In the Philadelphia area:
Philadelphia uses encrypted talkgroups for active fireground operations on their 800 MHz digital trunked system, but has 3 simplex analog frequencies that are mostly used for operations after the fire is under control or other misc functions, like searches, etc. I do not believe they are monitored by dispatchers.
Bucks County uses a 500 MHz digital trunked system, however all fireground operations are on 1 of 2 simplex analog frequencies. They are actually a pair previously licensed for repeater duty (501.3375 & 504.3375). Each tower site has equipment to transmit and receive on both channels, and are recorded. Although the dispatchers are not supposed to transmit on them, I have heard a dispatcher make contact with an out-of-county MedEvac chopper on one of them.
Montgomery County PA uses an 800 MHz digital trunked system, and they do one of two things for fireground operations. Either they use a set of analog talkgroups on the system (called "event" channels), or they can use 1 of 6 simplex analog frequencies. I cannot confirm if dispatchers have access or monitor them or not.
Chester County operates an 800 MHz LTR system, but has a set of analog simplex frequencies available for fireground operations. Again, unknown if dispatchers have access.
Burlington County NJ uses a 500 MHz digital trunked system, but uses a set of simplex analog "Ops" channels for fireground operations. Unknown if dispatchers have access.
That's all I can confirm from this area.
If you're looking for input on these setups, I think the Bucks County setup is the best. The dispatchers can transmit and receive, they are recorded by dispatch, and can be heard if you are close by. There is even a repeater owned by a fire company that repeats the channel most commonly used (Fireground 2, 504.3375). The agencies that do not monitor or record their simplex channels are just asking for trouble, I think. And don't get me started on Philly using encrypted talkgroups. There was already one incident where 3 firefighters died a few years ago, and it is widely believed that their mayday call from the basement was never received by the trunked system's tower.
I hope this helps you in your research!