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Power by the Hour

THE ENGINEER’S WAY

Pence per minute; quarters per hour; that’s the information that we all need. Not just engineers. Let me tell you that nowadays, the designers and builders of engines for aircraft do not just sell the engines to the airlines. They sell them Power. The engine builder knows how much they cost to run and the airline likes to avoid the hassle. So the builder sticks a reasonable profit on top of the running and insurance costs; lends the airline the engines and charges them for however much power the airline uses. One builder at least calls it Power by the Hour.

That’s how we all need to think, not just the engineer’s family. Save the pounds or the dollar. Make it easier to save energy. Make it easier to save power. Make it easier to save money. It’s easy to help this to happen.

The Lad has been shouting this to himself today. His power bills are sky high and painful to pay. So are yours probably. In the modern household there are a multitude of electrical appliances. Some are power gluttons: they are mainly heaters of one sort or another. Some are only sipping at the meter: IT gadgets are such. Unless you are obsessed by the problem as is The Lad or any engineer, you will have little idea about how much power it takes to heat anything. An enginer can tell you, it’s enormous. In any flavour you want, it’s gigantic; be it kilowatthours, simply pedalling a bike or, if you prefer, horsepower.

Just running the hot water tap – especially running the hot water tap – costs a fortune over the month. The Lad’s old Physics master at school said to him that the specific heat of water [that is energy required to raise water by a degree or two of temperature] is higher than almost anything else except some gases. The Lad will dig out the figures for a future post.

Big Towel rail — Can you see it? At the right above the box. (c) The Lad 2011

Anyway, there was The Lad crawling around on the floor trying to find the Rating Plate of the various heaters in the house so that he could rant at the family. “Did you know it costs gold dust to run this thing for five minutes?

Small Towel rail — Another one lurking. On the left, behind this time! (c) The Lad 2011

But the Rating Plate was round the back or underneath or, better yet, inside. He cricked his neck looking up at the plate between the base of the appliance and the floor. Then the bifocals, joys of late-middle age, were the wrong way round. The distance reading area of the bifocal, intended for seeing the football or cricket ball a hundred metres away, were failing to assist him in reading the plate one centimetre from his nose.

Under the vacuum cleaner — This time it is underneath! You try turning a vacuum cleaner upside down! (c) The Lad 2011

No, No! Do it better. Help the Mother to harangue the family to do things better. Maybe in this day and age, it will be an ecologically conscious child. “Don’t waste money!”

We need a new label that the manufacturer of the appliance is required to supply. It will be applied prominently by the on/off switch. Or it could be one that we choose to make prominent. The most visible or even the only text would be a box into which the owner can write in a number which is a running cost, cash value and, after the box, will be printed the words ‘per minute’ or ‘per hour’.

The new owner will use her utility bill [which gives a cost of power per kilowatt hour] and the Instruction Leaflet or Rating Plate either of which will give the power absorbed by the appliance to help to calculate the cash cost. The Instruction Leaflet will also have a Table with a few lines with possible cash cost per kilowatt hour charged by the utility and, next to it the corresponding cash cost per hour or minute. Like this for a 1kW appliance:
                          Electricity                       Cost
                      pence per kWhr         pence per 15min
                                  20                                5
                                  30                               7.5
                              …………. and so on……………….

Easy, says the engineer! The new owner will consult this table and she can find the number to write in the label.

The Mighty Hunter felled by the Coalition

The gripping intro to the written BBC report begins

In a distant corner of a fenced-off site in Cheshire a fleet of Nimrod MRA4 warplanes which cost taxpayers more than £4bn are being turned into scrap.

http://www.bbc.co.uk/news/uk-12297139

The video footage on the main News bulletin that night http://www.bbc.co.uk/news/magazine-12281640 certainly made The Lad wince. It was shot from a helicopter and showed an area surrounded by high tarpaulin and steel screens between two hangars. Within are the tattered chunks of a fuselage heaped beside another Nimrod that is clearly to be the next victim of the advancing dinosaur of a demolition machine. Both the remnants and the more-or-less complete aircraft shell have the matt, olive sheen of the treated aluminium skin of a part-finished aircraft. The RR engines have already been removed and they will at least have been saved for use in some other aircraft.

Was it wanton mindless destruction, or, as Unite’s John Fussey described it, the dismantling as ‘barbaric vandalism’?

It is fortunate that engineering design is not a function like entropy that can only be degraded by use. If it had been, then the destruction of these planes without going into service [that is some sort of use] would be more painful still. But bring the attentions of these engineers that worked on the Nimrod to another project and they will fire up other ideas into reality.

This report says that the project was 10 years in the making. The Lad has read somewhere else rather that they were 10 years late in delivery. The Wikipedia story, http://en.wikipedia.org/wiki/BAE_Systems_Nimrod_MRA4 , is very detailed and seems to confirm his memory. This and £4 billion of sunk costs and £2 billion to operate are eye watering and show that this is not a good engineering project. Whether it is the MoD or BAe that is to blame for beginning and sustaining this project is an entirely different question.

Don’t take ourselves too seriously

This is just a quick post about something that makes The Lad laugh. He is a fan of Dilbert who is greater than or on a level with ‘Peanuts’. Dilbert, with the patience of Job, daily wrestles with the low level war which is the modern technical office. The strip is about Dilbert and his co-workers and their bosses and the demons that afflict the organisation.

In this particular episode, Dilbert is confiding in his doctor who notes that he is an engineer and that this is classified as a disease these days.

See all the rest of them daily and chuckle at the incisive insights at http://www.dilbert.com . It will improve your life.

Trussed in the ‘Scientific American’

The season of goodwill has just passed, so the Lad is on the lookout for slights.

The magazine ‘Scientific American’ is well known internationally: indeed The Lad could perhaps irritate it, that is if it deigned to notice, by referring to it as a “venerable institution” http://www.scientificamerican.com/

The Lad read the feature “SCIENTIST IN THE FIELD” in the Jan 2011 edition. This very title of the feature has the flavour of a scientist sallying forth from the Grove of Academe to assist, and patronise, the toiling agricultural peasants.

The particular feature was on Pamela Fletcher, who holds down the job of a Global Chief Engineer, no less, for the multi-national, vehicle manufacturer General Motors. See http://www.scientificamerican.com/article.cfm?id=practically-green . She is clearly responsible for leading and managing the team of engineers who will have designed and developed the insertion of power trains into future vehicles including the like of the new US car, the Chevrolet Volt.

From her own words, her curriculum vitae includes, academically, her B.Sc. and M.Sc. both in Mechanical Engineering and what appears to be the equivalent of an M.B.A. [Master of Business Administration]. Her commercial, engineering experience within GM must be considerable although not in the public domain. See http://coe.uncc.edu/newsletter/newsletter-home/91-pamela-fletcher.html .

We can, perhaps, perforce more accept with a shrug when the hacks of the common press describe engineers as scientists. Quite different however is it when the scientists try to arrogate engineers to themselves and their profession. Doesn’t it somehow aggravate the misdemeanor too that this very senior engineer is a woman?

I wonder how many other engineers have featured in this section. Perhaps if I bring this post to their attention, they will tell The Lad.

Start the car; slow the wear

DO as The Lad does, on the coldest days. He starts the car and runs it at about twice the tick over speed or so for about a minute [whilst sitting in the driver’s seat of course]. Meanwhile put the blower on the windscreen and recirculating at full chat. This way heating and reheating the same air will get it hot sooner than heating fresh charges of outside air. Put the rear window heater on. Then switch off, lock the car and return indoors and have breakfast for ten minutes or so. After that the engine will have got itself and the oil warmer by conduction mainly. Now come back and drive off to work or wherever at a reasonable speed.

DO NOT start the engine and leave it on tick over for the ten minute breakfast, then get in and drive madly away or even quietly away. One reason is that a lot of people have had their car stolen by a thief walking up, getting in and driving away. The more certain reason is that the tick over method induces vast amounts of wear in the engine.

ball bearing and shaft — Some of these are whirling all the time.

Even at slow tick over speeds, engine pistons are still being flung to and fro in the cylinders; many shafts are whirling at high speeds and gears are rapidly meshing. These must all be stopped from wearing amazing quantities of metal away and the engine then becoming at best inefficiently petrol gulping. Eventually it will stop because the leaks through the worn parts mean that it will not have enough power even to turn itself over. The oil has a vital function in the engineering of the engines by keeping metal sufaces apart. But, when the engine is cold, there won’t be any oil there.

Why is this? Even the most modern oil will be much thicker [engineers call it more viscous] when it gets as cold as it has recently been in the UK, that’s why.

The engineers who designed your car engine set the number of cylinders and their size, the way it grabs hold of your car, the way the electronic systems will control it, the exhaust system and answered a myriad of other questions. At around this time the engineers had to design a pump and oil system to push the oil around the engine and galleries to get them to all the sliding surfaces and rolling parts. This oil system will be optimised to work best with hot oil and a hot engine because this is how it spends the great proportion of its life. Except for those few minutes on the cold days at start up. With cold, cold oil being very much thicker it is pushed towards the surfaces much more slowly and little arrives. Wear is rampant.

You can find here an excellent discussion of the how and why of lubrication. It has some American wording and technology and is a little technical. http://www.zddplus.com/TechBrief11%20-%20Internal%20Combustion%20Engine%20Lubrication.pdf

The Lad will agree with any souls who want to argue that the time of running and the engine speed that it runs at could do with being optimised to acieve the best result of minimum wear. It is so that also the optimum figures are likely to be different for every car and engine. All the same, the method of The Lad will be far, far better than leaving the car at tickover for ten minutes on its own. besides which the theft is a terrible blow to the pride. The insurance won’t pay up either.