Feedback: your letters

This issue: the side effects of RoHS, the tricky world of spam, the knotty problem of skills vs. experience, the economics of wind and more.

The side effects of RoHS

In 'Made for life' (#13), E&T's manufacturing editor Bob Cervi states that the EU Restriction of Hazardous Substances Directive places environmental responsibilities on producers' shoulders. I disagree.

In terms of the lead-in-solder issue, the EU has neglected to take its own responsibility for the negative environmental effects the RoHS legislation has engendered.

The result of this measure has been an increase of tin consumption in the electronics industry of about 50 per cent, and this industry uses about half of the tin mined throughout the world, resulting in an overall increase of over 25 per cent. Tin is mined mainly from alluvial deposits in tropical rain forests in South America and South-East Asia. RoHS is therefore responsible for an increase in the destruction of these valuable forests which are the world's lungs.

And that is not all; the melting point of the lead-free alloys is typically about 30°C higher than that of the leaded alloys. This means that all the soldering irons, wave soldering machines and reflow ovens in the electronics industry throughout the world have to work at a higher temperature, with more consumption of electricity. In most countries, this means that the EU has forced carbon emissions to increase with this ill-thought directive.

There is another problem: the reliability of electronic devices soldered with lead-free solder is lower (less ductile joints, higher strain due to higher differential temperature coefficients, tin whiskers and tin pest). This results in the products having a shorter working life, despite the best efforts of the design engineers. Is this environmentally friendly, if you have to change your electronic goods more frequently?

And what are the benefits of removing the lead from solder? I can't think of any, can you?

This kind of 'progress' is the antithesis of common sense, resulting from a mixture of vested interests and politicians who do not have the means for an environmental risk assessment. As Gertrude Stein may have said, "A RoHS is a RoHS, is a RoHS, is a RoHS - and it stinks!"

Brian Ellis MIET, Cyprus

Spam in the eye of the beholder

Diego d'Ambra's article 'Spam spotting: man vs computer' (#13) and the spam test in which the reader is challenged to spam from legitimate emails assume there is an objective way of classifying mail. All the article and test show is that people and spam filtering software sometimes differ on how they define, and recognise, spam.

A Google search shows that spam is commonly defined as 'bulk mail from a stranger', or as 'unwanted email'. Now 'stranger' and 'unwanted' are two terms whose definitions depend on the recipient. My stranger may be your trusted contact; I may not want an email on Project X but that email may contain vital information on your vital project.

Any email I don't want is spam. A bulk mailing from a stranger is spam. These simple definitions set the rules for how I manage my inbox. Messages similar to messages I have previously rejected as spam are automatically filtered into a spam trap. Adaptive software that learns my definition of spam seems the best way of handling the problem.

In the spam test I classified all the emails as spam as they all fitted my definition. That, for me, was the correct answer.

Neil Roberts MIET, Nottingham

The experience gap

Whenever I read something about skills shortages, such as Mark Langdon's 'If you ask me' column in issue 13 of E&T, I am driven to ask when people are going to ask about experience shortages. A skill is a subject one learns at university or from a training course, say; experience is what one learns from actually doing some work, and learning from both one's own and other people's mistakes.

Two engineers may have been taught, and learnt, the same skills, but one will be superior to the other because he or she has subsequently had occasion to apply those skills to practical problems in industry, made a few mistakes, and learnt from them. By a mistake, I do not mean something catastrophic causing a fatal accident, but where, if some equipment were to be designed again, it could have been made more effective, using fewer components, costing less, and more quickly manufactured.

As far as possible, engineering courses should keep to teaching design skills that are applicable generally and not limited to the latest and most fashionable technologies. The application of these general principles to practical engineering problems will vary, depending on what company or organisation the engineer subsequently works for, and the body of experience it has built up for its own products and systems.

To summarise, skills = theory, experience = practice. We don't just have a skills shortage, we have an experience shortage too.

Richard Wilson, Stafford

Nuclear control

My attention was drawn to the comments by Paul Tooley of British Energy concerning analogue vs digital control of nuclear power plants in the article 'Power is nothing without control' (#14). As a newly graduated engineer in the mid-1980s I was privileged to work as part of the team in Rolls-Royce which was contracted by the then Nuclear Electric to design, build and implement a dynamic test system for the Sizewell B microprocessor-based control system.

Nuclear Electric was faced with the same concerns stated in the article relating to the provability of digital design in safety-critical applications. Its concerns were heightened by the fact that the Westinghouse control system was to be the first digital system in any UK civil reactor. Rolls-Royce was contracted partly owing to its experience with digital control systems in non-civil nuclear applications. We built a dynamic test harness to test quite literally millions of combinations of reactor parameters prior to the reactor going live.

Undoubtedly this approach would have continued on further nuclear plants, but little did we realise at the time that it would be another generation before new plants would be considered in the UK. To my knowledge this approach remains one of the best means of proving digital systems, and, if utilised in conjunction with formal methods, would provide robust support to the overall plant safety case.

Guy Phoenix, York

Economics of wind

I wish I had 'reason to believe' that renewable energy schemes were economic, as the article by Don Swift Hook suggests (#13). It may well be that in isolated areas with no existing electricity infrastructure some form of renewable energy may be economic, but in developed countries, except for hydro power, it doesn't seem likely. If we ignore hydro power, the biggest obstacle for renewable energy schemes is that they are intermittent. Back up spinning reserve plant must be installed to cover for periods when energy is not being produced and installation on a grid system such as Britain's would surely create stability problems if their contribution was of any significant size.

To reduce our dependence on gas and oil, it seems to me the only option we have in the UK is to increase power generation from coal and nuclear sources and to start building the Severn barrage scheme as soon as possible.

A Anderson CEng MIET, by email

Don Swift Hook states that all forms of renewable energy "…will have little or no on- going operating costs". He might be quite correct to a certain extent, but he has not taken into consideration the enormous amount of maintenance that will be required particularly on wind turbines after a few years, more so even on those off-shore.

I predict that there will be a breakthrough with nuclear energy, which will eventually result in all these wind turbines becoming redundant and become rusting hulks with their blades laying on the ground or on the sea bed, constituting a hazard to animals and shipping. And then who will have to clear up the mess? The taxpayer, of course.

Geoff Parry, Chester

Think ahead

Keith Deal raises the issue of the supply of batteries to support the large-scale use of electric vehicles (#14). Has anybody made any serious estimation of the amount of electrical power needed to recharge all these vehicles, and the surge in demand each evening when everyone gets home and plugs their car in to 'refuel'?

If the predictions of the 'energy gap' that is looming in the next ten years are correct, it is possible that recharging large numbers of electric vehicles could make things even worse. I notice from recent articles in E&T that designers are applying themselves to developing electric vehicles with greater range and performance and faster recharge times. This trend could do much to increase the use of electric vehicles outside the current niche area of inner city travel, so it is probable that the take up will accelerate over the next few years. Is the power generation industry ready for this?

Peter Lister CEng MIET, Ilminster

BBC at Savoy Place

The Library and Archives column of the August 2008 issue of IET Member News refers to the development of the BBC at the Institution's Savoy Place building in London from 1923 until 1932 and recommends the free booklet 'The BBC at Savoy Place'.

That suggests (inter alia) a book by my brother, Brian Hennessy, 'Savoy Hill: The Early Years of British Broadcasting'.

However, this is now superseded by his later and more extensive book (to which I gave the finishing touches): 'The Emergence of Broadcasting in Britain', which covers the years from 1912. Much of this refers to the years at Savoy Place and members can find an introduction on the website, which can be found at: www.emergenceof [new window].

In preparing his book, Brian received a great deal of help from Institution staff and much of his original research covering these important years is still unpublished. This ought not to be lost and I should be happy to pass the material, in its raw state, to the research department of an interested university. My e-mail address is

John Hennessy FIET, Lympstone Exmouth

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