PLT OF BE18 IS UNABLE TO EXTEND LNDG GEAR FOR LNDG.

Narrative

I HAD FLOWN VFR PLANNING A FUEL STOP AT ZZZ. ON FINAL AT ZZZ; I WAS UNABLE TO GET THE GEAR DOWN NORMALLY. AFTER GAR AND IN CONTACT WITH FBO ON UNICOM; I TRIED THE LNDG EXTENSION SEVERAL TIMES. THE MANUAL HAND CRANK WOULD NOT ROTATE AFTER THE LNDG GEAR CLUTCH PEDAL WAS DEPRESSED. NO AMOUNT OF FORCE I COULD APPLY WOULD MOVE THE HAND CRANK. MANUAL EXTENSION OF THE FLAPS WORKED OK. ZZZ HAS ONE RWY 5000 FT X 100 FT; SO I DIVERTED TO ZZZ1 WITH RWY 5001 FT X 150 FT. ENRTE TO ZZZ1; I MADE 2 MORE ATTEMPTS TO MANUALLY LOWER THE GEAR. NO JOY. ON FLY-BY N TO S AT ZZZ1; AN FBO EMPLOYEE ADVISED ON UNICOM THE GEAR WAS NOT DOWN. I THEN DECIDED TO LAND (GEAR UP). THE FBO EMPLOYEE ADVISED THE EMER EQUIP WOULD BE STANDING BY. I MADE THE APCH WITH FULL FLAPS ABOUT 100-110 KTS AND WHEN LNDG ON THE RWY WAS ASSURED I PUT BOTH MIXTURE CTLS IN IDLE CUT-OFF AND GANG-BARRED ALL 4 MAGNETOS AND GENERATOR BATTERY SWITCHES. CONTACT WITH RWY WAS SMOOTH WITH FLAPS TAKING UP MOST OF THE IMPACT. THE MAIN GEAR WHEELS PROTRUDE ABOUT 4 INCHES BELOW THE NACELLE; SO ON ROLLOUT; BRAKES WERE EFFECTIVE FOR STEERING AS WELL AS STOPPING. I SAW NO FIRE OR SMOKE; HOWEVER; THE EMER CREWS SAW SOMETHING UNDER THE R-HAND WING AND SHOT SOME FOAM. I WAS ALONE; NO PAX; NO INJURIES.