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Phil The Main Editor

We’re back after quite a long lay off busy on other things.  I thought that I would start with a subject close to me  (if not close to my heart);  that is the amount of bureaucracy in modern engineering products for projects.  Some engineering companies see it as a huge burden, jumping through hoops or worse just to get to be an approved supplier to major programmes.

Worse, others see this bureaucracy almost impossible to get on many tender lists as they have the expertise in abundance, but perhaps being a young and rapidly expanding engineering company, they don’t have the mandatory 3-year’s accounts and have not yet aspired to the “essential Link Up or other such supplier industry specific entry qualifications.

Others regard the bureaucracy of  modern health and safety legislation and how it is interpreted, especially by the public sector, as intolerable and a complete disincentive to trying in the first place.   You can bet that just about everybody has, at one time, exclaimed: “This is health and safety gone mad” when you read stories such as making children wear goggles and safety gloves when playing conkers at school.  More pertinently perhaps, all workers   need a CSCS certification just to go on a large construction site and then only with all the personal protective gear (PPE) including safety glasses and gloves.

If you are nodding your head to all this, then you are possibly one of life’s cynics working to keep up in this modern age.   In this modern world, we are all getting risk averse and just about everything we do is bounded by risk assessments that we have carried out or most often by somebody else ostensibly on our behalf.  These days it is backed up by legislation and powerful quangos,  e.g. the Health and Safety Executive.   And so the inevitable bureaucracy grows.

Quality goes hand in hand with safety and it is no more true than in the safety-critical industries such as aviation and rail transportation where the potential for large-scale tragedies in one event is obvious.  In any large rail infrastructure programme in the rail industry for example, every new bit of lineside infrastructure kit like new design of bogies, new piling designs or signalling kit needs to be evaluated with some trialling in the lab or on special test  infrastructure.   When the piece of kit passes muster in terms of long-term reliability, it then goes through the Product Acceptance bureaucracy , at the end of which, it receives it’s “PADS” certification allowing it to be used anywhere on the rail network.

Similarly, any novel  design of product  in an infrastructure project has to go through a “Form A” design evaluation before allowing it’s adoption throughout the infrastructure programme to which it applies.  As there are potentially many applications in such programmes, there is a trend to work up generic designs accredited under Form A.  Any departures from this generic design (known as “Proforma”) requires a Form B submission where the design is evaluated by the project team.

I have only scratched the surface of this kind of project bureaucracy and whilst a bit of a pain and cost the project money, it is an essential part of the interconnected processes to ensure that risks are minimised to personnel and the travelling public and helps keep costs down.

Until the next time…

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Phil The Editor

Hi there again friends – it has been a little while hasn’t it.  Anyway, I thought that I would visit a number of things that caught my eye in the technical press to get you thinking about which way some technologies are heading.

You will all have heard of the famous engineer’s KISS principle: “Keep It Straightforward and Simple”.  Mimicking nature is one way of ensuring that the solution is practical in technical terms but will it pass muster commercially?

Have you ever been annoyed with that fly buzzing about your office or home and defying all your attempts to catch it?  One solution is to to buy a venus fly trap or a pitcher plant to attract and capture it and its many cousins over the following weeks.  However in the weeks and months ahead it won’t work be working for much of the time.  The problem with this idea is that such plants need high maintenance.  Well, reading the New Scientist this week, I saw this intriguing article about bug-catching robots powering themselves.

Venus Fly Trap

According to the New Scientist,    Seoul National University researchers have created a robotic Venus fly trap using two clam-steel carbon fibre leaves that act like those on the Venus fly trap leaves, and a connecting micro-spring made of shape memory materials that has two stable configurations.  When subjected to heat,  electricity or force,  they suddenly flip from the one shape to the other.  In this case, the fly lands on the spring and causes it to contract suddenly and pulls the two clamshell leaves together; thus trapping it.  To open the trap, electricity is passed through the spring and thus opens it again.

There is clearly a race on to commercially exploit this unusual application of technology.  The University of Maine are developing a different method using electrically charged polymer membrane leaves covered with tiny gold sensors.  The fly triggers the sensors which then uses a power source to reverse the charge on one of the leaves thus causing the leaves to close together.

The Bristol Robotics Lab in the UK have already come up with their Ecobot which uses bacteria to digest the fly including its exo-skeleton in-situ and also to generate small amounts of dc power that can be stored in a battery.  The trick is now to establish a non-powered resource to act as a lure.  Apparently, they have not yet come up with such a lure.  This is where I reckon the KISS principle comes in.  The good old Venus fly trap uses scent and colour to attract them.  This will require another biological research team to come up with such a lure.   No doubt a commercial developer will come up with an integrated system that will be seen by the million in years to come.  Perhaps they will make a mosquito -sized version to reduce the misery of malaria in the warmer climes.

Another piece of technology recently seen in the news on the BBC’s  technology programme Click is the soon-to-be-launched Lytro post-focusing digital camera.   The camera uses plenoptic technology that was postulated nearly a 100 years ago but only recently has been technically possible.  The principle is that you have millions of sensors on a retinal plate that not only record the intensity of each “ray” of light hitting it, but also it’s colour and direction.

The idea certainly uses the KISS principle in its concept as it allows one digital device to simulate many cameras  to record one scene.  The digital information is recorded in such a way so that it can be manipulated in the manner of a RAW image later to change the focal distance of any object in the image set.  You can see the effect by playing with the images on the Lytro website.

Moreover, it is possible to extend the effect by changing the point of view.  However, the quality of image at launch is likely to be inferior to a single focus digital camera image.  No doubt this will change with time as digital imaging companies vie for supremacy in the months and years to come.

I have a strong feeling that we will be visiting this topic again before long.

Chao

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I thought that this week, we should talk about solenoids and solenoid valves as they have wide use within industry, commerce, transportation and general security.  This was prompted by an unpleasant memory that involved them some years ago.

I remember once finding myself and a colleague  trapped inside an airport fire station storeroom at night once when the power failed.  That is not a pleasant experience I can tell you as we couldn’t get out of the door we came in.  Luckily we had a glim keyring torch between us and found the building’s MCB distribution board and restored the power.  I was very puzzled why the door wouldn’t open as it should.  On subsequent investigation, I noticed that the personnel access door had a solenoid shoot bolt that failed safe closed when the power went off.  Good for perimeter security but no good for people trying to get out.

So what is a solenoid?  A solenoid is a form of transducer that converts electromagnetic energy into linear mechanical movement.  More particularly, the vast majority of solenoids use a spring-loaded steel (or other magnetic material) plunger that is attracted into a toroidal coil when energised.  When the coil is de-energised, the plunger returns to its rest position.

With such a simple action, it is important that the design closely matches the duty.  For example, the holding force to keep the plunger in only whilst the coil is energised, should sufficiently exceed the return force from the spring to ensure rapid responses for the full cycle but not to cause other problems such as bouncing.   Also, by suddenly cutting off the power to the coil, this induces a sudden voltage surge which will delay the return drop out time.  In the same way,  This surge does assist the other half of the cycle on energisation to improve the pull-in time.

Often, a high value resistor, varister or diode  is incorporated in series with the  coil to dampen this surge.  This however has the effect of increasing power consumption and/or drop out time.

Solenoids can be either AC or DC energised and they work in the same way although the application design will vary considerably.  DC Solenoids are normally used for high frequency operations such as are found used as actuators for 2 or 3 way pneumatic and hydraulic valves on trucks and manufacturing production lines.  AC solenoids are normally found in the security industry where low frequency and low cost but high actuation forces are required.

Another factor is temperature.  DC solenoids’ power requirements are not influenced by the position of the plunger (or armature as it is sometimes called) whereas the AC solenoids are.   AC solenoids are thus limited by the frequency of operation to avoid overheating them, especially enclosed to IP65 to IP68 ones for wet or difficult environments.

Al this tells us that the design of a solenoid is a balance to optimise cycle times whilst reducing the energy used to keep the solenoid energised for typically, long periods.  For this reason the range of solenoids and solenoid valves available is large such as those by industry leader Penny and Giles.   These electromechanical solenoids are therefore used for an eclectic mix of applications such as paintball machines, dot-matrix printers, fuel injectors, automotive air systems and many manufacturing processes.

Latching solenoids are an interesting variation on the simple spring-loaded push-pull solenoid and these use  permanent magnets in conjunction with the solenoid coil to maintain the position of the armature with no current applied.  The solenoid coil is therefore used to electromagnetically move the armature only with a burst of current and it will otherwise remain in either set energised position even if there is a power failure.

The latching solenoid is thus used for automatic door closers, latching mechanisms and other locks, security devises and battery powered equipment.

Another type of of electro-mechanical solenoid is the rotary voice coil in which the permanent magnet stator surrounds a coil, in which when energised,  moves through an arc.  One of the most prolific of applications is for PC disc drives.  It can move bi-directionally.

The principles behind a solenoid action are very simple, but the applications are varied.  There are other non-electrical solenoids that are about using hydraulic and pneumatic power.  These and the fascinating world of fluidics will be the subject of a future post, so keep visiting.

Au revoir.

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Phil The Main Editor

In a previous post in April, I talked about What’s In Hydraulic Seals?.  This time, I thought I would regale you with a few stories about the use of sealing technology in the engineering industry.  Sealing technology has moved on a-pace since the age of steam. Going hand-in-hand with the development of really clever designs of seals for every size and complexity of applications, the use of esoteric materials continues to grow to fulfil these applications.

Take radial lip seals.  In case any of you don’t know what these are, they are the seals that retain oil and grease within large shaft bearings or rotating machinery such that that can contain up to 2 bar pressure differential.   This is pretty remarkable considering that the seal is typically one retaining radial lip of an elastomer material pressing against the rotating shaft or machinery surface that is slipping past at 15 m/s but could be up to 30m/s.

A typical Radial Lip Seal from James Walker

Hydraulic seal manufacturers  now make radial lip seals in all sizes.  I believe the record is 11 metres diameter (for a tunnel boring machine or TBM).  For anything above say 2.2 metres diameter, moulding a precision-made radial lip seal in one piece becomes a bit impractical both on economic and practical grounds.  To meet this large-scale need, continuous moldings or extrusions are manufactured. Naturally these continuous mouldings need to be jointed to make a ring.

By using a specially tooled manufacturer’s jig and typically a high-performance epoxy adhesive, these rings can be jointed on site.  Site jointing opens up the possibility not only for OEM fitting, but also for retrofitting in place.  Dismantling to expose a shaft end over which to place a ring is rarely feasible and many tunnel boring machine contractor will attest.  They want that drive bearing radial lip seal replaced in hours otherwise the TBM may become jammed by geological redistribution of rock strata and thus can become entombed.  No pressure then to get it turning and cutting again!

There are many types of radial lip seal to suit the different duties, some are designed to work within a machined radial groove and some not retained and sit within a radial recess.    Yet others work with a retaining ring that is fixed into position after the radial lip seal is set in place.

Tunnel Boring Machine Uses Radial Lip Seals

For such arduous duties such as the tunnel boring machine, lubrication can be a problem in such an aggressive environment.  One solution that I have seen, has two radial lip seals set into a groove and a lantern ring set in between them.  This lantern ring is bored through and connected to a pressure lubrication system.  The increased security of a two ring system that is positively pressure lubricated certainly increases the operational life of this vital peripheral bearing.

Radial lip seals are manufactured in a number of modern elastomer materials to suit the temperature and peripheral speed of the shaft or rotating machinery.  Such material have been specially developed or modified in some way to suit hydraulic seal applications. Pressure resistance is of lesser importance in this respect as the detailed design shape features of radial lip seals  take care of the relatively low pressures involved (>2 bar).

Contact with the rotating part is more-often than not is helped by use of a metal peripheral spring moulding into the seal section. Temperature is of critical importance for radial lip seal design and the selection of the material to be used.

An unfortunate property of most modern elastomers is that if an elastomeric radial seal in tension is subjected to frictional heat, it tightens on the shaft to generate higher friction, wear and more heat. This counter-intuitive property is known in science and the seal manufacture industry as the Gough‑Joule Effect.  They ways to overcome this are to reduce the temperature rise or as at least one manufacturer has done, modified the shape so that the critical seal element is in compression rather than tension.

Typical elastomers in use on these seals include Nitrile (NBR) which is suitable for use with water and the majority of oils and greases.  The maximum lip (peripheral) speed varies between 12 and 15 m/s.   One of the latest developments is Hydrogenated Nitrile (HNBR).  This  reformed Nitrile material has an especially low coefficient of fiction for improved running at higher speeds and greater abrasion resistance for longer life.

Other materials that are used on more specialised applications include fluoroelastomer (FKM) for high working temperature applications for self‑retaining seals in open housings and  where electrical insulation is necessary,  polytetrafluoroethylene (PTFE) for those aggressive chemical  environments.

As you can imagine, rotating body misalignments have to be kept in check even with the use of radial lip seals.  To meet these problems, ingenious designs include floating cartridge rings that follow the misalignment whilst retaining the lip pressure on the shaft within operating parameters.  Other solutions include specialised long lip sections and modified lip sections. So whatever the application for large lip seals, be it retrofitting bow thruster seals on Queen Mary II cruise liner or new 1,800mm diameter slew ring seals on elevated wind turbines, there will be a radial lip seal design for the application.

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As you read this, you will no doubt be thinking how topical the subject is today!  Sophisticated surveillance of public places in the UK and elsewhere in the developed world has been increasing in the face of increased terrorism threats, more rampant criminality and now social unrest. A recent report published by CCTV Image magazine suggested that there were over 1,850,000 CCTV surveillance cameras in the UK alone, both public and in private premises.  The UK leads the way by far with 1 for every 32 of the population and there have been other, perhaps more fanciful estimates, that put this figure at 1 in 14!  This has prompted a debate on the relative benefits of crime reduction balanced by loss of privacy in this home of democracy.

What seems to be in no doubt until the unfolding of the complete lawlessness this weekend in cities around Britain, was that CCTV surveillance is effective in reducing crime.  I now want to outline some the technology behind some of the surveillance in areas that the public has access to.

Gone are the days when the image is a fuzzy black and white where the operator just eyeballed the bank of images, reported what he saw and hoped he could find the video tapes when the police asked for them.  Yes this type of operation still goes on, but the image is now high-definition (HD) in full colour, even in poor light or infra-red for special purposes and night vision.  Furthermore, image acquisition and image  processing software has moved on tremendously in recent years with the coming of the digital age.

All these applications use common platform standard such  Common Vision Blox s for  3-axis image stabilisation (anti-shake), multi-image integration for clear still images and even for multi-viewpoint analysis.   This digital data can be transmitted over ethernet cabling and sharing the image via the Internet.   Automatic tracking of a target that interests a camera operator from one CCTV to the next in a group of cameras is now possible.

Infra-red images are especially useful at night for identification of heat sources such as fugitives hiding in the undergrowth and when digitised and  linked to police, DVLA and insurance databases for automatic numberplate recognition (ANPR) in dark car parks.

One of the most exciting and new aspects of manipulating digital video sequences, from a technical point of view, is the possibility of lifting of biometric data from the image sequence to give height, weight, build, facial features and, of course, clothing.  This data can be processed so that it can seek a match with known data from the CRB in real time.

The UK Highways Authority have been using their 1,500 CCTV Monitors located at key junctions, not only to monitor Traffic levels but recently, they have started using  CCTV imaging for  APNR in real time.  In future, there could even be monitoring in the infra-red spectrum to seek hot spots on cars and especially lorries for impending problems with under-inflated or burst tyres before accidents are caused.

This canter through the new technology available to security organisations demonstrates that real-time evaluation and identification of problems and targeting of ne’er-do-wells in real time automatically is already a real possibility.  It may be that automatic monitoring of criminals and terrorists will soon become a reality.

It is only a short step to that recent film about the near future (the name escapes me) where everything is monitored and “sniffer” sensors located at every underground (metro) could read DNA of all the people passing and the wanted person (the hero) was tracked all the way across the city.  It strikes me that the technology is rapidly reaching that point where passive monitoring can give an automatic GPS fix. Scary or what!

Finally, the police seem to be quite confident that a significant number of these rioters will identified from the various surveillance sources in the next few days.  Part of me says there should be plenty of imagery for the police to work on.  Indeed, some of the youngsters caught by the media on news reports looked very clear on my TV and anyone who knows them could immediately identify them.  But will they or can the police use the automated recognition tools I described to make a real difference.

Londoner Clean Sweep Protest After Riots 9 August 2011

The answer, I fear, may be not yet because of the cut backs to police numbers and the political will to really get as many of these feral youths to pay for their immorality, whatever the cost.  Let’s hope this present rioting does not continue and the real fear of arrest grows by the rising numbers being arraigned at the magistrate courts.  I am of the school that says:” if you are not breaking the law, you have nothing to fear from blanket surveillance in this modern democracy.”

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Having just got over a hard disk failure on my business pc, it got me to thinking about how vulnerable we all are when it comes to making notes.  The proprietary back up system did work up to a point but I found that simple things like the automatic address book on MS Outlook needed re-populating and this slowed me down tremendously whilst I scrabbled around looking for them elsewhere.

There have been a number of articles in the media in recent years on the subject of human vulnerabilities when it comes to modern computer technology on the lines “Is Google making you stupid?” and “Is the Internet changing the way we think?”    With respect to the first, I love the saying that was quoted by a well-known technology author: “I used to swim in the ocean of words but now I am like a guy on a jet ski skimming across the waves”.

“How true” I thought.  I too find that I can no longer use a pen and paper to draft articles but I draft on the PC, drafting a sentence or two then cutting and pasting, looking things up on the Internet and generally skimming around.  I think I would now be lost, well, at least for a while without my “technology dummies”.  What I do know is that my notebooks are a mass of manuscript crossings out showing clearly how I now think (which is quite different to how I was brought up and did my exams!).

Now scientists are actually building on lots of anecdotal evidence to carry out some serious research.  In the press only today (on the BBC website – what else?) I saw a fascinating article datelined 16 July by Jason Palmer reporting on a scientific study on “transactive” memory by Columbia University.    Apparently, they have demonstrated that modern humans with long-term access to the Internet, have a poorer memory for facts that they know they will be found on the Internet than other information.   This was demonstrated in a test of volunteer students where they retained a remarkable memory of which file information was stored rather than the information itself.

The term “transactive memory” has been coined by researchers to mean the Internet as an adjunct to our own memory.   One of these researchers has said: “ I don’t think Google is making us stupid – we’re just changing the way that we’re remembering things…”  Personally, I’m not sure this is the only explanation.  Technology is incredibly powerful but human adaptability is probably just as powerful wherein lazy thinking is indulged and we would still revert back to more reliance on our own memory should we have to.  Are we evolving as a result of this “transactive memory” extension, the jury is out on that one.

NASA picture of Asteroid Vesta

Turning to another item that caught my eye, was that the robotic spacecraft “Dawn” powered by an ion engine has just entered orbit round a large asteroid between the orbits of Mars and Jupiter and is currently some 188 million miles from Earth (as the crow flies metaphorically speaking).   This was a great feat of engineering given the delicacy of control required first just to get there, and then to orbit a relatively small and low-gravity celestial object.   I got to thinking of the control systems that must be using tilt sensors, accelerometers to guide it and other electric motor driven systems that need to operate for years on its long journey far in excess of the direct route.

I always am amazed at some of the stories of the longevity of both some highly expensive engineered systems as well as the some more humble items off the shelf.  Yet we can all relate to buying something complicated, taking it home only to find that it is faulty.  I suppose this is a case of you only get what you pay for in the long run.

Au revoir for now.

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Phil The Main Editor

This time I am having a general rant about equipment efficiency and whole -life costing principles.  As practical people, Engineers will have considered doing some do-it-yourself (DIY) in the home and most will have actually done some in their lives. It could be something as simple as tiling the bathroom, a new “heart transplant” for an ageing heating system or a major self-build house project.

This is all very laudable and other, less practical people, will be envious of the expertise involved.  What is more it saves the householder money.  Now is the same true for businesses?  Recently, I came across a business (who shall remain nameless for obvious reasons)  that liked to do everything themselves “to save money” as the Managing Director proudly said.  This had, over the years, become the company style.

Whilst visiting one day,  I happened to pop into the company’s factory boiler room and I couldn’t believe my eyes.  Apart from the squalor, the additions and repairs to the heating system over the years had the effect of rendering the boiler very nearly useless and potentially dangerous.   When I asked the boss what was going on there, he said that he had some years ago moved to an in-house solution and stopped using external contractors to look after their building services.   He said that he had saved a packet on maintenance fees.

He used some of his engineering staff to look after the services on an ad hoc basis.  It wasn’t appropriate at that time to say anything other than I thought that the heating system was dangerous and needed expert attention.   On delivery of this news, the atmosphere went decidedly chilly and I left.   This made me wonder how prevalent this practice is.  I would love to be a fly on the wall at a board meeting where the Financial Director reports his services costs,  querying why they are so high and where can we save money.

With this in mind and moving on to industrial heating installations, it is amazing how many businesses do not realise the benefit of whole-life costing when it comes to reviewing their heating and air-conditioning installations.  When does a heating system need replacement?  Certainly not when the replacement parts cannot be sourced any more 15 years down the line.

Like any piece of fixed machinery that needs servicing over its life, it is a good plan to work out how much it costs over an expected life span including its funding costs, capital write-down values, maintenance costs and major overhaul costs at planned intervals as recommended by the manufacturer.  There is always a time in the is plan when it is cheaper to replace it rather than to “run it into the ground”.

Taking the above example, that company certainly did not use whole life costing in assessing their overall costs.   What the MD saved on external servicing costs, he certainly lost many times more over the years in energy costs and lost productive time by factory operatives spending time on the heating system instead.

Moving on to energy efficiency, why are new build warehousing and small to medium sized industrial units still using traditional boiler and air-conditioning installations when it is clear that more innovative solutions are available?  These include ground-source heat pumps, air source heat pumps and photovoltaic solar electricity are available; the latter being the subject of government payback on the excess electricity generated.

The answer may, of course, be related to the fact that such units are often spec-built to the minimum capital cost with little regard to the user companies’ costings.  With such a disconnect from a whole-life costing point of view, it is little wonder why the practice continues.  Improvements only come, it seems if the building regulations demand better standards.

Concerned Engineers should, perhaps, lobby for greater regulation in this regard to ensure that spec-built properties must be equipped with the latest and most efficient system available.  Alternatively, we should be looking for longer-term involvement of the developer of these units for continuity of cost planning to ensure that cost savings are planned and benefits shared.  What do you think?

Hasta la vista.

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London's New Thames Passenger Cable Crossing

In April 2011, Transport-for-London (TfL) announced that the Thames spanning cable car crossing project connecting the ExCel Exhibition Centre on Victoria Dock in London Docklands to the O2 arena site on the North Greenwich peninsular will start construction this summer.

In case you haven’t heard by now it will cost £25+ million and  it will have a capacity of 2,500 passengers per hour.  It comes with the prospect of magnificent views  over 50 metres above the Thames, of Docklands and London and it will give London Eye a run for its money as a London Icon  according to London Mayor, Boris Johnson.   It will be the first mass transit aerial tramway in the UK and it will join others  including Barcelona, Cologne, Hong Kong, Singapore and Memphis (memorable for the action scenes in “The Firm” featuring Tome Cruise).

When first planned in 2010, this new link was to be completely privately funded and take two years to construct.  Boris Johnson and TfL are now pushing to have this ropeway transit link operational by London’s 2012 Olympics to link two Olympics venues, the O2 and the ExCel Arena as well as the main venue just a few hundred yards North of the Victoria Dock.  This will undoubtedly provide a real wow factor to the Olympics.

You can see that the time to build this significant structure in time (11 months) is quite an engineering and logistics challenge and to make it happen, TfT will fund the whole cost up front – a bold move some may say in these straitened times.  Whilst this has not really impinged on the national news to any great extent, the race to get it ready for the Olympics has undoubtedly accelerated the project to give the operators a chance to get an early boost to their revenues.

Transport and construction industry commentators believe that whilst completing the project and getting it operational in 11 or 12 months will be a huge challenge.  The aerial tramway would provide both a medium-term benefit to the transit infrastructure to the East of London and across the Thames, as well as a long term money-earning tourist attraction once the cross-Thames rail link tunnel comes into use in a few years time.

There have earlier, largely unreported attempts to provide a very similar capacity scheme based on aerial tramway technology in 1992/3 a for a privately funded aerial ropeway across the Thames.  It’s raison d’etre was to provide a short and medium-term solution for North Kent Rail passengers to quickly get into Canary Wharf, London City Airport and to kick start commercial development in East London and the Royal Docks.

The aerial ropeway service was a simple idea to get things moving to the East of London prior to any rail tunnel under the Thames from North Woolwich to South Woolwich, was planned to be an extension of the North London line on the North Woolwich peninsular.   We are still waiting for a rail link under the Thames in this area and perhaps it will still never happen.  This latest “temporary” solution is little difference from the previous one except there is another, more prestigious, reason for promoting it.

The only worries are likely to be the current scheme’s business model and the airport safeguarding. If it is built in time with the TfL up-front funding, then there is a good chance that the 2012 Olympics will give the scheme a great financial boost right at the start of its life.  If, as the engineering lobby think, time is too short for completion in 11 months from a summer start, then it has to have other longer term attraction and longer-term funding to achieve a reasonable pay back period.

In setting up London City Airport’s 1,200 metre long runway operation less than a mile away to the East, the runway safeguarding surfaces were also set up as a set of “safety zones” for aircraft operation, within which no structures should be present.  Let’s hope that 55+ metre high tramway construction is sufficiently far away to the West on the extended runway centreline not to further limit the now successful London City Airport operations.

What do you think? – White Elephant or future London Icon.  I think the latter (with a “fair following wind”).

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Phil The Editor

This week, I am concentrating on the functioning of engineered systems in adverse conditions prompted first by the news that Icelandic volcanic ash is again causing disruption to the airways of the UK and Northern Europe. We can all remember and many will have experienced the misery and expense  of trying to get home from holiday in the face of such massive breakdown in air communications.  This puts a spotlight on the reliance that western society now places on its engineering systems and communications.

Last year European aviation authorities took no chances when the ash plume from Eyjafjallajokull volcano and grounded thousands of flights on the basis that the ash particles were largely siliceous, angular and would quickly erode engine parts and ‘sandblast’ windscreens and other critical parts with perhaps catastrophic effects to the safety of the flying crew and public.

There was good reason for this caution as previously in 1982, a British Airways Jumbo jet lost power in all its 4 engines whilst flying near a volcanic ash cloud over Indonesia.   It was fortunate indeed that the crew managed to re-light the engines at low altitude after losing some 30,000 feet.   It was reported that some accretion to the turbine blades had occurred to the engines and along with some sensor damage and they were replaced as were some other critical parts.

Despite many grumbles from airlines that the aviation authorities were being too stringent, they toed the line.  However, Ryannair boss,  Michael O’Leary made the news headlines by announcing this week that he had ordered two of it’s jets (without passengers) through the ash plume in affected airspace with reportedly no ill effects to the aircraft.     I hasten to add that the aircraft only few through low ash concentrations to make the point that the authorities were being too cautious and he could back up his claims with good data.  Was he lucky or was he foolhardy?  Hmmm.

The disruption from this latest eruption from Grimsvotn volcano is proving to be less disruptive because a) the authorities are taking a more pragmatic view based on recent research and b) the ash less angular and of larger particle size so that it will fall to the ground much quicker.  Whatever the facts are in this case,  it is a tribute to the aviation industry that aircraft are well engineered to achieve the highest safety standards for passenger safety.

NASA Mars Rover Spirit

Again in the news this week, is the news that NASA have abandoned attempts to re-establish contact with their Mars Rover, Spirit after it got stuck in soft sand and last communicated some 14 months ago.  Spirit was launched in January 2004 at the same time as it’s sister craft Opportunity which is still trundling around on the Meridiani Plains on Mars and still sending back valuable data.  This is remarkable given  that both rovers had an expected lifespan of 3  months.

Opportunity is however, feeling its age with an ‘arthritic’ robot arm and problems with some of its instruments.  However, it is a testament to the good design and engineering that both Mars rovers have functioned so long in such a harsh environment.

Instances of long-lasting engineering abound.  The one I particularly like is about a mono drainage pump that was only discovered walled up under an Australian department store when the basement got flooded with sewage.  On checking the reference number with the manufacturer, they discovered that the pump had been installed over 40 years previously and had been working unseen and forgotten since that time.  Tough or what?

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It is one thing as an engineering company to purchase raw materials, whole assemblies, tools, large items of equipment or a whole production line project from recognised brand-named suppliers. However, it is not always easy to get certain items for your factory engineers to build or adapt a mechanical/electrical production facility. The purpose of this article therefore, is to give you some idea what is available off-the-shelf in the way of small precision engineering stock items.

Spur gears are needed for a whole range of industrial projects ranging from bespoke conveyers, mobile machinery, farm machinery modifications and motor drives in clean environments or a complicated milling operation. Such projects need a whole range of stock components not normally available from your local friendly hardware merchants. To complete your project, you need items ranging from precision couplings, chains, motors, lead screws, spindles, castors, pillars, bushes, gearboxes, right angle drives, V-belts, pulleys, chain drives, universal joints, rod ends, linkages, collars, clamps and keys, brakes and clutches.

Actually, the engineering industry in the UK as a whole has a number of specialist manufacturers and stockists with a huge range of engineering stock items to serve wider industry. For example, precision-made spur gears are available in several materials and sizes. For example, at the low-cost end, acetal gears are injection moulded plastic with machined bores, straight-cut teeth with a pressure angle of 20 deg, capable of withstanding 100 deg.C and high chemical resistance. For more durability, delrin gears come with a similar vast range of sizes that are machine cut and milled for great accuracy.

Brass spur gears are widely used where sparks cannot be entertained in hazardous atmospheres.

Steel spur gears are supplied with our without hub in a number of grades of steel to suit the application and size. Stainless steel versions are available for use in say clean or exposed environments where ease of cleaning is a factor or rust unacceptable.

Another such engineering stock items where accuracy of manufacture and wide size range are available are precision ball screws for heavy duty industrial applications, miniature precision ball screws and many other advanced development projects. Accuracies of the order of 50 microns per 300 millimetres with axial backlash as low as 20 microns are achievable. These ball screws are available in virtually any size, lead size and length. Each part can be supplied with custom machined journal ends and integrated thrust bearing and radial mounts. Also, end threaded, cylindrical and flanged ball nuts are available, as are a wide range of pitches and leads.

Another engineering stock item available in a wide range of materials are castors. The industrial castor offers smooth running and wear resistance.

These industrial castor products meet the needs of a variety of industries and the demands of many different applications. These are available in a number of standard configurations including wheel only, brakeless wheels with brackets and zinc plated turning or fixed plates, brakeless wheels with an assembly pass, brakeless wheels with fixed plates and brackets and wheels featuring stainless steel turning plates and brakes.

Typical coverings are a hard polyurethane and a chemical and oil-resistant polyamide centre. The axles of these castors are a precision calibrated tube designed to allow the wheel bore to rotate freely onto the axle. Turning plate bracket industrial castor models feature direct contact between the ball race ring and plate along with two ball turns to provide a high degree of manoeuvrability and to reduce clearance.