The numbers will usually indicate what fire station the unit is from. An "5" before the station number indicates that the station has two of that type of unit. For example, station 10 has two basic ambulance units, one "A - 10" and the other "A- 510".
A- Ambulance
MD-Medical Directors
ACR-Airport Coordinator
M-Medic
AR-Airport Rescue
MS-Medical Safety Unit (airports)
AS-Ambulance Supervisor
OPS - Special Events Unit
ARS-Arson
RB - Rescue Boat
B-Booster
RH-Rehab Unit
BL-Mobile Fan
RUT-Rescue Utility
C-Cascade
SC-Shift Commander
CV-Command Van
SEE-Engine (special event)
D-District Chief
SEFC-Fire Cart (special event)
EB-Evacuation Boat
SEMBT-Med. Bike Team (special event)
E-Engine
SEMC-Medical Cart (special event)
EMSD-EMS Medical District Chief
SEM-Medic (special event)
FB-Fire Boat
SERC-Rescue Cart (special event)
F-Foam Truck
SF-Safety Officer
FT-Foam Trailer
SR-Senior Ambulance Supervisor
HD-Hazmat District Chief
SQ-Squad
H-Hazmat Truck
TR - Technical Rescue
HS-Senior Hazmat Coordinator
UT-Utility Trailer
L-Ladder
VL-Village Ladder
MC-Medical Cart (golf)
WS - Water Supply Unit
To See where the different apparatus are stationed go to the > Fire Station List.
Currently, the Houston Fire Department has (units per shift):
86
Engine Companies- The primary purpose of an engine is to find, locate and put water on the fire.
32
Ladder Trucks - The primary purpose of a ladder is for search and rescue and ventilation.
5
Tower Trucks - The primary purpose of a tower is the same as a ladder, but the ladder has a bucket at the end of the ladder.
11
Booster Trucks - The primary purpose of a Booster is to put out small fires (dumpster, trash) and/or respond to grass fires and/or used as directed by the district chief at a fire scene.
21
District Chiefs - District Chiefs respond to all incidents within their district, be it fire or other incident / non-fire related (accidents, firefighter injuries, at citizen's request, etc.)
3
Safety Officers
1
Shift Commander Suburban
57
Basic Ambulances (BLS) - An ambulance staffed with EMT's and/or paramedics, not operating in the capacity of an advanced life support prehospital care provider. (BLS)
24
Medic Ambulances (ALS)- An ambulance staffed with EMT's and/or paramedics, operating in the capacity of an advanced life support prehospital care provider.
19
Paramedic Squad - A Squad consists of two paramedics, usually in a suburban or other vehicle, that respond to an incident to administer advanced care. If they are not needed to actually transport the patient, once a BLS unit has arrived, the BLS unit can take the patient to the hospital.
10
EMS Supervisors
2
Hazmat Response Units - The primary purpose of a Hazmat unit is to define chemicals, what type of incident they are dealing with and stop the flow of the substance .
1
Hazmat Foam Engine - There are several types, the HazMat Utility Truck responds with a trailer that carries foam.
9
ARFF Crash Trucks - These units respond only to airport emergencies.
4
ARFF Trucks - These units respond only to airport emergencies.
2
ARFF Medical Service Units
2
ARFF Rapid Intervention Units
1
ARFF Triage Vehicle
2
ARFF Triage Trailers
2
Special Operations Rescue Trailer
1
Special Operations Rescue Triage Trailer
2
Special Operations Rescue Incident Vehicle
3
Technical Rescue Trucks - The primary purpose of the Rescue unit is to exuviate and rescue.
10
Evacuation Boats - Placed into service during times of high-water, primarily used when there are a large number of people trapped in high waters.
5
Rescue Boats - The primary function of the rescue boat is to be used to effect rescue in high water situations, removal of a victim and/or stranded individual.
4
Fast Water Rescue Craft - Jet Bikes arrived 2007.
3
Cascade Trucks - These units see that all air bottles are in their quadrant are kept full. They also respond to the request of district chiefs at working fires to fill air bottles.
1
Rehab Truck - This special piece of equipment is designed to re-hydrate firefighters and can be called for use by captains and district chiefs to an incident.
1
Command Van
1
Big Blow - This special piece of equipment is used to disperse large volumes of smoke within a designated area.
ARFF Trucks - These units respond only to airport emergencies. 
