Split-Lift Howitzer Trunnion and Recoil Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current lightweight howitzers, particularly those designed for 155mm ammunition, face challenges in stability and transportability due to high recoil forces and size, limiting their deployment via mainstream helicopter airlifting capabilities.

Innovation Solution

A split lift howitzer design with a sub-optimal barrel length, low trunnion height, and extended recoil stroke, combined with a recoil brake and recuperator system, and a modular configuration that separates traversing mass from the lower platform, enhances stability and mobility by maximizing mass distribution and reducing recoil forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the howitzer uses conventional 155mm configuration with standard barrel length, then firing power and range are sufficient, but the mass and size become too large for helicopter transport

Engineering Contradiction:
Improvehowitzer massVSAvoidfiring capability
Core Design Contradiction:
Weight of moving objectVSProductivity

Solution Approach 1:

The howitzer is divided into separable components: the ordnance assembly (barrel, cradle, saddle) that can be lifted by helicopter, and the lower carriage that remains on ground. This segmentation allows the heavy firing platform to be transported aerially while maintaining full 155mm firing capability when assembled.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design transitions from a single-platform ground-based system to a dual-platform system where the upper ordnance assembly can be positioned in three-dimensional space relative to the lower carriage. The ordnance can be lifted vertically by helicopter and positioned over the lower carriage for assembly, adding vertical dimension to the deployment strategy.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Weight of moving object

If the barrel length is reduced to L30 for weight reduction, then transportability improves, but recoil resistance and stability deteriorate

Engineering Contradiction:
Improvebarrel massVSAvoidrecoil stability
Core Design Contradiction:
Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The design uses the lower carriage with its large mass on the ground as a counterweight to compensate for the reduced mass of the shortened barrel. The trailing spades dug into the ground provide additional anchoring mass, creating a stable base that resists recoil forces despite the lighter barrel.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The recoil management system extends into the vertical dimension by allowing the breech to recoil past the trunnions and by using trailing spades that dig vertically into the ground. This adds a vertical component to recoil absorption, complementing the horizontal recoil brake system.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Stability of the object's composition

If the trunnion height is lowered to reduce overturning moment, then stability during firing improves, but accessibility of the breech at high elevations becomes difficult

Engineering Contradiction:
Improvefiring stabilityVSAvoidbreech accessibility
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The breech accessibility problem is solved by separating the breech operation from the lower carriage. The breech is mounted on the upper ordnance assembly, which can be independently positioned and manipulated by the breech mechanism without requiring access from the ground level where the lower carriage is located.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The low trunnion position moves the breech to a lower horizontal position to reduce overturning moment, but the breech accessibility is restored by allowing vertical movement through the elevated position of the upper ordnance assembly on the saddle, creating a multi-level operational space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Device complexity

If the howitzer uses a single integrated platform, then structural simplicity is maintained, but transport flexibility and deployment speed are limited

Engineering Contradiction:
Improveplatform configurationVSAvoiddeployment time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The howitzer is segmented into the upper ordnance assembly and lower carriage that can be transported separately by different vehicles (helicopter and ground vehicle) and quickly assembled on site, enabling parallel transport operations and rapid deployment without requiring the entire system to move together.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from a static single-platform design to a dynamic modular configuration where the upper and lower components can be independently positioned, transported, and assembled. The split-lift mechanism and quick-coupling features enable the system to adapt its configuration for optimal transport and rapid deployment.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design allows for increased stability during firing, reduced recoil forces, and improved transportability, enabling faster deployment and wider vehicle compatibility, while maintaining accessibility at high elevations without the need for digging pits.

Implementation Method 1

combined with a recoil brake and recuperator system, and a modular configuration

Methodology Applied
Scientific EffectRecoil brake: Friction

Implementation Method 2

combined with a recoil brake and recuperator system

Methodology Applied
Scientific EffectRecuperator: Spring

Implementation Method 3

In the second position, typically after firing and during the recoil the breech retracts behind the trunnions. This permits an extended travel path for the barrel to travel along, thus increasing the mitigation of the firing impulse.

Methodology Applied
Scientific EffectExtended recoil stroke: Displacement

Data Source

PatentEP2906898B1Field gun
Publication Date: 2018.10.10 BAE SYSTEMS PLC
  • EP2906898B1 patent drawingFigure 1~2
  • EP2906898B1 patent drawingFigure 3~4
  • EP2906898B1 patent drawingFigure 5

AI summary

A howitzer suitable for deployment on a ground plane, the howitzer comprising an ordnance for firing a projectile. The ordnance comprising a barrel defining a barrel axis and having a muzzle towards the front end of the howitzer and a breech assembly at the back end of the barrel; and a cradle for holding the ordnance at a traverse and an elevation; two trunnion pins located on said cradle, which co-locate with receiving trunnion bearings on a saddle, wherein in a first position said breech is located forward of said trunnion, in a second position, at the end of the recoil stroke, said breech is retracted substantially behind said trunnion, wherein said recoil stroke is variable depending on the selection of the elevation.