A seminal paper… published in 1956

Posted on November 2nd, 2011 in automotive history,pedal power,Suspension by Julian Edgar

Back here I described my search for the lightest possible springs for a lightweight human-powered vehicle. Although I didn’t say so at the time, it had been my desire to use rubber – light, cheap and readily available.

However, as that article describes, I found it impossible to find a rubber (or elastomer) approach that allowed high spring deflections without overstressing the rubber. High suspension deflections were possible with rubber, but in turn that required high motion ratios (ie leverage) that resulted in large stresses in the suspension arms and spring seats.

However, since writing that article in 2007, I have been reading everything I can find on using rubber as suspension springs – and I have to tell you, there’s not a lot around.

But today I found a paper that I think is worth sharing with you. I can’t share the content – it’s copyright – but I can say it’s the best treatment of using rubber as vehicle springs that I have seen. It was published in 1956 and the author is Alex Moulton, the man who later developed the rubber springing used in the Mini, and the rubber-and-fluid suspension used in the Mini, Austin 1800, Morris 1100 and other vehicles.

You can buy the paper from the Institution of Mechanical Engineers Proceedings Archive here – it will cost you US$30.

If you are interested in lightweight vehicles with sophisticated suspension design, I think it’s a must-read.

 

Designing a unique vehicle

Posted on February 4th, 2010 in Aerodynamics,automotive history,Materials,Safety,Suspension,testing by Julian Edgar

Recently I read Thrust, the book by Richard Noble on his life in breaking land speed records, culminating in the development of the ThrustSSC car – the current world land speed record holder. The record was achieved in 1997.

thrust ssc

 

The book is outstanding on a number of levels, including its honesty and clarity. The section where driver Any Green describes his techniques for steering the car is just amazing, as is the constant battle for funds that occurred every day of the project.

But one small part of the book particularly interested me: the section where the primary designer Ron Ayers describes how he went about designing the car.

The text is reproduced here:

How do you start designing a vehicle that is totally unique? Here are the characteristics of the problem that faced us:

1. By travelling supersonically on land we would be exploring a region where no-one had ventured, where even the problems could only be guessed at, so there were no known solutions.

2. As the aerodynamic forces involved were so enormous, any accident was likely to be fatal.

3. The project would always be underfunded, short of people and time.

4. There would be only one chance. The final car was also the first prototype. The first lines drawn on paper could well be the ones that are made. The very first assumptions and decisions, if incorrect, could put the project on the wrong track and there would be no chance of starting again.

Problem: how do you make those crucial first decisions when so much is uncertain?

First, every decision had to be a robust one. That meant it couldn’t be invalidated by subsequent decisions.

Second, we could only use technology we were very confident with. This militated against using the very latest technology in some cases.

Third, although direct experience of supersonic travel on land did not exist, we consulted widely, with aviation and automobile experts in industry, universities and research establishments. Experience with Thrust2 was invaluable, particularly in pinpoint¬ing practical and environmental problems that might otherwise be overlooked.

Fourth, where possible we left room for adjust¬ment or change, so we could incorporate knowledge acquired subsequently. Nothing was “hard wired”. One reason for using a steel chassis was that it could be modified if necessary.

Fifth, we didn’t try too hard to integrate the systems. If we needed to change one of them, we didn’t want to be forced to change them all.

Sixth, our choice of a twin-engined car made the design massively overpowered. Thus weight was not a critical factor.

The design resulting from such an approach must necessarily be “sub-optimum”. A second attempt, incorporating the lessons learned, would undoubtedly be better. But the design was proved in practice, and there was little about the basic concept that would need to be changed.

The more you read those notes, the more you realise the clarity of thought being employed: it’s also food for thought for anyone building a unique design of anything.

Noble and Green are currently involved with another land speed record car bid – the Bloodhound SSC.

An extraordinary man – and his car

Posted on May 12th, 2009 in automotive history,Opinion by Julian Edgar

I am not usually one to read business or financial thrillers; there’s too much I simply don’t understand. But Delorean, written by Ivan Fallon and James Strodes and published in 1983, is simply a helluva book.

The history of the Delorean DMC12 car is widely known – we’ve done a fairly typical story ourselves (see here) – but it’s the background financial and personal shenanigans that make for fascinating reading. 

The authors are ungenerous of John Z Delorean, but any feeling that they’re being mean just for sensationalism quickly goes out the window when we start learning about the financial approaches taken within the company.

The company – funded effectively by the British taxpayer – threw money around with an indefensible largesse, while Delorean himself appeared to have delusions of grandeur (the latter perhaps required of someone propping up a house of cards). 

Also rather interesting is the skeleton company set up to apparently channel tax-free money to Colin Chapman of Lotus (Lotus did most of the development work on the car) and to Delorean himself.

Used to dealing with ethical and sober companies, the British government – and its agencies – simply couldn’t believe what they were seeing happening to their money. But, caught in a political bind, they kept handing Delorean more and more!

The authors are financial experts – not automotive writers – and there a few automotive technology errors and shortcomings.  Tech detail on the development of the car itself is also only briefly covered (although even that coverage is often interesting).

But if you want to read a book that shows how one man can manipulate situations to his advantage – or, perhaps more generously, a book about the burning ambition of a man who would do anything to succeed - this is an amazing read.