The crew were heaving anchor on a tanker in ballast. As the starboard anchor came into sight above the water the officer noticed something was not right.
He stopped the operation and informed the bridge team. Upon closer viewing it could seen the anchor crown shackle was fractured. The port anchor was released and arrangements were made to have the starboard anchor disconnected and a new crown shackle installed. The investigation could not establish a cause for the fracture. The crown shackle...
https://www.marineinsight.com/case-studies/real-life-incident-fractured-crown-shackle-spotted/