The Broadsider is the answer to that age-old question: "Would it be fun to walk around and shoot people with a portable naval cannon?" Yes. Yes it would.— VDSG Catalogue No.9708

The Broadsider is a unique weapon in Fallout 4.


An unusual heavy weapon mixing 18th-century ordnance with 23rd-century technology. The main body consists of a small old-fashioned naval cannon (possibly a muzzle-loading swivel gun) strapped to a makeshift rig with metal rivets and thick ropes. This rig allows it to be carried around with both hands easily and includes a hinge allowing the cannon to be angled vertically for easy reloading. It fires explosive cannonballs via an electronic trigger taped to the back handle.

The Broadsider's base damage is affected by the Heavy Gunner perk.

Weapon modificationsEdit

Slot Mod Description Weapon prefix Damage per shot changeIcon damage Fire rate changeIcon attack Range change Accuracy changeIcon spread Magazine capacity (shots per reload) changeAssault carbine extended magazines Weight changeIcon weight Weapon value change in capsIcon merchant Perk needed Components Base ID
Barrel Standard barrel Standard. Adhesive x4
Screw x10
Steel x13
Light barrel Better hip-fire accuracy. Fluted +2 -4.5 +10 Gun Nut 1 Adhesive x8
Aluminum x13
Lead x6
Oil x4
Screw x10
Grip Standard grip Standard. Screw x8
Steel x13
Steady grip Better recoil and hip-fire accuracy. Steady +2 +1.3 +45 Gun Nut 1 Adhesive x10
Aluminum x14
Rubber x6
Screw x12
Spring x11
Shot Canister Standard shot canister Adhesive x2
Steel x4
Multi shot canister Better ammo capacity. Repeating +18 -16 +2 +5.4 +100 Gun Nut 1 Adhesive x5
Aluminum x10
Screw x6
Spring x8


Rewarded by Ironsides during the quest Last Voyage of the U.S.S. Constitution. Siding with the scavengers instead makes this weapon unobtainable.


  • The Broadsider is a powerful weapon, only surpassed by a fully upgraded Gauss rifle, a missile launcher and a Fat Man in terms of raw damage output. However, its considerable weight, very limited range, lack of aiming pointer, low ammo capacity, pronounced ballistic trajectory of its projectiles and exceedingly rare ammunition (although it can be bought from shops) make it less convenient to use than some of the more regular weapons.
  • Use of an eyebot pod to search for cannonball ammunition will yield 35 - 40 each time. It is entirely possible to use this weapon as a mainstay. Even with full perks the AoE is small enough to use this weapon in much tighter battles than expected for an explosive armament.
  • The Broadsider uses less AP per V.A.T.S. shot than a missile launcher– almost half– while weighing significantly less than a fully upgraded missile launcher. A V.A.T.S.-based heavy weapon character may find it substantially more useful in this regard.
  • The cannonball reward from the end of Last Voyage of the U.S.S. Constitution appears to be tied to the weapon. Adding another one to the player character's inventory will also add the cannonballs.
  • At some point in development, the weapon was intended to have weapon mods that would change the properties of the cannonballs. In the game's archives, there are meshes for an alternate version of the front part of the electronic trigger, along with a mesh for a cannonball with a fuse. This cannonball variant is a cut projectile that appears to have been intended to produce timed detonations.
  • Additionally, there's another cut projectile that causes a larger explosion on impact, similar to the explosion caused by cars. The name of this, BroadsiderProjectileMortar, suggests that it was to be similar to the projectiles used by the artillery pieces.
  • A "Nuke" variation of the weapon can be added with the console command player.additem 65df2 1.
    This version of the Broadsider launches gigantic nukes, and uses a custom ammunition type called "Nuke," which can be added with the console command player.additem 65df3. However, being a cut weapon, it does not actually consume the "Nuke" ammo, making it a weapon with infinite ammo.
  • Even though it has no legendary modifier, the Broadsider cannot be scrapped at a weapons workbench.

Behind the scenesEdit

  • The term "broadsiding," or "firing broadside," is a naval term, referring to firing all the cannons (in jargon referred to as 'guns') that can be pointed to one side of a ship, all at the same time.
  • The marking on this cannon is the Royal Cypher of King George III, who was born in 1738 and reigned from 1760 to 1820. There appears to be a date on the first reinforcing ring above the cypher which shows the year 1820. King George III died in January 1820, meaning that this cannon was cast in the foundry during that month. The second reinforcing ring above the cypher is illegible but the info on that ring might state the weight and inspector's mark. There is no historical reason for a British cannon from 1820 to be aboard the U.S.S. Constitution, so it is safe to assume that it came with the robots.