LONDON/OSLO (Reuters) – Four gigantic Norwegian-made plastic pipes up to 480 meters (1575 ft) long were discovered washed up on the English coast after a collision with a container ship in the North Sea, officials said on Friday.

The pipes, approximately 2.5 meters in diameter and under tow to Algeria from Norway, washed up by Horsey and Sea Palling in Norfolk. Eight pipes remain under control offshore.

Authorities said the beached pipes ranged from around 200 meters to 480 meters long.

They said there was no danger or potential for pollution from the pipes and that two specialist companies, Dutch Marine BV and Marine Towing Services, were working to remove them.

All pipes are expected to be secured at a single location before being towed back to the manufacturer, Pipelife Norway.

“The pipes were under transport to Algeria when a container ship crashed into them and drove right through,” Pipelife Norway CEO Kjell Larsen told Reuters. He declined to name the vessel or its owners.

He said that the accident happened on July 18-19 and that the pipes were part of a delivery totaling 3,200 meters long for a construction project in Algeria.