Rare Roman graffiti from AD207, which includes a quarry worker’s caricature poking fun at a commanding officer and a good luck phallus symbol, is to be recorded for future generations because of it is danger of being lost.

Details have been announced of a project to document inscriptions in a Roman quarry near Hadrian’s Wall known as the Written Rock of Gelt, which are among only a handful left in England.

They were made by workers quarrying stone for a major repair and refortification of the wall on the orders of emperor Septimius Severus.

First discovered in the 18th century they became a popular local landmark, but they have been hard to reach since a steep path leading to them collapsed in the 1980s. It is that inaccessibility and the risk of further erosion that has prompted the collaboration between Historic England and archaeologists from Newcastle University.

“They haven’t been recorded to modern standards, no one has really looked at them for 30-plus years,” said Mike Collins, the inspector of ancient monuments for Hadrian’s Wall.

The inscriptions are mostly of the ‘‘this is the part I’ve done” type, and include the names of men and in some instances rank and military units. One of the inscriptions, EPPIVSM, is thought to be the individual who made it, M Eppius.

Another inscription reads VEX LI EG II AVG OF APR SVB AGRICOLA OPTIONE, which translates as “a detachment of the Second Legion Augusta, the working face of Apr... under Agricola”, the word OPTIONE indicating the rank of Agricola.

Archaeologists believe this face was intended as a cheeky dig at the workers’ commanding officer. Photograph: Historic England

That is the bureaucratic side to the inscriptions. The human side is two eyes and a mouth which archaeologists believe is a humorous cartoon of the commanding officer. “It is very rough. Classical sculpture it is definitely not,” said Collins, adding that after a hard day in the quarry with a demanding boss it is easy to imagine the circumstances in which it was done.

Other graffiti only discovered on Tuesday during day one of the project includes a phallus. “Phallus carvings are very common in the Roman period and are more a general symbol of good luck.” A representation of a torso was also found for the first time and the letters MV.

The writings can be precisely dated because one of them reads APRO ET MAXIMO CONSVLIBVS OFICINA MERCATI, which translates as “In the consulship of Aper and Maximus”. Aper and Maximus were consuls of the Roman Empire in AD207.

That was a year when the emperor himself was in Britain leading Roman military campaigns against troublesome tribes. He ordered major improvements to the wall, which had been built a century earlier. Such were the changes that it was not until the 19th century that it was conclusively established that the wall was started by Hadrian and not Severus.

Roman Britain at the time was a turbulent place with frequent attacks on the wall. After a generation of frontier conflict Severus attempted and failed to subdue Caledonian tribes in the far north. He was planning a new push when he died in York in the winter of 211/212.

The Roman graffiti is seen as important because of its rarity. The site, in Gelt Woods near Brampton in Cumbria, is one of only a handful of Roman quarries in England which still feature inscriptions.

Archaeologists are working with climbing specialists, and the operation involves them being winched 30ft down to the graffiti using ropes and pulleys. They are carrying out light cleaning before using structure-from-motion (SfM) photogrammetry to produce a 3D record.

The inscriptions have been hard to reach since a steep path which led to them collapsed in the 1980s. Photograph: Historic England

The results will be made public later in the year on the 3D content sharing platform Sketchfab. The project, funded by Historic England, has a degree of urgency because the rock is soft Cumbrian sandstone and has suffered natural erosion which will only continue.

Collins hoped the graffiti records would be enjoyed by anyone interested in Roman history as well as being useful for the next generation of archaeologists. “We don’t know what questions future archaeologists will have, so if we can record these now to the very best of our abilities then the information will be available even if there is a gradual, natural process of erosion.”

Ian Haynes, a professor of archaeology at Newcastle University, said: “These inscriptions are very vulnerable to further gradual decay. This is a great opportunity to record them as they are in 2019, using the best modern technology to safeguard the ability to study them into the future.”