Yes, same concept. The problem was the power plant was underpowered and it couldn't build up enough speed to sally out and engage in battle. So, they anchored it in the river and used it as a battery to protect the fort and city from Union ships attempting to sail up the river. Sherman's arrival broke up that party.
The Confederate States Navy patterned all of its ironclad rams after CSS VIRGINIA.
The United States Navy patterned all of its ironclad gunboats after USS MONITOR.
Both designs “worked” after a fashion.
IIRC ‘Merrimac’ is the name of the ship when it was a US Navy frigate. The US Navy scuttled it at Norfolk, the Confederate Navy raised it and rebuilt it as the ironclad ‘Virginia’.