The deadly collision between the HMS Victoria and HMS Camperdown
The British Mediterranean Fleet's maneuvers result in a tragedy with hundreds of men drowned. The two ships were roughly of equal mass although the weapons layouts were different; these ships predated the Royal Soverign and Majestic classes which set a standard for British and other nations' battleship designs. Accidents such as these may have contributed to the belief in the ram as an effective weapon in actual combat, as depicted in fictional accounts at the time. However, except for some destroyer battles in WWI, deliberate ramming proved to be too difficult against mobile enemy fleets.
A good description of the incident and theories about why it happened can be found on this link
