There is a difference between rank & title within FDNY.
So lets talk about the fire side because there is a difference with EMS.
Start off as a Prob. And upon completion of the Fire Academy a new member is assigned to either an engine or a truck co.
Unlike some fire departments, in FDNY there is no promotion or change in the fire helmet color for chauffeurs. Company Captain picks them.
A fire company is commanded by a captain with three Lieut. assigned. There are anywhere normally between 20 to 30 firefighters assigned depending upon the need for that company. This includes engines, ladders, squads, and the rescues. Haz-mat 1 has over 30 firefighters assigned.
The company's members are assigned to work a 25 group system with six groups on duty each shift. Because of this system it requires once every 25 days a covering officer, either a Lieut or a Captain to fill in the open tour. If a spare officer can not fill the open slot then overtime is authorized.
Firefighters can transfer between companies at their request. After being on the job for several years a firefighter can request a transfer into a specialized unit such as a rescue, squad, or even a marine unit.
Lieut's & Captains also wear black helmets. White helmets are for chiefs only starting off with the rank of Battalion Chief.
Each Battalion and division are assigned four chiefs. Now one of the four will be designated that unit's commander. The only change in their uniform is the collar brass. Battalion Chief wears a gold leaf & the commander wears a silver leaf. At the division level, the normal collar brass is a full eagle but for the commander it's one gold star. Remember that both the battalion & division are both assigned extra chiefs to cover group 25, sick leaves, special details, or assignments. On the fire side, there is no difference in the two titles division chief or deputy chief. EMS is a different story.
Each administration makes the needed changes to help steer the department in what they think is the right direction. In some cases this information is not made public and does not appear on department orders. Don't get me wrong, you will see reassignments, promotions, and transfers, but not what or how they will respond. In some cases, responses are regulated by the persons title and ongoing incident.
Staff Chiefs - Deputy Assistant Chief (2 stars) & Assistant Chief (3 stars). Normally they perform administrative duties based on their assignment.
Staff chiefs assigned as Borough Commanders can be found traveling in their assigned area possibly checking companies and assigned battalion or division chiefs. They even attend community meetings besides responding to various incidents.
Some bureaus require move then one assigned staff chief so that is why you see an Asst Chief & several other staff chiefs.
Years ago, Operations, Training, Fire Prevention and Personnel had Asst. Chief as the leader but they were given the title of Chief in Charge (CIC) and wore a 4th star. Today, only the Chief of Department wears five stars.
Years ago FDNY had two staff chiefs on duty around the clock. Today there is only one but a division chief can always be activated
during non-business hours & also weekend to cover in case there is another incident.
The on duty staff chief responds on third alarms, but can also respond on second alarms at their pleasure. You can also hear the Safety Cmd Chief, or even the SOC Commander responding to various incidents.
Deputy Commissioners - I expect to see some changes made in their structure in the future. Just look at the FDNY Medal Day Book. It hits me that FDNY just might be too heavy. There trimming that can be done. Today's new fire commissioner ran his own company and we do not
know yet what ideas he may have. Let's just give him some time.