B737-300 captain reports tug failed to give way to taxiing aircraft on ord ramp.

Attributes
ACN	712725
Time
Date	200610
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : ord.airport
State Reference	IL
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 140 flight time total : 16900 flight time type : 8900
ASRS Report	712725
Person 2
Affiliation	company : air carrier
Function	oversight : flight attendant in charge
Events
Anomaly	ground encounters : vehicle non adherence : published procedure non adherence : company policies
Independent Detector	other flight crewa
Resolutory Action	flight crew : took precautionary avoidance action
Supplementary
Problem Areas	Company
Primary Problem	Company

Narrative:

Taxiing south on the C line. Noticed a tug ahead and to our left moving perpendicular toward the C line. Tug made no effort to stop or yield the right of way to us. I was required to bring the aircraft to almost a complete stop as the tug passed just in front of us. We could not make out any identifiable numbers or letters on the tug; but did make a radio call to ramp about the incident. Conditions were night; good visibility and taxi light on.

Original NASA ASRS Text

Title: B737-300 CAPT RPTS TUG FAILED TO GIVE WAY TO TAXIING ACFT ON ORD RAMP.

Narrative: TAXIING S ON THE C LINE. NOTICED A TUG AHEAD AND TO OUR L MOVING PERPENDICULAR TOWARD THE C LINE. TUG MADE NO EFFORT TO STOP OR YIELD THE RIGHT OF WAY TO US. I WAS REQUIRED TO BRING THE ACFT TO ALMOST A COMPLETE STOP AS THE TUG PASSED JUST IN FRONT OF US. WE COULD NOT MAKE OUT ANY IDENTIFIABLE NUMBERS OR LETTERS ON THE TUG; BUT DID MAKE A RADIO CALL TO RAMP ABOUT THE INCIDENT. CONDITIONS WERE NIGHT; GOOD VISIBILITY AND TAXI LIGHT ON.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.