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November 27, 2021 by Edward Blomstedt / Ville Vuorisaari

Myth - were manhole covers the first manmade object in space?

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Have you every wondered what was the first manmade object in space? Well, there is a persistent legend that it in fact would have been a manhole cover.

But in fact, the very first manmade object is said to have been the MW 18014, a German A-4/V-2 rocket test, which was launched on the 20th of June 1944. It was the first man-made object to reach outer space and surpass the Kármán line by reaching an apogee of 176 kilometers.

But before revealing why we are referring to space, let us drill a bit into the history of manhole covers.

The history of manhole covers – and why it is called so?

The first manhole covers known to man are from 3500 BC. According to the "History of Sanitary Sewers " (sewerhistory.org) they have basically seen very little change until the 1870s and they were made of stone or wood.

Sewage systems have been around almost since the dawn of civilization. The ancient Roman Empire built aqueducts to transport not only water to the city, but waste away from it. Once mankind began burying their pipes to carry sewage, they needed a way to access these lines, and these access points came to be known as manholes.

At first manholes were not the access points to the sewer lines for workers. Designers knew that a new underground system would need a way to access the pipes. To fulfill this need, they added points along the plumbing known as lamp-holes. These holes were between 25 and 35 centimeters in diameter, depending on the materials used. Due to the restricted size, the lamp-holes didn’t accommodate an average person. They were only good for shining a light down to verify the system was flowing normally.

Realizing they needed a way to access the gravity sewer, engineers began adding man-sized holes or “manholes” to the sewage lines. It is common to see these gaps in the streets and sidewalks. They are covered by manhole covers to keep pedestrians from falling in or injuring themselves on the open holes.

Modern manholes and manhole covers were developed in the nineteenth century. The oldest available foundry catalog for manhole covers dates back to 1860. The basic design and philosophy of a manhole cover has not changed a whole lot after 1870 relative to the philosophy of manhole design, though materials and installation techniques have changed. In Europe we have a product standard called the EN 124 which applies to covers old in the EU. Circular shapes are the norm but they come in many shapes and forms – also square shaped and triangular covers are being used.

The name "manhole" is sometimes changed to make it gender neutral. The city of Berkeley, California, for example, changed the official term to "maintenance hole" in 2019.

Manhole covers in space

So to return to this interesting topic. If manhole covers weren’t first in space, why did we mention it in the first place?
There is a good chance that a manhole cover was the second ever manmade object in space. Because in August 1957 USA was performing underground Pascal nuclear tests (Operation Plumbbob) in Nevada. They wanted to understand the power of a nuclear blast. In the test they detonated a nuclear bomb in a test shaft. On top of the shaft they had welded a 900 kg steel manhole cover. They assumed that it would fly off so they installed a set of high speed cameras to measure the speed. The explosion was barely caught on the the high-speed camera, which was able to record one frame per millisecond. The covers speed after the blast was calculated to be approximately 240000 km/h.

This was an approximation since the cover was only partially seen in one frame before it then subsequently disappeared. This would have been the fastest ever object set in motion by man and the velocity according to some calculations was so considerable that the cover could even have reached through our atmosphere and into space. The more likely outcome would of course be that it has burned up during its flight, basically vaporized before reaching outer space. Many facts regarding the fate of the cover of course remain unclear but what is for certain is that it was never to be seen again. We however wish to believe that somewhere out there is a manhole cover, making its way to new worlds.

So myth busted – but manhole covers were still second in space. Pretty decent for our iron covers.

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