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Your Letters

A selection of the latest letters and emails from the E&T postbag and inbox.

Who owns your information?

The technology versus privacy debate has been raging for some time, but with social media in every walk of life it is, without doubt, one of today's most elusive subjects ('Technology versus privacy?', June 2011).

At the heart of this debate is the issue of ownership of information and who is held liable, particularly when any salacious information is disclosed and then widely shared digitally in the form of re-tweets, as well as on other social networking sites and blogs. This raises the question of where the boundaries lie between privacy protection and freedom of speech, and also introduces the aspect of regional and international laws regarding privacy. How will the law cope with re-tweets from outside the UK, for instance?

This isn't the first time we've seen social media challenge our concepts of privacy. With any social medium, proper use can be extremely complicated and convoluted – it's unexplored territory and the law hasn't caught up yet. It will undoubtedly take a few high profile cases before a precedent is set and procedures are standardised.

Howard Sklar

San Francisco, USA

Hot water solution

In response to George Moulder's problems obtaining enough hot water for a full bath, which he attributes to a 'new' standard for domestic hot-water thermostats, the relevant safety standard BS EN60335-2-73 incorporates an amendment introduced in May 2004 and enforced in May 2006: 'The water temperature shall not exceed 98°C.' This was to introduce the safety cut-out following instances of thermostats failing in short-circuit mode with tragic results in at least one instance.

The essence of safety legislation is that one single fault should not cause a hazard, and so we have the adjustable thermostat (typically 40-65°C) plus a thermal cut out (typically 80-90°C) in immersion heaters. The thermal cut-out should not effect the normal temperature range of the thermostat. To my knowledge the adjustable range of the thermostat has not been changed to accommodate the thermal cut-out, and if the correct length of heater is chosen for the water tank then it should produce a full tank of hot water.

The popular arrangement of a vertical element positioned almost centrally in the tank will produce convection, and heated water will rise to the top, drawing up cooler water from the bottom and producing a toroidal convection pattern throughout the tank.

I recently replaced my tank and heater, and after adjustment it now produces enough hot water at 58°C for a family of four bathing and showering on a busy winter morning. The element is a 27in unit in a 48in-high tank. I can only think that maybe the heater element fitted to Mr Moulder's tank is too short, which would then only heat a small volume and also impede the mixing process.

Rod Duggan CEng MIET

Senior Approvals Engineer, Intertek Commercial & Electrical, Leatherhead

Take cyber war to the criminals

Your recent articles on cyber attacks and information security left one question in my mind. Why isn't more being done to trace the source of malware and bring the miscreants to justice? I find it difficult to accept that a worm can be inserted into a software-control system by an anonymous programmer from an unknown enemy.

The theft of or interference with another's property is a crime. Whatever the motivation, the main deterrent to any crime is the probability of detection, exposure and possible prosecution. So long as the criminals can act under a cloak of anonymity, they will see it as a green light to carry on.

No doubt the solution to improving information security is not that simple. In some cases that might be so, but at least have a go at mischief-makers and small-time thieves. That ought to cut down the staggering number of daily incidences.

The threat to information security has spawned a whole industry. According to your articles this is mainly bent on protection, which is part of the problem. Defence is essential, but building higher walls will not deter the attackers. If we do not tackle the root of the problem, no amount of palliatives will do.

Arther Varney MIET

Sidcup, Kent

Danish wind power

We are being subjected to an increasing stampede to install on-shore wind farms to meet 'climate change' targets. It seems to me that this is going ahead, against uneasy feelings some of us have, with full government approval. I wonder if there are many IET members sufficiently aware of the huge pitfalls in this blundering plan who are prepared to lay down some limitations based on sound supply network operation?

Consider first the problem of network stability when linking to diverse and unpredictable wind farm outputs. We can get some idea of how forlorn this proposal is by studying the effect that smothering Denmark with wind turbines has had on their system: the dearest electricity in Europe, network stability nightmares for their system engineers, export of the wind farm output power to Sweden and Norway who use this cheap imported power to pump water to their storage reservoirs, and last, but not least, the fact that Denmark has to import electrical power from its neighbours to meet demand.

Having found itself in this quandary, Denmark is ploughing ahead as the major supplier of wind turbines, using a 50,000+ work force, for sale to other unsuspecting customers globally. Do we really want to lumber our future generations with this?

Ian Hubbuck CEng MIET

By email

At 13:17 on 17 June 2011, Denmark's wind-power fleet was generating 1,377MW, about one-third of its total capacity (www.emd.dk/el). Each CHP machine was generating as much as its associated industrial process would allow – the fleet was producing 533MW, while 1,591MW was coming from fossil-fuelled 'central power plants'.

Thus total power infeed to the country's grid was 3,501MW, but power consumption is shown as 2,693MW, so they could have reduced their fossil burn by the difference. Instead, they chose to export it. To whom? France, knee-deep in nuclear, would not be buying fossil-fuelled energy, nor Holland – both were exporting to us. Germany?

Angela Merkel needs political support from Greens, who are fanning the Fukushima flames. She has just shut down eight nuclear power plants. Less exposed than Denmark, German wind performance is probably producing less than Denmark's 30 per cent. Certainly, in a Europe-wide anticyclone, on a January day when the Danish wind fleet was producing 1.4 per cent output, and Germany's wind performance was published, her 23,196MW wind fleet averaged 0.13 per cent, with a low point of just 1MW, 0.0043 per cent. So what are they paying for Denmark's fossil MW?

What really annoys me is that a relatively small group of Germans are swaying their government. This large nation in the EU has swayed it to produce the ruinous commitment to wind, waves and other inadequate and/or untried technologies, for which we are all paying.

Bill Hyde CEng FIET

Offham, Kent

Engineers in business

On last night's 'The Apprentice', property developer and self-proclaimed 'electronics expert' Alan Sugar said: 'I've never met an engineer who could turn their hand to business.'

Presumably he has never been introduced to James Dyson, Robin Saxby, Hermann Hauser, William Hewlett & David Packard, Steve Wozniak, Robert Noyce, Gordon Moore, Andy Grove, Jeff Bezos, Larry Page & Sergey Brin, Pierre Omidyar, Mark Zuckerberg, Leonard Bosack or Jerry Sanders, to name but a few.

Frankly, for prize money of £250,000, I'm throwing my hat in the ring for ITV's 'The Cube'.

Dr David Laverty, MIET

Belfast

[Have your say on Lord Sugar's comments in this month's 'For & Against']

Enigma variations

It was interesting to read Frank Slater's reminiscences of the British Typex cipher machine (Letters, July 2011). When I was a volunteer tour guide at the Bletchley Park museum I met a number of visitors who were delighted to see the machine on display. Mostly they had used it in British embassies overseas in the 1950s and 1960s.

Nearly all the cipher machines from the 1920s onwards (including Typex and Enigma) used sets of wired rotors which stepped each time a key was pressed. This ensured that the electrical path to encipher each character bore no relation to the path of its predecessor. The rotor principle is thought to have originated with two Dutch Naval officers in 1915, but they did not manage to take out a patent.

I have no knowledge of any patent taken out by the Poles. Their tremendous achievement was to break into the German Enigma machine in the 1930s, but their method relied on a procedural weakness that the Germans had corrected by 1940. Knowledge of the Poles' success was no doubt an inspiration to Turing and others at Bletchley Park in 1940, but they had to start afresh with a new methodology.

John Pettifer FIET

By email

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