Pierce Manufacturing asked firefighters to help configure the ideal fire truck for both safety and efficiency, from the broadest concepts to the smallest details. The final list of firefighter specifications helped Pierce create its strongest and most innovative custom chassis — Impel® and Velocity®.
The Impel and Velocity chassis are the industry’s most heavy-duty fire chassis, featuring 13-⅜ inch frame rails. A heavy-duty fire apparatus is ideal when a large engine and increased horsepower is required; in environments with hills and steep inclines, and where added strength and durability is required.
With many similarities, the Impel and Velocity chassis can offer your department rugged durability, horsepower, and strength. Get to know the similarities and differences of the Impel and Velocity heavy-duty chassis below.
What are the Similarities?
1. Heavy-Duty Chassis Design
Perhaps the most striking similarity that sets the Impel and Velocity apart from every other chassis on the market is the frame construction. The chassis sits on 13-⅜ inch frame rails, the largest, strongest, and stiffest in the industry. As a result, Impel and Velocity transmit less stress to the vehicle body.
The key advantages of heavy-duty frame rails are:
- Reduced apparatus wear and tear
- Enhanced apparatus longevity
- A smoother ride quality
2. Large Interior Cab
Pierce has used every inch of space in the 100-inch wide cab to ensure firefighters have optimal leg, head, shoulder, and hip room. In fact, the chassis can hold up to 10 occupants.
3. Designed for Increased Visibility
The Impel and Velocity chassis offer exceptional visibility with the following design features:
- A panoramic windshield offers a large single-piece bonded windshield and daylight windows for increased visibility. With no outside curves of the glass, there is minimal distortion in the corners, so the driver can clearly see the road, traffic, and pedestrians.
- A three-blade wiper system improves visibility in inclement weather.
- Pierce’s One-Eleven Mirrors offer excellent visibility around the vehicle. The mirrors are positioned to minimize the required body and head movements of the driver and to improve overall visibility.
The Impel and Velocity chassis offer fire departments both ease of maintenance and low cost of ownership. The custom chassis features a Fast Access Service Tilt (FAST) hood, which is an innovative one-piece, full-width, lift-up hood that makes routine maintenance of fluid levels and wipers quick and easy. Engine and transmission checks are done through the engine tunnel right inside the cab, so you no longer have to tilt the cab to perform routine maintenance.
5. Wide Cab Doors and Handles
Generously sized door handles and forward cab doors are added ergonomic features in these custom chassis.
- Extra-large interior and exterior door handles can be easily gripped by gloved hands.
- Wide cab doors make vehicle exit and entry safe and quick for firefighters.
What are the Differences?
The main differences between the Impel and Velocity concern the body configurations available on each custom chassis and the available engine size and horsepower. Velocity can support much heavier body configurations and larger aerial products, including the Ascendant® class of aerial products. Impel is available with single axle Ascendant products.
Detroit Diesel DD13, Cummins X15, X12 or L9
|Engine HP||370 – 450 hp||370 – 600 hp|
|Transmission||Allison EVS 3000||Allison EVS 3000, 4000 or 4500|
|Alternator||270 – 430 amp||270 - 430 amp|
|Front GAWR (max)||23,000 lb||24,000 lb|
|Rear GAWR (max)||54,000 lb||60,000 lb|
60”, 70”, 84”
60”, 70”, 84” or 104” inch split-tilt
If your department is seeking a heavy-duty apparatus with the ability to power through tough conditions, the Impel or Velocity may be the right choice for you. With a very similar chassis, each has the flexibility to meet the unique needs of your department.