Bluestone Transport

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So how did the so called “Bluestones*” get to Stonehenge from the Preseli Mountains?  Depending on whether you think that the “bluestone phase” of the monument was ever completed, and it seems likely it was not, you need to transport 40 to 80 stones most weighing around 0.5 to maybe 2.5 tons (Abbott & Anderson-Whymark, 2012).  There are three potential methods: human transport by sea, glacial Transport, and human transport by land.  I’ve thought about transport by sea and concluded it would seem unlikely.  Brian John (e.g. John, 2018; 2024) is a strong proponent for glacial transport, and I’ll come to that.  However the archeologists seem to favour human transport by land  (e.g. Parker Pearson et al. 2015, henceforth MPP).

A recent detailed case for land transport has been describes by Pitts (2022) so I’ll use that plus MPP and consider if it is believable.

Number of Stones to be transported:  English Heritage say that 43 Bluestones currently exist although some are buried. They estimate that there were originally around 80, but that assumed the bluestone circle was completed.  Pitts (2022) says initially there would have been at least 56. The survey of Abbott & Anderson-Whymark (2012) lists 23 which were above ground and could be scanned.

Distance to be traversed: Using a route similar to the “A40” route suggested by MPP Apple Maps gives 190 miles by road from the Preseli Mountains to Stonehenge (306 km).  MPP’s route is 220 miles (354 km). Pitts (2022) suggest various variants on the route but I can’t follow his arithmetic, so I’m going to take 200 miles as a round figure.

Time for the journey:  Pitts (2022) estimates around 3 miles per day for moving the stones over rough terrain (5km/day), which for 200 miles implies 67 days.  However he suggests that for part of the journey the stone could be floated on a raft, down the River Usk for example, and gives an overall time of 41 to 56 days. Allowing for stops that comes to about 2 months.  But where did the people come from in the first place?  If we assume that the people initially travelled from Stonehenge to Preseli, and, since it was a multi-day hike, they could manage 12 miles per day, the 200 mile trip adds another 17 days.  So realistically, with preparations, rest days, bad weather, etc. the project is going to extend over a period of at least 3 months.

Number of people required:  Based on observations of people who transport monoliths using manpower, MPP say “a 4m-long monolith of 2 tons could have been carried by up to 60 people”.  Moving 43 to 80 stones in one operation would imply up to 2560 to 4800 people!  And of course you have to add in support staff for carrying baggage, food, cooking, and so on, so “up to” becomes “at least”.   But even if the required manpower were available, moving so many stones in one operation surely would not be feasible? Moving the first few stones would probably turn the ground into a quagmire making it impossible to move more.

Is it believable?  Pitts (2022) suggests that the stones are moved over a number of years, possibly only at a rate of one per year.  In that case we are asking some 60 people to devote at least 3 months of presumably each summer, year after year, over a period of 40 years or more.  Of course that might have happened, because we know that people will do otherwise inexplicable things if driven by religion…

A Religious Hypothesis:  Imagine that a great religious figure was born in the Preseli area and died on Salisbury Plain.  Thenceforth there is an annual pilgrimage in which the acolytes drag a random stone, selected and blessed by a priest, over the route, and erect it at the embryonic Stonehenge.  It is something any one person only needs do once in their lifetime to be absolved of their sins and win everlasting life.  It has been ordained that the eventual completion of the stone circle will signal the day of judgement over the whole world.

Do I believe it?  It could have happened, but despite the very assertive statements made by some archeologists, there is no way anyone can know.  However, one fact does worry me.  The bluestones do not all come from the same source, indeed they are not all the same type of rock.  (see e.g. Pitts, 2022, chapter 2).  So, for example, if the imaginary hypothesis outlined above were true, why did the priest select a random rock, rather than always choose one from some outcrop of particular religious significance?

I think that glacial transport of the bluestones, at least part of the way, seems a much simpler explanation, I’ll look at that next.

References

Abbott, M. and Anderson-Whymark, H. 2012. Stonehenge Laser Scan: Archaeological Analysis Report, English Heritage Research Report Series no. 32-2012, App. 1, Table 2.

John, B. 2018. The Stonehenge Bluestones, Greencroft Books, 256pp.

John, B. 2024. The Stonehenge bluestones did not come from Waun Mawn in West Wales. The Holocene, online 20 March 2024, 15 pp.

Parker Pearson, M. and 13 others, 2015. Craig Rhos-y-felin: a Welsh bluestone megalith quarry for Stonehenge. Antiquity  89 (348), 1331 – 1352.

Pitts, M., 2022. How to Build Stonehenge. Thames & Hudson, 240pp.

* where “bluestones” tends to mean any stone which was not one of those great big sarsens which people think of as “Stonehenge”.