B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 120; Flight Crew Total 21000; Flight Crew Type 15000
Fatigue; Communication Breakdown
Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
General Flight Cancelled / Delayed
Procedure; Equipment / Tooling; Human Factors
The First Officer and I had our pairing modified on day 4. After a night of reduced rest due to bad weather we flew and the following morning from to ZZZ. Upon arriving at ZZZ the printer showed that we had been reassigned. We were instructed to proceed to a new gate and we would no longer be flying our turn in an hour and thirty minutes but now were to report immediately to fly ZZZ to ZZZZ and back to ZZZ. After arriving at the gate we learned that this flight was delayed by the ZZZZ Airport because they had an inoperative Fire Truck. The original crew was going to time out so we were put in their place. I called the dispatcher on the paperwork and asked what was going on. I was told that they should have heard back from ZZZZ by now but as of yet nothing. I felt this was unsatisfactory and said I needed someone to call and find out what the hell was going on. After a brief period I received a call back from the dispatcher and he advised me that ZZZZ said they would provide an update Four (4) hours for an update is not satisfactory with the resources available to this airline. To allow people to just sit in the gate area where they still were; why board a plane that probably isn't going for hours if it goes at all is not acceptable. This bothered me if not only for the passengers but for the flight attendants; the FO; and me. Short night and now an exceptionally long day that I'm not certain we would even be legal for is courting disaster. We agreed that calling scheduling and indicating that we would not be able to complete the reassignment because of fatigue was the best move in the interest of safety. In nearly 20 years as a pilot with this airline I have never been late for a show or called in fatigued but I felt like in this situation it was the safety minded thing to do.
[Report narrative contained no additional information.]
B737 flight crew reported being unable to depart prior to fatigue setting in due to an equipment problem at the destination airport.