Phoenix Metropolitan Area Fire Apparatus

[Guest]

I believe, 40 stands for a 40 hour engine co.

Like Gilbert E2540 at 253's & Chandler E2840 at 288's,  they run during peaks hours,  usually from Mon to Thur 7am to 5pm

Gilbert's adding a 2nd 40 hour engine co on the 1st at 255's to help fill the gaps untill Station 259 opens in 2015