A bomb disposal squad was called to a Cornish beach on Saturday morning after lifeguards reported a possible explosive object.
Lifeguards found the corroded object on Porthmeor Beach in St Ives at around 10.30am on Friday and alerted Falmouth Coastguard.
Coastguard crews in St Ives were called to the scene and police initially set up a 100m (328ft) cordon.
Photographs of the object were taken and sent to the Royal Navy bomb disposal team, which is based in Plymouth.
The squad studied the photos before attending the scene at low tide this morning (Saturday), where they confirmed the object was a ship’s boiler.
It is understood necessary precaution was taken in case the object was some sort of explosive or anti-submarine warfare weapon.
A Falmouth Coastguard spokesperson said it is believed the object had been there for some time but had only recently been uncovered by sand.
The incident, which was ongoing during the night, was cleared by 11.30am today.