They helped to move a replica eight-tonne Viking trading ship from sea onto land to see how the Scandanavians would have attempted such a feat 1,000 years ago.

Researchers believe the Vikings moved their boats across land in order to avoid the hazardous journey round the tip of mainland Shetland.

Local volunteers were on hand when the ship arrived at Shetland from Norway to unload its cargo and pull it over Mavis Grind and back to water.

Muscle power moves the decks

Organisers spurned modern conveniences such as the crane, preferring in the interests of authenticity to use ropes, pulleys and logs.

Despite the number of hands available, the exercise took four hours to complete, leaving the islanders happy but exhausted.

Adventurer Robin Knox-Johnston, who helped organise the move, said the exercise was undertaken in order to see exactly what kind of problems the Vikings would have experienced in their time.

He said: "We were trying to show that it was possible to move a trade vessel across bits of land.

"We know the Vikings did it - but that was 1,000 years ago. Although the people of Shetland have moved boats around, this is a heavy Viking boat."

The manpower required to move the boat served to underline what researchers had already suspected - that the Vikings would probably have kept a ship of this size in the water rather than move it on to land.