On this same idea about DFR doing things I never understood, someone PLEASE tell us what a "Heavy Rescue" is, that they dispatch for Motor Vehicle Accidents with Entrapments, and also if every Rescue is an MICU, or if only certain Rescues are MICUs.
Also, is every Rescue ALS or are some BLS only? I think the Engine and Truck companies are both BLS, and all Rescues are ALS but I'm not sure. I wish I knew someone on DFR to ask, but unfortunately I don't. Funny thing is I walk by a station every single day.
All of the current "rescues" are MICU's, or what some of the other cities call "Medic" units. Staffed by paramedics, with ALS capability. The engines & trucks are used as first responders, especially when the 'rescue' is coming from a distance (out of district). On Heart attacks & 'unconscious person' calls an engine or truck responds anyway, in case the rescue needs extra help for CPR or whatever. So, I would imagine you'd consider the fire apparatus as roughly equivalent to BLS. Right now, Dallas does not operate any BLS ambulances. There was an experiment a some months back, where basically a paramedic in a car or SUV responded to certain screened calls, instead of a rescue unit. He (or she) would evaluate the patient, then call for a DFR rescue if needed. This was part of a study, I believe, with U.T. Southwestern Medical, which was ended early.
At one time, Dallas Fire had a few engines operated as "paramedic engines". These had one or more paramedics in the crew, and had some of the equipment you'd expect for an ALS-type vehicle. The idea was they could start stabilizing the patient while a regular MICU (back then, that was the term, not 'rescue') was en-route. The two that first come to mind were Engine's 9 & 12. So, for a medical call in 9's district, they would answer it as "709" (MICU's used 700 series call signs then), while the actual ALS capable of transport (say 734 or 751) headed their way.
The "heavy rescue" response is for people trapped, usually a motor vehicle accident. That usually brings a truck (second truck, if a freeway accident, or if the closest truck does not have everything needed, like a Hurst tool, or airbag for up-righting a vehicle) plus a battalion chief, in addition to the engine company and rescue unit.
Where it gets confusing is when you also add the "USR" (Urban Search and Rescue) units to the mix. These two are really more like 'teams', and would be, I suppose, what some cities call
their rescues or squads.
You've got two USR units- 15, just south of downtown, in north Oak Cliff, and 19, off E. Grand & Beacon in East Dallas. These respond to people trapped in trench collapses (construction accidents), building collapses, where climbing or descending via ropes might be required (bridge jumpers, stranded window washers, somebody stuck down in a ravine). They usually respond to multi-alarm fires as well; generally at least one of them is assigned on the third alarm. In general, when, say USR 19 responds, you'll actually get (assuming their not on another call) Engine 19, Truck 19, & Rescue 19. Usually the engine or truck crew will actually man the USR vehicle with it's equipment. Lately, I've noticed that on calls other than multi-alarm fires, 660 has also been dispatching the "home" battalion chief for the USR unit assigned. (That would be 3 for USR 19, or 6 for USR 15.) That's similar to what happens on a Haz-mat call. You call for Haz-mat 3, you really get Engine 3, Truck 3, Rescue 3, and (usually) Battalion 3. Most of the time, Truck 3 actually goes out of service in the station, & the crew mans the Haz-mat vehicle. If the truck was "on the air" (not in the station), but the engine was 'in the house', then Engine 3 might go out of service to man the vehicle & meet Truck 3 at the scene.