May 16, 2020

Steel crisis must be tackled to prevent industrial skills crunch

steel
UK
Britain
Engineering
Admin
3 min
Steel crisis must be tackled to prevent industrial skills crunch
Britains steel crisis could trigger a wider industrial skills emergency, and must be tackled – says specialist engineering and construction recrui...

Britain’s steel crisis could trigger a wider industrial skills emergency, and must be tackled – says specialist engineering and construction recruiter Randstad CPE.

Expert workers themselves agree. In a snap poll of specialist engineering workers, an overwhelming 94 percent support some form of action by the UK government to render Port Talbot and the UK steel industry sustainable and profitable.

More than a third (35 percent) of expert engineering and construction workers feel the best course of action is to impose tariffs of some kind on foreign steel imports, such as those from China.

In the eyes of specialist workers, this is ahead of other possible courses of action, from a ‘buy-British’ policy for all public sector projects, exempt steel makers from green levies or business rates, and the arguably more drastic option of nationalisation (backed by just 14 percent).

This is also supported by the fundamentals of steel demand and supply in the United Kingdom – and the much larger number of jobs that indirectly depend on related skills and industry.

Owen Goodhead, MD of Randstad Construction, Property & Engineering, comments: “Jobs and skills simply don’t behave like volatile commodity markets. Once you have a skills shortage, it is here to stay. Steel itself could just be the tip of a terrible iceberg – and the start of a far longer industrial skills emergency.

“Today the price of steel is low because of an error of oversupply on the other side of the world. If that was a permanent factor, we might need to think twice about trying to compete. It is not. But as a result we are talking about permanently shutting down our own centres of global engineering expertise.

“A whole ecosystem of specialist firms is dependent on the expertise that comes with a flourishing steel industry, just as many of them are also dependent on a sustainable source of steel itself. Our economy in ten years’ time will depend on the support for talent and ambition we can offer workers now – as employers and at all levels of government. The British economy of the 2020s will barely remember the latest blips and eddies of last week’s steel price. Will cheap steel be available from elsewhere in 2026? And more importantly – will the engineering jobs, the strategic defence contractors, the rail workers or the much-needed construction capacity be here in a decade’s time, if Britain jettisons its industrial heartland in 2016?

“Competing with a fundamentally better competitor is a bad idea – but throwing in the towel after a couple of hard knocks is just as shameful. Against unfair and aggressive competition, dumping steel in European markets at a loss, there is space for a constructive and proportionate response. This isn’t controversial in other areas – for example the public accepts supplying a large proportion of our own food as a ‘strategic’ priority, and subsidise British agriculture happily. But steel is treated differently. Even as France declares the yoghurt company Danone a ‘strategic industry’, British ministers are too scared to tiptoe towards the letter of the law. Their Chinese equivalents would have no such scruples.

“There is so much more that could be done to support valuable workers, boost industrial productivity and invest in the human capital we will always need for the future. Meanwhile, Britain needs millions of tonnes of steel every year – and it will have to come from somewhere. This country produces both too little steel, and too few skilled people to feed our industrial economy, and this combination is forming into a growing Skills Crisis.”

 

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Jun 17, 2021

Why engineers must always consider human-induced vibration

Vibrations
Engineering
design
Structuralintegrity
Dominic Ellis
3 min
Human-induced vibration can lead to a number of effects upon the structure and its users

Human induced vibration, or more accurately vibrations caused by human footfall, often conjures images of Millennium Bridge-style swaying or collapsing buildings.

But in reality, the ‘damage’ caused by human-induced vibrations is less likely to ruin a structure and more likely to cause discomfort in people. Though not as dramatic as a structural failure, any good engineer wants to make sure the people using their structures, be it bridges or buildings or anything in between, can do so safely and comfortably. This is why human-induced vibration must be considered within the design process.

Resonance v Impulse

There are two ways that human-induced vibrations affect structures: resonant, and impulse or transient response. Put simply, resonance occurs when Object A vibrates at the same natural frequency as Object B.

Object B resonates and begins to vibrate too. Think singing to break a wine glass! Although the person singing isn’t touching the glass, the vibrations of their voice are resonating with the glass’s natural frequency, causing this vibration to get stronger and stronger and eventually, break the glass. In the case of a structure, resonance occurs when the pedestrian’s feet land in time with the vibration.

On the other hand, impulse or transient vibration responses can be a problem on structures where its natural frequencies are too high for resonance to occur, such as where the structure is light or stiff. Here the discomfort is caused by the initial “bounce” of the structure caused by the footstep and is a concern on light or stiff structures.

Engineers must, of course, design to reduce the vibration effects caused by either impulse or resonance.

Potential impacts from human induced vibration

Human induced vibration can lead to a number of effects upon the structure and its users. These include:

  • Interfering with sensitive equipment Depending on the building’s purpose, what it houses can be affected by the vibrations of people using the building. Universities and laboratories, for example, may have sensitive equipment whose accuracy and performance could be damaged by vibrations. Even in ordinary offices the footfall vibration can wobble computer screens, upsetting the workers.
     
  • Swaying bridges One of the most famous examples of human-induced resonance impacting a structure occurred with the Millennium Bridge. As people walked across the bridge, the footsteps caused the bridge to sway, and everybody had to walk in time with the sway because it was difficult not to. Thankfully, this feedback can only occur with horizontal vibrations so building floors are safe from it, but footbridges need careful checking to prevent it.
     
  • Human discomfort According to research, vibrations in buildings and structures can cause depression and even motion sickness in inhabitants. Tall buildings sway in the wind and footsteps can be felt, even subconsciously by the occupants. It has been argued that modern efficient designs featuring thinner floor slabs and wider spacing in column design mean that these new builds are not as effective at dampening vibrations as older buildings are.
     
  • Jeopardising structural integrity The build-up of constant vibrations on a structure can, eventually, lead to structural integrity being compromised. A worse-case scenario would be the complete collapse of the structure and is the reason some bridges insist that marching troops break step before crossing. Crowds jumping in time to music or in response to a goal in a stadium are also dynamic loads that might damage an under-designed structure.

How to avoid it

As mentioned, modern designs that favour thinner slabs and wider column spacing are particularly susceptible to all forms of vibration, human-induced or otherwise, but short spans can also suffer due to their low mass. Using sophisticated structural engineering software is an effective method for engineers to test for and mitigate footfall and other vibrations at the design stage.

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