Castaway activating a Quarryman Hammer.
The Quarryman Hammers are both the main weapon and a symbol of the Quarrymen. The hammers were first created by the Illuminati before handing the reins of the Quarrymen over to John Castaway. 
The hammers are heavy, two handed weapons, resembling sledge hammers. A switch on the handle activates an electrical charge. One strike is capable of shattering a sleeping gargoyle, or dealing serious injury to a live one. ("Nightwatch", "The Journey")
On Halloween, 1996, Castaway ordered the Quarrymen to patrol Manhattan without their hammers, as he didn't want to potentially provoke a public incident. ("Invitation Only")