B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 220; Flight Crew Total 18900; Flight Crew Type 12000
Human-Machine Interface; Troubleshooting
Aircraft Equipment Problem Critical
Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Aircraft
First Officer (FO) was pilot flying.  During takeoff from [at] approximately 80K; FO asked if I was on rudder pedals.  I told him no as he was attempting to put in right rudder to keep airplane on runway centerline.  Aircraft remained on centerline.  We were then going through approximately 120 knots when he said 'Something does not feel right in rudder'  At this point I elected to continue takeoff as we were rapidly approaching V1.  We took off and continued with climbout and cleaned the airplane up.  He said he had [to] 'muscle' the right rudder pedal to keep airplane on centerline.  He said he felt as if there was no hydraulic assist in the rudders.  He asked me to 'feel' the aircraft.  I took control and the rudder felt very heavy.  I then engaged the autopilot and gave the FO back the aircraft.  We leveled off at 11000 FT to trouble shoot.  FO continued to fly the aircraft....  I went to QRH to look for assistance on rudder problems.  Nothing was found for that problem.  Contacted dispatch through Commercial Radio and also tried to consult with  Maintenance Control.  At that low altitude; it was almost impossible to talk with either over Commercial Radio.  We advised them we were going to return to [our departure aiport].  As we had a flight control problem; we declared and emergency with ATC; requested return vectors and requested ARFF.  We landed...overweight.  The landing was normal [with] a minimal sink rate.  We taxied off runway uneventfully and [taxied to the gate.]
A B737 flight crew declared an emergency and returned to their departure airport when the right rudder pedal was heavy and input unresponsive.