How did they tunnel through rock before gunpowder?

Humans have been tunneling and digging deep for millenia. Including through solid rock. Its only been in the last 500 or so year that explosives have been available.

How did they do the work before explosives?

Hammers, chisels, draft animals, and sometimes fire. ETA: Also splitting wedges probably.

In general terms, find something harder than the rock you want to tunnel, and then proceed to pound away at it. Repeat.

Limestone and sandstone, and some igneous rock is often relatively soft and excavating or tunnelling through them is more tedious than strenuous. Even though metals made tunnelling that much easier, systematic bashing with harder rocks was still the means by which we got pyramids, Incan architecture and Easter Island statues.

Tunnelling is more complex than quarrying, shaping or open excavating, because you lack the swing room for picks or people working shoulder to shoulder, and you cannot usually cleave rock towards a free face with wedges or work away at a mass from several directions.

Picks, wedges & sledge hammers and firesetting.

A few years ago I visied a silver mine in the Black Forest that worked from 1250 to 1608 (the Mexican mines put a lot of marginal European ones out of business). They worked narrow tunnels in hard rock with hammer and chisel and the guide said a very good miner could advance the face by 1cm (0,4 in) in a day‘s work.

Grimes Graves by the Icknield Way are Neolithic flint mines in Norfolk, England thought to be first worked around c. 2600 - 2300 BC using red dear antler as picks.

When the first pyramid was built, Egypt had had bronze tools for a few hundred, maybe 500 years. So no. The pyramids was not built by bashing soft rocks with harder rocks.

It’s more accurate to say the pyramids were not built solely by bashing soft rocks with harder rocks.

A recent example is the Guoliang Tunnel in China, dug entirely by hand and completed in five years in 1977.

The technique of fire-setting was often used.

The Wikipedia article isn’t very good. Vinegar was the preferred liquid used to split heated rocks, rather than water. As in Hannibal’s famous crossing of the Alps:

“At last, when men and beasts alike were worn out by their fruitless exertions, a camp was formed on the summit, after the place had been cleared with immense difficulty owing to the quantity of snow that had to be removed. The next thing was to level the rock through which alone a road was practicable. The soldiers were told off to cut through it. They built up against it an enormous pile of tall trees which they had felled and lopped, and when the wind was strong enough to blow up the fire they set light to the pile. When the rock was red hot they poured vinegar upon it to disintegrate it. After thus treating it by fire they opened a way through it with their tools, and eased the steep slope by winding tracks of moderate gradient, so that not only the baggage animals but even the elephants could be led down.”
  – Livy, XXI, 37

Modern experiments confirm this. A summary of the results from a paper published in Geology Today:

Four different types of rock were used in a series of laboratory tests. … Briefly, the results of these tests, confirmed by field experiments, showed that a 50% acetic acid solution produced a greater number of cracks in the rock samples and that all broke easily on tapping. This dilution proved to be almost as effective as greater concentrations of acid.

Each type of rock was also subjected to an application of red wine in the same quantity. The wine had been allowed to become sour when left uncorked in a warm atmosphere over a period of three months. In the tests carried out with sour wine (14% vol.) the reactions were very violent, and the rocks fractured readily, ‘with much sizzling’

– SHEPHERD, R. (1993), How Hannibal conquered geology. Geology Today, 9: 102–106. doi: 10.1111/j.1365-2451.1993.tb01108.x


50% acetic acid? Isn’t normal vinegar from the cask like 5-7% acetic acid?

They did the tests with various acids at various concentrations and with various kinds of rocks. They’re just saying that you don’t get any greater effect if you go above 50% acetic acid.

The red wine was 14% alcohol and left open to turn to vinegar naturally. It was very effective.



There is good information concerning the location of the quarries, some of the tools used to cut stone in the quarries, transportation of the stone to the monument, leveling the foundation, and leveling the subsequent tiers of the developing superstructure. Workmen probably used copper chisels, drills, and saws to cut softer stone, such as most of the limestone. The harder stones, such as granite, granodiorite, syenite, and basalt, cannot be cut with copper tools alone; instead they were worked with time-consuming methods like pounding with dolerite, drilling, and sawing with the aid of an abrasive, such as quartz sand

Bronze wont cut granite.

I recall seeing some show about an ancient Egyptian tomb, and there was a big lump of some kind of rock (flint?) sticking down out of an otherwise perfectly squared off corridor in the tomb, and the host of the show pointed out that the bronze chisels and drills they used back then wouldn’t have scraped that type of rock at all, so they just worked around it.

If you go to Aswan, one of the attractions is Haptushet’s column. They were making a large obelisk when the rock fractured; they then tried to cut it down, it fractured again. So you have a column on its side with a trench around it, all in granite. The markings in the trench hint at some sort of grinding.

The pyramids are limestone; so the general thought was that tools like axes with a sharp hard rock head, plus copper chisels, were used to start gaps; wood wedges were pounded into this and wet down so they swelled and split the rocks. If you are in Cairo, you can visit the “Cave Church” which is across the river from the pyramids, a giant hollow in the limestone escarpment where many of the blocks were thought to have been quarried.

There’s the tunnel you can walk through under the City of David (south of the Temple mount in Jerusalem). It was made centuries BC to allow a spring to feed the Pool of Siloam and provide water during sieges. Apparently the workers tunneled from each end by moderately dead reckoning, and in the middle where they meet the tunnel weaves back and forth a bit as they tried to meet up (likely by listening for hammer sounds from the other side).

Did they use incendiary liquids instead of vinegar? Been around for several millennia as well.

Egyptians used diorite or granite adzes to cut slots on limestone. They then rammed wood soaked in water, causing the blocks to split off. The quarrymen’s hardest job was to maintain the 52% slant for the side and corner blocks.

For actual shaping and smoothing of the limestone, yes, bronze and iron tools were used. Quarrying much harder granite really required iron tools.

It wouldn’t have been effective to use oil, or pitch, or similar, because it would burn too quickly and not heat up the rock enough. The point is to heat the rock to a high temperature and then cool it suddenly so that it fractures. Cooling with an acidic solution works better than cooling with water.

The problem with doing this inside tunnels is burning fuel in a confined space without good air flow. So it’s only suitable in certain situations.

But note that the pyramids were built without the use of iron tools.