Energy cannon

An Energy cannon was a weapon utilized by Starfleet in the late 2380s. It was similar to Phasers although it fired highly energetic bolts of energy which had high yields, equivalent to over 36 tons of tnt.

The original example were the 3 mounted on Universe-class starships. The 36 tons of tnt they contained were highly compressed, thus making them as "destructive" as described in his [Jean-Luc Picard] encounter with them.

Energy cannons, as witnessed [/\] could cause serious damage to Bird-of-preys, all the way to blasting in a hull breach, and after 9-11 hits, obliterate them.

Energy cannons were not kept to secret as such weapons would be easy to copy.