Gears of War 3 - Hijack

At this point you will be attacked by a new type of flying machine gun enemy called a Shrieker. They are pretty easy to dispatch at range so take them out and make your way down the path. Kill the enemies there and then move forward but not down. When you get closer to the rail, you'll see the barge unload theron Guards. These are packing torque bows, as per usual so be careful when taking these out. If you are quick, they all get off the barge right near an exploding barrel which can help you out. Kill them and then head down either ramp. A door will be open to the left with more locust and a Digger. Take them down and head through the door.

Head down the hill and you'll come to a turret. Take out the turret but before proceeding, look back towards the hill you just came down. Just to the left of it is a room with a gate door. Go break the door down and inside you'll find a boomshot, some ammo, and a collectable on the left side of the floor. Turn back towards the gun emplacement and then you can go through a tunnel just to the left which will bring you out behind the gun emplacement. Clean up any remaining locust and then head towards the back and through the door.

Follow this path to the elevator at the end, grabbing the Retro on the way. At the top, you'll be attacked by the Gas Barge. It will shoot rockets as it circles and it will close in to drop of Theron Guards in groups of two. Once it lets the first two off, you will know where they are being dropped each time. Assuming the top platform is a clock with the first drop point being 12, the next drop will be at 6 and then it will drop at 12 and then 6 again. It never drops them at 3 and 9 and always drops when it passes 6 and 12 until eventually, once you've killed enough enemies, it will dock and you can board it (with resistance).