Friday, 28 October 2011

Who Knows?

As part of making Nottingham's Chemical and Environmental Engineering degrees more industrially relevant, I have had to consider what practical engineers know, and how they know it.

A degree in engineering can only put you at the point where you are ready to learn the things you need to know to be a practising professional. Graduate engineers are unlikely to be able to design a plant which works. There is a great deal of knowledge of the essential fine details of design which is not taught in Universities. I learned it largely from my colleagues in contracting companies, equipment suppliers and plant operators. I refined it by observing the effectiveness of different approaches and troubleshooting the consequences of bad design choices over a couple of decades.

Now I can usually diagnose problems and design solutions which work without much conscious effort in very short order. I don't have to do pages of advanced mathematics, or institute a five-year research programme. I may not have seen it all before, but I've seen a fair bit. I don't consciously use the stuff I learned in University very much, but it underlies all I do - it isn't just a matter of experience.

For example, by the time I am called in to look at problems on small sewage treatment plants, it is usually the case that people with lots of experience but no degree have been there before me.  Their experience is often of driving tankers to desludge such systems, then doing the simple maintenance jobs which keep them running, and after following the manufacturer's troubleshooting guide they start trying to invent their own fixes.

They don't know what they don't know, which makes them overconfident in their abilities. The people they work for usually have some sort of go-faster accessory for plants which misbehave, which gets offered every time to people with package plant problems. To a man who only has a hammer, everything looks like a nail. As our former tanker driver (or in some cases soldier) has no scientific or mathematical training, it never occurs to anyone to test the performance of the plant before and after making a change to see if it has made things better or worse, and as anyone looking into magnetic water softening will find out, it's very easy to kid yourself. It is however not so easy to kid the Environment Agency, which is where I come in.

So where is the knowledge of how to design and troubleshoot water and effluent treatment plants held? It isn't generally speaking in Universities, and neither is it held by tanker drivers, however long they have been pumping sludge or playing at engineers. Most of it is held in contracting and operating companies, and most of that in the heads of a few key individuals.

Most consultancies have rooms full of bright young graduates, who never get to design anything which gets built. Contractors have to politely and quietly redesign the outline designs originating with these beginners which they are given in tender documents so that they will actually work. They will not tell the consultants what they got wrong, so they never learn how it is really done. Similarly, the contractor will keep to themselves critical details of how to commission a system.

Some of this stuff may get written in design manuals of varying degrees of formality within the contracting organisation, and smart client organisations may also learn from experience, and may produce their own design manuals intended to crystallise their operational experience and constrain the design choices of the contractor to maximise chances of success. Not all clients do this, but an expert client's knowledge of the operational consequences of design choices is an essential part of the expert's knowledge.

So the things you need to know to go from being a green graduate to being a competent engineer are not to be found in a book. You ideally need guided hands-on experience and feedback about the results of your choices. Can this process start within a degree programme in such a way as to accelerate the post-graduate progress from unconscious incompetence to unconscious competence?

Saturday, 22 October 2011

Package Plants : Again

In addition to the Acorn Environmental/Bord Na Mona plant we have just finished uprating, we looked at an overloaded Titan/Entec/Kingspan plant last weekend, as shown above.

The evident maldistribution of effluent to the top media bale in the pic is as a result of the cack-handed attempt by another company to reset the airlift flow rates. This and other inexpert interventions cost the client £750 ex VAT for two hours of work, and resulted in his effluent going from a just failing level at 30:30:20 (BOD:SS:NH4) to a threat of prosecution 300:300:40 standard.

As is so often the case, the monkey passing himself off as an engineer failed to get to the bottom of the problem, which is a combination of biological overloading, a problem with one of the airlifts, intermittent and very high pumped flows, and high levels of untreatable solids being put to drain on the site.  Other than the biological overloading, these were all fixable on a one-day visit.

British Water's guidance for users of package plants should be given to all new and existing owners - my advice on what do do if your package plant misbehaves is also worth reading. Better yet, read them both before you buy a plant, and avoid problems in future.