Operation Megalithic Lift - The Stones and the Stars: Building Scotland's Newest Megalith - page 200

each stone and place it vertically with accuracy, it would take too
long to fix them in position - apart from the general reluctance to
have Sportsworks personnel working under the helicopter. It had
been clear for some time that nets would be used, and the Sea King
would simply lower each stone into the prepared pit and cast it off.
At first it was supposed that the nets would have to be
sacrificed, with the lower parts buried in the cement and their
tops cut off at ground level. But if Sportsworks men and machines
were going to sling the stones and raise them upright in any case,
they could be lifted high enough to clear the nets for retrieval. At
first the Ministry of Defense was adamant that arranging suitable
nets would be our responsibility, and John Braithwaite had con-
tacted various shipping and cargo handling firms in the city, look-
ing for suitable nets and ropes. 'A tip of the hat' is due to Martin
Black's and to Nevisport, who were willing to provide nets and to
sacrifice them if necessary, though they were relieved to hear that
they would get them back.
With only days to go, however, the Ministry of Defense informed
us that its own nets were to be used, and the supply of them from
the Royal Air Force was being flown north to HMS Gannet over
the weekend. Lieutenant Norman Leask, who was in charge of this
part of the operation, was relieved to learn that at the end of it they
would be returned intact. But whereas the nets we had arranged for
were stressed to 10,000 lb weight, the RAF ones were stressed for
only 5,000 lb. I estimated the weight of the central stone at 4,200 lb,
but if I was off by just one inch in my estimate of its mean diam-
eter the weight would rise to 4,800 lb. Norman Leask was unhappy
with my calculations and did his own for the central stone, adding
a safety factor of 25% instead of subtracting it as I had, and came
up with a weight of 6,678 lb - too much for the helicopter, let alone
the nets.
I pointed out that if his figure was correct, all the rest, includ-
ing the weighbridge results, had to be wrong. It would mean that
the central stone had 74% of the weight of the biggest lunar stone,
although they were made of the same rock and it had less than a
third of the volume. Still, with the new nets the safety reserve van-
ished. Should we abandon the symbolism of having the helicopter
complete the structure with the central stone, after proceeding
sunwise around the circle from the midsummer solstice? Sticking