The Confederate forces made a good job of penetrating the river obstructions (I had simplified these to a line of scuttled ships and log pilings - I didn't include the mines/torpedoes as that would have slowed things down a lot), but by the time they had punched a hole the Onondaga had arrived on scene and started shooting up the Confederate ironclads to great effect. Hunchback went town to a spar torpedo from one of the Confederate Squibs, Virginia was sunk in quick order by four concentrated shots from Onondaga which caused flooding criticals, Fredericksburg was also shot up and sunk.
Richmond looked to be getting past the Union fleet but a shot damaged her engines and she was slowed up (and had suffered heavy damage to her armament) and it was obvious that Onondaga would overhaul her and sink her quickly, so we called the game. A Union victory but it could have gone either way.
Thanks to Stuart and Nigel for running the Union and Confederates respectively (with occasional help from passers by), and to Helen and Nick for popping in. A fun day for all I think