Ballistic Partition Wall Structure for Lightweight Cab Protection

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Solution Overview

Problem

Existing motor train unit cab rear walls lack robust ballistic resistance, particularly against higher caliber weapons, and have aesthetic and material quality issues.

Innovation Solution

A ballistic-resistant partition wall comprising a ballistic-resistant armor plate with specific thicknesses, surrounded by sound and fire-resistant layers, and reinforced with honeycomb plates and toughened glass, ensuring enhanced protection and reduced weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If plywood is used as the material of the rear wall of the cab, then the aesthetic degree is improved with wood style exposed surface, but the ballistic-resistant function is weak and cannot protect against higher caliber weapons

Engineering Contradiction:
Improveballistic-resistant functionVSAvoidstructure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent employs a composite structure consisting of multiple layers: ballistic-resistant glass (6-12mm), intermediate layers (5-10mm), and inner lining materials (3-8mm). This multi-material composite approach provides grade B ballistic protection against 79 submachine gun bullets while maintaining structural integrity, directly resolving the contradiction between achieving strong ballistic resistance and avoiding excessive structural complexity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The partition wall adopts a nested layered structure where the ballistic-resistant glass is embedded within intermediate layers and inner lining materials. Each layer is nested within the previous one, creating a sandwich structure that maximizes protective function while optimizing space utilization and maintaining aesthetic appearance from both interior and exterior sides.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If existing cab rear walls are designed without ballistic resistance or with only pistol bullet resistance, then the device complexity is reduced, but the safety requirement for cab protection is not fully met

Engineering Contradiction:
Improvecab safetyVSAvoidpartition wall structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The partition wall uses a composite structure with ballistic-resistant glass (6-12mm) as the core protective layer, surrounded by intermediate layers (5-10mm) and inner lining materials (3-8mm). This multi-layer composite design achieves grade B ballistic protection against 79 submachine gun bullets, significantly improving cab safety while maintaining reasonable structural complexity through optimized layer thicknesses and material selection.

Inventive Principle:
Principle #40Composite materials

3Strength

If the thickness of ballistic-resistant armor plate is increased to improve protection, then the ballistic-resistant ability is improved, but the weight of the wall increases

Engineering Contradiction:
Improveballistic-resistant abilityVSAvoidwall weight
Core Design Contradiction:
StrengthVSWeight of stationary object

Solution Approach 1:

The patent uses a composite structure where ballistic-resistant glass (6-12mm) provides the primary protective function, supported by intermediate layers (5-10mm) and inner lining materials (3-8mm). This distribution of protective function across multiple layers achieves grade B ballistic protection while optimizing the overall weight compared to using a single thick armor plate, as each layer contributes differently to the protective performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The partition wall applies different material properties and thicknesses at different locations and layers. The ballistic-resistant glass provides localized high-hardness protection at the front, while intermediate and inner layers provide supplementary protection and structural support. This local optimization of material properties achieves effective ballistic resistance while minimizing overall wall weight through targeted material placement.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3919851B1Ballistic-resistant partition wall
Publication Date: 2026.02.25 CRRC CHANGCHUN RAILWAY VEHICLES CO LTD
  • EP3919851B1 patent drawingFigure 1

AI summary

Disclosed is a bulletproof partition wall of electric multiple units, the bulletproof partition wall comprising a bulletproof armor plate body (1), wherein an inner sound insulation pad (12) and an inner fireproof plate (13) are arranged on an inner side of the bulletproof armor plate body (1) from inside to outside, and an outer sound insulation pad (21) is attached to an outer side of the bulletproof armor plate body (1). The thickness of the bulletproof armor plate body (1) ranges from 2.3 mm to 2.7 mm. The bulletproof armor plate body (1) is arranged in the bulletproof partition wall, ensuring the overall bulletproof capacity of the bulletproof partition wall, and reducing the weight of a wall body. The sound insulation pad (12, 21) is arranged on either side of the bulletproof armor plate body (1), and the fireproof plate (13) is arranged on the inner side, namely the side close to a cockpit, of the bulletproof armor plate body (1), ensuring the sound insulation capacity of a working space.