Stonehenge Solved Its Three Observatories, Who built them, How and Why

Whether or not the third party was told the whole story of the Learner team, they surely would have known about the prospective and daunting initial task of constructing mast 156, Fig 49. Its 9m (30ft) long, 45tonne upright 56 was to be positioned on the site of the termination pit, with its unusually shaped fellow 55 close by, and near insecure ground. The veterans of the Model team would have contributed to their thinking about this, because their plans had taken it all into account at the outset. The evidence of all the third party's efforts justifies the name afforded to them: the Innovatory Team, although their achievements in bringing the construction process back on track were to be somewhat offset by an unfortunate event. This was to prompt their premature return home.

Unusually, at the quarry all the faces and sides of upright 56 were made smooth, the outer face flat, the inner one asymmetrically curved as viewed from the side. This suggests that because it was longer than all the other stones it came from an unusual location at the quarry. It would appear to have necessitated a special subsidiary trackway over undulating ground and feeding into the customary track, hence the curvature. Maybe at the junction the stone was turned over 180 deg to proceed on its flat face like all the other stones. The extra length of the upright enabled its foundation butt to penetrate the chalk the required 1.2 cm (4ft) below the bottom of the offending pit, thus ensuring the customary degree of stability in firm unweathered chalk. The first attempt to raise it to be vertical was while on its side in a trench, orientated northwest from its foundation hole. This, it is supposed, was to avoid employment of a ramp inwards of the foundation hole, which possibly could have rendered insecure the ground on which the fulcrums of the lifting levers were to be placed. However, the difficulty of lifting it from the trench must have proved insuperable, because in the event the inner ramp was ultimately used.

Its fellow upright 55, as identified at the quarry by the Model team, had a unique 60cm (2ft) wide outwardly orientated foot, worked smooth on its underside, which served to reduce its ground loading by a half; an arrangement designed to cope with the troubling insecure ground in its vicinity. However, this was not deemed by this team to be a wholly adequate safeguard, and as a further precaution the line of the whole mast was turned 7.5 deg anticlockwise, Fig 42. This served to distance upright 55 even further from the suspect area. When remembering the Model party's concern about this problem, and the mistake of the Learner party with their local circumference, and all that stemmed from it, it is ironic that when this upright ultimately collapsed, it fell in the opposite direction into the area of the ramp used for its erection.

The mast's horizontal bearer, with its temporary service ends, was three times heavier than a circle beam, and to lift it three tree stem levers side by side were operated in unison, Figs 50 and 51. As well as being an insurance against the suspect ground, this tricky task was facilitated by the three associated fulcrums being mounted on a stone bolster sunk into a trench dug parallel to the line of the mast. The stone used for this was the damaged cross-beam abandoned at the arch, which, in this guise, is conventionally called the Altar Stone 80. This fractured under stress in service, and was left in place on completion of the work. The bearer, in plan shape curved to match the circle, had a dimple sunk into its upper surface towards each end. Into these fitted lugs left on the underside of a matching timber half-log, or runner, over which the hoist lines would pass on their way to the bollards (via entwining round one or other upright), (i).

In preparation for its raising, the bearer had an additional 'service' length of stone left at each end, as mentioned earlier, under which would be stood timber props, or struts, of increasing lengths to support it as the lifting took place. It is speculated that the final form of these props enabled the bearer to be moved outwards and over the tenon formed on the top of each upright, and subsequently lowered on to them, Fig 52. Once in position the now redundant service lengths were chiselled off. For about 2m (7ft) above ground, the four corners of upright 56 were radiussed, the inner ones of these ending at notches cut into the corners. These facilitated the process of entwining the hoist line, otherwise made difficult by the smoothness of the stone. For an accurate, stable, setting of a spar a degree of friction was necessary between the hoist line and the upright's surfaces, Fig 49. The unique mast was now complete, needing only the greasing of its runner and the addition of bollards for eventual operational use.

The next main task was erection of the circle from upright 08 with beam108, round to upright 17 with beam 117. This would complete the third station of mast 152 and all three for mast 156, together with the intervening non-assisted spars, of course. However, as will be seen in the next chapter, none of the bollards serving the stations and masts were erected during this work, and therefore none of it could have been checked with the rigging and spars in place. This second main task was not a straight forward one, but challenging because of the need to overcome the difficulties created by the Learner team's mistakes with its uprights, particularly 07 and the misplaced mast 154.

The Innovatory team chose to position upright 08 accurately on the scribed circle, including circumferentially, and a parallelogram shaped (in plan) short beam 108 was installed. This positioning of the upright allowed a proper following gap at 109. The beam 108 provided support for beams 107 and 109 either side of it, but it did not host a spar itself; this was sacrificed. This is clear for three reasons: the gap was too narrow to accommodate a spar plus its rigging, the hoist line would have fouled that of 107, while ultimately mast 152 was to be afforded only three bollards implying two spars, (three spars would have had four bollards).

Seeking to understand the next three stations is more complex, Figs 3, 42, 53. The next upright,10, was much wider than the norm. It was skewed slightly clockwise so that its clockwise end was partly inside the circle, but its anticlockwise end was positioned correctly to it. The effect of the latter point was for beam 110 to be correctly positioned so that its hoist line would align appropriately to the 154 mast, had this been correctly positioned, which it wasn't! The consequence was the hoist line would just miss the anticlockwise end of the runner. (When the next team came to rig the mast they introduced a guy rope anchored to a stone peg, 35B, introduced in the 110 gap. They used this to slew the butt of the spar anticlockwise, which had the effect of safely bringing the hoist over the runner. This suggests the Innovatory team was in ignorance of mast 154 being misplaced, and that the Learner team was unaware of the error they had made. Be that as it may, the marginal positioning of the hoist on the runner precluded ranging movement of the spar, and this ensured that only one bollard would be needed to service it: an outcome the following team actioned with only three mast bollards in the four positions.)

The situation concerning the two following stations: uprights 11 and 12 and the beams 111 and 112, when put together with upright 10, is unique in the installation. Like 10, upright 12 was also wider than the norm, and to compensate for this, upright 11 between them, was made very narrow. Not only this, upright 11 was also positioned well outside the circle, and the consequences of this for beams111 and 112 are unmistakable. Beam111 was heavily skewed anticlockwise relative to the norm, while beam 112 was skewed only slightly less so, but in the reverse direction: clockwise. The consequence of this in turn, was that when rigged the hoists would cross one another before reaching the runner, to result in unhelpful chafing. The problem may have been overcome by modifying the runner to be stepped in height part way along its length, thus distancing the chafing hoists.

Regardless of whether or not mast 154 was incorrectly positioned, there seems to be no physical reason for these aberrations, yet clearly they were deliberate. A possible reason may have been a planned compensating modification of the mast 154 sighting capability, and windows in the dome of the sky, as follows. Station 112 as revised, would allow the window to be extended clockwise by 10 degrees. Station 111 was realigned 16 degrees anticlockwise, which could have been intended to compensate for the ranging of spar 110 being constrained by the end of the runner. In explanation of all this, perhaps early on in their work, the Innovatory team realised the mast was misplaced, and although the rigging operation had yet to be done (by the next team), they sought to correct what they anticipated would be a deleterious affect on the skyward sighting windows.

This leaves the question of whether or not these arrangements were preplanned: the following affirming hypothesis is advanced. At some earlier stage, perhaps when the Innovation team first arrived, in anticipation of the work, they ordered from the quarry, amongst other stones, two circle uprights of normal size, plus one very narrow one. When these arrived on site ahead of time they were, like the erstwhile arch, deployed for dual purposes until required. In this instance, circle uprights were erected one on each side of the entrance path to act as beckoning waymarks (the cranked joining of way SU 0637-1 and the entrance path at the erstwhile arch, may have proved to be confusing for new visitors). The narrow upright was erected just to the west of these in stone hole D, a ploy to deter possible misuse of it were it to have been left on the ground (ii). When the time came for work to start, prospective stone 11 was levered out of hole D and positioned at the circle. At this juncture it was realised the available stones for the beams were too short to span the gaps 111 and 112, if the two waiting, normal sized uprights were used. Better, they thought, to leave them standing as contingency spares at the entrance path, and order two much wider stones from the quarry as a matter of urgency. (The easterly stone of the contingency pair is prostrate today and is conventionally called the Slaughter stone, or stone 95, Fig 1.) The uneventful construction of the following stations 113 and 114, did not serve to lull the team's sense of innovation: the Z113 guide post hole was the scene of experimentation, Fig 47. Two lengthly sarsen stones, nos. 66 and 68, were afforded specially shaped cross sections, including matching tongue and groove respectively, and with a slow taper down their lengths. The idea was that when placed together in the hole, enlarged to receive them, 68 would be hammered down so the wedge action expanded their semi-circular flanks against the sides of the hole. This would ensure a continuing firm fit when in service with the tree stem lever. However, sarsen stone is relatively weak when stressed thus, and stone 66 cracked, thereby precluding further use, The idea was not pursued and the following team were to utilise the remnants.

Thereafter it is probable the intention was to erect upright 17 and beam117, thus completing the trio of stations for mast 156 (although in the absence of beam 118, station 117 would not have been properly secure for operational use). In the event this was not to be; they only got as far as erecting upright 16. This, with upright 15, was a little too far clockwise round the circle, although this discrepancy was not critical. It results in a Nominal, or Executed Axis for the installation through the mid point of gap 116 to gap 101, as distinct from the Design Axis struck through the midpoint of the entrance gap 101 and the circle centre (iii).

The reason upright 16 was the last to be erected, and not 17 after all, was because when raising beam 115 a mishap occurred which ensured ignominy would befall the team, especially in the eyes of their successors, Fig 54. In the process of raising the beam the tenons of the pommel and shackle frames were damaged beyond repair, thus rendering them useless, with the consequence that the task needed to be completed by improvised means. By this stage the pommel and shackle horizontal stones had undergone considerable wear, as evidenced by the underside of the former. But it is probable the principal cause of failure was their unwitting error of sinking the legs of the shackle frame into holes dug in the insecure fill of the ancient waymarking pit Fig 6. The team's frustration would appear to have prompted them immediately to leave for home. Workman who had commenced digging a hole for the following position of the shackle frame, ready to raise beam 116, abandoned the task, but not before throwing his antler pick into it, probably in disgust. This unfortunate legacy for the following fourth and final team, was seemingly compounded by the Innovation team leaving behind them barely enough beams to complete the installation. Possibly they had been too preoccupied with their problems to think about it.

The Innovatory team had the misfortune of inheriting the Learner team's mistakes, and perhaps through impatience, brought their planned assignment to a premature end, but their record of spontaneous initiatives is impressive. Their activities are summarised in Fig 55.