The war in Syria is now five years old. In that time, there have been so many factions vying for power and battlefield superiority, some under-equipped group was bound to have to get creative with their weapons tech. Enter the Hell Cannon.
First rigged up in the rural areas near Idlib, the Hell Cannon is an improvised, muzzle-loaded cannon, built by the Ahrar al-Shamal Brigade, then a member force of the Free Syrian Army. The homegrown howitzer caught on and was soon produced in and around Aleppo. The cannon's popularity is responsible for a grassroots weapons industry in the area.
The weapon is essentially a barrel mounted to wheels and towed to where it needs to go. It's entirely muzzle-loaded like an old timey powder smoothbore cannon. The powder is an explosive, usually ammonium nitrate (the explosive used by Timothy McVeigh in the 1996 Oklahoma City Bombing), which is ramrodded with a wooden stick. The round is a gas cylinder (commonly used in the region for cooking stoves) filled with explosives and shrapnel, and welded to a pipe with some stabilizing fins.The cylinder forms a tight seal in the cannon.
Each round weighs roughly 88 pounds and will fly 1.5 kilometers (just under a mile). Some variants of the weapon will have multiple barrels, from two to seven. Others are welded to vehicles like cars and bulldozers.
Newer developments in the weapon feature a 100mm shell used by Russian T-55 tanks attached to the tubes instead of the improvised gas tank. Others use real mortar rounds or compressed air cannons. The Syrian Observatory for Human Rights calls the cannons "wildly inaccurate," because it causes a lot of collateral damage and civilian casualties.