M777 Howitzer Parts
The M777 (M777E1 / M777A1 / M777A2) howitzer is a lightweight, towed 155mm artillery piece used by militaries worldwide. It was designed with a focus on transportability and ease of deployment, thanks to its extensive use of titanium and aluminum alloys.
Here's a detailed breakdown of its key components and functions:
1. Elevating mass
This section is responsible for the firing mechanism and comprises two main sub-assemblies.
- 155mm/39 Caliber Cannon Tube Assembly: This is where the projectile is launched from.
- Cannon tube: The barrel itself, where the projectile is loaded and fired.
- Muzzle brake: Located at the end of the barrel, it reduces the force of recoil.
- Primer feed mechanism: Supports a high firing rate by feeding primers into the breech.
- Screw breech: Allows for vertical operation, enabling easier loading of bagged propellant charges.
- Cradle: This assembly supports the cannon tube and manages recoil.
- Extruded titanium tubes: Provide structural support and minimize weight.
- Accumulator: Stores energy for the recoil system.
- Recoil cylinders: Absorb the recoil force from firing.
- Balancing gear: Works with the equilibrator to help balance the weight of the cannon and reduce the effort required to elevate or depress the tube.
2. Carriage
This section provides stability and mobility for the howitzer.
- Body: Forms the main structure of the carriage.
- Forward stabilizers: Deploy to the front to provide stability during firing.
- Split trails: Extend to the rear, equipped with self-digging spades and dampers to absorb recoil energy.
- Hydrogas suspension unit with road wheels: Allows for smooth towing and transport.
- Hydraulic hand pumps: Used at each wheel station to raise and lower the system for deployment and transport.
- Centrepost: Connects to the saddle and allows for traverse movement.
- Saddle: Mounts on the centerpost and facilitates elevation and traverse.
- Yoke-mounted roll screw and nut elevation gear: Manually operated by handwheels to elevate or depress the cannon.
- Traverse gearbox: Engages with the body's rack segment for rotating the saddle and traversing the howitzer.
3. Fire control system
The M777, particularly the A1 and A2 variants, employs advanced fire control systems to ensure accuracy and rapid deployment.
- Digital Fire Control System (DFCS) / Digital Gun Management System (DGMS): Found on the M777A1 and A2 models, it provides navigation, aiming, and self-location capabilities.
- On-board computer: Processes ballistic data, target information, and environmental factors to calculate firing solutions.
- Satellite Global Positioning System (GPS): Provides precise location data for both the howitzer and the target.
- Inertial Navigation System (INS): Offers accurate self-location and aiming, even in GPS-denied environments.
- Radio: Enables communication with observation posts and other artillery units.
- Gunner's Display and Chief of Section Display (CSD): Provide critical information and controls to the crew.
- Enhanced Portable Inductive Artillery Fuze Setter (EPIAFS): Allows for compatibility with smart munitions like the Excalibur GPS-guided projectile.
4. Recoil system
This system is crucial for managing the intense forces generated during firing.
- Pneumatic system (gas and oil): The barrel and cradle move backward with each shot, absorbing recoil energy.
- Spades and lift arms: These are used to secure the howitzer in place during firing and help absorb some of the recoil energy.
5. Other important features
- Equilibrators: These devices balance the weight of the cannon tube, making it easier to elevate and depress it
- Loading tray: Positioned behind the breech, it assists the crew in loading projectiles.
- Ammunition: The M777 can fire a variety of 155mm munitions, including standard projectiles, rocket-assisted projectiles, and the GPS-guided Excalibur rounds.
The combination of its lightweight design, advanced fire control systems, and ability to use various munitions makes the M777 a highly effective and versatile artillery weapon, capable of providing timely and accurate fire support.
