If you want to move earth, gravel or snow, then finding some way of steering a pushed board seems a good way to go.  And that’s exactly what the early graders were.

But if the board is at an angle to the direction of travel then the machine becomes very difficult to steer in a straight line.  And if you’re working on a sloped surface (like a cambered road) it can get very tricky indeed.

So, in 1885, when J.D. Adams invented the leaning wheel grader he showed how to use a lean applied to the steering wheels to counteract the side forces and so make the unruly machines much more controllable.  And in the early days of horse-drawn graders with no hydraulic assistance it was vital to keep the opposing forces of earth-moving and steering under control.  And this fundamental innovation has proved vital to grader operation ever since.  Caterpillar introduced the rear-engine configuration for ease of visibility for the operator, then, in 1934, the dual rear axle configuration which addressed the stability of the platform – and the architecture of the grader was fixed into a form still used today.

So, during a recent holiday visiting family in Western Australia, it was great to find an example of Adams’ pivotal early innovation in Cunderdin’s museum – a No 11, Adams grader from the 1920s.

And here’s a detail of the rack and pinion arrangement for the front wheels. (The rack needs to be curved to cater for the arc described by the tie-rod as the wheels lean – obviously! (?)).

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In 1898, CY O’Connor, the state engineer in Western Australia, was developing the plans to build what would be the world’s longest pipeline at that time to supply water from Perth to the goldfields (about 350 miles).  In those days pipelines were made of lengths of sheet steel curved into semi circles and either welded or riveted.  Riveting raised problems not only of corrosion but also of considerable friction over the length of the pipe.

In 1896, one Mephan Ferguson, head of the eponymous Adelaide engineering firm, had a stroke of inspiration, and observing the dovetail joints in his desk drawer realised that a similar approach could be applied to joining the steel of the piping sections.  He developed the ‘jointing bar’, a strip of metal formed into the shape of anl ‘H’.  The sections of pipe fitted into the gaps and the arms closed up to seal the pipe.

 

Section of the original pipeline, showing the locking bar and the cement liner of the pipe

 

He gained his original patent in 1897 and went on to develop and patent machines for closing the jointing bars.

O’ Connor was impressed by the performance of the system and let contracts to Ferguson and also to G&C Hoskins and Co, who agreed to use the same method, needing both firms to supply the amount of piping needed.

The jointing bar has become the symbol of the heritage trail of the pipeline in Western Australia.  And to me, a symbol of the power of analogy in invention.

 

See also the following for an excellent description of the whole project and its context: http://www.apia.net.au/wp-content/uploads/2009/08/The%20Coolgardie%20Pipeline%20-%20100%20years%20of%20service%20-%20Fletcher%20et%20al%20APIA%20Paper%20091002.pdf