Feedback: your letters

While most of the UK freezes to a holt we take a look at some of your emails; from stimulating wave energy to speeding up your computer's boot time, plus so much more.

Australia's biggest tram system

The article about the history of the development of Melbourne's tramways in Vol 4 #1 of E&T was fascinating.

I have been looking at the development of Sydney's tramway systems since finding out that a steam tram began to run to my old home suburb in 1889 (to which, 117 years later, an extension of the Light Rail tramway system was proposed).

It would appear that Australia's first horse-drawn trams ran from the old Sydney Station to Circular Quay, via Pitt Street, in 1861. This line was closed in 1866, however, because of complaints that its rails, which were proud of the road surface, ruined the wheels of the other road users.

In 1879, steam tramways, consisting of a locomotive that towed double-decker carriages, were established. They were reportedly of higher capacity but less frequent than the Melbourne cable cars. It should be noted, though, that Sydney did have some cable cars to cater for routes with steep terrain.

Electrification of the system began in 1898 and was mostly converted by 1910. The tram depot (later used by buses) at Circular Quay was Fort Macquarie on Bennelong Point, which is now the site of the Opera House.

Before the construction of the underground railway in 1926, a circular tramway existed between Circular Quay and Central Station.

By 1920, however, the system reached maximum coverage and capacity and 'overseas experts' were called in. They recommended that the system be closed in stages, much against public opinion but supported by the NRMA, a motorists' organisation. The wind-down began in 1939 and the last service operated to La Perouse in 1961. The system was replaced by bus services.

When the Harbour Bridge was opened in 1932, this provided the link that joined the north and south tramway services.

According to one source, Sydney's tramway system was the largest in Australia and second only to London in the British Commonwealth.

I can remember riding on such trams nicknamed Toastracks, Jumping Jacks and Corridors. There was many a time that we were able to 'shoot through like a Bondi Tram', i.e. depart in haste. The bravery of the conductors battling along the external running boards of the trams without any safety apparatus left one in awe - no health and safety in the 'good old days'.

Sydney has come some way to redressing the absence of trams with the introduction of the Monorail (1988) and the Light Rail (1997) Metro systems. For those interested in the tram services, the Sydney Tramway Museum operates trams on the 3.5 km Parklink tramline from the Sutherland terminus into the Royal National Park.

D Little MIET, Knebworth, Herts

Bandwidth baddie?

Your article on Internet bandwidth issues ('Traffic Cops and Bottlenecks', Vol 4 #1) describes BitTorrent as a "villain of the piece". I wonder if it might rather be described as a saviour?

BitTorrent's peer-to-peer model shortens the path that an average Internet download requires. If my neighbour downloads a film, and then I decide to download the same thing, should the data be sent all the way from the original source, or should my neighbour be able to pass the data on to me?

Such peer-to-peer models - along with other models that perform their downloads asynchronously to the users' usage patterns (such as podcasting) - also help to smooth out the peaky nature that Internet bandwidth demands.

There remains the question of service design and charging appropriately for such usage, but BitTorrent could quite easily be argued to have helped ameliorate the impact of the demand for Internet video.

Dan Stowell, London

Cutting computers' appetite for power

Dave Coustick (Letters, Vol 4 #1) and the rest of us will save a great deal of energy when we all switch our PCs off. I boot XP from mains off (not standby) in 42 seconds with a further two seconds to a clean page in Open Office. I use only good practice, no clever or expensive tricks.

This is not instantaneous, but is on the way to my target of 15 seconds that I have with Windows 3.1, which saves converting my legacy files. A sleek Linux distribution with a few carefully selected programmes would look after the majority of users, who would not even notice the different operating system.

Kristen Cadman, Marlow, Bucks

Lighting up the time

Philip Hartley (Letters, Vol 4 #1) says we can help save the planet by switching off street lights between midnight and 6am. A Welsh local authority has 'solved' the problem by removing lamps from lampposts. This is a draconian solution as the lamps cannot easily be turned on unless you replace the lamps, and has also caused a lot of ill feeling from residents.

A simple solution is to use the same technology that switches the metering from normal to night time 'Economy Seven' by sending a coded signal from a long-wave transmitter. The technology exists and has been proven over many years. If we expand its use to operate at other times, then local authorities can choose lighting periods best suited to their residents.

The emergency services can be provided with low-power long-wave transmitters to override this broadcast signal and switch on local lamps if required.

This idea can be extended to the motorways but using the local radio VHF FM transmitters for control. Alternate lamps can be switched off as the light spill, from the lamps which are on, together with car headlamps, will be sufficient to illuminate the motorway. During foggy nights the individual sections of motorway lights can be controlled dynamically by the police, overriding the automatic system. The ability to switch the lights on in a specific location can be given to the emergency services with their own low-power vhf transmitters.

Terry Beswarick CEng MIET, Beaminster, Dorset

Office blues

Your news story on the use of the Philips Activa fluorescent lamp reminds me of my experience 30 years ago with a lighting installation using 'full spectrum' fluorescent lamps, which were promoted as having a beneficial effect on the health of people exposed to their light.

I noticed that lamps with a blue tinge had replaced the 'cool white' lamps in a large drawing office. The chief draftsman told me that the new lamps were full spectrum, and had contributed significantly to the well-being of the draftsmen who were more alert at the end of a working day.

It so happened that I was wearing my University of London tie and noticed that the red stripes appeared brownish while the blue tended to shriek. Asking the man responsible for maintaining the lighting whether the office had full-spectrum lighting, the reply was: "They've got ordinary blue lamps not full spectrum. A full spectrum lamp would cost me $12; the blue costs 85 cents - and they don't know the difference".

Ernest Wotton FIET, Toronto, Ontario, Canada

John Woodgate (Letters, Vol 3 #20) can be assured that there are daylight CFLs on the market at around £6. Try Googling Daylight+CFL+Energy+Saving. Some results will be Chinese companies who want orders in the thousands, but there are a few British distributors. I bought a 6,000K spiral helix type some time ago for £20.

Dimmable CFLs are also available, as are dimmable daylight CFLs. The market is improving, but only if you are prepared to go e-shopping.

EurIng Brian Hammond CEng MIET, Lichfield

Museum piece

The article about application lifecycle management in the Vol 3 #21 issue of E&T ('Processes With a Point') uses the term 'artefact'. The dictionary definition of 'artefact' is "an object that is made by a person, such as a tool or a decoration, especially one that is of historical interest".

I suggest the man in the street would look to a museum if he wanted to look at an artefact. In the project management world, when someone produces something it is called a 'product' or a 'deliverable', both terms actually stating what is 'in the tin'.

My wife, who worked at ICL over 30 years ago, pointed out that maybe the software industry calls such things artefacts because they are always late and thus of historical interest. Some things never change - incomprehensible jargon and late delivery.

Barry Faith FIET, Wimborne, Dorset

Stimulating wave energy

If the UK government was serious about promoting wave power the simplest idea would be to copy the US X-prize for the first private company to put a space ship into space twice within two days.

The government could award a similar 'W-prize', payable over a trial period, to the first six companies to install a 1MW wave power generator on the UK coast, and agree to buy the power at a premium.

The advantage for the government is that it minimises the risk: it is only funding successful companies and gathering useful data about the relevant performance of each.

Having six prizes would allow it to encourage and compare different technological approaches.

David James, Graz, Austria

Too many chargers

Most of us have, in the recent years, changed our mobiles on a number of occasions, and every time the mobile is bought, a battery charger given free with it. At my house, where we use three mobile phone we have ended up with a box full of old chargers that I find it hard to throw away.

While at least some energy is expanded in manufacturing these battery chargers, disposing of old chargers is a problem too. A considerable number are now being thrown away simply because they are not compatible with the new mobile, or because a newer one is obtained anyway , free with the mobile.

Perhaps the time has come for the EC to consider abolishing the packaging of a battery charger and its being given free with the mobile, as well as the introduction of standards for one type of charging port on the mobile.

This can perhaps be assisted with a plug supplying different voltages on the same terminal or even the charging voltage can be standardized. Of course, the directive can then prescribe as well the performance characteristics of battery chargers that can be sold, stating maximum losses. In this fashion one can still retain the old chargers when buying a new mobile, and additionally use one charger to charge more than one mobile.

Anton Cutajar MIET, Birkirkara, Malta

Weblog:

What they're talking about on the Internet

A contributor to the communications forum on the IET website asked: Does anyone actually know how TV detector vans work? The TV Licensing Authority says the following, which makes the whole thing sound a bit James Bond: "Our vans feature a range of detection tools. Some aspects of the equipment have been developed in such secrecy that engineers working on specific detection methods work in isolation, so not even they know how the other detection methods work."

I'd suggest that the vans detect the frequency of a local oscillator signal that is mixed with the broadcast signal to down-convert it to the frequencies needed to extract the audio and video information and drive the TV electronics. I recall whenever these vans were shown that they had big centre-fed dipoles on the roof. Given that these weren't just a gimmick that would put them in the hundreds of MHz range - just right for the LO. However, mounted over a flat, steel van roof there would be no elevation resolution and very little azimuth.

I cannot see how a TV detector van could disseminate EM transmissions from a local oscillator in a house from those in other houses to a level that could be used as evidence. The purpose of the TV detector van would be to act as a deterrent.

I think they hold a computer with a database of addresses that don't have TV licences. Any aerials, dials and radio-like equipment inside is just for show.

Ever tried to buy a set top box? I was asked for my name and address "for licensing purposes" - it's all in a computer, somewhere. It's actually law that the retailer is required to obtain your name and address when selling any device which is capable of receiving and resolving TV signals.

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