Design engineering, learning from past failures 2017

The Titanic

The world of design engineering has made great strides over the last 100 years and today the vast majority of testing and retesting is done via computer aided design systems. However, it would be wrong to suggest that design engineering today is an exact science because many engineers still appreciate and learn from problems encountered many years ago. So what were the main engineering disasters which helped to mould the industry that we see today?

The Titanic

The Titanic

The Titanic is one of the most infamous engineering “failures” claiming 1500 lives when the ship sank on its maiden voyage. Deemed to be “unsinkable” those maiden voyage passengers had no idea of the tragedy that awaited them – the Titanic is still talked about to this day. There are many theories as to why the Titanic sunk so quickly and why this “unsinkable” ship effectively failed.

There may have been a number of contributing factors but the main problem was with the 16 watertight compartments used to keep the ship afloat. Over the years it has become apparent that because these compartments were not individually sealed, water began to spill from one compartment to another. When designed, the idea was that each compartment would be isolated from the others in the event of one or more compartments failing, allowing the ship to stay afloat. The rush of water when the ship hit an iceberg ran right through the 16 compartments destabilising and ultimately sinking the Titanic.

Many lessons have been learned from the sinking of the Titanic although unfortunately it took the lives of 1500 passengers and crew to highlight the main issues.

The Hindenburg disaster

Hindenburg-Disaster

The German passenger airship known as the LZ 129 Hindenburg caught fire and crashed in 1937 while attempting to dock in New Jersey. Hailed as a major breakthrough in air travel the Hindenburg disaster was a major setback for the airship industry. Interestingly, the industry is starting to make a comeback in the 21st century although we can all rest assured that problems of years gone by have been digested and acted upon.

While it took researchers decades to come to the conclusion that it was an electrostatic discharge which ignited leaking hydrogen there is much to marvel at with regards to the initial design. The ability to create an airship which used highly flammable hydrogen gas was a major breakthrough in itself. Unfortunately, the electrostatic discharge was not accounted for and ultimately led to the downfall of the airship and the industry. The Hindenburg disaster was caught on video and the speed at which the airship caught fire is frightening. Lessons have been learned, the industry was effectively dead for many years, but we shall see whether the general public will ever fully trust this type of air travel again.

Tacoma Narrows Bridge collapse

There are a whole host of bridge disasters from years gone by which have assisted with the creation of modern day bridge designs. One such disaster is the collapse of the Tacoma Narrows Bridge back in 1940 in the same year in which it became operational. When built, the Tacoma Narrows Bridge was the third longest suspension bridge in the world and caught headlines across the globe. There were many years of design and building which went into the opening in 1940 although unfortunately the life of the bridge was brief to say the least.

Even during the building process it became evident that the bridge was susceptible to vertical movement in windy conditions. This was taken into account to a certain extent but a “perfect storm” in 1940 led to what is commonly known as an aeroelastic flutter. This “flutter” decimated the structure of the bridge which then collapsed even though the winds were reported to be less than 40 mph at the time. Many design engineers believe that the Tacoma Narrows Bridge collapse still plays an integral part in the bridge design sector of today. Many lessons were learned, many changes were made and the bridges we have today offer a balance between a rigid structure and one able to accommodate the elements.

Conclusion

The engineering world prides itself on its ability to learn from past events although unfortunately many of these have been labelled as disasters. The sinking of the Titanic, the decimation of the Hindenburg airship and the collapse of the Tacoma Narrows Bridge all presented opportunities to learn from past mistakes. Thankfully many of the errors of years gone by have helped to create safer and stronger structures and expand the information pool from which many design engineers take their inspiration.

Top five benefits of plastic injection moulding

Injection Moulding machine

Plastic injection moulding is now commonplace in a variety of industries where products are produced on a massive scale. There are many advantages over traditional plastic machining which are sometimes not obvious at first glance. We will now take a look at the top five benefits of plastic injection moulding compared to other manufacturing processes.

Injection Moulding process

Accuracy

When mass-producing components it is vital that they are the same so that they are as efficient and durable as possible. While each plastic injection mould will be different, it is believed that accuracy during the moulding process is to within 0.005 inches. If you think about it, if you are creating a particular component for a machine then it needs to fit correctly to work. The way in which plastic injection moulds are used to build these components ensures each one is identical.

Labour costs

The greatest cost in the early stages of creating a plastic injection moulding line is the mould itself. Depending upon the complexity these can cost many thousands of pounds, but once it is finished, there is a massive reduction in ongoing labour costs compared to traditional manufacturing methods. In a world where competition and pricing can make or break a business, the ability to create identical components with minimal human supervision should not be underestimated.

Flexibility

Once an injection mould has been created, then it can be used to produce an array of similar yet slightly different components. This may involve mixing different materials, for various levels of durability and strength, or utilising different coloured materials, for visual impact, to name but two options. This ability to quickly adapt to different environments and consumer demand is priceless in the world of business. As the underlying injection mould does not change there is any further additional expenditure required in this area.

Injection Moulding machine

Minimal wastage

When you consider various manual or part-manual processes to create plastic components, there can be significant wastage. Whether this is wastage from the actual component manufacturing process, or when applying the finishing touches, it can add up over time. The fact that plastic is injected at high speed into the injection mould ensures that there is minimal if any, wastage and there is limited additional “finishing work” to do. It is also worth noting that any material wastage can be recycled by simply adding the plastic back into the molten plastic reservoir. In a business world where environmentally friendly products and recycling play a growing part, this is a significant benefit of the plastic injection mould process.

Speed of processing

If we compare the rate of plastic injection moulding to other component manufacturing processes which include manual work, there is only one winner every time. The consensus seems to be that cycle times for plastic injection moulding vary between 15 to 30 seconds – in reality, this will depend upon the complexity of the mould itself. In essence, the process is identical whatever the basic design, the injection of liquid plastic at high speed into a mould. While there is obviously additional costs and time taken to create the automated process, in a world where competition is rife, and price points are vital, the plastic injection mould process plays a pivotal role. We can only imagine how the manufacturing industry accommodated an excessive demand for particular components when the process was more manual based.

Conclusion

The world of plastic injection moulding has developed significantly over the years, and in reality, you only need to look around you to see the results. Accuracy, the speed of manufacture and material costs all have an impact on the end price of any component. The ability to create identical components ensures maximum efficiency when in use. There is also the opportunity to add different mixes to the process for durability and strength as well as different colours for visual effect.

The cost of everyday items would be significantly higher today if it were not for the plastic injection moulding process.

 

 

Is engineering suffering from an identity crisis?

engineering identity crisis

If somebody asked you what you perceived to be a career in engineering, there are dozens of different aspects you could look at. Civil engineering, chemical engineering, electrical engineering, design engineering, the list goes on. Is it fair to suggest that engineering is suffering from an identity crisis of sorts?

Engineering means something different to everybody

The word “engineering” is connected with a whole array of different careers all of which come under the engineering umbrella but can be very different. It is, therefore, difficult to educate the wider public with a one ideal fit. This is where we need to look at school education and post-school education so that potential engineers of the future do not fall between the gaps. Many people leave school with a particular set of skills and aims which would be perfectly aligned with a career in engineering. How many of them make it into the world of engineering?

engineering identity crisis

Different skills in engineering

Design engineering is very different from mechanical engineering, and chemical engineering is very different from electrical engineering, and the list goes on. As a consequence, the particular skill sets required for various areas of engineering need to be publicised to a greater extent. Skill sets, potential career advancements as well as remuneration and employment opportunities are all areas which need to be promoted a lot more than they are today.

The old idea of an engineer slipping on a set of overalls, working with engines all day and getting covered in grease and grime is long gone. True, there are various areas of the engineering industry where manual labour can take centre stage, but there are many other alternatives including computer-aided design, etc. In a world where computer skills are central to the development of children going forward, why are more people, both male and female, not even considering a career in engineering?

Male and female divide

The idea that the engineering industry is a male-dominated workplace is still relatively strong in the minds of many people today but is this a fair reflection of the opportunities available? As we touched on above, the perception that manual labour is an integral part of the engineering sector today has actually been superseded by the development of computer-aided design, etc. So, while many potential female engineers are more than able to hold their own in the manual labour stakes, those looking for non-manual labour intensive careers have more opportunities than they perhaps think.

Potential female engineers of years gone by have on numerous occasions mentioned what many see as a “sexist” element of this perceived male-dominated industry. It is easy to forget sometimes that recent equality legislation has changed the whole working environment right across the board. Any inappropriate language should be reported and challenged as soon as possible, inequalities between the remuneration of female and male engineers are now few and further between and in theory there should be equal opportunities for both male and female engineers.

In practice, there is still much to do, but there is no doubt that the perceived “male dominated” era of years gone by has been diminished somewhat.

Male and female devide at work

Why is engineering not a first choice career for many?

We have only just touched on the massive variation in engineering opportunities across the UK and indeed across the world. Whether you are looking towards electrical engineering, mechanical engineering, chemical engineering or design engineering, naming but a few, the opportunities are immense. The fact is that engineering as a career needs to be promoted more in schools and further education with more apprenticeships made available and more funding required.

It would be wrong to suggest we have not seen significant changes in the way in which engineering is perceived as a career, but there is still a long way to go. Inequalities in the workplace are being addressed, different types of career are now more heavily promoted and the old stigma often attached to a career in engineering is gradually disappearing. Have you ever considered a career in engineering?