From Revolutionary Tech Investor (Australia) –
You’ve probably heard of Hadrian’s Wall. It’s one of the oldest and longest standing man-made structures in the world. Built in 122 AD, it spans 80 Roman miles (117.5 km).
What you may not know is that it took 15,000 men around six years to complete. It’s the best known and preserved frontier of the Roman Empire, and received world heritage listing in 1987.
It’s approximately three metres wide by five to six metres high, and constructed from squared stone. Considering the wall is now around 1,894 years old, it is truly one of the world’s most magnificent pieces of engineering.
Imagine building something that will last thousands of years. If those engineers and labourers had known that their construction would still be standing and admired in the 21st century, I reckon they would have been pretty proud of themselves.
But when you think about it in modern day terms, taking six years — and 15,000 men — to build a 117.5 km wall sounds terribly slow. Though in their defence many of these men would have been involved in cutting the stone, moving the stone, and digging and compacting the foundation…not to mention that they commuted on foot.
As a matter of interest I decided to calculate how many blocks (rough estimation) it took to build Hadrian’s Wall. The blocks are approximately 46cm long, by 30cm deep, by 15cm high.
Let’s assume the average height of the wall is a bit over five metres. In reality it varies between five and six along it’s length, so this will do for simplicity’s sake. That means it would take five and a half blocks to get the required height.
And at 117.5 km long that makes the wall 11.75 million centimetres long — in other words, 255,434 blocks long.
So already we’re looking at 1,404,887 blocks. But let’s not forget the wall is also about three metres wide — that’s about 10 blocks.
If we total that all together we’re looking at around 14,048,870 blocks in the construction of Hadrian’s Wall.
And if it took six years to build then we can figure out that those 15,000 men (of course they weren’t all working on it at once) were laying around 6,415 blocks per day — that works out to 267 blocks per hour (over a 24 hour day).