Diesel Barrel

Since I could not find any lists online, I decided to search them. Here are my findings. Feel free to share!
Monuments possibly without:

• Train Yard: none found
• Any Harbour: none found
• Satellite Dish: none found
• Sewer Branch: none found
• Excavator: none found
• Launch Site: none found
• Abandoned Mil. Base: none found

Barrels found on:

• Dome: 2 on top/side, outer ring
• Power Plant: 1-2 near subway entrance, 1 in the back on a round metal thing above a pit, 1 at the back where you put the outside fuse
• Airfield: possible 1 at the tower right from hangars, 1-2 inside main scrapper room left of the bubbler, possibly 1 in the left hangar, all seen from the main building.
• Junkyard: possible 1-2 on top near scrapper/green card, possible 1-3 in inner-outer ring, possible 1 near the entrance with the car lift
• Water Treatment: 1-2 near the scrapper on the bottom floor, 1-2 at the building right next to it outside, 1 on top of a circle near the subway entrance
• Military Tunnels: 1-2 in the fuse room at the entrance, 1-4 at the end left side across blue door (train track)

Both oil rigs have multiple;

• Large: 2-4 on top near the crane to the left and right of a tanker, possible 1-2 on the floors below
• Small: 1-2 on top, possible 1-2 on the floors below

New locations:

• 1-4 Diesel Barrels can be found at the bottom of Missile Silo, on the flatbed truck.

This list might be incomplete. Please add findings not listed.
Edit: updated known locations, added new monument.

This collectible is found at...

• The dome
• Oil rigs
• The junkyard

and can be used in the Large Excavator.

Locations:
Junkyard • Located near the Chinook Military Crate spawn, a little down the path heading East. Will spawn with a tyre around it
Dome • At the top on a platform on the outside of the Dome
Small/Large Oil rigs

There are 2 locations on the Dome. One spawns on the catwalk and the other spawns hidden under it. It's not to dangerous if you jump off onto the rail.

Diesel Barrels Can be Obtained in the Following Ways:

[ul] [*] At the Large Excavator monument, a diesel barrel can be used to collect any of the following: 5000 Metal Fragments, 2000 Sulfur Ore, 10000 Stone, or 100 High Quality Metal Ore. [/*] [*] At one of the Pump Jacks found near the Power Plant, Trainyard, and Water Treatment Plant monuments, a diesel barrel can be used to collect 60 Crude Oil and 170 Low Grade Fuel. [/*] [/ul]

Diesel Barrels are used in the following ways:

[ul] [*]At the Large Excavator monument, a diesel barrel can be used to collect any of the following: 5000 Metal Fragments, 2000 Sulfur Ore, 10000 Stone, or 100 High Quality Metal Ore. [/*] [*]At one of the Pump Jacks found near the Power Plant, Trainyard, and Water Treatment Plant monuments, a diesel barrel can be used to collect 60 Crude Oil and 170 Low Grade Fuel. [/*] [*]At a quarry, a diesel barrel can be used in the following ways: [ul] [*]Stone Quarry) Used to collect 5000 Stone and 1000 Metal Ore [/*] [*]HQM Quarry) Used to collect 50 High Quality Metal Ore [/*] [*]Sulfur Quarry) Used to collect 1000 Sulfur Ore [/*] [/ul] [/ul]
Sidenote: Most players do not use their diesel fuel so if you would like to take advantage of diesel, a vending machine shop is a powerful way to collect a lot of the resource to use at one of the quarries, pumps, or the excavator.

Up to 3 can be found in the new Missle Silo monument, in the "garage" room with the computer that counts down to the wipe event, in the bed of the military pickup truck, next to an elite crate.

You can also buy it at Outpost for 300 low grade. Check the vending machines.