HDG TRACK DEV ON DEP BY A CL65 FLT CREW FROM EWR; NJ.

Narrative

DEPARTED EWR VIA EWR 6 SID FROM RWY 22R; WHICH REQUIRES AN INITIAL HDG UNTIL 2.3 ILS DME; THEN ANOTHER HDG UNTIL RECEIVING RADAR VECTORS. DEP CTL GAVE CLRNC OF A HDG TO FLY TO JOIN THE 350 DEG RADIAL OF COL VOR AND THEN PROCEED INBOUND TO COL VOR. OUR ACFT HAD THE FMS INOP UNDER MEL PROCS; SO WE WERE NAVING THROUGH RAW DATA MEANS. BY THE TIME WE SWITCHED FROM ILS DME FREQ FOR SID DEP TO THE COL VOR FREQ; COMPLETED CLB CHK; ETC. WE HAD FLOWN THROUGH THE ASSIGNED VOR RADIAL. I SWITCHED TO COL VOR; DIALED INBOUND COURSE; TOLD THE FOF (PF) WE HAD GONE THROUGH INBOUND COURSE; AND HE BEGAN A L-HAND TURN TO REJOIN THE ASSIGNED INBOUND COURSE. AT THIS TIME; DEP CTL TOLD US TO 'TURN L TO HDG 120 DEGS AND REJOIN THE 350 DEG RADIAL OF COL VOR.' NO TFC CONFLICTS OR ALTDEVS WERE APPARENT. ALT AT TIME OF RADIAL DEV WAS LEVEL AT 5000 FT MSL AFTER DEP. CONTRIBUTING FACTORS WERE FMS BEING INOP; HIGH WORKLOAD RIGHT AFTER DEP; AND NOT HAVING ONE SIDE NAV FREQ TUNED TO COL VOR FREQ. FO WAS HAND FLYING ACFT AT TIME OF OCCURRENCE BUT HAVING AUTOPLT ON WOULD HAVE HELPED HIM HAVE MORE TIME TO POSSIBLE NOTICE OUR NAV SIT. IN THE FUTURE; I WILL MORE ACTIVELY USE AUTOPLT DURING THESE HIGH WORKLOAD SITS; AS WELL AS ENSURE THAT ONE SIDE NAV FREQ WILL BE TUNED TO OUTBOUND NAV FIX SO AS TO AVOID THIS IN THE FUTURE.