In order to make use of the pipeline, your team needs to control the central objective. The capture switch is situated on a floating platform 300 meters above the ground. To facilitate access to the platform, there are two anti-gravity lifts connecting the platform to an oil derrick below, which is situated directly over an oil spill. Be careful not to fall into the oil during a dogfight, or you'll be a sitting duck while you slowly work your way out of the muck.
Once your team controls the objective, you then gain access to the underground pipeline, which make for speedy travel across the map. Making a quick entrance into the pipeline isn't exactly easy, so some cappers will skip the pipeline in favor of an overland route on the way home. However, if you do get into the pipeline, it's smooth sailing from there on, because the enemy can't get into the pipeline unless they capture the objective. Luckily, you can still get out of the pipeline if you happen to get caught inside when the other team captures the objective.
The flags themselves are perched on wide-open outcroppings at each team's base. This makes for fast and furious swoop-and-grab capping runs. The defense will have a hard time keeping their flag at home if the other team has a coordinated offense.
It's obvious that v5planet put a fair amount of work into Broken Pipeline, and the result is a very fun map.