Mid-Floor Railway Car Layout for Level Boarding and Flat Interiors

Solution Overview

Problem

Existing mid-floor height railway vehicles with level-access at middle platforms often require steps or ramps, posing challenges for wheelchair users and passengers with reduced mobility, as they do not provide a flat floor interior.

Innovation Solution

A railway vehicle design with variable passenger cars featuring reduced floor height, a flat interior floor, and access devices such as inclined areas, gap fillers, folding steps, and deploying ramps, ensuring level-access from middle platforms and compatibility with various platform heights.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a mid-floor height railway vehicle uses steps or ramps to achieve level-access from middle platforms, then accessibility is improved, but the floor interior is no longer flat

Engineering Contradiction:

Improvelevel-access from middle platformsVSAvoidflat floor interior

Core Design Contradiction:

Ease of operationVSShape

Solution Approach 1:

The vehicle floor is segmented into two distinct levels: a low floor for the passenger circulation area and a mid-floor for the entrance area. This segmentation allows the passenger area to maintain a flat floor while the entrance area can accommodate level-access requirements through steps or ramps between the low floor and the mid-floor entrance level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the vehicle have different floor heights tailored to their specific functions. The passenger circulation area has a low flat floor for easy movement, while the entrance area has a mid-floor level for level-access from middle platforms. This local differentiation resolves the contradiction by allowing each zone to optimize for its specific requirement.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If a low-floor train is modified to provide level-access from middle platforms, then accessibility is improved, but the floor height must be increased compromising the flat floor interior

Engineering Contradiction:

Improvelevel-access from middle platformsVSAvoidflat floor at low height

Core Design Contradiction:

Ease of operationVSShape

Solution Approach 1:

The vehicle floor is segmented into two distinct levels: a low floor for the passenger circulation area and a mid-floor for the entrance area. This segmentation allows the passenger area to maintain a flat floor while the entrance area can accommodate level-access requirements through steps or ramps between the low floor and the mid-floor entrance level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The solution introduces a vertical dimension with two floor levels (low floor and mid-floor) rather than a single flat floor. This dimensional change enables the vehicle to achieve level-access from middle platforms while maintaining a low flat floor in the passenger area, as the entrance area occupies a different vertical level.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Shape

If high-floor trains with flat floor interior are used, then interior circulation is improved, but at least one step is needed between the floor and the middle platform

Engineering Contradiction:

Improveflat floor interiorVSAvoidaccess from middle platforms

Core Design Contradiction:

ShapeVSEase of operation

Solution Approach 1:

The vehicle floor is segmented into two distinct levels: a low floor for the passenger circulation area and a mid-floor for the entrance area. This segmentation allows the passenger area to maintain a flat floor while the entrance area can accommodate level-access requirements through steps or ramps between the low floor and the mid-floor entrance level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of having a high floor throughout the vehicle, the invention inverts the approach by having a low floor in the passenger area and raising the floor only at the entrance area to mid-floor level. This inverted configuration maintains the benefits of a low flat floor for circulation while providing level-access capability at the entrance.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP4360981B1Mid-floor height railway vehicle with level-access at middle platform heights

Publication Date: 2026.02.04 ALSTOM HOLDINGS SA

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AI summary

The railway vehicle (10) is intended to circulate on rails (11) and comprises at least two cars (12), each car (12) having a structural body (14) defining a door entrance (29), and each car (12) having a floor (15) extending longitudinally along the railway vehicle. The railway vehicle (10) comprises bogies (16) having wheels (20) of a diameter inferior or equal to 1000 mm. Each structural body (14) held by a bogie (16) comprises lateral recesses (24) each receiving the upper part of a respective wheel (20). The floors (15) are all longitudinally flat and all at a same height. The door entrance (29) is at a height comprised between 800 and 1100 mm above rails (11).