What intrigues us?

This week in a motoring supplement to the Sunday Paper, someone was describing a new car coming soon onto the market. It was to be a new higher powered version of an existing sports car. The is was one of the things said in the piece.

“Behind the scenes, the engineers of the AMG division of Mercedes are putting the finishing touches to a test and development programme  ….. But as they worry about such things as noise, vibration, harshness and torsional rigidity, prospective owners  may be more concerned  which colour to order roof in and whether to choose the optional Bang and Olufsen sound system for added serenity.

For those who are concerned with future career paths yet to be chosen either for themselves or others that they may be mentoring, this is a useful snippet to consider, debate or discuss.

What topic catches the fancy?

 What is the correct approach or is there one?

What do the engineering topics mean?

What is the difference between ‘design’ and ‘development’?

[From the Sunday Times, 15 May 2011, ‘ingear’ supplement, page 2, ‘Car of the Week’]

“Engineering Connections” on BBC1

Isambard’s Lad’s not beating about the bush. He was impressed by the first programme of the series, “Engineering Connections” on BBC1 that he saw. It took a single project – in this case the Burj al Arab modern hotel in Dubai – and talked about a wide variety of  the engineering problems that had to be solved in the design of the building. They were real engineering problems; not just fluffy aspects of the dressing of the building.

The presenter was Richard Hamilton of Top Gear fame who is not, apparently, an engineer but whose relaxed, light and downbeat approach combined with clear presentational skills were admirably suited to the programme. A professional engineer who is equally skilled in the art of presentation will be rare, The Lad fears. Present company excepted, of course. The engineers who appeared on screen serving as assistants and advisors to Hammond were however, suitably highly skilled in the technology. Neither, at least, did they have leather patches on the elbows of their jackets. Indeed he cannot remember any of them wearing jackets.

Quite a good range of topics were covered and The Lad noted these down. The modern versions of wave energy absorption were vividly modelled in real life, not in a computer. They showed how they were used to protect the foundation island. The overall structure of the hotel had a steel exo-skeleton and the high Dubai, temperature variations meant that it expanded and contracted and this would have caused problems with dimensional changes during building. A clever but simple bolt hole cam arrangement was shown that was able to deal with this feature.

The way that several hundred thousand tons of building stood firmly in stand was also addressed. The modelling of this was one of the more striking coup de theatre. Skin friction between the sand and the piles is claimed to be the secret. Such friction can build from a tiny effect to a large force with interleaving. Hammond hung with his  feet off the ground from two books with their pages interleaved only. No glue or clamping force.

An entirely different problem was at first seemingly only a fluffy one. How do you get the jets of water in the foyer fountains to look like ballistic, polished, stainless-steel bars and not like water out of a tap. Maybe a fluffy problem but, anyway, it is not a fluffy solution.  The Lad has to confess that he has seen and admired this very effect in a lot of the works of the masters of the Modern Fountain Genre: the Japanese showing just this effect. They make the water flow laminar and not turbulent.  But he never realised before that this was the secret of the fountains. This difference is central in many problems that engineers deal with in fluid flow projects and aircraft design. Fluids flowing at low speed or high viscosity [a measure of fluid ‘thickness’ as between water and, say, syrup] flow in smooth sheets and the sheets do not mix with each other. Turbulent flow, at higher speed on the other hand, has a lot of mixing or churning as it flows. The TV programme showed how laminar flow is ensured by using tubular flow straighteners.

Then there was the problem of lighting, its dimming and not having the hotel going up in flames. Note though that, typical of the programme’s approach, a real shed went up in real flames. It was the Hammond humour, you know. Light dimmers operate by cutting on and off at high frequency the power supply to the light bulb. This dynamics of this frequent change in current usually causes spikes in the voltage and these could generate significant extra heat compared to steady alternating current.  This is an effect of what is known as an adverse Power Factor. In a building like a hotel and some industrial processes this adverse effect must and can be avoided by installing [usually in the basement!] banks of capacitors and inductors to ‘correct the Power Factor’.

The programme was also respectable and important in that it showed that there are different flavours of engineer involved in all such projects of a normal complexity.

“Engineers change the real world”

The First Law in the Garden Centre

In the Garden Centre The Lad saw a display of a pump for emptying the water from the garden rainwater butt; it takes the place of a tap at the bottom of the butt emptying into a watering can.


Versus the tap it seemed an example of inappropriate technology. This is a subject exercising his mind lately but as it will be a subject of another post shortly, we can move on.

Hozelok Waterbutt pump
Quite a sizeable pump as these things go in the garden.


Anyway, the display had one buzzing and pumping away sitting in the bottom of a water butt covered by only  few centimetres depth of water. The pumped water went up a length of straight garden hose about a meter and a half and poured out of a garden hose gun in a straight stream under gravity down back into the bottom of the water butt. As he walked by, The Lad let the water stream from the tap wet his fingers and he came to an abrupt halt as he noticed that the water was quite warm. Not hot, you understand, but quite warm enough to to make a really comfortable hand wash.

He pondered on where the heat energy came from and thought that there were several phenomena causing it.  He found that they were easy to envisage but were difficult to imagine in the form of the calculation of each contribution to the total heat of the water in the little [almost!] closed system. There would be heating from the shear flow of the leakage round the centrifugal impellor; there would be the friction of the flow against the walls of the hose as it rose up it; then there would be the heat generated as the water jet splashed into the bottom of the butt [the Joule Honeymoon effect according to The Lad – look it up!].

Then he realised that from the point of view of the water in the butt the net sum of velocity and displacement is [apart from the small amount of swirl in the butt] zero. This simple version says that , apart from the bit of swirl in bottom of butt the total power of the pump is changed into net zero velocity and displacement. It only turns into heat. So all the separate sources of heat can be sidelined by this overall calculation.

The summary version of the calculation in its simplicity is enough for us here. It also shows that a suitable insight can simplify estimates. But it is also true that in real engineering, where they have hot oil or hot water coolant flowing in a closed system, there is a need to control the heat flows and to ensure adequate cooling. Then they will have to calculate or experiment or, almost certainly, both to work out what are the contributions of every source of heat generation and sink of heat radiation, convection or conduction. Now that’s what real engineers working on engines or machine tools have to do and do do.

Butt and Pump
"In Memorium. James Prescott Joule 1818 to 1889. 772.55"

“Work is Heat and Heat is Work” is one version of the First Law of Thermodynamics. There it was – in the Garden Centre.

Catenary Support Eyesores

The Government has announced recently that £billions will be spent on UK Transport rail infrastructure. I assume that this will include the High Speed 2 plan linking London and Birmingham by electric railway. Those on the ground will always oppose the planned routes due mainly to the damaging effect on their house values.

But many also will cite visual horrors of the railway cutting through the contryside. The Lad, although an engineer, can understand that to some degree. The trains and their sounds are soon passed at any given spot. But the masts, skeletal arms and the wire arcs are permanently on display.

US array of cables
It should be possible to do better.

The Lad is not a catenary support designer but, in the UK, notes that it appears that standard RSJ uprights and other ugly components have been flung together. The idea?? of using standard parts or RSJ material is assumed to be the best way to achieve cost-effective structures. There does not appear to be any thought for the visual effect. See the pictures, which come from the excellent website, http://www.theoverheadwire.blogspot.com/ with the kind permission of its author Jeff Wood of San Francisco.

Second view of wire and mast array
Let’s design aesthetically better designs than this.

The Lad advocates a more holistic design. special components, possibly multi-use, could not only look better but also, he is sure, be more structurally and dynamically efficient. The cost of specially designed parts would not be more expensive. Why? Because in the hundreds of miles of line lengths there are multiple tracks and so there would be thousands of each given component. What happens to properly designed, component cost with large quantities? It plummets.

This post is The Lad’s quick response to a problem that has been irritating him in the back of his mind for some years. I will develop a strategy to try and move the idea forward. I will try to find the movers and shakers in this area and see if he can begin any sort of dialogue. The Lad will keep the blog in touch with any progress or none as transpires.