Crossover Fire Apparatus a Fit for Community with WUI Challenges


Twain Harte (CA) Fire has proudly accepted delivery of a new wildland urban interface (WUI) vehicle—Engine 723, also nicknamed the “crossover”. The term “crossover,” although not original, comes from the automotive world and is used to describe a vehicle that doesn’t fit in one particular class. This term is aptly used when describing the new engine because, by specification and equipment compliment, the unit is FIRESCOPE/NFPA 1901 compliant for both a Type 1 and Type 3 engines.

The department wrote the specification for this engine to provide a versatile apparatus for the community of Twain Harte, California, which is nestled in the Sierra Mountains of Tuolumne County and surrounded by the Stanislaus National Forest. Twain Harte has a significant WUI risk with narrow roads, steep driveways, and a collection of commercial and single-family structures all intermixed with wildland fuels. The community is home to approximately 3,000 year-round residents, but because of the quaint setting and ample recreation opportunities year round, the population grows considerably on weekends and holidays with visitors. The potential for catastrophic wildland fires is significant as evidenced by the 2013 Rim Fire that threatened the community and became the third largest fire in California history.


The concept behind the design of this apparatus was simple: build a fire engine that can handle a structure fire and also operate effectively in wildland fire suppression. The specifications for the rig filled 40 pages and eventually called for compressing all of the requirements of a Type 1 and Type 3 engine into a 27-foot bumper-to-bumper package. Following are some of the basic specifications:

  • Four-door cab with seating for four
  • Four wheel drive
  • 330-hp engine
  • Allison automatic transmission
  • Rear differential lock
  • 1,000-gpm Hale PTO pump
  • 500-gallon polypropylene tank
  • 250-gpm diesel auxiliary pump
  • Class A foam proportioner with automatic upload system
  • Full ladder compliment
  • 1,000-gpm telescoping master stream
  • Hosebed and compartment space for requisite structure and wildland hose compliments and tool compliments
  • Inverter system
  • Pump-and-roll-capable
  • 35-degree approach angle and a 23-degree departure angle

The engine build was awarded to the company Hi-Tech of Oakdale, California. Conveniently Hi-Tech is located one hour from Twain Harte, which proved quite useful during the build as this was a unique design for Hi-Tech and filled with specific features for functionality, durability, and aesthetics. Inside and out this engine uses materials and equipment to meet the demands of both the structure and wildland environments.

Although designed for rugged terrain, the engine has the element of modern technology as well. Engine 723 features all LED lighting, with the latest duplex wiring system. The engine is also equipped with an iPad loaded with community preplans, GPS functionality, and wildland topography maps to assist in daily response regardless of incident type. Although this apparatus specification might not be applicable in all jurisdictions, it is a perfect design for the Twain Harte community with its WUI risks and mostly single-story single-family dwellings. In this age of fiscal constraints and the demand of the public for prudent management, this apparatus was designed with multiple applications and provides a maximum benefit to the public.

TODD MCNEAL has 23 years of service and is the Chief of Twain Harte (CA) Fire.  McNeal previously worked as a captain for the Sonora (CA) Fire Department and for the United States Forestry Service (USFS). McNeal has a diverse background in wildland and structural fire management and suppression, and has been serving as a division/group supervisor on a federal Type II incident management team for 10 years.

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