Everitt Enterprises has apologised to neighbours for the noise as it transported thousands of tonnes of heavy steel from its Wilkie Rd, Dunedin, premises to Otago Harbour.
Drivers worked around the clock from lunchtime on Wednesday to late last night to transport 3200 tonnes from the company's yard to the ship ID Black Sea, owner Peter Everitt said.
As a result, the company had received calls from upset neighbours.
"I apologise for disturbing the neighbours."
Because of time constraints and costs, the ship had to be loaded as quickly as possible, he said.
The ship would transport the steel to Korea where it would be melted down and turned back into new product.
The scrap metal had piled up to "exceptional heights" due to the downturn in container shipping, so he had to bring in a ship to take the scrap away, he said.
ID Black Sea is due to leave at 7am today.
He hoped to continue putting scrap in containers to avoid another large pile growing at the Wilkie Rd yard.
