STOP PRESS! – Free Power!

We interrupt this thread on the helicopter briefly to mention the latest saver of the Planet. The Searaser and some of its simpler engineering aspects.

This is another proposal for generating electricity in an environmentally friendly way. The media is again trumpeting it as encouraged by press releases. http://www.guardian.co.uk/environment/2012/jan/23/bicycle-pump-searaser-energy?INTCMP=SRCH

The fact that the media say that it works like a bicycle pump does not induce confidence. The inventor’s backers Ecotricity  [http://www.ecotricity.co.uk/our-green-energy/our-green-electricity/and-the-sea/searaser] call it a double acting pump. It cannot be both. Virtually all bicycle pumps only push air into a tyre on the inward stroke; that is, it is single-acting. A double acting pump pushes its fluid both on the inward stroke and the outward stroke.

The Searaser is another oscillating device submerged in the friendly sea. The Unique Selling Point is that it generates its electricity on land to avoid electricity in the water. It is simple enough in principle. A large float at the sea surface bobs up and down with the waves. A rod attached to it passes down to a simple piston pump which is tethered to the sea floor by a cable. http://www.youtube.com/watch?v=_9jGis5V5LE

The Lad has to wonder how reliable such an arrangement can be as it flops around in the turbulence of the open sea. The pump and the float will each be subject frequently to different forces tending to flex the assembly. Even if the float and pump themselves can withstand these forces without failure; the piston rod seal at the pump will see large leverage forces. They will tend to make it leak or, at the least, make for inefficiency due to high friction. What is the L/D ratio for the bearing?

Speaking of friction, how much power at the pump is wasted through friction losses pushing the water through pipes from the pumps miles out at sea all the way to the land and its power generating turbines?

Each pump cannot be scaled up beyond the scale set by the sea wave length. If it is built much bigger than, say, one or two wavelengths like a ship, it will become stable – like a ship – and not move up and down at all or very little.

Full engineering design and development details cannot be expected to be given in the press. It seems clear to The Lad though that there is a very long way to go before the engineering production model is workable. Even then the economics will still be an unconquered enemy.

Note also that a reservoir is needed on land at a suitable height. This is to provide enough potential energy to generate a useful amount of power whilst not needing too much pressure head. Too high a working pressure for the system will lead to even more design problems. The storage of water in the reservoir is also needed to smooth out the variations in pressure inherent with an oscillating pump and also to provide some back up for these days, and they undoubtedly exist even in the UK, when the waves are small or in a flat calm.

But again, how big will the reservoirs need to be for every pump farm to provide continuous power and not have its beneficiaries sitting in the dark. After all the UK weather is known to everyone to vary from day to day. There tends to be a comparable number of weather states that are “too much” or “too little” as there are that are “Goldilocks”.

The video shows the first model giving some squirts of water that are, not to put too fine a point on it, not very big. Perhaps that is the origin of the Bicycle Pump name. Later models seem to give a better flow rate, it has to be admitted. Nonetheless, still the supporters of such proposed systems still cannot show, even if they understand it, the gigantic amounts of unremitting, 24/7 power generated by the Base Load Power Stations for a modern society.

The Lad is aware of an existing water power generating scheme on a nearby, quietly flowing river. To see the amount and velocity of the outflow which generates only 150kW is a reality check on the water flow and plant required. This is how it can, more realistically, be done. Visit here to see something of it;  http://www.derwent-hydro.co.uk/our_sites/index.html  . The Lad has no connection at all with this small organisation.

So, assuming that much can be done to develop the system, how many fully-engineered assemblies would be needed to generate, say, a megawatt hour of electricity? What is the cost per unit of electricity from such assemblies at the Grid?

 

Super Puma Down – I

Without Warning?

It was April 1st 2009 and the Eurocopter Super Puma L2 helicopter was expecting to land at Aberdeen at 1314 hrs. This was still 20 minutes away but, at the 2000 feet cruising altitude, the coast landfall 10 miles away was just in sight.

Super Puma
The crashed helicopter was one like this

It was about half way through its busy schedule to and from the rigs that day, flying at nearly full speed with a full complement of 2 pilots and 14 passengers. The co-pilot radioed base that all was normal. Only twelve seconds later came two MAYDAY calls

Below, was a modern, powerful, rig supply ship, the ‘Normand Aurora’, on a so-far uneventful trip. Someone on watch on the bridge changed all that. It was good visibility and there was a shocked shout of alarm. Two miles away, the helicopter was hurtling into the sea with separated rotor following it. Then came the bangs, the black smoke and the explosion. The ship swung towards the smoke.

Normand Aurora
Normand Aurora was the nearest ship to the crash site and rushed to the rescue.

 

Launching their fast,-rescue inflatable. It hit the water with a loud slap and accelerated away. Leaving the mother ship quickly far behind as its helmsman gripped the steering wheel with white knuckles and stiff-armed the throttle fully forward. He and his crew were desperate with hope that there would be something that they would be able to do: that there would be someone that they could help among the unfortunates in the helicopter cabin that had plummeted into the sea at high speed. But fearful at the same time. After the headlong two miles, its crew found a large circle of churning water. Within there were life rafts and debris. They also saw eight people; none were alive.

Epicyclic Gears

Planet gears recovered
Recovered from the sea bottom. Note the missing pinion at four o'clock.

 

Above are planet gears from the downed helicopter showing corrosion from their immersion in the sea. They are without an outer casing destroyed in the accident. There should be eight gears but it can be seen that one is missing. The destruction of the one, missing planet gear was the cause of the tragedy. Above shows only a part of the gear boxes and trains in the Super Puma [and other similar helicopters].

Had there been no advance warning of the impending catastrophe at all?

The drive shaft from each of the two engines in the helicopter runs at 23 000rpm [that is, the internals of each engine is rotating 380 times in one second or around 5 times as fast as a family car engine!]. The main rotor blades rotate at 265rpm. This means that the helicopter design engineer had to design a gear box to give a reduction of nearly a factor of 100. It has to fit in as small space and have as low a weight as possible.

When the designer needs to slow down the rate of rotation of a shaft by a large amount like this, she usually goes for an epicyclic gear design. These are commonly known as a sun and planet gear sets. This is what is found in a Super Puma between the fast spinning engines the relatively slowly rotating main rotor.

This epicyclic design was shown in the textbooks of The Lad like this, and similar diagrams are still shown today.

Textbook diagram
The textbook version is rather lightweight compared to the real thing.

 

In real life where very large power has to be transmitted in as small a space as possible, there are more planet gears than in the textbook diagram. They fill the circumference and each is wide and massive. Such planets of half of the Super Puma epicyclic gear train are shown in the salvage photograph above.

To see how designers calculate the variables in a real design of epicyclic gears see – http://www.roymech.co.uk/Useful_Tables/Drive/Epi_cyclic_gears.html

Magnetic Chip Detectors

Even though the designers seek to make engines and gearboxes as reliable and free from the risk of components failing as possible there is still a need to keep a check on machinery health. For a Power Station generator or a car engine there is no great, inherent problem to be anticipated if it rapidly comes to a halt after 30 sec of noisy running. It is quite a different problem if the engine is powering an aircraft flying several miles high over the ocean. Here a significant risk of such a sudden stop is not acceptable. They must head off such failures before they happen. They must search for signs of any problems well in advance.

The magnetic chip detector is one of the neat ideas that help maintenance teams do this. It is a simple concept. Many of the most highly stressed components are made of steel which is magnetic. One of the commonest symptoms of failure, when such a component wears or suffers fatigue cracking, is that chips of metal are generated and released from the parent component. The oil, as it is circulated throughout the engine, washes such chips away and usually takes it to the lowest part of the engine. En route, if it washes over a single small magnet, it will be captured by the magnet. The maintenance team simply unscrew the magnets at regular intervals and an early alarm can be raised if any chips are found sticking to the magnet.

Such detectors are positioned at various places within the engine oil flow where any chips may be washed over them. An alternative design is to provide twin magnets close together. Coupled to this type of device is a power supply and electronic detector to signal to the helicopter pilots, even in flight, when a chip bridges the two magnets. Such a design is shown below.

Chip detector
This is the operating principle of the more capable design that can provide a signal in flight

 

There are many such detectors designed into the Super Puma. Several are in the vicinity of the main gear box. The design of such detectors is another one of the many examples of the nexus where the design principle of “simple and reliable” approaches close to the principle of “too crude for the risk burden”. The designer has to consider which is the truth in every such case. Did the detectors work this time or not? If not, why not? See the next post.

Memento Mori

Engineering turns the forces to the benefit of mankind and the results have immense consequences. These consequences are, on the whole, beneficial but sadly, as with any efforts of the human race, for some individuals can be malign.

Bloody skirmishes to understand each way that a structure can fail and to avoid them all are a repetitive feature in engineering history. For ordinary structures most of the skirmishes have been avoided and, nowadays, fewer new ones appear. But fresh demons occasionally burst forth to confound us in new campaigns to complete new tasks or use new materials. When they do, they extract their price in blood or treasure.

Professional engineers have to be continually alert. The engineer knows that the nature of her or his work usually brings great benefit. But it can, also on occasion, bring tragedy.

So it was with G-REDL on 1st April 2009.

RIP deceased

Engineers’ responsibility

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.

Madeleine trumped by Ruby Loftus

Trefolex and Tufnol ride again in Mechanical Engineering 101.

Famously, the hero of Marcel Proust’s multi-volume novel, “A la Recherche du Temps Perdu”, found that memories of a period many years before were triggered by a smell and taste of tea and a dipped madeleine.

Immediately the old gray house on the street ….. rose up … and the entire town, with its people and houses, gardens, church, and surroundings, taking shape and solidity, sprang into being”
http://www.gutenberg.org/catalog/world/readfile?pageno=29&fk_files=1466063

Risking the bathetic after such a graceful idea and prose, The Lad found the opposite the other day: smells from his youth were triggered by this striking picture. It had been featured in a recent exhibition, Women War Artists (now closed), at the Imperial War Museum, London – website www.iwm.org.uk .

Reduced Ruby
IWM2850 Dame Laura Knight - 'Ruby Loftus screwing a Breech-ring'. 1943, Oil on canvas

 

Instantly, the workshop with its high roof appeared; it’s the Fifties. Machine tools are ranked in bays each controlled now by an apprentice in a white boiler suit. Each bay patrolled by its white coated Instructor. There was the low rumbling of the milling machines, the hum of the lathes just like the one in the picture, the hiss of the grinding machines. Equally pervasive was the smell of cutting oil and often the raw, burning smell of machined Tufnol – a composite material of linen and resin – still going It seems, [http://www.tufnol.com/tufnol/default.asp ].

But if it is a really vile smell you are after then it is in the fitting bay in the corner of the machine shop. Here are the benches and vices where there was hammering and a continuous swish of filing. There, on the bench were the pots of Trefolex, a thread-tapping paste, green coloured and with a vile stench. You can still get it today [http://www.warrenbestobell.co.uk/trefolex-cutting-compound.asp ] though they may have got rid of the smell by now.

The Training School entertained both Trade Apprentices and Technical Apprentices. The Trade Apprentices were being aimed at careers as skilled machinists; whereas the Technical Apprentices were intended for the draughtsman’s career. Notice the suffix ‘man’. No women or girls then in the Fifties: they were all long gone after the Second World War. Not even an office girl. “Disturb the youths, you know”.

But, contrary to the popular vision, the Training School does not represent the milieu of the professional engineer. It is Mechanical Engineering 101 where, then, he or nowadays often she discovers the basics before moving on. The mechanicals move on to design or work on new products for the machines to make, the production guys to introduce better machine tools or ways of dealing with difficult materials.

It was here, in the Training School, that The Lad first tried cutting an external screw thread on a lathe with a single point tool. He found it difficult while the Trade Apprentices seemed always only to thrive on the challenge. Then they moved on to using the same technique to cut an internal thread. This is what Ruby Loftus in the picture is doing: under intense pressure in War time using the high skill of cutting what would be a buttress thread for a breech block of an artillery piece.

This magnificent picture though is much more interesting than just for the memories of The Lad. The picture is, most importantly, but also so powerful, painted in 1943 the middle of the War, shows only a one male, a single small figure in the distant background. The thunder on the Home Front had changed everything. The painting of this picture shows that the changes were so radical that they had to be recorded. It was a peak in women’s employment never reached again even today. However, almost 70 years later, girls and women do take their proper place as apprentices and professional engineers.

The dignity of Ruby and her concentration on the complex machine and work piece stands four-square with the haughty gaze of Henry VIII in Holbein’s painting. http://darkpassenger.tumblr.com/post/727152626/hans-holbein-portrait-of-henry-viii-1537  The painter was Dame Laura Knight who had, pre-war, specialised in painting dancers and circus performers. http://www.damelauraknight.com/biography.html . Though less important, The Lad believes this powerful painting is also the most accurate, realistic canvas of a rare subject – a snippet of Production Engineering. Unless, that is, someone else knows better.

There is the contained poise and tension of the lean of Ruby. It is that of a dancer yet with stillness. Countering the figure of Ruby and closely observed, are the dark, gleaming masses of the lathe: the tool post, the carriage and the tail stock. The tools are there too: a scraper to remove burrs, an internal calliper for measurement, parting–off tools and tool holders and a ring spanner for the bolts on the carriage.

Ruby is gazing intently at the spot lit tool. It is cutting the thread inside the breech ring during the very brief period as the tool passes from the side of the work piece nearest her out of the side within the rotating chuck. Her hands are not just supporting her but a part of her vital control of the machine. She rests the fingers of her left hand on the tool post to check and confirm the faint, continuous, humming vibration showing that all is well with the single point cutting tool. Her right hand performs the same check on the gearbox driving the feed screw and confirms that the carriage is moving. That same right hand was also well placed to switch off the drive to carriage and work piece in an instant when it left the inside surface of the work piece before reversing it back out in the same helical groove of the buttress thread but with a slightly deeper cut.

Now, in the Twenty First Century, a CNC Turning centre does it all more quickly, just as accurately but with less involvement of a human operator – male or female.

 

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.

Some machines swim

One, unseen, already-submerged diver was filming near to a hole in the thick ice sheet above: as the elegant cylinder dropped vertically at high speed through the still, -1°C, water below. Immediately, as though alive, the vehicle swung gracefully into level flight towing a tail of yellow cable behind it. Ministering to and checking on the machine on this, one of its early test swims, was a black-clad, scuba diver.

The Lad was transfixed by the magic sight in the vast under seascape of a thousand shades of blue and green. The voyager looked as though it had been born there instead of being designed by human beings. Tell-tale features, though, were the lights: a white searchlight beam for a camera and a pair of scarlet, laser beams lancing through the gin-clear water from each side of the nose of the vehicle. Another was the complex internal structure clearly visible with, not the fluent curves of a living body, but the lineaments of straight lines and exact circles of a densely packed machine. It was about 2m long and 20 cm in diameter.

It was the 30 November 2011 and “The Frozen Planet” Part 6, ‘The Last Frontier’ on BBC Television that was the unexpected carrier of the strikingly beautiful images of this example of the art of the engineer.

Then the vehicle darted straight ahead at least twice its previous speed into a corridor among the irregular blocks of the ice pack above. It gave an impression of a shark but without any sweep of a muscular tail but with a rapidly accelerated spin of a propeller.

The Lad was captivated and vowed to find out more of this masterpiece. A search only just begun and the results will be reported here. This machine seemed to The Lad to encapsulate what engineers do.

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.

Not in the Media

 

The movers and shakers of the media live by the word and the image: therefore they attend only to those with a rich word stock or some excited footage. Discuss.

 

The Lad is in one of his periodic bouts of surly introspection about how the world owes engineering, if not the continuous, close attention that his ego suggests, at least more frequently a proper look.

Today – a random day – triggered this when he noticed some randomly spaced topics in the press.

Eight hundred or so smartly written words are given over to a theatre director and an actor performing a version of Macbeth single handed in Gdansk, Poland. It spoke of how they both got there, the problems of the rehearsals, the highly strung performances and, finally the relief when it was all over. Deeply realistic, technical, and actorly detail there was on the struggles of the actor. The worries of the director radiated from every word.

One thousand words and five full colour images [two being full page] tell us about  a music radio station broadcasting a wide variety of pop and jazz globally from the UK. The pivot of the article is their disc jockey. Oh yes, by the way, the DJ is young ,female with long blonde hair of course.

A review noted that a book had been published of a lost novel by Jack Kerouac, “The Sea is my Brother”. He, at the age of 20, had sailed with the American merchant navy for all of three months. Hallo? The insubstantiality of this miniscule scrap of experience bearing the weight of the title and plot of a first novel claiming realism was accepted without comment.

Trying to avoid being too patronising or obnoxious, these are solemn delineations of the fine detail of transitory matters. The Lad wants to know how we get frequency of media attention devoted to the less transitory engineering.

An easy answer is that the topic is not ‘interesting’ or that such a question “tells us more about the questioner than about the world”. Too slick: we need a more thoughtful answer. It’s not “Culture” you say? But it is or at least should be when the machines and their makers shape our world or fill our field of view in some places or modify our behaviour. Another easy answer is ‘It’s boring.’ Or ‘It’s not interesting.’ This may well be true but why is it not interesting or boring? It needs to be more than an answer of better writing: provide constructive detail.

Real engineers have struggles and triumphs. They are of every technical, personal and gender stripe: there are chemical, civil, mechanical, electrical, stress and production engineers There is an end-product or sometimes a dramatic failure: a true, rich textured creation to end on.

Hell! Is it back to the rich verbosity and the exciting or excited footage?

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.

UK enters Swedish Turf

The Queen Elizabeth Prize for Engineering” certainly has a ring to it.

The Lad is glad to see the announcement of a big new prize devoted to Engineering excellence. Its aspiration to be equivalent to a Nobel Prize by being open to engineers across the globe shows admirable boldness and determination. http://www.raeng.org.uk/prizes/qeprize/default.htm http://www.bbc.co.uk/news/science-environment-15778326

Was it a problem The Lad wonders, that this global reach made it more or less difficult to raise the money from the financial backers in the engineering industry . Depends if they have a global presence themselves, he supposes. The website says they are BAE Systems, BG Group, BP, GlaxoSmithKline, Jaguar Land Rover, National Grid, Shell, Siemens, Sony, Tata Consultancy Services and Tata Steel Europe. That’s seven UK or UK based companies and four non-UK based companies.

A group of the great and the good have so far have been appointed to be Trustees to manage the endowment fund and thus deliver the Prize. The Lad is reluctant to venture into the political [with a small ‘p’] snake pit but he thought it worth having a quick look from an idiosyncratic standpoint at their engineering antecedents.  They are

Lord Browne of Madingley [Chairman of the Trustees] who seems to have started as a Physics graduate and a BP apprentice forty-four years ago. The plan seems to be that he is there to provide serious gravitas via the enormous chemical and petroleum engineering clout of his BP past.

His fellow trustees are

Sir John Parker, who studied Naval Architecture and Mechanical Engineering at the College of Technology and Queen’s University, Belfast and began as a member of a shipbuilding design team forty-seven years ago. He is chosen as, presumably, the nearest they knew in the London network to an engineering creative;

Sir Paul Nurse is a geneticist [geneticist!?] and cell biologist and won a Nobel Prize in Physiology or Medicine in 2004 and can only have been chosen to offer, one imagines, judgement on the benchmark to the Nobel standard, and

Mala Gaonkar is a Harvard economics graduate and 1996 MBA presumably will monitor the care of the endowment funds in the maw of the City.

The Government Chief Scientist, Professor Sir John Beddington is a biologist and has accepted an invitation to be an adviser. His is the task of advising the Trustees on how, when required, to screw a response out of the government departments. Sorry! Guess it would be better to say ‘how to press the hot buttons‘.

Anji Hunter, who was an history graduate 23 years ago and sometime advisor and Director of Government Relations to Tony Blair, has been appointed Director of the Prize. Because ‘administrator’ is no sort of term for an engineering outfit, can The Lad suggest that she takes to herself the title of ‘Clerk of the Works’. Now this has a good engineering flavour and a long pedigree. Nay! An ancient pedigree it has; far older than that of ‘Prime Minister’ for example. As a job, it dates back to the reign of Edward the First when such a Clerk was the vital organiser of the building of those mammoth civil engineering feats: the Castles in North Wales around 1285.

A fine group. All the men have lately spent many more long years at the stellar managerial, coal face than at the engineering design scheme. They will appoint a judging panel next year who will include additional members presumably. It will be interesting to see who they turn out to be.

He notes that all, or at least the head office, has not ventured to far from the warmth of Westminster. Carlton House Terrace,SW1, darling!

Well, even if the current staff, sorry – Trustees, do not clearly have ‘engineer‘ running right through them like seaside rock, The Lad wants to give them the benefit of any doubt and wishes them success in making the Prize a glittering success and all engineers proud of them. He will be watching them.

How will the MacRobert Award fare now?

A pinch of Chemical Engineering

A live, engineering topic in this environmentally conscious time is how to reduce the carbon footprint of the various methods of producing electrical power; coal, oil, nuclear, wind, tidal and so on.

Coal fired power stations are regarded as very polluting because an unavoidable by product of the combustion of coal is carbon dioxide. Carbon dioxide is a greenhouse gas widely regarded as bad for the environment.

There are, though, apparently still large reserves of coal globally available close to some regions with a high demand for power. For other areas further away it is economically transportable. The extraction cost is quite reasonable compared to some other sources of energy. If the emissions problem could be solved there would be some potential economic benefit if coal could be used. Thus it is that some projects are looking at ways to reduce or eliminate the problem of carbon dioxide emissions.

Diagram from http://www.co2storage.org.uk/

The whole carbon cycle including CCS

This is where the idea of Carbon Capture and Sequestration [commonly known as CCS] comes from. See the diagram above. This project, or series of alternative projects, will have many problems in addition to the engineering ones. However the engineering is what will feature in a simple way in this post. The project, as does the engineering, has two flavours although they overlap a bit: petroleum engineering and chemical engineering.

What is this CCS; what does it need to do? Whole textbooks and complete journals of technical research papers can and will be devoted to the projects. In this post we can only touch upon the first, major challenges in the simplest possible way. The Lad is using his engineering judgement and that without close experience of the problems. He apologises to the engineers struggling in the field if he does not do justice to their work. Please add your comments and enlighten us.

The carbon capture phase is one of chemical engineering whilst the sequestration draws upon much oil-drilling technology, which is petroleum engineering.

The gas fumes normally pour from the Power Station chimney as a fast-flowing mixture of carbon dioxide, CO2, and many other gases and particulates. From this we must remove the CO2. We could scrub the fumes in some fluid. Try an analogy here. You pour sugar [equivalent to the CO2] into a cup of tea [the scrubbing] and the sugar dissolves. Imagine that the sugar also bonds with the tea molecules. This is equivalent to passing the gas fumes and grabbing all the CO2 and holding it back whilst the remainder continues on. That’s easy enough with tea and sugar and not quite so easy with CO2. But that’s only the start of what the engineer has to arrange.

Now she has to get the sugar out of the tea again. That’s stripping the CO2 out again. That’s carbon capture and quite a clever trick but chemical engineers perform clever tricks all the time. Then there’s the sequestration. All you have got to do is to take the CO2 somewhere and bury it. How does this grab you? Say, drive it out to the middle of the North Sea – and The Lad means DRIVE it using a lot of power – and 10000ft down.

Think of doing all this at a rate of about 2000 tons an hour. Do it reliably and without hesitation for every hour. 24/7. This is for 1000tons of coal per hour, taking from the atmosphere and binding to a similar amount of oxygen. This is for one power station alone. There are, of course, other power stations.

Engineers have faced bigger problems. Not many, The Lad admits, but some. Think of Nuclear Power Stations, big bridges, rockets to the Moon and back, and tunnels. Your modern group of engineers on being presented with this project will smile slowly. “OK.” they’ll say, “Let us at it” They are facing their old enemy: the forces of nature in several of their myriad forms. They have to overcome forces to pull the CO2 out of the flue gas. Then overcome those forces again to pull the CO2 back out again after the stripping process. Then they have to force again the CO2underground into the tiny pores in some rock.

Stripping is taking a lot of power to achieve. Problem one is to need to use less power than the Power Station is generating. The Lad supposes that that’s obvious enough. Well, obvious or not it does not make it easy to achieve. If it takes a lot of power to do, maybe they will try to find a catalyst to reduce the required power. In many chemical processes where compounds interact beneficially it may, naturally, proceed quite slowly. However, some chemical compounds speed up the process solely by their presence and, by the end of the process, are still present and unchanged. You could regard such catalysts as being a form of lubrication of the process. There is a catalyst in your car doing a similar job to clean up your exhaust [but not CO2]. And that is platinum or something similarly expensive.

The Lad is willing to bet about another of the problems. Problem two is, he is willing to bet, the process will need high pressure to work. The engineer tries to design such chemical plant out of steel because it is less expensive than most other materials. So add to that, Problem three. CO2 frequently morphs into carbonic acid which is nasty and corrosive to most steels. Unless you take great care in designing your plant pressure vessels and piping, this is like taking a pin to a balloon.

Most of the mentions in the media so far have told me only that sequestration consists of putting the carbon into porous rock underground. There is nothing on the carbon capture phase of the process. The media do not have engineers, you see. They do not understand much of the problem. Correction, they do not understand any of the problem.

One Bing ref is
http://www.wri.org/project/carbon-capture-sequestration

This is from ‘World Resources Institute, a US based ‘thinktank’. They claim that they are independent. The WRI first  video mainly [most of the 5 min video – but not all] speaks of the injection process, not of the capture and sequestration processes and any difficulties thereof.

Of course another is
http://en.wikipedia.org/wiki/Carbon_capture_and_storage#United_Kingdom

Also project funded partly by EU and many other Big Oil and other companies, called CO2Remove. Link to this is [could not link to this – try again later!!!!]

CO2 REMOVE
is a 5 yr study project funded by the European Commission under the Sixth Framework Programme

http://www.co2remove.eu/

This study project is coming to an end with a Feb 2012conference in France.

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.

 

 

 

 

Ignorance, quarrels and the feedback loop

Or people shouting at each other

Some commentators are a constant irritation. The grand panorama of modern media allows any ideology by any believer to be broadcast. This is a complex world and some have little underpinning of demonstrable truth and others have an unwavering fixation upon only one of several alternative world views.

There are those who advocate a particular belief system. Some such are militant proselytisers for religious beliefs. Others are those, finding the world behaving incorrectly, setting out to drive everyone down the ‘correct’, usually narrow, path

Then there are those who are driven less by unwavering urgency and more by a plan to make a comfortable living from the commentating process. They have a facility with words; access to the prints; and no restraint from knowledge of their ignorance. They do like the sound of their own voice and their words in print are, for them, like a nice, warm bath.

These latter, articulate writers are insidious in their effects when they comment on engineering topics. None are engineers and many are politicians. Too often it is here that the irritation develops due to a faulty premise.

Faulty premise.             If some project is not yet completed then it is obvious that it cannot be done or will be too difficult.

This premise is applied widely but has appeared in connection with safe burial of nuclear waste and, more recently, Carbon Capture and Sequestration.

Forsaking the phrase “Let us be clear that….” destroyed by politician when matters are obscure or untrue, let us go for a bald statement instead.

Correct premise.           Engineers create something when it is needed and has some apparent economic basis. If a project does not violate one of the laws of physics or thermodynamics, it can probably be done.

If you ask them in advance, engineers will take the line boldly, and not unreasonably in the evidence of the historical record, that if a project does not violate one of the laws of physics or thermodynamics, it can probably be done.

What is it that inflames this irritation by lathered ideologues or flushed commentators? There is heat when each holds forth in isolation. But it is the process of interaction with each other that increases the din greatly due to the engineering effects of positive feedback and synergy.

Feedback is a widespread and important operation in control engineering. Feedback is the process of measuring changes in a process as it proceeds. There is negative and positive feedback. Negative is changing a process to reduce the measured change. Positive feedback is changing the process to increase the size of the measured change. A problematic feature of positive feedback is that it is frequently unstable sending a process rocketing to some far off regime. Thus it is with the irritating commentators.

There is also synergy which is defined as increased effects produced by combined action. Working together, even if it is in opposition, means that both sides of an argument work each other up to a frenzy.

There is a interesting example roaring away in the field of climate change where all these features can be seen. There are a multitude of websites. Just visit one of each and you will be rapidly flung into many others There is Greenpeace of course at http://www.greenpeace.org/international/en/campaigns/climate-change/science/ for those who discuss how worrying are the changes and what should be done to reduce them. Then there is another, The Global Warming Policy Foundation http://www.thegwpf.org/ , that believes that climate change is not what it appears and that many plans to modify the changes are misbegotten.

Speaking above of Carbon Capture and Sequestration, this is a topic of the next post.

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.

A step in the long road.

Give thanks to the Sunday Times in the 23 October 2011 issue, or more especially Joe Watson of Swansea, for a letter that moves a little way down the road. That is the road to an understanding of engineering reality by the general public and those thinking about choosing a career.

Mr Watson rightly chides a previous writer for suggesting that engineering is a manual job. His own definition of the properties of an engineer is hard to better. The engineer is a ‘graduate who has competence in physics, mathematics, IT and design – to mention a few’. This is not true of the tradesmen or women who are the artisans. While this tells us what they are, and is fine as far as it goes, it does not tell us what the engineer actually does. But, fair do’s, it is progress.

Why, though, is such a simple definition still necessary in the modern world? Think about this. The distinctions between patients, doctors and nurses and even finer graduations such as Registrar or consultant seem to be quite clear to everyone. The Police uniformed branches and its sub-branches compared to the detectives are well-known. Is it because each of those professions is the subject of a vast number of programmes on television? Is that the reason: people learn through the TV stories?

The Lad will not support this as he does not want to encourage the already over-mighty, super-confident denizens of that medium. No, the ignorance is more likely to be because the general public does not normally come into any contact with engineers in person or read about them. Yet, for goodness’ sake, they come into contact with their products every hour of every day. Perhaps this blog will add a few bricks so that the profession rises into view a little more.

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.

Get it right on Site

Something has come up. It means that we must re-visit the post on the old and new diggers.

The trigger for this was the comparison drawn by The Lad between the old, 1935 Quarry Shovel and one modern machine that JCB, its maker, calls a Tracked Shovel. The Lad is not a student specifically of heavy earth movers so he made a couple of assumptions as he wrote the post. One assumption was that if a particular design was in a museum; it no longer, shall we say, appeared in the wild. The second assumption was that a large manufacturer of current modern earth movers will produce all the different types.

A little further browsing soon showed both to be in error. Caterpillar Inc is a very large, US based company specialising in Mining equipment. Its catalogue soon revealed to the surprised gaze of The Lad the error of assuming that the Museum machine had become extinct. There were some machines they now called Electric Rope Shovels. Here are some pictures that you can find along with much more data at https://mining.cat.com/cda/layout?m=435120 .

The smallest of this type of Caterpillar machine

 

The Big Brother of the Caterpillar family

This machine handles 90tons

 

 

Look familiar? Apart from the trebling or even quadrupling in size [note the size of the control cabins in all three and the access stairway in the third machine], these modern machines are still of the same design or general architecture as The Abbey Pumping Station Museum Steam Navvy. The increase in size of these modern machines brings with it a major increase in strength. The machine in the first image above is the smallest of the range and the load capacity of the dipper is 20 tonnes whilst that in the third image is the largest and its payload is a mere 120 tons. The latter machine itself weighs in at well over 1000 tons.

The market for such machines across the globe is probably not large and so accounts for the second assumption of the previous post being in error as such an enthusiastically commercial company as JCB declines to make such machines. Engineers still have to operate and try to turn an honest profit in the global marketplace.

The engineering aspects of the replacement of steam with hydraulic rams for machines of the size of the Ruston Bucyrus Quarry Shovel of 1935 is, however, still absolutely true. But there is more to it than that. First of all we have to be clear that those two machines – old and new – were not designed for the same objectives.

It is surpassingly vital that, in whatever project the engineer is pursuing, she is very clear as to her objectives. It frequently needs a lot of effort to get them right. If they are not right then the project can fail altogether or at least be mired in confusion. If there is neither of those two outcomes, it may become too expensive for what it does. In this latter case a good piece of jargon is to be ‘not cost-effective’. This piece of jargon was introduced by Robert McNamara, once of CEO of the Ford Motor Co in the US, and later Secretary of Defence for President Kennedy. He attempted to bring a scientific approach to Defence procurement and thus had a considerable effect on President Eisenhower’s military-industrial complex, the US Defence industry] http://en.wikipedia.org/wiki/Robert_McNamara ,
http://www.chomsky.info/books/warfare01.htm .

However, The Lad is getting side-tracked again: let us return to the diggings.

The old machine reigned in quarries and opencast mines. It had as its objective the removal of large quantities of the ore which is the stuff that you want – pay dirt. Or, first, the overburden, which is the dirt or rock covering the ore.

The new Tracked Excavator has as its main design objectives a somewhat different type of task. It is to carry out landscaping [shall we say – engineering of the shape of an area of land] or carving out trenches. Its workplace is the brown or green-field of a building site; the route of a new road. That is not to say that it cannot turn its hand to removing ore or overburden it is just that it is not designed exclusively for this task.

The modern Electric Rope Shovel also has as its home the quarry and open-cast mine although many of these are now much larger than they used to be in the first half of the Twentieth Century. This, of course is the driver of the design of the modern Cat machines. Why do they not use hydraulic rams? There will be a limit to the operationally effective length of a hydraulic ram due to its method of manufacture. The Lad does not know for certain, but he suspects that it is limited by the size of grinding machines for the bores and rods of the ram. [Perhaps someone will comment and correct him if necessary.] If the machine design needs to exceed that limit, then other methods have to be used or, perhaps in this case, sticking with the old ones. The Lad believes that the geometry of the jibs and big machines required rams too long for effective manufacture and the pull of cables became a good principle to retain. With the use of cables, the original architecture was not easily bettered.

Then there is the ‘electric’ of the title Electric Rope Shovel. It is electric powered too. The prime mover is not mounted on board and lugged around. It is firmly ground based somewhere in the mine. It will be large, heavy – and efficient – power generator. Power is supplied to the Shovel by cable.

Beware as an engineer of assumptions. The Lad does not say that in the day-to-day engineering assumptions will never be made. Sometimes to allow the job to proceed, they have to be made. Just make sure that they are robust. Then, never let the assumptions drift on as correct; check their correctness properly as soon as possible.

Caterpillar Inc has just this year completed a takeover of another earthmoving machine firm. It was that firm, not Caterpillar Inc, which designed this giant Shovel. The name of that other firm was? Bucyrus. Does the name ring a bell? It is the US company that licensed the UK firm Ruston in the 1930’s to build the 52B Steam Quarry Shovel.

Engineering is one of the three drivers in the advancement of the human race. This blog aims to give to career seekers and also to the general public a taste of how this might be so. They are not well served by the current media. It is an engineer posting: not a ‘scientist’. It describes real professional engineering as it is in the real world usually in the present and occasionally as it was in the recent past.