Deluge Fire Extinguishing System for Railway Tunnels

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current fire-fighting systems in railway and urban subway tunnels are ineffective due to the delay in activating fire extinguishers when voltage is present on the power rail, leading to prolonged exposure to toxic smoke and heat, and lack of immediate and localized fire suppression.

Innovation Solution

A deluge-type fire extinguishing system using a foam made from a combination of water, concentrated foam liquid, and air, which can be activated in the presence of voltage, physically separates oxidants from fuels, cools materials, and prevents the outflow of flammable vapors, with sprinklers positioned according to tunnel geometry to effectively reduce heat rating and smoke production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the conventional fire-fighting system is used with hand-fed pumps and stationary hydrants, then the system can operate in the presence of voltage on the power rail, but the activation time is delayed by 30-40 minutes due to voltage shutdown procedures

Engineering Contradiction:
Improvefire suppression effectivenessVSAvoidactivation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary action by pre-positioning foam liquid in tanks and pre-configuring the deluge system with sprinklers and nozzles throughout the tunnel. Upon fire detection, the system immediately activates pumps and opens valves to discharge foam solution, eliminating the need for manual intervention and voltage shutdown procedures. This preliminary preparation enables fire suppression within seconds rather than minutes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention replaces the manual mechanical system (hand-fed pumps, stationary hydrants requiring manual operation) with an automated electromechanical system. Electric pumps automatically draw water and foam liquid, control valves automatically open to discharge the mixture, and the system is triggered automatically by fire detectors, eliminating the 30-40 minute delay associated with manual voltage shutdown and hydrant activation procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Quantity of substance

If the main pipe replenishment is performed manually in the tunnel, then the system can be refilled, but the process takes 20-30 minutes during which smoke concentration reaches high levels

Engineering Contradiction:
Improvewater supply capacityVSAvoidreplenishment time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The system performs preliminary action by pre-storing large quantities of water in external reservoirs and pre-mixing foam liquid in dedicated tanks. This preliminary stockpiling eliminates the need for time-consuming manual replenishment operations during fire incidents, ensuring sufficient extinguishing agent is available immediately for extended fire suppression operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system enables self-service by incorporating automatic pump systems that can draw water from external sources and automatically refill the main pipe without manual intervention. The electric pumps activate automatically upon system initiation, maintaining water supply continuously without requiring the 20-30 minute manual replenishment period that allows smoke concentration to reach dangerous levels.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If conventional fire hydrants are used in cubbies, then the system is simple to operate, but immediate and localized fire suppression cannot be achieved due to voltage shutdown requirements

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidfire suppression speed
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The invention replaces the simple manual hydrant system with an automated deluge system that maintains operational simplicity for the user while achieving high productivity. A single activation action (manual or automatic) triggers the entire system - pumps start, valves open, and foam solution discharges through multiple sprinklers and nozzles simultaneously, providing immediate localized suppression without requiring the user to perform multiple manual operations or wait for voltage shutdown procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system applies segmentation by dividing the tunnel into multiple zones with dedicated sprinklers and nozzles in strategic locations. Upon activation, the deluge system can target specific zones or the entire tunnel simultaneously, providing immediate localized suppression where needed while maintaining the simplicity of a single activation command. This segmented approach eliminates the need to wait for voltage shutdown while preserving ease of operation.

Inventive Principle:
Principle #1Segmentation

4Stability of the object's composition

If the tunnel environment is adiabatic with no heat exchange, then the tunnel structure is sealed, but heat rating produced remains inside and smoke capacity increases over time

Engineering Contradiction:
Improvetunnel structural integrityVSAvoidheat rating produced
Core Design Contradiction:
Stability of the object's compositionVSTemperature

Solution Approach 1:

The system converts the harmful adiabatic condition (heat and smoke trapped inside) into a benefit by using the confined space to concentrate and direct the foam solution's cooling effect. The foam, discharged through strategically positioned sprinklers and nozzles, creates a cooling barrier that prevents heat from rapidly accumulating. The sealed tunnel environment, while trapping heat, also contains the smoke and foam mixture, allowing the foam to effectively suppress fire and cool materials without heat loss to the external environment.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 system allows for immediate and localized fire suppression, reducing smoke delivery and CO concentrations, temperatures, and heat radiation, thereby enhancing evacuation safety and reducing structural damage, with the ability to decelerate the smoke front and high-temperature advancement.

Implementation Method 1

The extinguishing action of the foam is mainly based on the following principles: To physically separate the oxidant (O2) contained in the air of the fuel.

Methodology Applied
Scientific EffectPhysical separation:

Implementation Method 2

Make cold the materials close to the blaze.

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 3

Impede the outflow of flammable steams by the fuel.

Methodology Applied
Scientific EffectPhysical barrier formation:

Data Source

PatentEP2032215B1Railway or urban subway's route tunnel with a rail in combination with a fire extinguishing device of deluge type
Publication Date: 2012.04.18 S T S SRL
  • EP2032215B1 patent drawingFigure 1
  • EP2032215B1 patent drawingFigure 2
  • EP2032215B1 patent drawingFigure 3

AI summary

The invention is relative to a new fire-fighting device of deluge type for the control and suppression of blazes, installable in railway and subway's tunnels, that uses as extinguishing the liquid foam extinguisher and that, further to the particular placement of the sprinklers (10), consents to be activated in presence of voltage along the railway route or along the urban subway routes. The invention comprise moreover a fire-fighting device comprising at least two fire-fighting devices opportunately connected.