The arrows of aerial fire trucks are subject to oscillations, also known as boom bounces, due to rapid movements and disturbances such as wind, the flow of water being pumped, or people on the ladder.

Further magnification of this oscillation occurs as the boom extends. However, Eaton has developed a system solution for aerial gunnery devices that can help OEMs eliminate arrow rebound and address a variety of challenges and trends in modern aerial design.

Boom extension

Raising, extending and rotating the boom are essential hydraulic functions on aerial fire trucks, whether it is a pumper or platform model the boom must reach its location targets quickly but safely.

While modern ramp controls are an improvement over the hard starts and stops of yesteryear, the uncontrolled movements resulting from these ramps limit boom extension speed and placement accuracy. In some cases, ramp controls can also present a safety risk.

Reduces design complexity

Eaton’s solution for aerial fire apparatus can increase truck safety and capabilities while reducing overall design complexity

Eaton’s system solution for aerial fire apparatus can increase truck safety and capabilities while reducing overall design complexity.

The centerpiece of the system is Eaton’s Advanced CMA Mobile Valve, a CAN-compatible electro-hydraulic valve with on-board electronics and built-in software algorithms that, beyond eliminating boom bounce to maintain overhead stability, offers several benefits. additional.

For example, the system provides more precise response for increased operator control, helps firefighters deploy the aerial boom faster and with greater placement accuracy, and simplifies the customization of the aerial device.

Boom stability control

Boom Stability Control (BSC) technology, an integrated control application on the CMA valve, reduces boom oscillation by up to 75% and stabilization time by up to 90%. The BSC can be active even when the operator is not in control of the boom, keeping the aerial aircraft stable and in position at all times.

This technology offers superior control to increase operator skills, reduce the impact of external disturbances and provide peace of mind for those on the ladder or platform. In short, BSC maintains device safety and manual override functions, and works in tandem with Eaton’s balancing valves to reduce CBV-related jerks.


In addition to safety, Eaton’s system solution helps improve capacity, especially with regard to rapid point-to-point movement.

The faster it is possible to position a ramp, the faster firefighters can get to work, whether it is accessing a building, rescuing people at height or extinguishing flames. Compared to boom controls, the BSC allows operators to deploy and stop the boom more quickly, safely and accurately.


With software-driven configuration and electronic tuning, Eaton’s CMA valve streamlines configuration and optimization Another advantage relates to the simplification of the system. The growing demand from aerial fire truck manufacturers to provide customers with ever increasing levels of customization means that there is a real need for simplified interconnected systems.

With software-driven configuration and electronic tuning, Eaton’s CMA valve streamlines configuration and optimization. Notably, CAN communication simplifies controller requirements and integration with other CAN-based systems.

Customization and advanced controls

OEMs can therefore adopt hardware common to all models of aerial fire trucks, as the software facilitates customization and advanced controls without the need to change coils or wire harness.

The valve’s on-board controller and sensors further facilitate system integration, while minimizing external components and providing a wealth of data that can be used for functions such as load sensing. The result is reduced costs and complexity.

Design flexibility

Finally, it is possible to configure CMA valve groups with CMA sections and / or CMT sections recently introduced by Eaton, allowing OEMs to create a tailor-made solution that combines performance and capability with the specific function of the machine. .

The streamlined CMT mobile valve section has the ability to control two bi-directional services from one section – an industry first. As a result, CMT valve sections increase design flexibility and reduce the size, weight and overall cost of the CMA valve system.

OEMs can also stack CMT mobile valve sections with CMA sections. The availability of two stackable section options simplifies the use of CMA valves on high-end and mid-range machines due to the sharing of components and procedures.

Mobile valve

Ultimately, Eaton’s system solution with its advanced CMA movable valve (with CMA and / or CMT sections) helps counter rapid boom movements and external disturbances that can cause boom tip oscillation. .

The solution also overcomes the limitations on the speed and control at which firefighters can deploy the boom while reassuring those climbing the ranks on flatbed trucks.

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