The History of Tarmac
We don’t tend to pay much attention unless there are potholes in the road. But without it – cars wouldn’t roll, planes wouldn’t take off, and we wouldn’t have smart driveways! Pelsall Tarmacadam take a look at this bituminous substance, in a bit more detail……
Who Invented Tarmac?
Edgar Purnell Hooley – to be precise.
In 1901, literally at the end of the Victorian era, and right in the middle of huge industrial changes, transportation links and ease were vital.
Canals formed a huge part of the industrial network, but road travel was becoming more viable. Petrol-powered cars had been around for approximately 15 years and people wanted to get places – faster! That meant the road surfaces had to be improved.
How Did The Idea Come About?
Purnell-Hooley was a county surveyor in Nottingham, who was in the course of his business one day when he noticed an un-rutted and dust-less patch of road as he was leaving the local iron works.
With his curiosity fired-up, he made enquiries, and it was revealed that a barrel of tar had burst open, and the spillage covered with slag.
Hooley immediately saw the potential and began to experiment – with a British patent for the process of mixing tar with slag being obtained in 1903.
By the middle of that year, he’d chosen a traffic-heavy spot and laid a length of his new invention along the road. This was monitored by the local paper, ‘the Newark Advertiser’, who reported it as being ‘as good today as when new’. The rest is history!
However, Edgar was actually improving on previous efforts – there had been other attempts, most notably those of John Loudon McAdam – a Scottish engineer who pioneered a type of road construction around 1820.
McAdam’s method was simple but more effective at protecting roadways than previous efforts. He asserted that massive foundations of rock upon rock weren’t needed and that just native soil alone would support the road and traffic using it,
(as long as it was covered by a road crust that would protect the soil underneath from water and weather).
McAdam’s method sufficed for a period of time, but quickly became obsolete due to its high manual labour requirement. This left the door open for subsequent improvements, including those of Edgar Purnell Hooley, whose method involved mechanically mixing tar and aggregate prior to lay-down. This was then compacted with a steamroller. The final flourish was to add small amounts of Portland cement, resin, and pitch.
What’s In A Name?
Tarmac – (short for tarmacadam) is the name for the material patented by Edgar Purnell Hooley. It’s also used (rightly or wrongly), for a variety of other materials which include:
Bituminous surface treatments
Tar-grouted macadam and,
modern asphalt concrete.
and even airport aprons, “ramps”, and runways – (as in ‘the plane is on the Tarmac. Even though this is technically concrete!)
Facts and Figures
In 2014 the UK Government spent £967m on pothole repairs – enough to fix 18 million potholes a year!
The average asphalt surface drops only 40% in condition during the first 75% of its life. This means that if you maintain your asphalt over the years, it will last you a long time.