article from 'MiniWorld'
Suspension engineer Dr Alex Moulton was a fundamental part of the design
team that worked on the original Mini back in the late 1950s. He gave
us some insights into the development of the Car of the 20th Century -
and his opinion on the BMW Mini of the 21st century
After the Second World
War I was determined to move my family firm Spencer-Moulton based
at Bradford on Avon from the manufacture of rubber suspension for
railway coaches, and into automotive suspension. I had heard of Alec Issigonis
by reputation and we met socially before we worked together. Issigonis
was working at Alvis in Coventry at that time, on a new large car to replace
their (famous but dated) Grey Lady model. He was given a free
hand to do what he liked, more or less. He had heard of an experimental
rubber-suspended Morris Minor that Jack Daniels and I had built at Cowley.
It had been driven over 1000 miles on the pave at MIRA, an unimaginably
tough test that the standard car would not have been able to withstand.
Following my experimental developments of the mid 50s. Issigonis
was determined that he should have interconnected fluid and rubber suspension
on his Alvis. Interconnecting front and rear suspension units with fluid
in pipes meant that the pitch mode was separated from bounce and roll.
As a result, the car moved smoothly over a bump in the road, giving a
much higher quality ride. The Alvis was an interesting technical
exercise, but it never reached the production line.
Leonard Lord and George Harriman had formed BMC in tbe mid 50s
by merging Austin and Morris. Lord was determined to make a range of new
and innovative cars, and he plucked Alec Issigonis back from Alvis to
design them. The Suez crisis occurred in 1957 and petrol rationing meant
that tiny bubble cars, mostly of German manufacture and including some
BMW-Isetta models, began to flood the roads. Lord wanted to sweep them
away and so Issigonis got the order to build the smallest of his new cars
first, a proper miniature four-seater. Issigonis told Lord that he wanted
me to be involved with my suspensions and so I went to the Kremlin
at Longbridge to meet him. He looked at my portfolio of experimental work
and said, If youve done this, youll do more. He
was very gruff but I got the OK.
I formed Moulton Developments to work on the Mini suspension and
other projects. BMC took a shareholding and paid all the costs of development.
This left me free to work on the things I wanted to do. We actually developed
the principles of the Hydrolastic system during the 5Os but it wasnt
ready for production in time for the Mini launch in 1959. I had previously
designed the rubber cone suspension system it was a specially shaped
rubber and metal unit that gave a smoothly rising spring rate. This meant
that, when the car cornered or went over a bump the suspension stiffened
up as it was deflected. When practically undeflected (ie: the car was
at rest or on a smooth road) the rate was low and so the ride was soft.
We fitted this system to the original Mini of 1959. It was a parody of
the interconnected hydraulic system but that simply wasnt ready
Issigonis took Jack Daniels from Cowley and got together a small
team, no more than six people. Jack had been running an experimental transverseengined,
front-wheel drive Morris Minor on the road over the snowy winter of 1956/7.
It performed particularly well in the wintry conditions and Leonard Lord
and George Harriman were well aware of the benefits of the transverse
set-up as Jack parked it outside the Kremlin every day where
he knew they could see it. Issigonis team designed and developed
the Mini from start to production in 27 months a fantastically short
time. They had total authority from Lord: the whole of BMC was at their
disposal plus all the component suppliers. The whole of the Midlands was
committed to the new project.
It is unfair to say that the Mini was undeveloped when it was introduced.
OK, there were some small problems, such as the floorpan sealing, but
when you think of all the technical innovation in that one small vehicle,
it was amazingly right, and look how little fundamental change it then
needed in the following 40 yearsl
The next suspension innovation for the Mini was the Hydrolastic system
introduced to the saloon models in 1964. Hydrolastic suspension involved
similar rubber cones to the Dry set-up, but they formed a
displacer unit with an integral diaphragm and damper valves. They were
filled with a water and antifreeze mixture and interconnected front to
rear via pipes under the car. This gave the car a rising and falling motion
rather than the sudden pitching of the rubber cone system. Alex Moulton
takes up the story once more...
The Morris 1100 was introduced in 1962 with the first Hydrolastic installation.
It was a great success, and Ford in particular were very upset by it.
Dunlop and Moulton Developments took some time to make a unit small enough
to fit in a Mini, but it was done by the early 1960s. The majority of
the Minis racing and rallying success was achieved with Hydrolastic
cars. The whole Mini racing thing was started by John Cooper. We never
thought about racing during the design phase; we were worried about safety,
particularly when the car was overloaded with lots of students aboard
or such like.
The final phase of the Moulton suspension system evolution was the Hydragas
system. In this later version of the interconnection principle, the rubber
cone was replaced by using a gas under pressure. Hydragas was introduced
with the unloved Austin Allegro in the 1970s and is still in use on roads
today fitted to the MGF. Hydragas was never fitted to a production Mini,
but Alex Moulton has some fascinating prototypes in his stable: a 1966
Cooper S fitted with Hydragas suspension and a 1980 Metro fitted with
a more developed, fully interconnected and refined version of the system.
We were able to take a short trip in both of these cars, and the sophistication
of ride and handling has to be experienced to be believed.
The prototype Metro installation I have is the ultimate expression
of interconnection for a small car. I showed the Mini Cooper S with Hydragas
to BMW during the early development of their new Mini and I am certain
they were impressed. We then worked with Rover on the Minky 2, a one-off
based on extended Mini sheetmetal that was essentially a test rig for
a potential suspension set-up for their new car. However, there was a
major personnel change at board level. Bernd Pischetsrieder, with whom
I had had encouraging discussions left and the decision was taken that
the new Mini should be wholly conventional in its suspension.
Alex Moulton has some forthright views to share on the BMW Mini: Its
enormous. The (original] Mini was the best-packaged car of all time this
is an example of how not to do it. The interior space is not much bigger
than the old Mini, but its huge on the outside and weighs the same
as the Austin Maxi! The crash protection has been taken too far. I mean,
what do you want... an armoured car? Princess Diana was killed in a two-tonne
Mercedes: you can have a fatal accident in anything if you drive fast
With the original Mini, we set out to prevent any accidents by having
excellent handling, not by cushioning people from the consequences of
their own folly The old Mini was the absolute apogee of this philosophy
of built-in safety via the handling people avoided accidents by
driving around them. The suspension of the [BMW] Mini Cooper is set far
too stiff, giving a most uncomfortable ride. To he honest, its an
irrelevance in so far that it has no part in the Mini story.
We were also able to get a second opinion on the BMW Minis handling
from Doug Milliken, an American suspension engineer who happened to be
visiting. After his first drive in the BMW Cooper he confirmed Alex Moultons
opinion that the suspension was too hard for comfort and that it was overdamped.
His conclusion was basically that he would not want to drive it on anything
other than dead-smooth tarmac.
What is the future for Dr Moultons innovative interconnected suspension
systems which were first demonstrated in the Mini and other BMC cars of
its generation? I can do no better than to paraphrase his published thoughts:
There will he a new breed of small cars, sufficient in size for
the typical [urban] journey, but with the convenience in driving on crowded
roads for the longest journey, provided they have big car ride comfort
and absolute security of handling. I suggest that these cars will have
the Issigonis layout of transverse engine and front wheel drive. Their
suspension could comprise fore and aft fluid interconnection to separate
pitch from bounce and roll. These cars could have uncompromised damping
which, with the wheel at each corner layout. gives the [ultimate] handling
capability. (Moulton Suspension. Past and Future Institution
of Mechanical Engineers. Automobile Division, 2000)
Amazingly. 42 years on from the production of the most enduring of his
and Sir Alec Issigonis collaborations the Mini, of course
Dr Alex Moulton is still thinking about the development of suspension
for small cars. No doubt the Minis eventual successors, whatever
they may be, will benefit from his highly original thinking.
Sir Alex Moulton passed away on 09.12.2012. R.I.P.