It took me some time to research this one ...
What a Halligan tool is
A Halligan (or Halligan bar) is a multipurpose forcible-entry tool used mainly by firefighters, rescue teams, and law enforcement. It’s a single forged steel bar with three principal ends that let you pry, punch, twist, and lever open doors, windows, locks, and other obstructions.
Main parts
Adze — a wide, chisel-like blade for prying and wedging.
Pick (or spike) — a tapered pointed end for punching or creating anchor points.
Fork (or claw) — a two-pronged fork used to grip or spread material.
Typical specs
Common lengths: 18", 21", 24", 30" (shorter for tight spaces, longer for more leverage)
Material: forged carbon steel
Weight: varies by length — generally a few pounds (heavier models for more leverage/durability)
How it's used
Prying a door or window frame open by wedging the adze and twisting the bar.
Striking with a halligan or pairing it with a flat-head axe (the combination is commonly called “the irons”) — one person drives the adze/pick with the axe while another manipulates the bar.
Forcible entry: breaking locks, pulling hinges, creating purchase points for other tools.
Rescue: opening vehicles, cutting through thin metal (with additional tools), or creating openings.
Origin / note
It’s named after Hugh Halligan, a New York firefighter who developed this design; the tool became widely adopted because of its simplicity and effectiveness.
I hope this resolves this dispute between valued HQ2 posters....