 and 70,000 construction workers are believed to incur musculoskeletal injuries each year in the UK. These cover back and upper/lower limb disorders. This short article provides some basic advice for safer manual handling.
Entering into and working within confined spaces is potentially extremely hazardous. Regrettably, on a number of occasions, these actions have resulted in human tragedy. This article provides an overview of the issues and risks involved.
The Institution's Health and Safety Panel set out the measures that should be taken in order for engineers to work safely at height in this manner.
An overview of the importance of temporary works (as evidenced by the significant number of historical failures) and the roles of both temporary and permanent works designers.
An overview of the risks inherent in the design of concrete structures, that can occur during the pouring process and through the removal of supports.
Although the number of fatalities in the UK is expected to decrease, there is still significant risk to workers who come into contact with asbestos. This short article provides an overview of the safety measures employees should take.
Many construction sites have been previously built on and may contain a residue of waste products that have contaminated the land; these are known as ‘brownfield sites’. Some commonly found waste products pose a health risk to people who come in contact with them.
Within the construction industry, the most significant respiratory risk after asbestos is presented by exposure to respirable crystalline silica (RCS). As well as raising awareness of the long-latency ill-health risk associated with RCS, the HSE also encourages the correct use of effective control measures to minimise the risk.
According to the Construction (Design and Management) Regulations 2015, the standards of health and safety on site are not dictated solely by the contractor. This article discusses some ways in which clients can influence health and safety standards.
Although the hazards arising from any works on operational railway sites are assessed to be considerable, in the UK Network Rail has taken comprehensive measures to manage risks by putting in place compulsory
systems and procedures.
This article considers the effect of changes introduced in the Construction (Design and Management) Regulations 2015 (CDM 2015) for small-scale and domestic projects. Generally the requirements of CDM 2015 do not change with the scale of the project if there is likely to be more than one contractor; however, there are some changes if a single contractor will undertake the work.
Working on fragile roofs is hazardous. The Health and Safety Executive (HSE) reports that falls through roofs and roof lights account for about 20% of all fatal accidents within the category of “falls from height”. These result in about seven deaths a year, with many other serious injuries. Most of these instances occur during roof maintenance. The hazard and risks are foreseeable – and in severe incidents, where employees have not been properly protected, corporate manslaughter charges have been brought. All parties to the project, such as designers, contractors and the owners themselves, have a duty to be aware of the risks and cooperate in preventing accidents. Owners need to be familiar with the condition of their property and ensure that competent contractors are employed for any work required.
A check on stability is required for all structures in both their permanent and temporary states. An unstable structure is one that can begin to displace significantly under a small disturbing force and where further gross displacement follows any initial displacement. Reported failures have usually arisen because the parties involved just failed to consider the possibility. Many failures have occurred during construction when elements of the structures are necessarily not interconnected, or in building refurbishment/demolition when stabilising elements have inadvertently been removed out of sequence.
The forces that may cause instability are often unclear, but as a general principle, anything in its temporary or permanent condition should be considered to have an applied horizontal force acting. For external structures, an obvious force is wind. A clear danger for internal structures is the absence of wind, which leads to the possibility that a destabilising force will be overlooked.
The use of glass in buildings is very common and increasing as designers look to utilise its transparent properties. There are four main types: annealed, toughened, laminated and heat-strengthened. (These terms may vary in different countries, e.g. in North America “tempered” is used for glass with any form of heat strengthening, including toughened.) There are particular safety hazards associated with glass and these need to be a consideration in selection of type.
Normal glass breaks into shards, with obvious dangers. Laminated glass will also break, but the shards are held in place by the inner plastic layer. Toughened glass, too, will break, but it shatters into small pieces; hence its use in car windscreens.
This note focuses on a particular issue with toughened glass.
Transporting materials to construction sites is an everyday activity. Materials normally have to be procured, loaded, conveyed, unloaded and stored at site before use. Accidents have occurred at all of these stages and designers should be aware of the associated hazards, of what might go wrong and of measures that can minimise the risks.
Structures degrade with time, typically as a result of the environment they are in. That degradation can have safety implications, since strength predictions by calculation are only valid if the assumptions about component size and strength remain constant; in fact, both properties typically reduce with time. Hence, “safe design” demands that attention is paid to durability.
This article provides a brief summary of the impact of the most common forms of degradation on the safety of structures. This is illustrated by examples of where deterioration has caused collapse.
The article ends with a discussion of what structural engineers can do to minimise the risks of deterioration in new structures and the implications for the assessment of degraded structures.
Any risk assessment consists of three parts: identifying hazards; assessing the probability of occurrence; and considering the consequences. Historically, some of the worst failures have occurred when the hazard was unforeseen and the consequences severe. Normal foundation design consists of checking the bearing capacity of whatever is provided, but the possibility of losing foundations altogether is to be feared. This can occur through general ground movement.
Recently the UK has commemorated the 50th anniversary of the Aberfan disaster (south Wales) in which a whole mining spoil tip moved, engulfing housing and a school. In total, 116 schoolchildren and 28 adults were killed, buried by the soil. The tip was unstable (partly because material had been dumped on flowing water) and the potential for movement had been ignored).
A review of CROSS (Confidential Reporting on Structural Safety) and press reports suggests that lack of stability during construction is a prime cause of accidents. In May 2016, the centre section of a new elevating bridge at Barton on the Manchester inner ring road in northwest England collapsed while being tested. The failure can be viewed online. While the cause has not yet been published, it is clear that the lifting process was uncontrolled. Other reports in CROSS discuss concerns about the stability of steel frames during concreting.
Note 64 in this series introduced the topic of risk assessment. Such assessments are often required in support of design and site execution. In recent years, the inevitability of ‘risk’ has become widely accepted and much thought has gone into understanding how risks arise and how they can be mitigated.
Note 64 focused on hazards, but to complete an assessment, it is necessary to consider the probability of the identified hazards occurring.
Buildings and structures come in a wide variety of forms, but all will demand inspection and maintenance throughout their life. Modern buildings contain a large amount of plant: air conditioning, heating systems, lighting, lifts, etc. and all these need maintenance with occasional replacement. Window cleaning is another activity requiring access; on tall buildings, facade gantry provision will be needed. Industrial plant containing cranes will require access provisions; in some plants, the sole purpose of cranes is for them to facilitate through-life maintenance of other plant.
All structural fabrics degrade and their design lives are usually qualified via expressions such as ‘life to first maintenance’. Anticipating this, heavily exposed structures, such as bridges over water, may be provided with purpose-built access gantries from the outset of operation.
A report on the latest accident death rate, 'specified injury' rate and ill health and occupational disease death rate in the UK construction industry.
All electrical work is potentially dangerous. In addition to the usual risks
inherent with any electrical supply, site work can be particularly dangerous due to the risk of underground cables being cut or overhead wires being touched. The evolving nature of construction sites generates considerable uncertainty. Structural engineers will not be involved in power circuit design, but they should be aware of the inherent dangers on sites, particularly when planning alterations.
At certain times, engineers will be required to visit construction sites. All sites, whether large or small, are potentially hazardous. Junior engineers need to become acquainted with the general hazards they might encounter, as well as the corresponding means of assuring personal health and safety.
While the previous article in the series described the general dangers posed by electricity on site and identified isolation of electrical circuits as a key activity to control risks,
this article provides more detail on the need for electrical isolation. It is of
particular relevance to refurbishment and demolition projects.
The Construction (Design and Management) Regulations (CDM) are the primary regulations for managing the health, safety and welfare of all construction projects in Great Britain. The CDM Regulations were first introduced in 1995 (CDM 1994) and were revised in 2007 (CDM 2007). CDM 2015 came into force on 6 April 2015. This article provides a brief overview of the key changes and then focuses on those changes most likely to affect structural engineers.
Working at height is always hazardous. When very tall buildings are being designed, constructed or modified, a number of standard hazards become exaggerated and require special attention.
All excavation work is potentially hazardous; the collapse of excavation faces can have serious consequences,
both for life and purely as an economic loss.
There have been several recent cases of houses being destroyed following gas leaks. The fact that such incidents fail to raise much alarm shows how common they are. Yet there should be no complacency, since one of the most infamous failures of recent history, Ronan Point, was initiated by a domestic leak and subsequent ignition that blew out one supporting panel in the system-built block of flats. Gas leaks and their consequences should therefore be one of the standard hazards considered in any risk assessment.
Fixing reinforcement is one of the most basic tasks in construction. There are a number of hazards linked to this work phase and, perhaps surprisingly, they do not appear to be well appreciated among the design/construction community. Collapses of rebar arrangements prior to concreting have occurred and, in the worst cases, workers have been killed. Other incidents have been ‘near misses’.
Article No. 55 in this series discussed structural safety and highlighted ‘robustness’ as a key attribute. The demand that structures be ‘robust’ is enshrined in building regulations, yet it causes difficulties because, unlike other safety attributes, it is not a quality easily defined by mathematical equation. Hence, there are problems for designers in knowing what to do (and how much to provide) and there are problems for regulators in verifying that what is provided is sufficient. Many safety issues on site can be traced back to a failure to assure robustness in temporary works.
The services of structural engineers may be required in certain demolition situations e.g. where advice is needed on propping, stability or the sequence to be followed. This article provides brief guidance on the planning of a demolition project, as well some appropriate techniques and methods to ensure that on-site safety is prioritised.
Everyday slips, trips and falls are one of the commonest sources of injury in the home, in the street and on construction sites. The Health and Safety Executive (HSE) reports that several thousand workers are injured in this way in the UK every year, with injuries ranging from bruises, through broken limbs to the more serious. Day-to-day good housekeeping on construction sites should ensure that slip or trip hazards are minimised.
All designers need to take account of all actions (loads) that may foreseeably be applied to a structure over its intended design life. In doing so, they should account for the risk of each load case being exceeded. This is implicitly built into design codes, with material and load factors of safety, and explicitly required in the English Building Regulations for Class 3 structures in respect of disproportionate collapse.
But what constitutes something reasonably foreseeable? Mostly, engineers have to learn this from experience and that learning process ought to include keeping up to date with publicised events describing things that have gone wrong. Certain hazards relate only to particular structures and a risk assessment should be appropriate. Risk assessments should always consider the potential for human error along with the consequences.
In recent news in the UK, the bodies of three workers killed when Didcot power station collapsed in February have finally been recovered, and the major central section on a new moveable bridge being built on the M60 ring road around Manchester collapsed under test. Major failures continue, so “structural safety” remains topical.
What is it that makes a structure safe and how can “safety” be tested? It is not just “compliance with codes” in the sense of keeping stresses low, for codes of practice also define (or implicitly try to promote) other useful attributes and it is incumbent on professional engineers to achieve those objectives within their designs.
Transport-related accidents are the second largest cause of injury in the workplace after falls from height. Every year in the UK, around 50 people are killed and 2000 seriously injured in such incidents in and around construction sites and other workplaces. This article considers the safety issues regarding both visitors to a construction site and staff employed full time on a site.