How many engineers?

See the mechanic working on my Renault Clio.

Do you know what he’s doing? Looks like he’s trying to squeeze his arm into a tiny space between some metal beams in the engine compartment frame. Why is he doing that? Because he wants to replace a burned out light bulb in the headlamp assembly.

Renault Clio lamp change

Actually I carry spare lamps in the trunk, so I thought I could change the bulb myself. But after a long struggle I decided to take the car in to a garage shop, in the hope that the mechanic there could solve the riddle: how do you access the headlamp’s back side and extract the lamp?

Why, what’s the problem? Here is the problem:


The headlamp is wedged in behind the tube with the yellow cap, and is practically impossible to reach without disassembling the metal beam behind it. Yep… Renault designed this car so you need to take it apart to change a light bulb.

How many design engineers does it take to make it impossible to unscrew a light bulb?

An elegant hydraulic calculator

Robert Owen Wynne-Roberts, MICE (Member of the Institution of Civil Engineers), FRSI (Fellow of the Royal Sanitary Institute), was a talented civil engineer. He passed away in 1935, but at least one result of his engineering talent abides: the Wynne-Roberts hydraulic calculator, a specialty circular slide rule for computing flow in water pipes and sewers.

Wynne-Roberts' Hydraulic Calculator

You can read about this elegantly packaged device in a new article on my history of computing site.

Form and Materials: swords of yesteryear

Form follows function; but often both must follow the available materials.

Consider the image that comes to mind at a statement like

The great king raised his mighty sword to smite his enemies.

Surely, you imagine a sword structured something like this:


Photo courtesy Søren Niedziella, shared on flickr under CC license.

This, after all, is just about what a proper King’s sword would have to look like to serve him well.


Well, how about this instead?

Khopesh sword

Photo courtesy Dbachmann, shared on Wikimedia Commons under CC license.

Would you recognize this as a sword? If you were an Egyptian or Mesopotamian soldier some 4000 years ago, you certainly would. In fact, this was what a standard battle sword looked like between 2000 and 1300 BC. This one, missing its hilt at the right end, is from 1750 BC.

These weapons were in use across the ancient near east, and were called Khopesh in Egyptian. Their only sharpened edge was the outer side of the curved part at the left. You used this edge to beat on people, much like you’d use a club; stabbing was not even an option.

So, what’s going on here? A sword should be long, thin, sharp and pointy, so you can stick it into people at arm’s length; why make one that looks like a short, thick, bent metal rod that can only be used to clobber your enemies?

This is where a key fact comes in: we’re talking Bronze Age, when iron (and much less steel) was unavailable. Weapon designers were constrained by a metal that was too soft for anything long and thin; nor would it stay sharp for long. A one-sided “sickle sword” like the Khopesh could have a thick backside that would give the bronze both durability and hitting momentum.

Over the years the design varied somewhat; notably the sharp part grew longer at the expense of the handle, as in the sword below:

Khopesh sword

Incidentally, I wasn’t kidding about the king: below you see a PR image of Ramesses III smiting his enemies with a curved sword just like this one. He grabs the smaller-than-life enemies by the hair and is ready to smite them with the sword’s edge (the kings of those days, unlike today’s ornamental ones, were pretty hands-on where smiting was concerned). In fact, this image makes sense of the fact that “smite” is defined in the dictionary as “to strike with a heavy blow or blows” – strike, not skewer as with later sword designs. The guy on the right is more than a king – he is the Akkadian God Nergal, no less, and he holds a sickle sword in his left hand, its blade resting on the ground.

Ramesses III and Nergal

But then came the iron age, and it became possible to craft sharp long blades that wouldn’t break; and the bronze Khopesh went the way of the flint axe, doomed by a new technology that enabled new forms and new functionality.

That’s Progress for you…

A truly uncool armrest design

Back from vacation, having flown a Boeing 737. This lacked the personalized screens seen in longer haul craft but it had a headset jack and a set of volume and channel controls for each passenger. The controls were set in the armrest, in easy reach of the passenger, like this:

Boeing B-737 armrest audio controls

Cool, huh?

Not cool. The two rocker switches for the volume control and channel selector are flush with the surface of the armrest. This means that if you rest your arm on the thing – or if your neighbor in the next seat does – your channel is bound to skip up or down every few minutes. If you watch a movie this can get truly aggravating.

And all they had to do was recess the controls a couple of millimeters under the surface…

A curious slide rule design

For some reason, inventors in the first half of the 20th century thought that incorporating a slide rule into a mechanical pencil was a great idea. In reality, these combination devices were of dubious utility, gives their low precision as calculators… but they are certainly ingeniously designed.

Pencil Sliderules

I describe three of them,  including one extremely rare device, in a new article on my history of computing site.


How cool is that?!

Evolution has crafted some amazing design solutions to the problems of life, and I never have enough of their elegance.

Take the crocodile’s heart.


Crocodiles have a special bypass short circuiting blood flow to their lungs. Specifically, although they have the same four chambered heart configuration as us mammals, which pumps the blood first to the lungs to get oxygenated and then to the body to use that Oxygen, they have a special hole – the Foramen of Panizza – that connects the blood vessels leaving the heart’s two ventricles so that blood can flow from one circuit to the other without visiting the lungs. What’s more – and this is the cool part – in some species, a special valve enables the short circuit only during prolonged diving, when the lungs are useless anyway.

Is that cool, or what?!

Ingenious design sighting at Heathrow

Here is a bit of outstandingly smart design I saw in Terminal Five at London Heathrow airport.

Heathrow Terminal 5 signTo fully appreciate the ingenuity, you should know that there are two security inspection areas (you know, where they check your shoes and X-Ray your hand luggage): Security North and Security South. Both serve the same function, and they’re located a minute’s walk apart in this huge hall.

What this real-time information sign (and the similar one at the South area) does, is tell you that right now, you’ll be much better off to make that one minute trek, because the other area has a much shorter line.



My Dad’s tin suitcase

My father, God rest his soul, was a young physics student when Israel’s war of independence broke out, and he was among the defenders of the Jewish Quarter in Jerusalem’s Old City. When the quarter fell to the superior forces of the Jordanian Legion, he was taken prisoner and spent 9 months in a POW camp near Mafraq in Transjordan.

When he came back he brought with him a humble but interesting artifact: a small suitcase, about the size of a modern carry-on, made entirely of tinplate. This survived to this day, and has an interesting story to tell.

Tinplate suitcase from POW camp

My father, it turns out, had ample time on his hands in that camp, and he devoted it to studying Physics (he was to become a Physics professor for the rest of his life) and to teaching it to any of the other prisoners who found it preferable to doing nothing. In return, one unnamed prisoner used his skill as a tinsmith to produce this suitcase for my Dad.

The source of the material is obvious if you turn the thing over:

Tinplate suitcase from POW camp

This was a standard tin of biscuits, provided to the camp’s residents either by the Jordanians or by some welfare organization. They must’ve been rather stale, as they date to 1945, but in war you aren’t choosy; meanwhile the empty tin was recycled into this suitcase.

The craftsmanship and attention to detail in this item is wonderful indeed, considering the difficult conditions of its manufacture. The potentially sharp edges are all doubled up for safety and convenience. There is a folding handle, hinges, even a hasp – and everything is made from tinplate and steel wire. Here are some photos of the details:

Tinplate suitcase from POW camp

Tinplate suitcase from POW camp

Tinplate suitcase from POW camp

Good job, unknown tinker!


The little details… bless ’em!

When I was QA manager in an Intel fabrication plant I had this Honda Acura ad copy stuck to my cubicle partition:

To fully appreciate the precision that goes into our 24-valve, 2.7 liter, 161-horsepower engine, touch the ashtray.

And indeed, a quality product – be it a car or a flashlight – reflects its quality in attention to every detail. Every now and then I run into such a small detail where the designers went the extra mile to make a better product, and it makes my day.


Take this clock I recently bought. It’s a standard wall clock, with the usual battery operated quartz movement, meant to be hung on a wall by use of a screw.

Back of clockBut when I turned it over I found the screw, affixed to a specially molded clip on the back of the clock. Of course it costs the same to make the unit with or without the clip, and the nylon bag they saved costs nothing anyway; but only one maker in a hundred would bother to pay attention to such a detail.

Made my day!

Independence Day pins: a case study in deteriorating design

Unlike the US, Israel doesn’t celebrate its Independence Day by sending its president to fight invading aliens in huge spaceships (our presidents are too advanced in years for that). We do, however, have other traditions, and one of the earliest of these has been for the Jewish National Fund to issue each year a small lapel pin celebrating the young state’s birthday. Since my childhood these would be sold for a small donation to the JNF’s activity, and I’ve kept some of them and bought some others later, making a nice little collection.

Here they are. Each row stands for one decade; the oldest pin I have, with the stylized number eight, is from 1956; the newest, #40, is from 1988.

Israeli independence day lapel pins                                        Click photo to enlarge

And as I look at the series, I’m amazed to see that while the state of Israel has progressed from humble and austere beginnings to become today’s vibrant “start-up nation”, these pins have moved in the opposite direction: their design and quality of manufacture have degenerated considerably with the advancing years!

Like this:

Israeli independence day lapel pins

This photo shows the pins from years 20, 25 and 38. See what I mean? The leftmost pin is cast in a solid bronze alloy; all the years before it use embossed metal too. But year 25 uses a flat metal disk with a paper sticker, as do subsequent years (and years 31 and 37 shamelessly recycle the same design on the paper!); then, in year 38, we see a move to the el-cheapo buttons used for political rallies and countless other mundane uses.

And it gets worse. Year 39 had three versions: the cheap button, a flimsy plastic “paperclip”, and a disposable paper sticker!

Israeli independence day lapel pins

Incidentally, year 10 also had a choice; but not between flimsy and disposable. In that year there were two respectable, embossed metal pins – one in tinplate and one in bronze.

Israeli independence day lapel pins

Consider the change in raw materials in this sequence:

Israeli independence day lapel pins

Bronze in year 10 (this was the only material in use in the first decade), tinplate in year 16, and the yucky plastic in year 39.

Lastly, consider the complexity of structure in the year 14 pin from 1962 (the wooden backplane was meant to celebrate the JNF’s highly successful reforestation efforts), in contrast to the trivial technique in the paper sticker from 1987.

Israeli independence day lapel pins

Of course, we see this decline of craftsmanship in many manufactured goods in our modern world – and here it is captured nicely in a microcosm of ID lapel pins!