This map is very close-quarters. These tactics are for 2v2 or 4v4 matches.
In a 2v2 match on this map if you are on the Assault team you both run downstairs then go down to the West Elbow and go down to West Extraction Sewer. From there one of you goes to the other side and watches the East Extraction Sewer. You camp there until you see enemy movement. Take the enemy down from there. If on the Defending team you both rush down and the first one that makes it down the East Sewer runs into the East Extraction Sewer and goes to the West extraction sewer. The other guy takes down the people at Main Junction and then moves forward into the East extraction sewer and covers for remaining Opfor.
If it is a 4v4 match it is almost the same plan as in a 2v2. The difference is that 2 people do the same on the other plan for a 2v2 and the other two on your team goes up and rushes trying to either flank the enemies downstairs or take out the Opfor upstairs. If the upstairs people need backup because the whole Opfor stayed upstairs, return to provide them backup. This should give you a 7-0 win if you play it right.
Tips :
- When going up: When you start new round, go up and flash the other side quickly, then enter their side and flash 'em, if there are few people on the server. There is lower chance to flash 8 of them than flashing 4 of them.
- Rushing the objective: If you are on Defense team, and if Assault team is rushing the objectives go down and try to run fast and keep your head down then rush to the objective, also bring someone with you so you two can cover the east and west entrances which are the only entrances for the objective. This way Assault team can no longer rush objective!