P A N E L O N E
As part of the BBC series Secrets of Lost Empires, engineers whitbybird, archaeologist Julian Richards and stonemason Roger Hopkins carried out a series of practical experiments relating to Stonehenge's construction, using (as far as possible) tools and methods thought to be available in the Neolithic Age.
Investigation of work done in 1923 revealed that the Neolithic holes made for the upright stones were of a very specific shape. The presence of elements such as a 20 degree sloped side and a cut-back opposite it suggests that the stones may have been rotated into position.
Using 130 volunteers as manpower, the team tested this theory, plus various methods for transporting the stones and raising the lintels.
Moving large stones in the Neolithic Age
Illustrations © 2017 Paul Weston
When the three stones of the Great Trilathon were re-erected in 1923, the original holes the uprights had stood in were uncovered.
They turned out to be holes of a very specific shape. The lower half of the diagram shows a section through one. The shape of the holes suggested the method that might have been used to raise the stones. Using a pivot block beside the hole would provide a stable edge.
To conduct the experiments, the team constructed a concrete replica of Stonehenge's Great Trilithon.
Trilathons have three elements: two uprights and a lintel. The lintels have mortice holes that fit over hemispherical tenons on the uprights.
The uprights of the original Great Trilathon were buried 2.5m deep and rose 6m above ground.
weight of each upright ... 40 tonnes
weight of lintel ... 10 tonnes
weight of tilting stones (see panel 3) ... 6 tonnes