Isambard's Lad | The sun shines out of the Engineers

DIY Fusion Design 101?

Can’t touch! Won’t touch!

If you can’t touch it, how are you going to use it?

BBC had a piece in early August 2013 on ITER or the International Thermo-nuclear Experimental Reactor. This is the new, globally international project, similar in size to CERN based in the south of France, to develop fusion power.

OK. Let’s assume that we can get fusion to work for a useful period. How are we going to get the [expletive deleted] energy out?

Are you listening to me, ITER? Course they aren’t. Engineers and scientists have been working on the myriad problems for more that 50yrs. They don’t need the help of The Lad. But some students, general public and certainly the meejah might.

Here’s an engineer, The Lad, putting his head on the block. He is venturing into an engineering place in which he has no specific expertise: no change there then. He just thinks in general terms of engineering forces. At least this is more than do most bloggers and general media. Remember, it is the working with physical forces that defines an engineer.

Fusion will only occur at temperatures that transform anything into stellar plasma. That includes ANY solid structure trying to contain it. Such energy by transmission of heat, in quantities difficult to imagine, will sublime any structure that it contacts.

Here is what happens now for most of today’s prime movers. There are several heat sources in current use; such as oil, gas, coal, wood and nuclear fission. This heat source drives the heat energy by conduction; moving energy by interaction between atomic particles. The energy passes through a pipe wall so as to heat water or gas or some other intermediary. This expands and drives a turbine or piston engine or hurtles out of the back of a jet engine generating a useful reaction.

OK. It’s currently impossibly difficult to get fusion to stay ‘alight’ for more than split seconds [or am I already out-of-date?]. Anyway that is the reason for the €billions being spent on ITER. If we assume that we will be able to improve on this; what then?

Now we need to get the energy out.

If we try to drive the energy though a pipe wall by conduction from a fusion plasma cloud, the pipe will melt it in a millisecond or less. So – not conduction then.

In boilers, both domestic kettles and Drax power station plant, they use conduction. Here bulk gas or liquid move themselves as well as their energy. Both bubbles and hot water rise because they are less dense than the surrounding water. This leads to mixing and heat transfer; producing steam for turbines driving the generators. Thanks, Archimedes. It so happens that this is also the way that radiators [a misnomer: they would be better called ‘convectors’] warm a room in a house.

Sorry, we cannot use convection. Why? Precisely because plasma is carefully arranged to be closely contained in a doughnut-shaped, Magnetic Bottle [part of a Tokamak machine]. This is a magnetic field that is designed precisely to stop the searing plasma from churning about where it is not wanted, i.e. touching anything solid.

What can be done? The Lad thought that he was asking a very difficult question. But then, it transpires, not so much. He remembered that engineers recognise three standard ways to transfer heat energy: conduction, convection and radiation.

heat transfer in the kitchen — Heat Transfer in the kitchen (c) Hilary Morgan

So if it can’t be conduction or convection what have we left? It must be radiation where heat energy is transmitted like light or radio. This is how warmth from the Great Fusion Reactor in the Sky [as Alan Partridge might refer to, of course, the Sun] gets transferred to us on Earth. There will be a ridiculously intense, thermal heat flux. Not only that though, there will be an equally ridiculous flux of nuclear radiation that will, itself, hammer at the structural integrity of the whole machine.

For ITER there is quite and impressive technical illustration here. Not a drawing,note: it’s an illustration so a lot can change.

While everybody that The Lad has seen talking about ‘limitless fusion power’ speaks of the fusion reactor generating the power, nobody seems to talk about getting out for our use. It seems to The Lad, radiation it has to be. But in detail how is quite another question. It is an equally giant problem. After all solar panels or black radiation absorbers on the roof of your house won’t hack it.

But don’t worry. Let the scientists get the physics of fusion and plasma nailed down and you can rely on the engineers to turn it into Power Stations for the benefit of us all.

Only three ways …

Oh yes – from the last post, who is this Sir John Rose?

He stood down from RR at the top of his game in a blaze of glory in March 2011 after having been with the firm from 1984 and Chief Executive from 1996.

He is one of a small group at the top of Rolls-Royce plc who, over the last couple of decades have transformed the engineering company. It has changed by expanding its product ranges, entering new markets whilst retaining a global reputation and financial strength.

Sir John Rose - Captain of Industry — Sir John Rose – Captain of Industry

The striking thing, at least to The Lad, is that he was apparently not trained as a professional engineer. The Daily Telegraph newspaper related that, born in Africa, he came to Scotland gaining an MA in psychology; it is not clear whether that was the subject of his first degree. Then he went into banking of all things. Eventually he fetched up in 1984 at RR.

On his watch, the achievements have been spectacular. Clock this! At the end of 2010 The Daily Telegraph told us that

“In 1995 – the last full year before Sir John Rose became chief executive – the company’s order book was worth £7.6bn. Today it is worth £58.3bn”

“Rolls-Royce’s figures speak for themselves. In 1995 – the last full year before Sir John became chief executive – the company’s order book was worth £7.6bn. Today it is worth £58.3bn. Revenue in 1995 was £3.6bn, today it is £10.1bn and is expected to double in the next decade. In 1995 profit was £175m compared to £915m today. Since 1996 the company’s share price has increased from 188p to 603.5p.”

Note that in mid 2013, that share price has doubled again. This is in global engineering.

His speech to the RSA offered a striking insight. He said:

“ … there are only three ways to create wealth – you can dig it up, grow it or convert something in order to add value. Anything else is just moving it about.”

That thought floodlights the churning in the modern, economic world: much of which is as useful to UK prosperity as the driven fluff. There was much more: it was a fabulous fighting speech. Read it and run with it.

The Lad found it striking but significant that in all the video footage of the speech he found on the net, the beginning has been cropped and only starts at the paragraph that has the first mention of “… politicians, economists and commentators …”. Good Grief, so many of the media only twitch or open their eyes when these people are mentioned.

There are other points about John Rose’s term as CEO of Rolls-Royce plc. On his watch the preferred principle of commerce with airlines changed and the RR business model changed with it – for the better.

Engine makers, during most of the Twentieth Century, sold their machines to the aircraft makers and, in the aircraft, on to the airlines. The airlines had their own engineers to maintain the engines, repair them as necessary and to buy new engines when they reached the end of the engine life. All this is a continuous, organisational, burden for the airlines. This approach was replaced by a new model: “Power by the Hour”. In effect the engine maker promised that he would take the full responsibility to provide the necessary power in the aircraft.

It is not clear whose idea “Power by the Hour” was originally but certainly it came to full, Roll-Royce flower under his leadership. It lead to increased engineering design emphasis on reliability and easier maintenance now that it affected the RR financial performance directly instead of being sloughed off onto the airline. The Lad is reminded of a saying that probably dates back to Henry Ford “An engineer does for 50c what any fool does for a dollar”.

It was a win-win result. The airlines were more comfortable with a cash outflow that did not vary [accountants do not like uncertainty] and, as a result, RR got more engine orders and its financial turnover grew massively.

He likes less what an accountant once told him. An engineering business [or any business for that matter] is merely a process linking buying money cheap and selling it dear. In the heat of recent financial meltdowns, that seems to be too abstract, ungrounded and risky.

All this is engineering too.

Engineering is one of the three drivers advancing the human race. This blog describes professional engineering in the real world as it is not well served by the current media. An engineer is posting: not a ‘scientist’. Its target is the career seeker and also the general public.

Metals and knowledge is not enough.

Engineers need more than metals and knowledge to benefit the world. There is something else.

In late July, 2013 Rolls-Royce sounded a fanfare. In the previous six months the engineering company had made sales of £7.3billion. That’s nearly £40 million of stuff and services sold per day.

Over the same time you’ll be pleased to hear, the organisation made a profit. This was £840 million, or £4.5 million per day

They were very pleased about these numbers as each was an increase of around 30% compared to the previous half year.

The customers seemed to be pleased enough too because they had signed on the dotted line for more stuff and services in the future at a total price of £69 billion.

Now you don’t run that sort of operation with a few guys in a shed out the back and some cash in hand. Such an operating company needs to buy stuff, pay 40 000 staff and pay for continuous research. These costs go up and down with time as does the sales income and they won’t be in phase.

You will have guessed by now that the extra ingredient needed is – Money. ‘Shed-loads’ of it. Although I haven’t worked it out, it will be more like ‘sports-stadium-loads’ of it.

At around the same time as those numbers were announced, the market had invested in Rolls-Royce some £22.5 billion. Only Big Pharma and Big Oil are in the same UK league intellectually and financially.

Very few enterprises can be successful using only the funds of an individual engineer. Isambard Kingdom Brunel knew all about this when he was building railways and giant steam ships. Brunel University tells how “Indeed he … suffered financially by supporting his ventures with his own money.”

This is a fact for every engineering firm in the capitalist economies: they all need money or capital to operate on the large and economical scale. Hence the name: ‘capitalist economy’. Usually money comes by way of the firm borrowing it from people who expect to get a bit extra back or by generating its own wealth by holding back some of the profits made.

Not all need as much as Rolls-Royce; smaller firms need less.

All this is engineering too. Sir John Rose knew all about that.

Systems and their Safety

Almost any piece of engineering is more complicated than it appears to the untutored eye. That is as true of a single component as it is of a complex system.

Whereas the engineer may discover ways for a component not to perform as she designed it, it is also vital that a system be studied with its many components interacting. The engineer may find that, in a system, every component may behave perfectly in itself yet still those components interacting may give problems.

System engineering is is an important subject and many engineers wrestle with and study the performance of complete or partial systems. It is very difficult too.

It is a fact of simple statistics that many components interacting offer many, many possible combinations of ways to go wrong or just not perform as planned. That also means that it is so very easy to imagine what it is that is giving the problem. Beware of getting fixed on such an idea: for it can just as easy for it to be wrong.

The Lad’s car was losing water, but only a certain volume – not all of it. Then there was the strange bubbling in the coolant tank. On hearing this, the garage mechanic said that’s probably a leaking header tank; that model is prone to it. OK, some things now seemed to hang together. The garage ordered a new header tank. Took a few days as it had to come from abroad. That with the labour costs as well took it to about £150. Drove off. System still leaked.

Then we looked – instead of making such an easy, unexamined assumption. It wasn’t the header tank. It was the radiator. Ooooohhh Noooo. Not one our finest moments – not the way an engineer should do it. The seemingly significant point that not all the coolant disappeared – but only a certain amount – was not significant at all. Only a little disappeared because we were checking frequently – it would all go eventually. Radiator replaced and problem solved!

Comet 1 nose — Comet 1 – The face of triumph and tragedy.

On a much more serious level but many years ago, was the Comet crash problem. When one crashed losing many lives, they held an enquiry. Wreckage was inaccessible at the bottom of the Mediterranean. The designers developed several ideas for the possible cause and designed ways to put each right. The Abell Committee concluded that:

“Although no definite reason for the accident has been established, modifications are being embodied to cover every possibility that imagination has suggested as a likely cause of the disaster. When these modifications are completed and have been satisfactorily flight tested, the Board sees no reason why passenger services should not be resumed.'”

The Air Safety Board concluded that:

It realises that no cause has yet been found that would satisfactorily account for the Elba disaster…… Nevertheless, the Board realises that everything humanly possible has been done to ensure that the desired standard of safety shall be maintained. This being so, the Board sees no justification for imposing special restrictions on Comet aircraft.

Sixteen days later another Comet crashed in the Mediterranean taking with it all the passengers and crew. There was fatigue failure between two openings in the top of the fuselage that had not been considered.

The authorities did not know what the cause of the first accident was but let the aircraft fly again with passengers. Hindsight is a marvellous thing but The Lad believes that the authorities should only allow an aircraft to fly after a crash

WHEN THEY KNOW THE CAUSE AND THAT THE PROBLEM IS PUT RIGHT

Is this too strong? Do the current Regulators follow this principle?

An Essence of Engineering

A small machine needs a continuous supply of oxygen. Chemistry is too complex. Why not pull it from the air all around us. No shortage of raw material.

Chemists tell engineers about adsorption [see diagram] Note though, that our process b) is gas to solid not liquid to solid as shown Nitrogen gas clings to some fine powders. Pass air over the powder; nitrogen is trapped and out comes pretty pure oxygen.

But there is a problem, so the engineer comes up with a clever solution that is not science but quintessential engineering.

Concentrated oxygen gas is needed for many uses in the modern world. Industrial processes such as steel making, engineering cutting, medicine and others need vast tonnages of the stuff. Modern steel production needs oxygen by the tonne; as do many large-scale chemical processes.

This school chemistry toy process of potassium chlorate or hydrogen peroxide is not going to give that. Engineers use cryogenic air separation to extract it from the air. For this, in simple terms, air is cooled down till it is a liquid and then very carefully allowed to warm up and at-196C [if it is at atmospheric pressure] the nitrogen boils off leaving, the liquid oxygen (which boils at -183C) behind

On a slightly smaller scale it is needed for oxy-acetylene cutting torches and supplies for whole hospitals. Here, although still produced cryogenically, it is distributed to customers in enormously heavy, forged steel bottles.

On a smaller scale still, many people with breathing problems need extra oxygen to live. They need pure oxygen all the time in a form that they can breathe. Sometimes, for use by one person it comes in quite small bottles say only about 20cm long but, even so, it is still quite heavy to carry for any length of time.

Similarly, extra oxygen is needed to keep the transplant liver of the recent post alive throughout its journey, be that 2 hrs or 30 hrs. Machine portability also meant low weight was very important. Doing it cryogenically would be too heavy and power hungry.

The answer for the engineer was an oxygen concentrator using adsorption.

The fine powders have an enormous surface area for the gas to cling. But air contains a staggeringly large number of nitrogen atoms. When the area is coated by nitrogen, more nitrogen passes through and contaminates the oxygen stream. It must be regenerated to free the old nitrogen.

But for an hour of oxygen, chemists tell us we will need an enormous heap of powder. This is possibly acceptable in a large plant with room for a big machine: but not for continuous oxygen for a liver transplant machine or an ill person to carry.

This brings us to the crux of the problem. Either we arrange a heavy container of a very large quantity of powder to give us long life before oxygen supply stops for regeneration. Or we have a small light container of powder that has a short life before oxygen supply stops for regeneration. Apparent stalemate.

The engineer’s insight was to use two very small containers at the same time. Air is pumped through the first container of zeolite powder until the powder is saturated and nitrogen comes through. So we stop using the first and start pushing air through the second. While the second is doing its job, the pressure in the first is dropped and the powder regenerates by releasing the nitrogen it has adsorbed. Then when the second is saturated, the first is now ready to take over and the second can regenerate.

So it is that small, light containers can produce a continuous supply of oxygen. Here is a good graphic. Now that’s engineering!

Without going into a lot of detail, absorption is that to absorb one substance within another. An example is of sugar being absorbed into a cup of coffee and being very difficult to separate again. Adsorption, on the other hand, is where one substance clings, fairly lightly, to the surfaces of another. Some say that, although not seen by The Lad, if a cube of pressed carbon powder is dropped into a glass of dyed water the colour will be removed as the dye clings to the surfaces of the carbon powder. But, crucially, this process can be relatively easily reversed: vigorously shake the glass of water and carbon and the colour will return to the water. This is regeneration.

Beyond the boiler suit.

The Lad saw an excellent article in The Guardian on 27/6/13 on encouraging women into engineering. He liked it so much that he stole part of its sub-head for this post title. He hopes that the writer, Oliver Wainwright, or his paper do not mind: that – and the quotes below. Such golden words and the nous to report them should be broadcast far and wide.

Just as woman are rare in engineering so is a good article on the topic by an Architecture and Design Critic; which is Oliver’s present task. He has found these engineers and their views.

As a water engineer for the great consultants, Arup, Ms Yewnde Akinola won the Young Woman Engineer of the Year award last year. The Lad lauds her for hitting the nail on the head. She said,

“…the job [engineering] is all about design, creativity and innovation”. She had already said “…when you’re at school it’s difficult to see that there’s anything beyond hammers and metalwork and boilersuits…. She made a cracking suggestion “…let them go see JLS and think about how the stage, lighting and sound engineering works.”

Putting a slightly different slant, Ms Roma Agrawal is Structural engineer at WSP who worked on the Shard. She is involved in university and schools programmes trying to change the perceptions of the industry. Her point was also equally important; “A lot of people still think it’s all about sitting on the computer doing really hard maths all day. But most of my time is spent on creative problem solving – drawing and sketching out ideas.”

The Lad cannot better that in such a few words; so he won’t try. He will, if he can reach them, invite both Ms Akinola and Ms Agrawal to guest post on their speciality.

The Name of the Engineer

At the back of many of these posts lurks the definition as well as the name of the engineer. From the earliest posts to the more recent , The Lad implies a definition of what makes an engineer and what does not .

The core is that the engineer works with the various forces that exist in nature to turn them to the advantage of all humanity. At first, the ‘forces’ aspect seemed to be sufficient. Then recently he saw a newspaper [what else?] carry a picture of roustabouts on an oil platform and called them engineers. It is clear that they are vital workers, but, although central to the oil industry and estimable for their herculean work in terrible conditions, to all except the media they are not engineers.

From the newspaper — Such proud men probably do not call themselves ‘engineers’.

Why not? For aren’t they are wrestling with those natural forces in the massive rig and drill steelwork and the weather? Not half! Something similar can also be used to promote car mechanics to the ranks of engineers. A spanner and a hydraulic car lift certainly consist of natural forces, don’t they? They surely do.

The definition of the engineer, as The Lad knows her, needs to reflect how the roustabout and the mechanic are not engineers.

The mechanic and the roustabout do not design the equipment on which they work. This is the crucial difference.

The posts also implied that the benefit ought to be to all humankind. There are two difficulties here. One is to ask who knows whether an engineering artefact is really a benefit to all or only to some and also whether, in the long or medium term, it could damage. The other is that the engineering may be of benefit to some that are not of humankind. Think of a salmon ladder in civil hydraulic works or modern enclosures in a zoo.

Let us leave out Humankind. Let it stand as ‘benefit’ with the implication of ‘as best we know and can’.

So! Here we have it.

Update, June 22, 2013 – Realised that essential Production Engineering is not subsumed in the definition. To clear this most succinctly, the word ‘forming’ is added

Engineering directs for benefit any or all of the processes of imaginative conception, design definition, forming or analysis of devices or structures that use any of the forces acting in the universe.

3D Printing – Gift or the End of the World?

3D printing is appearing more and more often in the media. Admittedly, it is mostly in the more excitable screeds, but nonetheless a lot of people see it as a game changer. But then they would: writing about it makes media content to sell. A more technical name is stereo-lithography. This gives a clue as to how the idea works. It is like printing slightly different images on successive sheets of paper from your printer. Cut out each image and stack them up and glue them together and, lo, you eventually get a solid shape.

This is how the 3D process works. Image thanks to Materialgeeza.

Some internet enthusiasts claim that it will let anyone make anything and everything in their office or even their bedroom. “Buy nothing ever again: just copy it from the internet.” They are apparently almost wetting themselves in their excitement.

Others on the other side of the divide forecast the end of the world as we know it. Anyone will be able to make guns from freely available data files from the internet. Horrors! Even that device has to have at least one metal part – the firing pin. Made from a nail, since you ask. The Lad would be wary of going near to such a weapon being used, let alone lifting it near to his head and firing it at someone Wouldn’t you be wary of it exploding into a myriad pieces like an old blunderbuss? Or even one part splitting under the propellant forces, taking your face with it.

The fact that 3D printers currently cost a fortune and are large is the central problem at present. This may not always be the case though; they may follow the same path as computers whose prices dropped like a stone over the years. The picture is of a simple machine.

This is a simple version of a 3D printer. Image thanks to Bart Dring

Actually the idea has its uses now. No doubt more will appear in time. Because it is expensive and fairly slow and available only in a small range of not very capable or strong materials, its main use is to produce models of hardware straight from CAD designs on the computer. Prototyping it’s called: making model parts without complex machining set-ups.

OK. Let’s get down to the nitty-gritty-the essentials. Yes, it’s engineering again. It’s all about the material of the parts. How much of your world is made of plastic. Yes, quite a lot but nowhere near everything. Even in your computer, the heart of the nerd’s world, much is made of metal especially the strong, structural parts and the electrically-conducting parts. Most load-bearing things everywhere are metal. Of those that are not, the majority are composite materials; not yet possible stereographically. Also, see the gun firing pin mentioned above. Many of those metal parts have to be heat treated too to give them enough strength.

The Lad’s view is that it is likely that the process will be a nine-day wonder like fluidics. What is fluidics? A previous erstwhile Great New Technology that came to very little. Ask any engineer active in the Sixties.

OK, wait for The Lad to be proved wrong.

What the Engineers did next.

Engineering saving lives Part 2

The last post told how customers, scientists and engineers interact. This is the story of the engineer.

The surgeon and the scientist asked the design engineers, Team Consulting, to design and make a machine to do the job in the real world. This was to become the OrganOx® metra™. The finances meant the prototype must be operating in 9 months.

Gen Arrgt — One of the Engineering drawings would have looked like this, but without colour. ©Team Consulting

Stuart Kay, Project Manager, led the engineers’ design team. There was a lot to learn about the problem.

“[The customer] had some outline user and product requirements,” Stuart told The Lad. “ and knew what the basic fluid circuit needed to be like, there were a lot of verifiable requirements that needed to be un-earthed in order to ensure that [the customer and designers] had a common understanding of the end goal.”

To avoid problems later the Project Manager always writes a Design Specification. This records all the many dimensions, operating features and power requirements.

In existing transplant technology, the liver sits at 4˚C without nutrition or oxygenation for up to 12hrs. Some livers have features that mean, although they are otherwise perfectly usable, they cannot be cooled like that and still be re-used. Cooling can itself sometimes damage a healthy liver; and, during its journey, certainly no one can tell how well it is surviving.

The new technology keeps the liver at body-heat, ‘feeds’ it and supplies it with oxygen. This alows more livers to be usable; they last for up to twice as long and can be checked for survival during the journey. In simple terms, the plan is to keep the liver beavering away outside the body doing what livers do inside the body, while it was being moved. That way we can even measure that it is doing a digestive job properly.

Any design of a machine using body fluids has special problems. Blood can clot on surfaces or be damaged in a pump. Everything must be kept absolutely sterile. These problems are not new though: some have been overcome before by designers of heart-lung and dialysis machines. So they save time and money by using existing, proven pumps, valves and pipework. All wetted parts are single use and disposable to keep everything sterile.

The blood circulating has to have quite a lot of oxygen as it is used up by the liver. Normal, steel, bottles of compressed oxygen are too heavy. What’s to do? Extract it from the air as we go along-that’s what. The existing, brilliant, engineering idea of a Concentrator leads to a much lighter assembly. That will be another post soon.

The machine has to feed, preserve and monitor the health of the liver. Firstly, there is the rather beefy power for the pumps and heater; and, secondly, the delicate listening and sampling systems checking the performance of the liver. The electronic system engineers have to take great design care that the great, bouncy, power supply does not electronically deafen and interfere with the sensors.

Prototype machine almost complete — The whole machine but without its wheels. © Team Consulting.

Then there is the system engineering. The engineer cannot just plan to have all the components bolted together. She has to think clearly and deeply about how to get them to work together. Standard parts may need ‘tuning’. As a very simple example, think of a system full of liquid that has a standard temperature-measuring switch for a standard heater. If that system contains a transplant organ, a simple switch off at the right temperature could result the organ temperature overshooting or undershooting. The engineer may have to arrange always to switch off a little ‘early’ or a little ‘late’. Only this way can the possibility of damage to the transplant organ be avoided.

Liver box — This is the container that actually carries the liver. © Team Consulting.

This kit does not sit lazily in a laboratory; it has got to be moved safely from hospital to hospital. There must be not the slightest damage either to the system or the payload. It all has to fit into one trolley with a protective shell. They designed an elegant transport and protection frame which is lowered into a neat, tubular chassis with castors.

Travelling in Hospital — Machine [without the transport shell] travelling to or from theatre. © OrganOx.

There are other functions too. The hospital technicians need to boot the machine simply and absolutely reliably. There are several possible power supplies: on-board battery or a 12v vehicle power supply or by hospital mains power. Clinicians can monitor an on-board screen continuously for pressures, flows, temperature, blood gases, and pH and bile production?

The designer has to decide how best to manufacture machine parts, and, vitally, how the technicians can service the machine to high standards. As Stuart wrote to The Lad, “The only way to achieve this is with a dedicated and highly skilled engineering and design team, and we had one. We hit the 9 months target, and the system worked beautifully.”

All in all, this is a marvellous piece of engineering. If this stuff appeals, remember that you, female or male, could join such a team.

The Lad is grateful to Stuart Kay, Project Manager and Team Consulting for their informative help. Top notch engineers.

Engineers and Scientists

Engineering saving lives Part 1

first picture — New Liver Transplant preservation and transport machine. Copyright Team Consulting

The OrganOx ® metra™ project is a story of real engineering. This post is about how it nicely shows the distinction between customer and scientists and engineers. For The Lad this is not a new topic, here and here, to the point of perhaps tub-thumping tedium. So, he will keep it brief this time. The next post will talk about the OrganOx® metra™ engineering in more detail.

There was a customer, a liver transplant surgeon. His field, Medicine, is one of the three that form the Tripod of Civilisation .He has developed his skills using existing technology. He knows that he could save many more lives of gravely ill patients, if only more livers were suitable for transplant. More livers are potentially available but some are damaged during their chilling for preservation and others have minor features that prevent them from being chilled. Because of this there is a great shortfall between usable livers and the demand for transplants. He and his colleagues could do so much more!

Every year improving transplant technology increases the demand for the operation and the need for donor organs goes up. To save more lives we must make best use of all available organs: we cannot afford to reject possible donor organs for non-physiological reasons. Neither can distance between the donor and the recipient be allowed to be a problem.

“Why not,” he suggests “try to preserve livers warm instead of chilling them??

The scientist agrees with him. He says,

“Yes. Why not? But there is a lot we don’t know. We need answers first. It will be, in effect, keeping it alive and working outside the body.”

He investigates. He asks questions about the behaviour of such organs and carries out the experiments that will answer those questions. The work concerns the temperatures and pressures and chemistry of a warming process. These, at length, confirm that the ideas of the surgeon are possible. Now we come to the rub. These features have to be set up in the real world every time that they are needed. Only then can more lives be saved. But how?

Every time there is success: then a life is saved. Should there be a failure then a life will be lost or, at best, be left on a knife edge again. You cannot just drop a liver in a glass jar and carry it to the recipient. The surgeon and the scientist turned to the engineers.

“We have had these ideas. Can you design and make something using them in the real world?”

The engineers know that it is very difficult to design a machine that works reliably, in what is virtually a life-critical situation, day-to-day in a hospital. How can these features be brought into play EVERY time that they are needed? The machine has to be always available to do exactly the right job in the right way whenever it is needed. It has to guarantee to protect and transport the organ without the slightest damage. For the engineer designing this machine, some of her knowledge was developed yesterday and some three hundred years ago.

It’s simple. Scientists ask questions: about how things happen. Engineers use the answers for our benefit.