There is an on-going challenge facing the management of all underground transport systems; namely the requirement for constant vigilance of fire safety. Adaptaflex, examines the fire safety standards and solutions that protect the underground rail infrastructure used by over 1.2 billion people every year.
Originally created in the 19th century, the London Underground (LU) is one of the world’s oldest and most famous transportation networks with even its map held as a design icon. Thousands of people use the transport network every day and cover its 249 miles of track, including 113 miles of tunnels and 260 stations, 118 of which are sub-surface.
Both old and new rail infrastructure environments, especially underground networks, are unique in design and therefore demand specialist safety measures. After all, fire safety in this challenging environment is as much about preventing the creation of smoke and the provision of an escape route, than combatting flames.
This means that a high-quality, flexible conduit system which ensures the safety and reliability of critical cable and wiring, is essential. This protection extends to a variety of external influences, be they mechanical, electrical, or environmental. In many sectors, and particularly across rail infrastructure and in relation to fire, compliance with strict standards and regulations is mandatory.
The requirement for constant vigilance and improvement of fire protection standards is reinforced by the history of the London Underground. In November 1984, 14 people (four passengers, one police officer, and nine staff) were taken to hospital for smoke inhalation at Oxford Circus. In November 1987, 31 people were killed at King’s Cross with many more injured. The fire burnt out the top level of the station which mainly consisted of entrances and ticket halls. This tragedy led to the introduction of new fire safety legislation and fortunately, is still the last major loss of life due to a fire in the UK.
A key measure for controlling fire risks continues to be through the safety properties of all the materials used in the stations themselves. The Fire Precautions England Regulations 2009 and the G-085 Code of Practice specifically relate to the fire safety of materials used in the Underground, whilst rolling stock requirements are covered by 1-085 A3 – Fire Safety Performance of Materials.
“Products meeting the EN45545 standard allow engineers and designers to plan ‘interoperability’ across systems, ensuring compliance to stringent local and European fire safety requirements from the design stage.”
There are seven parts to the standard but only Parts 1 and 2 are applicable to conduit systems. Part 1 covers general definitions, operation, and design categories, in addition to fire safety objectives. While Part 2 recognises the reaction to fire performance, harmonising the requirements for fire safety on railway vehicles that operate within Europe.
The highest risk applications naturally apply to sleeper cars, where passengers would have to be woken before being evacuated and when in operation as side evacuation is made impossible. The material requirements for these advanced risk HL3 applications cover the highest levels of flammability, smoke emissions, and toxicity. Not only do these stringent requirements need to be met, but all rail products need to be type-tested to the fire tests specified for their application in the future EN45545-2. This is where the new SPL-EF conduit systems and SPB fittings from Adaptaflex play a crucial role.
The new system, meets the EN45545-2 standard achieving the highest HL3 fire performance rating for both interior and exterior locations. The system provides higher performance levels of flexibility, impact and abrasion resistance, combined with enhanced chemical resistances especially to oils and greases, with a much higher and lower temperature rating (-40°C to +105°C), than any other metallic conduit system with a EN45545-2 HL3 rating.
The SPL-EF system can be installed both interior and exterior locations requiring the highest level of fire protection such as, sub surface line stations and tunnels. The system can also be used to protect data cables connected to wider rail infrastructure, such as escalators and lifts, HVAC, passenger information systems and CCTV applications.
Ultimately, the threat of fire is always going to be a potential risk to the rail sector. The good news is that the forthcoming introduction of EN45545-2 will bring even greater protection and there are innovative products readily available to have a positive impact on the 1.2 billion people using the underground infrastructure annually.