B737-800
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 19900
Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Returned To Gate; General Flight Cancelled / Delayed
Procedure; Airport; Company Policy
We were assigned [gate] in ORD. While approaching the gate on the taxiway ramp control cleared us 'to the gate when wing walkers are present'. I turned towards the gate and saw the guide man; but no wing walkers. I stopped the airplane; and the First Officer called twice ramp control and asked for the wing walkers. Ramp control both times assured us that wing walkers were on the way. After a few minutes ORD Ground Control inquired what was going on since we were blocking the taxiway. Since the wing walkers still had not arrived; we were instructed to taxi to the penalty box. On the way the First Officer talked to ramp control again to make sure that the wing walkers would be present next time. A supervisor came on the radio and told the First Officer; that [gate] had a special procedure. The wing walkers drive luggage carts onto the road; paralleling taxiway A to block traffic and then remain in the cab while the airplane taxies in. I returned to [gate] and parked the airplane. After thinking about it; I now believe; that I should not have parked the airplane at [gate]. This procedure is not written down anywhere. The wing walkers cannot observe the airplane and wingtips while seated inside the luggage cart cab. The instructions from ramp control were to have wing walkers present. Just because some supervisor overruled these instructions doesn't make it safer or gives it any sense.This event occurred because I followed the instructions of a ramp control supervisor. I should have parked the airplane and insisted on the wing walkers standing in a position where they actually can see the airplane.In the whole [company] system; wing walkers stand on the roads and stop traffic during push back or taxi-in events. I have to assume that this is too dangerous at [gate] in Chicago. Therefore; luggage carts are being parked on the road to stop traffic. I suggest that the wing walkers park the carts and then get out with wands and make sure that the airplane does not hit anything. They should not remain inside the cabs. I also suggest that local procedures like this one are being published in the appropriate Jeppesen company pages. We already have published special procedures for that gate. Adding some unusual wing walker operations like wait until the road is blocked by luggage carts should be easy.
B737 Captain reported they parked at the gate without wing walkers to comply with a local unwritten procedure for their particular gate.