1 The four hundred or so enormous stone statues, or moai, that dot the landscape of Easter Island have puzzled visitors ever since the arrival of the first Europeans. Weighing up to two hundred and seventy tons, and some of them as tall as a five-story building, they were first carved in a volcanic crater and then transported and erected on huge stone platforms all over the island. Yet Easter Island’s Polynesian population had possessed no cranes, wheels, machines, metal tools, draft animals, or any means other than human muscle power to move the statues. How had the islanders managed to transport and erect them?
2 Many theories have been proposed as to the origins of the moai, such as attributing them to visitors from the Inca empire, or even to visiting extra-terrestrials! Some evidence can be found in the oral traditions of the islanders themselves, and more can be found by carrying out experiments using different transport methods.
3 But whatever means the islanders used for transporting and erecting the moai, at the very least they would have needed heavy logs and strong ropes. Yet, when the first Europeans arrived, there was not a single tree on the island. In fact, apart from a few low bushes, it is the most tree-less island in Polynesia. Where were all the trees that provided the rope and timber that would have been needed?
4 Now investigators have recovered and identified plant remains that show that Easter Island was not always a tree-less wasteland, but was once covered by tall, sub-tropical forest. The forest was home to a wide variety of birds, which would have been hunted for food. Many of the forest trees would have supplied food, firewood, bark for making cloth, and wood for making harpoons. The most distinctive of these now-vanished tree species was the world’s largest palm tree. The huge leaves of these palms would have provided roofing material for their houses, and sails for their canoes. Their thick trunks would not only have provided hulls for the canoes, but would have served for transporting and erecting the statues.
5 But how do you move a statue that weighs over 10 tonnes across 10 kilometres of rough, hilly, rocky ground when you don’t have draft animals or even wheels? This is the mystery of the Easter Island statues. How did the islanders transport them? There is no shortage of theories. The Easter Islanders themselves believed that the statues could be made to walk by people who had supernatural powers. This theory inspired a Czech researcher, Pavel Pavel, to try “walking” the statues. He made a life-size replica and stood it on its base. Using a crew of 17 people divided into two groups, he tilted the statue onto its back edge. With one rope around the head of the statue and another around the base, they walked the statue forward by rocking it from side to side. Using this method, Pavel estimated that it would take about three days to move a statue about 1 kilometre. But there are doubts that the method would work over anything but the flattest and smoothest terrain.
6 The Norwegian explorer Thor Heyerdahl has his own theory as to how the statues were moved. He took one of the original statues, which weighed 10 tonnes, and laid it on its back on a sledge that was made from a forked tree trunk. One hundred and eighty islanders pulled the statue using two parallel ropes tied to each side. The problem with this method is that it requires a huge work force. If it takes 180 people to move a statue weighing 10 tonnes, it would take an estimated 1,500 people to move the largest of the statues, which weighed up to 80 tonnes.
7 A third theory was proposed in the 1960s by William Mulloy in an attempt to explain how the biggest of all the moai – the 80-tonne “Paro” – was moved. The basic idea behind this theory is that the statue was laid face-down on a kind of curved sledge and also supported by two enormous wooden legs, attached by ropes to its neck. By inching the legs forward, and at the same time rocking the statue on its curved belly, it may have been possible to cover the 6 kilometres from the quarry to its platform using just 90 men. However, the theory has never been put to the test, and the size of timber needed would have been enormous. Also, it's doubtful that the statue's neck could have withstood the strain.
8 In the 1980s, Charles Love, using a 10-tonne replica statue, attempted to advance it by pulling it side to side, with ropes tied around its head like a refrigerator being walked forward. However, he was only able to move it a little way before it fell over and suffered some damage. On a second attempt, they placed the statue upright on two sledges on top of log rollers. Using this method, 25 men were able to move the statue 50 metres in two minutes. But again, like Pavel Pavel's walking method, the chances of advancing without accident over rough terrain are very slim. In short, despite years of adventurous experiments, we are still not much wiser as to how this extraordinary feat was achieved.