B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 165; Flight Crew Type 30
Situational Awareness; Other / Unknown
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
This was the first time either of us would fly the TERPZ4 Departure.  We briefed the new TERPZ4 departure. We even emphasized the new waypoint; PIRCH. We were in a -300; so we could not arm LNAV on the ground. We were cleared for takeoff from 15R with the simple phrase 'cleared for takeoff.'At 400 Feet AGL; we continued on runway heading. This was the old TERPZ procedure.  At approximately 1;200 Feet AGL; we realized we needed to begin our turn to PIRCH. This turn should have been started at 667 Feet MSL (524 Feet AGL). We engaged LNAV to begin the turn.   At this time Tower 'reminded' us to turn to PIRCH. We acknowledged their call and continued our turn to follow the departure.   The rest of the flight was uneventful. The new departure procedure is significantly different from the old SID; which was in place for many years.
The TERPZ Departure had just changed from 3 to 4. We briefed up the new departure highlighting all the new points and verified them in the FMC. We failed to notice that it was no longer a; 'fly heading 155 and expect vectors.' I saw the 155 heading and the line but didn't pick up on the fact that it was an RNAV track requiring a turn at 667 Feet. As we were passing 1;200 Feet MSL; Tower came up and mentioned that we were turning towards PIRCH (a friendly reminder). We began the turn and the rest of the departure and flight were uneventful.We have been flying runway heading for so long; I just assumed the departure was asking for the same thing. Obviously; read the whole thing in detail; especially after a change. What I'd recommend to fix this has already taken place; and that would be to put a note on the weather release about this change. I suspect a lot of flights did the same thing and when we came back to BWI later in the trip; this note was there.
B737 flight crew reports a track deviation flying the new TERPZ4 departure from Runway 15R at BWI. The TERPZ3 had required runway heading after takeoff while the TERPZ4 requires a turn direct PIRCH. ATC issues a reminder.