Tunnel Systems

NETWORK

NETWORK

P

ARSONS BRINCKERHOFF

systems

N E T W O R K

ISSUE NO. 78 DECEMBER 2014

Fire and Life Safety

Table of Contents

INTRODUCTION

Global Perspectives on Tunnel Systems

John Munro, Kate Hunt, Steven Lai, Argun Bagis ...3

FIRE AND LIFE SAFETY

Subway Tunnel Cross-Passage Spacing: A Performance-Based Approach

William D. Kennedy, Justin M. Edenbaum, Mia Kang, Kirk G. Rummel ...10

A Note on Fixed Fire Fighting Systems in Road Tunnels

Anna Xiaohua Wang, Norman Rhodes ...13

Fixed Fire Fighting Systems in Road Tunnels – System Integration

Matt Bilson, Sal Marsico ...16

Fire-Life Safety and System Integration: The Functional Mode Table

Matt Bilson, Andrew Gouge ...19

VENTILATION SYSTEMS

Using Quantified Risk Assessment to Inform Ventilation System Responses

Kate Hunt ...23

A Risk-Based Approach to Jet Fan Optimisation

Anthony Ridley ...26

Cost-Effective Ventilation System for a Light Rail Transit Project

Silas Li, Andrew Louie ...30

Meeting the Challenges of Smoke Duct Fan Selection for Australian Road Tunnels

Chris Chen ...34

Analysis Considering the Conversion of an Existing Road Tunnel Transverse Ventilation System to Transit Use

Jesse Harder, Andrew Louie, Vamsidhar Palaparthy, Silas Li ...37

Long Road Tunnels and Portal Emission Control

Argun Bagis, Duncan Saunsbury ...41

Merging Emergency Ventilation System Sound Power and Pressure Drop Calculations

Michael MacNiven ...44

Cost-Effective Power Supply Scheme for Tunnel Booster Fans in Long Tunnels

CC Cheung, Steven Lai ...48

Air Purification System for a Road Tunnel Project

Cathy Kam, Chris Ma, Steven Lai ...51

PRESSURE TRANSIENT

Elimination of Portal Flares

Kenneth J. Harris, Bobby J. Melvin, Steve Gleaton ...52

Comparison of 3-D and 1-D CFD Simulation Approach for Aerodynamic Effects in a HSR Tunnel System

CLIMATE CHANGE AND RESILIENCY

Railway Cooling Challenges

Mark Gilbey ...60

Dynamo – Enhancing Tunnel Ventilation Modelling

Jolyon Thompson ...63

ASSET MANAGEMENT AND PROGRAM

SUPPORT

Asset Management Database for the Brooklyn Battery Tunnel

Ferdinand Portuguez, Debra Moolin ...67

COMMUNICATIONS / POWER AND

ELECTRICAL SYSTEMS

SCADA System Security for Two UK Road Tunnels

Peter Massheder ...71

CCTV Design for a US Road Tunnel

Ryan Williams ...73

How Alternating Current Interacts with Direct Current in the Shatin to Central Link Traction Systems in Hong Kong – A Quantitative Approach

Sam Pang ...76

CONSTRUCTION AND REHABILITATION

Tunnel Inspection Basics for Mechanical and Electrical Systems

James Stevens, Mark VanDeRee ...81

Tunnel Sump Construction Savings Through Drainage System Design Modification

Kevin Stewart ...86

LIGHTING

The Modernization of Tunnel Lighting and Controls: Technology, Challenges, and Cost of Implementing a Tunnel LED Lighting System

Christopher J. Leone, Jonathan T. Weaver,

Kimberly Molloy ...89

SES AND MODELING

Evaluating Freeze Protection Needs with CFD

Raylene C. Moreno ...92

Computational Modeling as an Alternative to Full-Scale Testing for Tunnel Fixed Fire Fighting Systems

Kenneth J. Harris ...96

Latest Enhancements to the Subway Environment Simulation (SES) Program

Andrew Louie, Tom O'Dwyer, Silas Li ... 100

Use of Building Information Modelling (BIM) on Road Tunnels and Metro Projects

YF Pin, R. Ashok Kumar, Steven Lai ... 102

Tunnel Systems

Table of Contents

Fire and Life Safety

Introduction

Introduction

Introduction: Global Perspectives on

Tunnel Systems

For decades, Parsons Brinckerhoff has been at the fore-front of providing innovative tunnel systems solutions to our clients. In 1973 at the First International Sym-posium on Aerodynamics and Ventilation of Vehicle Tun-nels in Canterbury England, attended by representatives from 26 different countries, a paper was presented on the Subway Environmental Simulation (SES) program co-developed by the late William D. Kennedy. That paper led directly to a contract for the design of an extension to the Hong Kong Metro and, out of that project, Parsons Brinckerhoff’s Hong Kong office was established. Over 40 years later in 2015, Dr. Norman Rhodes of Parsons Brinckerhoff will chair the 2015 16th International Sym-posium on Aerodynamics, Ventilation, & Fire in Tunnels to be held in Seattle.

Advances in tunnel systems have evolved to account for a changing world, and Parsons Brinckerhoff’s response has been to ensure that we are both anticipating and responding to these changes and challenges as they oc-cur and that we continue to provide innovative and robust solutions to our clients.

Responding to the challenges of climate change, and the resiliency needed to adapt to a rapidly changing climate, or providing sustainable energy and environ-mental solutions require advances in existing tunnel system technologies and new technologies. Examples of this could be the design of a sustainable LED light-ing solution for the Queens Midtown Tunnel in New York or using groundwater to cool the rising temperatures in the London Underground tunnels (see Mark Gilbey’s article in this issue).

Parsons Brinckerhoff remains at the forefront of the provision of tunnel safety system solutions and their continued improvement as technology evolves. Our un-derstanding of fire behavior and development in tun-nels has increased considerably as a result of testing

programs such as the Memorial Tunnel Fire tests1 _in

West Virginia, led by Parsons Brinckerhoff, and more recently the Runehammer fire test program in Europe. This has allowed us to develop more focused strate-gies that address individual tunnel fire sizes and spe-cific risks. For example, Parsons Brinckerhoff designed a tunnel fire suppression system for the Doyle Drive tunnel project in California. The recently opened Airport Link tunnel in Australia has emergency exits with built-in voice messages to guide users to safety built-in the event of a fire incident.

Although systems technology has advanced significantly over the years, we must keep asking: What will the needs be for future tunnel owners, operators, and users and how do we develop our tunnel systems to respond to those needs?

The imperative to provide resiliency in our designs and to ensure that our designs are also energy efficient and sus-tainable are what drives our solutions. Parsons Brincker-hoff has become a charter member of the Institute for Sustainable Infrastructure to affirm our commitment to the underlying principles of sustainable infrastructure, as well as the specific, evolving practices that characterize sustainable solutions. Our tunnel systems designers are trained in sustainability assessment.

We also need to keep researching and innovating. Our 2014 William Barclay Parsons Fellowship winner, Anna Wang of our tunnel systems team in New York, is devel-oping a model to predict the interaction of fixed fire fight-ing systems on tunnel fires. The outcome of this work will be used to achieve more efficient designs leading to considerable cost savings for our clients. (See Anna Wang and Norman Rhodes’ article in this issue.)

Finally, we need to recognize that smart or connected

road and rail vehicles are a rapidly developing part of our _{DECEMBER 2014}

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present and future. Parsons Brinckerhoff is involved in a program to evaluate connected vehicle technol-ogy. The potential for connected vehicles to interact with tunnel systems is limitless. Imagine a tunnel ven-tilation system that automatically regulates its airflow based on the number and type of vehicles travelling through the tunnel or a deluge system putting out a vehicle fire without waiting for a tunnel operator to re-spond to the emergency.

Tunneling Overview in the United States

by John Munro, New York, NY, US, +1-212-465-5588, [email protected]

Standards such as NFPA 130, ‘Standard for Fixed Guide-way Transit and Passenger Rail Systems,’2 _{or NFPA 502,}

‘Standard for Road Tunnels, Bridges, and Other Limited Access Highways,’ have been a cornerstone guiding the design of tunnel systems for the last few decades. In many countries, these have been used as the de-facto international standards shaping the design of tunnel so-lutions globally.

In the United States, Parsons Brinckerhoff has been cen-tral in shaping the direction of both NFPA 130 and NFPA 502 through active committee participation and chair-manship. Perhaps the most significant development in recent years is the change from purely prescriptive standards to standards that allow performance-based approaches. For example, NFPA 130 states: ”Nothing in this standard is intended to prevent or discourage the use of new methods, materials, or devices, provided that sufficient technical data are submitted to the authority having jurisdiction (AHJ) to demonstrate that the new method, material, or device is equivalent or superior to the requirements of this standard with respect to fire performance and life safety.”

The change from prescriptive to performance-based designs has led to a situation where designers can exercise a greater level of flexibility and innovation in providing solutions for our clients. For example, previ-ous standards prescribed a fan inlet temperature that had to be met without regard to the actual temperature that a fan inlet may experience in a fire. The current standards require that designers analyze the actual fan inlet temperatures that would be experienced for the type of fire that could be realized in relation to the spe-cific rolling stock for that system. Another example is

described in “Subway Tunnel Cross-Passage Spacing: A Performance-Based Approach,” by Kennedy, Edenbaum, et al, which shows that the spacing of cross-passages, the width of walkways, and the width of cross-passages all have an effect on the simulated evacuation time from a train stopped in a tunnel.

Performance-based design challenges designers to more accurately define inputs and parameters, and thus create more accurate models. As with any engineering design, the more accurately you can define and analyze the situation, the less conservative the design and, hence, more value is provided to our clients.

An example of Parsons Brinckerhoff adding value for our clients by more accurately defining design inputs is in the area of analyzing design fires. Historically, de-sign fires were prescribed, often conservatively, based on limited information at the time. The advancement of analysis tools, such as computational fluid dynam-ics (CFD), coupled with better research data, allows us to much more accurately define the design fire which is a major criterion in tunnel system design. CFD and risk analysis were used on recent projects to determine the fire curves for the projects, ultimately leading to a cost-effective design. (See “Cost-Effective Ventilation System for a Light Rail Transit Project,” by Silas Li and Andrew Louie.)

As alternative procurement and delivery methods, such as design-build, become more frequent in the US, perfor-mance-based tunnel systems design can play a central role in providing value. Design-build projects are essen-tially outcome-based and innovation plays a central role in defining their success. The flexibility of performance-based design not only allows but encourages innovation, making it an ideal design methodology that is suited to design-build projects. On recent projects, we have been using the latest fire modeling and heat transfer tech-niques to refine tunnel structure thickness requirements due to fire effects. Reducing structural thickness can reduce construction cost and delivery schedules.

In addition to the design and construction of new tun-nels, such as the recently opened Port of Miami Tunnel, there is an increasing focus in the US on aging infra-structure. MAP-21 (the Moving Ahead for Progress in the 21st Century Act of 2012) includes funding for contin-ued improvement to tunnel conditions that are essen-tial to protect the safety of the traveling public. Parsons Brinckerhoff has continually developed and refined our

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Fire and Life Safety

Introduction

techniques, including using the latest inspection and as-set management technologies, to efficiently assess ex-isting tunnel infrastructure (see articles by Stevens and VanDeRee; and by Portuguez and Moolin). Following the assessment, our performance-based methodologies are used to develop innovative upgrades that provide a level of safety equivalent to code-compliant solutions and that minimize or eliminate interruptions to tunnel operations.

High speed rail projects frequently involve long tun-nels and long distances between stations. Parsons Brinckerhoff can draw on global and local experience to provide solutions for unique challenges such as analyzing the pressure waves associated with high speed trains (see article by Wu and Ye) and providing cost-effective tunnel ventilation and fire and life safe-ty strategies to accommodate the extended egress distances of long tunnels.

Tunnelling Overview in the United Kingdom,

Europe, and the Middle East

by Kate Hunt, Godalming, UK, +44 (0)1483 528966, [email protected]

The UK’s tunnelling market has seen substantial and rapid growth in recent times, with more tunnels predicted in the near future for the rail, metro, road, and utilities networks.

The 1990s saw a number of significant new tunnelling projects including the opening of the Limehouse Link tunnel (road – 1993), the landmark Channel Tunnel (rail – 1994), the Jubilee Line Extension (metro - 1999) and, more recently, the High Speed 1 tunnels (high speed rail – 2007), the Lower Lea Valley utilities tunnel (2012), and the long-awaited Hindhead Tunnel (road - 2011). The Docklands Light Railway added new tunnels as part of the Lewisham (rail – 1999) and the Woolwich Arsenal extension (rail – 2009). The Crossrail project, a new com-muter line railway running East/West below Central Lon-don, is also in construction.

In addition, significant investment has been made to refurbish, upgrade, and improve a number of key road tunnels around the UK including the Hatfield and Bell Common tunnels (on London’s M25 orbital motorway), the Mersey tunnels (Liverpool), Tyne Tunnel (Tyneside), Saltash Tunnel (in the South-West), and refurbishment is ongoing or planned for the North Wales Coast Road tun-nels and the Brynglas Motorway tunnel (South Wales).

Alongside this infrastructure investment, Transport for London’s metro operator, London Underground, has been investing heavily in replacing the fleet and increasing the service levels on all their lines. Parsons Brinckerhoff has a long and ongoing history of assisting London Underground in these works. Looking to the future, we are working to-wards the construction phase of High Speed 2, linking London with Birmingham and on to the North East and Scotland; phase 1 of the route alone features a dozen new high speed rail tunnels ranging in length from just 500 metres (1640 feet) to an impressive 13 kilometres (8 miles). Other tunnel-related rail projects in the plan-ning stages include the Northern line extension to Batter-sea, the Bakerloo line southern extension, and Crossrail Phase 2. In addition, further tunnelled crossings of the River Thames are being considered, along with a number of urban road tunnels on the periphery of London.

However, the investment in the UK’s tunnels market was small in comparison to the enterprising projects under-taken in Scandanavia, Istanbul, the Middle East, and Is-rael. A new fixed link between the countries of Sweden and Denmark was opened in 2000: the Øresundsbron linked the metropolitan areas of Copenhagen in Den-mark and Malmö in Sweden via a combined rail and road link consisting of the 8 kilometre long (5 mile) Øresund bridge and 4 kilometre (2.4 mile) Drogden tunnel. Simi-larly, the Marmaray Crossing in Istanbul (opened in 2013) successfully negotiated the Bosphorus Strait - one of the busiest shipping lanes in the world - to connect the Euro-pean and Asian parts of the old city via a 1.5 kilometre (.9 mile) immersed tube tunnel – the world’s deepest at 60 metres (196 feet) below sea level.3

Meanwhile, in the Middle East, more than $279 billion worth of projects were being planned or underway in 2012. A high proportion of these are in the transport sector, including metro schemes for Abu Dhabi, Cairo, Doha, Jeddah, Kuwait, Riyadh, and Tehran.

Similarly, designs for the proposed metro in Israel’s Tel Aviv urban district continue to be developed, with the construction phase drawing nearer. At the same time, plans for a high speed rail line from Tel Aviv to Jerusalem are being developed.

Many of our past and current projects involve technical in-novations, or cutting edge techniques to address clients’ unique challenges. Whether we are providing strategic ad-vice to operators (see the “Railway Cooling Challenges”

article by Mark Gilbey in this issue), leading discussions DECEMBER 2014

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Introduction

with the UK’s Climate Projections group (UKCP), develop-ing a new toolset such as DYNAMO to address a devel-oping market (see Dr. Jolyon Thompson’s article in this issue, a version of which won the 2014 Parsons Brinck-erhoff Emerging Professionals Technical Paper competi-tion), developing sustainable designs through the use of innovative cooling techniques such as groundwater cool-ing or embedded liners, uscool-ing the latest risk-based tech-niques to optimise designs and operations (see articles in this issue by Kate Hunt and Anthony Ridley), or intro-ducing world-class high speed rail to the UK, our team of engineers is at the forefront of innovation.

Parsons Brinckerhoff continues to retain its high profile in tunnel systems capability through many of the major proj-ects being undertaken. Parsons Brinckerhoff’s in-depth knowledge and internationally renowned global team is able to deliver technical excellence to clients across all geographies and all sectors. As we engage with WSP, the challenge in the Europe, Middle East, and North Af-rica regions is to enhance our service offering across a broader range of sectors, to embrace the many exciting opportunities available, and to continue to provide our clients with the technical excellence they rightly expect of Parsons Brinckerhoff.

Tunneling Overview in Asia

by Steven Lai, Hong Kong/Singapore, +852-2963-7625 / +65-6589-3661, [email protected]

Parsons Brinckerhoff has a rich history of working on major tunnel projects and designing innovative solutions for tunnel systems in Asia. Some of these designs, con-cepts, and challenges are presented below.

Closed systems and platform screen doors. In the

1970s, Parsons Brinckerhoff introduced an energy ef-ficient closed system for the first metro in Hong Kong thereby providing a comfortable air-conditioned station environment for passengers. Then in late 1970s, with the availability of a more advanced signaling system for accurate train stopping positions, Parsons Brinckerhoff introduced the platform screen door (PSD) system for the first metro in Singapore and has continued to be involved in this design for other metro systems in the region (e.g., Japan, India, Mainland China, Taiwan, Thailand, and Viet-nam). A PSD system can provide a more comfortable and less dusty environment inside the station, for example, 25 degrees C instead of 28 degrees C (77 degrees F

instead of 82 degrees F), a reduction of air velocity at the platform edge and staircases, and a lower noise level.

Better land use and increased carrying capacity. Parsons

Brinckerhoff provided engineering design support in the conversion of an elevated metro line to an underground metro line in Taiwan, resulting in better land use and a better interchange (transfer) arrangement with other met-ro lines. Parsons Brinckerhoff is also assisting various clients in increasing the capacity of existing metro lines through extending the catchment area, modification of roll-ing stock, and reducroll-ing headway of the trains. Subway En-vironment Simulation (SES), computational fluid dynamics (CFD) modeling, and evacuation models have been used to study the impact of these methods on the environmental control systems (ECS) and the fire and life safety systems in stations and tunnels and to assist clients in establish-ing cost-effective design schemes.

Fire engineering approach. Since the mid 1990s, a

performance-based fire engineering approach has been widely used to analyse the heat release rate from a train, the tenable environment along the evacuation path, etc. Parsons Brinckerhoff has adopted this approach for proj-ects in Hong Kong, Taiwan, and Singapore, and was rec-ognized with an award for innovation for the design of a station with an atrium in Shanghai. Parsons Brinckerhoff has also assisted metro companies in the integration of individual operations control centers (OCC) for existing lines and new lines in the region.

Pressure transient from high speed trains. The high speed

trains in Taiwan and Mainland China travel at 300kph (186mph) or even greater speeds. The pressure transient created by high speed trains can create issues for the passengers inside the trains, stations, and areas around ventilation shafts and tunnel portals. Parsons Brinckerhoff has developed various mitigation schemes which have been used to resolve the pressure transient issues in the Hong Kong Airport Express Railway, Taiwan High Speed Railway, West Rail in Hong Kong, several metro systems in mainland China, and Express Railway Link in Hong Kong. (See article by Dicken Wu and Rambo Ye in this issue.)

Parsons Brinckerhoff’s work on road tunnels includes: • design of the 2km (1.2 mile) Cross Harbour Tunnel in

Hong Kong in which a transverse ventilation system was used;

• design of a longitudinal ventilation systems for road

tunnels in Singapore with the use of the critical veloc-ity concept;

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• minimizing the tunnel construction cost of the 3.9km

long (2.4 mile) Tate’s Cairn Tunnel in Hong Kong with the use of construction shafts as permanent ventilation adits, which also resulted in early completion of this design-build project;

• design of the 2km long (1.2 mile) Western Harbour

Crossing in Hong Kong with optimized mechanical and electrical (M&E) services and ventilation ducts. This re-duced the overall immersed tube tunnel cross-section and resulted in construction cost savings; and

• design of an Air Purification System (APS) for the Central

and Wanchai Bypass project in Hong Kong in order to pro-duce cleaner air at the tunnel portals and the ventilation buildings. This system has been applied to various road tunnels in order to achieve a better environment. (See ar-ticle by Cathy Kam, Chris Ma, and Steven Lai in this issue.)

New challenges in tunnel systems. Nowadays,

excep-tionally long tunnels with large cross-sectional areas and/or multi-purpose tunnels create new challenges to engineers. Parsons Brinckerhoff has participated in the following design of tunnel systems for several spe-cial tunnel projects in China:

• the 18km long (11 mile) Zhong Nam Shan Tunnel with

very long ventilation shafts, more than 500 meter (1640 feet);

• the 6km long (3.7 mile) Chongming road tunnel which

links Shanghai to the out-lying Chongming Island and has an upper deck for vehicular traffic and a lower for the metro line;

• the 2km long (1.2 mile) Fuxing East Road Tunnel in

Shanghai which also has an upper deck and a lower deck both of which are used for vehicular traffic; and

• the Macau Sai Van Bridge which has an upper deck

used for vehicular traffic and an enclosed lower deck used for light rail operation (normal condition) and ve-hicular tunnel operation (during typhoon conditions).

Value engineering and cost effective design. Parsons

Brinckerhoff has developed various value engineering schemes and creative approaches to achieve cost effec-tive design for our clients and provide a better environ-ment for the people. These schemes include:

• the use of combined ventilation shafts instead of

indi-vidual ventilation shafts to reduce the constraint on the station planning and the size of aboveground structures (Suzhou metro);

• the use of a centralized chilled water system to reduce

the overall spatial requirement and result in a more en-ergy-saving system (Tsuen Wan Line in Hong Kong);

• the use of higher voltage to supply the power for

tun-nel ventilation equipment in long tuntun-nels to reduce the cable cost and overall spatial requirement, as described in an article by CC Cheung and Steven Lai in this issue (Airport Express Line in Hong Kong, Cheung Ching Tun-nel in Hong Kong);

• sharing of tunnel ventilation fans for different lines

(Tai-wan Nankong Extension);

• use of Saccardo nozzles to replace numerous jet fans

(West Rail in Hong Kong, KPE in Singapore);

• use of tunnel cooling systems for long tunnels to reduce

the number of ventilation shaft structures (Tsuen Wan Line in Hong Kong); and

• the use of water mist systems to cool down long

vehicu-lar tunnels (Chongming road tunnel in Shanghai).

Apart from the above, with the use of CFD modelling, Parsons Brinckerhoff has designed and developed cost-effective ventilation systems for various cable tunnels in Hong Kong, Singapore, and Mainland China.

Building Information Modelling. To increase productivity

and provide a better visualization of complicated engi-neering solutions to stakeholders, Parsons Brinckerhoff is the first company in Hong Kong to use building infor-mation modelling (BIM) for the tunnel systems of a road tunnel project. Parsons Brinckerhoff is also the first com-pany in Singapore to use BIM for designing the mechani-cal and electrimechani-cal (M&E) systems in a metro project, and has also used BIM for a cable tunnel project in Singa-pore. (See article by YF Pin, R. Ashok Kumar, and Steven Lai in this issue.)

Tunnelling Outlook in Australia and New

Zealand

by Argun Bagis, Sydney, AUS, 61-2-9272 5435, [email protected]

Australia’s population is projected to grow significantly by 2050, with Sydney, Melbourne, and Brisbane identified as cities where the majority of this growth will take place. Ac-cordingly, the development of road and rail infrastructure has been at the forefront of the Australian government’s priorities and has resulted in the construction of a num-ber of strategic road tunnels, and the safeguarding of rail corridors, primarily on the eastern coast of Australia.

There are a significant number of tunnelling projects in the works for the latter half of this decade. Funding has

already been approved for most of the nine new tunnels DECEMBER 2014

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Introduction

currently being planned along the east coast of Austra-lia, with the west coast expecting some movement as well with the planning of an extension to the existing metro system.

In addition, the Australian government is focused on shifting the transportation of freight from road to diesel rail. This raises the need to upgrade existing rail infra-structure as well as to develop new rail routes to relieve the already congested east coast rail network. Rail proj-ects linking the city of Brisbane with Melbourne over a new inland rail path, the extension of this rail path to the Port of Brisbane, and the Maldon to Dombarton rail link in New South Wales are initiatives that have been brought to the forefront of infrastructure spending. Tun-nel ventilation and fire & life safety are key aspects in the successful delivery of these projects.

Figure 1 provides both a summary and a forecast for the tunnelling sector in Australia, from 2003 through to 2023. As is evident from the graph, the outlook for tun-nel projects from 2014 onward is looking very positive, and there will be a strong need for specialist engineer-ing services, such as in tunnel ventilation. Brisbane, QLD in particular became (and continues to be) a ma-jor centre for tunnelling construction in Australia, with the construction of the M7 Clem Jones Tunnel (Clem 7), Airport Link and Northern Busway, and Legacy Way (still under construction) road tunnels. Parsons Brinck-erhoff has been involved in the detailed design work on many unidirectional traffic tunnels. Chris Chen’s article on “Meeting the Challenges of Smoke Duct Fan

Selec-tion for Australian Road Tunnels” describes the unique fan duty requirements for this type of tunnel ventilation system, employing a combined longitudinal and distrib-uted smoke extraction ventilation (smoke duct) system for fire emergencies.

In New Zealand, the Waterview Connection for Auckland’s Western Ring Route is the largest road project ever un-dertaken in the country, including a 2.5-km long twin-tube tunnel with three lanes in each tunnel. Parsons Brincker-hoff is a member of the Well-Connected Alliance which is both delivering the project, and operating and maintaining the facility for 10 years after the opening. Kevin Stewart’s article on “Tunnel Sump Construction Savings through Drainage System Design Modification” describes how this DBOM project structure gave all parties an interest in cost-effective design for both construction and maintenance.

Parsons Brinckerhoff has diversified into non-traditional road and rail tunnel services. The re-development of ex-isting rail stations, provision of post construction servic-es to tunnel operators, and even mine ventilation have been markets where Parsons Brinckerhoff has delivered successful outcomes. Other examples of technical chal-lenges include:

• The planning and design of longer tunnels which is

gain-ing momentum in Australia. A reduction in vehicle emis-sions, traffic fleet composition, and recent innovations in ventilation plant design have enabled the design of tunnel lengths to be almost double that of existing Aus-tralian tunnels, with fewer intermediate tunnel

ventila-DECEMBER 2014 http://www .pbworld.com/news/publications.aspx 8.0 6.0 4.0 2.0 0.0 $ Billion

Melbourne Rail Link (VIC)

M4 South (NSW) East-West Link (QLD) East-West Link Western Section (VIC) Brisbane Underground (QLD) Forecast

Toowoomba Range Second Crossing (QLD) Lane Cove Tunnel (NSW) Cross City Tunnel (NSW) North-South Bypass Tunnel (QLD) Legacy Way (QLD) Airport Link (QLD)

CityLink Western (VIC) East-West Link Eastern Section (VIC)

03 05 07 09 11 13 15 17 19

Source: BIS Shrapnel, ABS Data

Year ended June 21 23

East Link (VIC)

M5 East (NSW) M4 East (NSW) North West Rail Link (NSW) Forrestfi eld Airport Rail Link (WA)

M1 to M2 Link (NSW)

Fire and Life Safety

Introduction

Steven Kam-Hung LAI

Director, Infrastructure, China Region

Hong Kong

Kate Hunt

Service Leader, Tunnel Ventilation & Fire Engineering (RMS), Rail & Transit

Godalming, UK

John Munro

Director, M&E

New York, NY, US

tion plants. There are currently three tunnels in the early design phase with lengths expected to be in the 8-9 kilometre (5-5.6 mile) mark.

• The current Australian policy to limit emissions at

tunnel portals (see the article on “Long Road Tun-nels and Portal Emission Control” in this issue) con-tinues to be a major factor in increased energy use in Australian road tunnels.

• The relatively hot Australian climate, principally in mid

to north Australia, has made the effects of climate change a key consideration in the design of tunnel ventilation systems, particularly in relation to rail

tun-nels. Climate projections beyond 2030 and 2050 are now commonly used for the design of tunnel ventila-tion systems.

Overall, the future demand for tunnel ventilation and tun-nel systems in Australia looks strong, with funding for major road and rail tunnel projects already confirmed. The challenge remains to fully utilise Parsons Brincker-hoff’s capability outside of the traditional concept phase by taking on leading roles in the detailed design, con-struction, and operation phases, as on the Victoria Park Tunnel and the Waterview Connection projects.

Argun Bagis

Principal Engineer, Tunnel Systems

Australia, New Zealand

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Tunnel Systems

Fire and Life Safety

Subway Tunnel Cross-Passage Spacing:

A Performance-Based Approach

by the late William D. Kennedy; Justin M. Edenbaum, Toronto, Canada, +1-917-225-6314, [email protected];

Mia Kang (formerly of Parsons Brinckerhoff); and Kirk G. Rummel (formerly of Parsons Brinckerhoff)

The US National Fire Protection Association's Standard 130, "Fixed Guideway Transit and Passenger Rail Sys-tems," requires that tunnel-to-tunnel cross-passages shall be spaced a maximum of 800 feet (244 meters) apart. No guidance is provided on how the actual spacing should be determined. Intuition says that the spacing should vary with the length of the train, the number of passengers on board the train, the walkway width, the design fire scenario, etc. This paper presents a performance-based approach for calculating cross-passage spacing for downstream emergency evacuations from the fire site, and discusses NFPA 130 compliant methodologies for reducing the num-bers of cross-passages required. The performance-based calculations include the use of computer software for ana-lyzing and comparing exiting strategies. The simulations account for the geometry of a bored tunnel.

Introduction

Based on earlier emergency ventilation studies, it was concluded that the maximum cross-passage spacing should be such that those downstream of the fire could evacuate to a point of safety within the time that it takes for the floor of a train car to burn through (which leads to flashover of the entire train car).

This leads to the conclusion that increasing the car-floor burn-through time would allow greater tunnel-to-tunnel cross-passage spacing and possibly reduce costs. This is suggested in NFPA 130 (Section 8.5.1.3.2(1)). Another possibility is wider walkways or cross-passage doors to speed passenger movement away from the fire site.

It also leads to the inference that an interior or post-flash-over fire should not be allowed to stop a train in a tunnel. Driver override should allow the movement of the train to the nearest station even if a passenger activates the emergency brake. The analysis for this paper assumes that this is the circumstance and that the only fire that will stop a train in a tunnel is a below-car fire that critically damages the propulsion system or derails the train.

Physical Scenario for Computer Model

Physical scenarios are simulated using computer mod-eling to predict the evacuation times for passengers downstream of the fire site to reach a point of safety. Seven cross-passage spacings, ten walkway widths, and one passenger load were analyzed. The computer model accounts for the unique geometry of a bored tunnel by considering shoulder space requirements. The simula-tion results provide sample engineering informasimula-tion to develop a sample of cost-effective alternatives without compromising safety.

The physical scenario for modeling is selected to be typi-cal of a heavy- or main-line rail passenger system. The results of this type of analyses are affected by many spe-cific project factors. Therefore, the results provided in this paper MUST NOT be directly applied to any projects. See Figure 1 for data used.

A number of assumptions were made in the model in or-der to be conservatively safe and simulate a reasonable worst case situation, such as:

William D. Kennedy, an internationally recognized expert in tunnel ventilation, died in June 2012. During a

46-year career with Parsons Brinckerhoff, he was instrumental in the development of tunnel ventilation systems for road and rail tunnels worldwide. His reputation in tunnel ventilation was recognized in March 2012 by the International Symposium on Tunnel Safety and Security, which awarded him its 2012 Achievement Award, citing his “long and illustrious career in ventilation engineering of tunnels” and calling his lifetime body of work “a shining example of wedding practice and theory in the design of tunnels.”

This abstract is condensed from a paper that was originally prepared for the 2006 APTA Rail Conference and has been updated to reflect the current 2014 version of NFPA 130.

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• The location of the fire is in the middle of the train. • The to-be evacuated train has a fire that is aligned with

a cross-passage.

• A population of rail passengers consists of typical

“commuters” with a range of demographics and walking speeds. (When the given walkway is wide enough, the model allows faster individuals to over-take slower walkers.)

• The fire scenario was assumed to be:

- Time 0 minutes, fire ignition;

- Time 5 minutes, fire reaches below-car fire heat release rate;

- Time 10 minutes, fire stops train; and - Time 15 minutes, evacuation begins.

Therefore, when calculating the minimum car-floor burn-through time required, 10 minutes (15-5) should be added to the evacuation time. This does not include any allowance for modeling accuracy.

The emergency exiting analysis was done using the computer program SIMULEX1, which simulates the

emer-gency exiting of people. The program algorithms for the movement of individuals are based on real-life data and predict realistic flow of people. It simulates the escape movement of each person instead of using a mathemati-cal formula for uniform flow rates and average speeds of groups of people. This program is well-validated and has been used to model rail system emergency evacuations for a number of years2.

The evacuation method was assumed to be all doors open to the walkway with movement to the nearest cross-sage downstream or adjacent to a stopped car. The pas-sengers were considered to reach a point of safety after reaching 10 feet (3048 mm) inside of the cross-passage.

Bored Tunnel Geometry

Cross-passage spacing is particularly important in bored tunnel construction where cross-passages have to be mined in poor soil. Costs to construct each cross-pas-sage in this situation can be high. The SIMULEX model inputs are adjusted for a bored tunnel construction. This leads to the concept of “Constructed Width” vs. “Effec-tive Width.” Constructed Width is the actual width of walk-way on the ground. Effective Width refers to the width entered into the SIMULEX model to accurately simulate the evacuation, relating to factors such as walkway width at shoulder height and the natural inhibition of walking near the edge of an empty track.

Figure 2 presents the results of the simulations for 250 people per car and seven cars being evacuated.

Some observations

These observations are based on the sample data and should not be directly applied to other projects.

• Clearly the spacing of cross-passages has a significant

impact on evacuation times. For the assumed data, any evacuation times required to be lower than 30 minutes, with train capacities in this study range, and with reason-able walkway and cross-passage widths, require spacing of cross-passages significantly shorter than the 800 foot maximum in NFPA 130. Other variables such as walkway or cross-passage width would also have an impact.

• There are significant benefits of wider walkways and

wider cross-passage doors at cross-passage intervals above 700 feet or so. This is because the wider walk-way after the train allows faster passengers to overtake slower passengers. In general, wider walkway widths help evacuation scenarios when the spacing has cross-passage doors that are not adjacent to the train and

1_{"SIMULEX Users Manual"; 1998, Integrated Environmental Solutions, Limited; 141 St. James Road, Glasgow G4 0LT, Scotland.}

William D. Kennedy, Norris A. Harvey, and Silas K. Li, “Simulation of Escape from Rail Tunnels Using SIMULEX,” American Public Transportation

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Figure 1 – Evacuation Scenarios

X= Cross Passage Spacing (200, 300, 400, 500, 600, 700, and 800 feet) (61, 91, 122,152, 183, 213, to 244 meters) W= Constructed Walkway Width (36, 38, 40, 42, 44, 46, 48, 50, 52, and 54 inches)

(914, 965, 1016, 1067, 1118, 1168, 1219, 1270, 1321, to 1372 mm) Downstream Under-Car Fire Upstream 595' (181 m) X X W W

Fire and Life Safety

are located far away from the end of the train. Under these circumstances, wider walkways can be considered as an alter-native to shorter cross-passage spacing.

• In the scenario adopted for analysis, it

is obvious that shorter cross-passage in-tervals (in the range of 200 to 500 feet) result in one to three cross-passages adjacent to the train immediately ac-cessible as soon as the evacuees move onto the walkway. Because the train can discharge passengers at a greater rate than they can exit through cross-passag-es, the effect of wider walkways in these shorter intervals is minimal.

• While not immediately apparent from the

data shown, the effect on evacuation times due to varying passenger travel speeds is significant, again, at the

lon-ger intervals; of interest where continuous movement is occurring as opposed to the accumulated conges-tion immediately next to the train that dominates the shorter spacing cases. Thus, if performing analysis around cross-passage spacings that are beyond the train, careful attention must be given to the model inputs for evacuation speeds.

• Finally, the model examines the paths of evacuation

up to the point of safety - the cross-passage. A close examination of the dynamics of the evacuation paths suggests that a project-specific application might want to consider the entire evacuation path—to whatever ends: a rescue train, a station platform, the opposite bore trackway, etc. The effects of the complete path should be modeled to study if there is an adverse af-fect of the evacuation in the non-incident tunnel. At a minimum, such analysis could suggest appropriate instructional and training emphasis.

Conclusion

A performance-based approach for estimating evacua-tion times downstream from a tunnel fire site and mini-mum car-floor burn-through times has been presented. It allows the trade-off among cross-passage spacing, car-floor burn-through time, and walkway and pas-sage door width. For existing systems with fixed

cross-passage locations and widths, this approach could be used to select car-floor burn-through times when cars are retrofitted or new rolling stock is ordered. For future designs, this approach could be used to develop a cost analysis combining cross-passage spacing and widths, car-floor burn-through time, and walkway width; possibly increasing the cross-passage spacing beyond the NFPA 130 maximum of 800 feet (244 meters).

Recommendation

After peer review this approach could be used to devel-op an enhancement to NFPA 130. This enhancement, in relating cross-passage to other project characteristics, could provide a more logical basis for cross-passage spacing that could be greater or lesser than the current 800-foot requirement (244 meters).

William D. “Bill” Kennedy was instrumental in the development

of tunnel ventilation systems for road and rail tunnels worldwide and he led the development of the Subway Environmental Sys-tem (SES) software program, widely considered the standard tool for the analysis and design of transit systems.

Justin Edenbaum is a Supervising Mechanical Engineer in the

Toronto office of Parsons Brinckerhoff specializing in tunnel ven-tilation and fire life safety.

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Figure 2 –Time vs. Width

Evacuation T ime (min:sec) 36:00 30:00 24:00 18:00 12:00 06:00

Constructed Walkway Width (inches)

34 38 42 48 50 54

1200-foot Cross Passage Spacing 1000-foot Cross Passage Spacing 800-foot Cross Passage Spacing

Cross Passage Spacings (feet) 800 700 600 500 400 300 200

Fire and Life Safety

A Note on Fixed Fire Fighting Systems in

Road Tunnels

by Anna Xiaohua Wang, New York, NY, US, +1-212-465-5756, [email protected]; and

Norman Rhodes, New York, NY, US, +1-212-613-8861, [email protected]

Introduction

Historically, the disappointing results of the Ofenegg Tun-nel fire tests (1965, Switzerland) had a negative impact on sprinkler application in tunnels. The tests, which employed pools of aircraft fuel, led to the view that visibility was much reduced by the sprinkler systems and hot steam was generated that could cause scalding at long distances from the fire. The steam production also displaced smoke more quickly causing temperatures to be higher than with-out sprinklers. After extinguishment the fuel continued to evaporate, reaching critical concentrations within about 20 minutes. Subsequent deflagrations occurred that created air velocities of up to 30 meters per second.

It was the impact of this experience that was reflected in the World Road Association (PIARC) recommendations which, between 1983 (World Road Congress in Sydney) and 2004, consistently advised against the installation of fixed fire fighting systems (FFFS) in road tunnels, and this position was reflected in US standards.

One of the factors that maintained this attitude against the application of FFFS in tunnels was the fire sizes gen-erally used. The fire sizes chosen on which to base the design were relatively small—20 to 30 MW—typical of a bus or truck fire. Such fires were regarded as man-ageable and ventilation systems were sized to control smoke for such events.

Several severe road tunnel fires - the Mont Blanc Tunnel (France/Italy, 1999), the Tauern Tunnel (Austria, 1999), the St. Gotthard Tunnel (Switzerland, 2001), and the Fre-jus Tunnel (France/Italy, 2005) - resulted in loss of life, injury, and infrastructure damage that were far more ex-tensive than if they had occurred on surface roadways. These fire incidents demonstrated that fire sizes could be much larger than 20-30 MW and completely changed the perception of the design fire size. Since then the maximum design fires utilized in tunnel design have in-creased as much as tenfold in some cases. These

re-cent incidents have emphasized the need for further im-provement to be made in tunnel fire management; the FFFS is one technique that is actively being promoted.

Types of FFFS

Several types of FFFS have been used in road tunnels worldwide:

• Sprinkler/spray (water deluge) systems, based on dense

water jets consisting of large-size droplets;

• Water mist systems, based on very fine water droplets;

and

• Foam water suppression systems.

Water sprinkler type FFFS have been installed in road tunnels of significant length for many years in Japan and Australia. Tunnels that have water deluge fixed fire fight-ing systems installed can also be found in the United States, Norway, Canada, and Sweden. These have been found to be effective in preventing fire spread and en-hancing cooling of the tunnel structure. In 1999, two fires occurred in the underwater tunnels of the Tokyo Metro-politan Expressway and the FFFS helped control the fires so firefighters could approach and eventually extinguish the fires. The deluge system in Sydney Harbor Tunnel in Australia is reported to have worked well during a van fire in 2004. Another example is the Burnley Tunnel fire in 2007; the deluge system was activated quickly and this was deemed by firefighters to have kept the fire under control. Based on this experience, and the development of alternative types of FFFS, PIARC re-evaluated its posi-tion with regard to FFFS and at the same time the Europe-an Community undertook research programs to examine fire suppression and the impact of larger design fires.

Several relevant European research programs, including UPTUN (Multinational European Research Project) and the SOLIT (Safety of Life in Tunnels) Project, have dem-onstrated through independent tunnel fire tests that, with early activation, high pressure water mist systems can be

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have been installed in the A86 tunnel in Paris, the M30 tunnel in Madrid, the Roertunnel and the Tunnel Swalmen in the Netherlands, and other tunnels in Europe.

Therefore, FFFS are now increasingly being considered in the design of tunnel systems worldwide. This position is also reflected in changes to the recent NFPA 502 and PIARC documentation.

Choosing a Fire Suppression System

Choosing the type of fire suppression system for a road tunnel is not an easy decision to make. Some of the dif-ferent aspects of the systems are as follows:

Water Sprinkler Fire Protection System

The water sprinkler fire protection system (see Figure 1) has existed for over 100 years and is a commonly used and reliable technology; deluge water sprinkler systems are the common FFFS in Australia and Japan. The system performs very well for Class A (solid fuel) fires, but is con-sidered to be less suited for Class B (liquid fuel, oil) fires or where "splashing" of the fuel is to be avoided.

Water Mist Fire Protection System

Compared to the water sprinkler system, the water mist system (see Figure 2) generates much smaller water droplets and therefore has advantages in promoting more efficient gas-phase cooling and uses 2 to 3 times less water for road tunnels (depending on the system used). Both the water mist and water vapor system can measurably reduce radiant heat flux to objects near the fire - this helps firefighters approach the fire and provides better conditions for evacuation. However, be-cause the system contains fine water particles, it may be less efficient in cooling or wetting the fuel surfaces; therefore, the system is less efficient to combat solid fuel fires compared with the water sprinkler system.

Fixed Foam-Water Fire Suppression Systems

Fixed foam-water fire suppression systems may be an-other alternative to combat tunnel fires. A foam agent is especially suited for the control and extinguishment of flammable and combustible liquid-type fires. There are two types of foam-water fire suppression systems pro-posed for road tunnels:

• the foam-water sprinkler system (see Figure 3); and • the compressed air foam (CAF) system (see Figure 4).

The use of the foam-water sprinkler system against die-sel pool fires was investigated in the Memorial Tunnel

in West Virginia by Bechtel/Parsons Brinckerhoff. The foam-water sprinkler deluge system has been installed in several tunnels in Seattle, Washington. The com-pressed air foam (CAF) system has been tested in road tunnels in the Netherlands. For both types of foam-water suppression systems, corrosion protection is required for the storage tanks and the pipe systems, and the system can be costly in the long run because of the cor-rosion problem associated with the use of foam agents.

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Figure 3 – Schematic of a foam-water sprinkler system Figure 1 – Water sprinkler nozzles in the tunnel

Figure 2 – Water mist nozzles in the tunnel

Nozzles Alarm Check Valve Proportioning Controller Main Control Valve Water Supply Piping Network Bladder Tank

Figure 4 – Schematic of a compressed air foam (CAF) system

Piping Network Releasing Controller Air Mixing Chamber CAF Generation CAF Nozzles Water Foam Concentrate

Fire and Life Safety

For longer tunnels, the use of foam-water fire suppres-sion systems may be challenging:

• for the foam-water sprinkler system, the delivery time

of the foam may be too long as the foam tanks have to be installed at the tunnel portals and it may take time for the foam to reach the fire if the fire is located in the middle of the tunnels; and

• for the CAF system, additional mechanical rooms need

to be installed at specific intervals of length in the tun-nels which increases the initial capital cost of the instal-lation of a CAF system.

Conclusion

The FFFS is also being considered in road tunnels to re-duce the size of the ventilation system required. When authorities prepare to permit all types of traffic, such as dangerous goods or heavy goods vehicles, to cope with in-creasing economic activities, mitigation options that can combat 200 - 300 MW fires would be necessary for tun-nels, as recommended by NFPA 502 and most European standards. Without FFFS, large fires (such as 200 - 300 MW) dictate the need for a very powerful ventilation sys-tem, increasing space requirements and adding signifi-cant cost. In addition, FFFS, unlike a ventilation system, can provide benefits for firefighting, tunnel system protec-tion, and operational continuity.

Although the benefits of FFFS are clear, many design issues remain, such as: the reduction in the design fire size with the inclusion of the FFFS and the subsequent reduction in venti-lation requirements; the impact of the FFFS on the structural protection system; the performance of the FFFS under op-erational conditions that have not been tested in the tunnel fire experiments; and the impact of the FFFS on the overall tunnel safety concept and operation procedures.

The most reliable method available to date for those un-solved design questions is full-scale testing, but that is extremely expensive and impractical for new or existing tunnels. A computational fluid dynamics (CFD) fire mod-eling approach is an alternative and holds great promise once a reasonable correlation between numerical simu-lations and full-scale tests has been achieved.

References

• Haerter, “Fire Tests in the Ofenegg-Tunnel in 1965”,

International Symposium on Catastrophic Tunnel Fires, Boros, Sweden, November 2003.

• PIARC 2008: Road Tunnels: An Assessment of Fixed

Fire Fighting Systems.

• UPTUN, Fire development and mitigation measures,

Work Package 2 of the Research Project UPTUN, 2008.

• Starke, H., “Fire Suppression in Road Tunnel Fires by

a Water Mist System – Results of the SOLIT Project”, Fourth International Symposium on Tunnel Safety and Security, Frankfurt am Main, Germany, March 17-19, 2010.

• Water Mist Fire Suppression Systems for Road

Tun-nels, Final Report, The SOLIT Research Project, 2007.

• NFPA 502, Standard for Road Tunnels, Bridges, and

Other Limited Access Highways, 2014 Edition, Nation-al Fire Protection Association.

• Huijben, Ir. J.W., “Tests On Fire Detection Systems

And Sprinkler in a Tunnel,” ITC Conference Basel 2-4, December 2002.

• Liu, Z.G., Kashef, A., Lougheed, G., Kim, A.K.,

“Chal-lenges for Use of Fixed Fire Suppression Systems in Road Tunnel Fire Protection”, NRCC -49232, Sup-pression & Detection Research Applications – A Technical Working Conference (SUPDET 2007), Or-lando, Florida, 2007.

• Quenneville, R., “The Emergence of CAF Fixed-Pipe

Fire Suppression Systems”, Fire & Safety Magazine, Spring, 2006.

• Memorial Tunnel Fire Ventilation Test Program, Test

Report (section 8.10), Massachusetts Highway Depart-ment, by Bechtel/Parsons Brinckerhoff, Nov. 1995.

• Lemaire, A.D. and Meeussen, V.J.A., “Effects of Water

Mist on Real Large Tunnel Fires: Experimental Deter-mination of BLEVE-risk and Tenability during Growth and Suppression”, Rept. 2008-Efectis-R0425, Efectis Nederland BV, June 2008.

• Grant, G., Brenton, J., Drysdale, D., “Fire Suppression

by Water Sprays,” Progress in Energy and Combustion Science 26 (2000), 79-130.

• Tunnels Study Center (CETU), "Water Mists in Road

Tunnel," State of knowledge and provisional assess-ment eleassess-ments regarding their use, June 2010.

• NFPA 15, Standard for Water Spray Fixed System for

Fire Protection, 2007 Edition, National Fire Protection Association.

Dr. Anna (Xiaohua) Wang is a Principal Technical Specialist in

Parsons Brinckerhoff’s New York office.

Dr. Norman Rhodes is the Technical Director of the Parsons

Brinckerhoff Mechanical/Electrical Technical Excellence Center.

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Fire and Life Safety

Introduction

Fires that occur in road tunnels can grow rapidly and reach very high heat release rates. As a result, road tunnels are designed with mitigation technology and procedures to help reduce the detrimental effects that can occur.

The main goals of the mitigation measures are to:

• Provide a tenable environment for motorist evacuation; • Assist firefighters with their operations; and

• Maintain the structural integrity of the tunnel.

A fixed fire fighting system (FFFS) is one type of mitiga-tion measure implemented to help achieve these goals. The major components of the FFFS include water deliv-ery infrastructure (pumps, pipes, valves, and nozzles – divided into separate zones for water delivery) and also components for water removal (drainage, pumps, pipes, water treatment).

A FFFS is typically installed to help reduce the fire growth rate and air/smoke temperature, which helps to prolong occupant tenability and provides structural protection. Proper integration of the FFFS with other tunnel fire-life safety systems is essential to achieve the FFFS goals.

The first important question in FFFS integration is wheth-er or not the tunnel has a full-time opwheth-erator. In many tun-nels with FFFS, a full-time operator is present. In this ar-ticle the integration question is considered in the context of a full-time operator being present, but it is noted that if an operator is not present there will be different integra-tion consideraintegra-tions. Tunnel systems and funcintegra-tions that require particular attention for integration with a FFFS, with full-time operator present, include:

• Closed circuit television (CCTV); • Ventilation systems;

• Egress provisions; • Drainage;

• Fire alarm systems, control systems, heat detection

systems; and

• Traffic and operations.

Poor system integration can lead to a reduction in FFFS performance and fire safety.

System Integration with Fixed Fire Fighting

Systems

CCTV

Activation of the FFFS at an early stage of a fire incident is the best way to assure optimal performance, and this is

Fixed Fire Fighting Systems in Road

Tunnels – System Integration

by Matt Bilson, New York, NY, US, +1-212-465-5510, [email protected]; and

Sal Marsico, New York, NY, US, +1-212-465-5576, [email protected]

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Figure 1 – Example of good CCTV and FFFS integration

179 Plan view of roadway:

178

Fixed camera

Deluge zone/ventilation zone Tunnel wall

Traffi c and airfl ow Linear heat detector Roadway

LEGEND

CCTV vision example:

Zone N178 is in the foreground Zone N179 is in the background

Fire and Life Safety

typically accomplished through manual activation by the tunnel operator. The tunnel operator relies on the CCTV system to assist in identifying the fire location, as the CCTV system would typically detect smoke or stalled traf-fic well before a heat detector senses the fire. Once the fire has been located, the operator activates the corre-sponding FFFS zone. It is imperative that operators can easily and accurately identify the fire locations. Figure 1 provides an example of effective design integration be-tween a CCTV and FFFS system.

The figure shows an example of good systems integration with camera locations relative to their proximity to FFFS zones. Placing a camera within a zone, instead of at zone boundaries, may generate confusion for the operator be-cause, instead of the CCTV image showing the start of a zone, the image would be starting halfway along the zone, requiring the operator to cycle through views to confirm the location.

Ventilation

The ventilation system in a tunnel is used to direct heat and smoke away from the egress path by producing a lon-gitudinal tunnel air velocity flow in one direction (longitu-dinal ventilation); extracting the heat and smoke through vents along the tunnel (transverse ventilation); or a com-bination of the two.

The air velocity can cause water in the FFFS’s water deliv-ery region to shift away from the active zones. Computa-tional fluid dynamics (CFD) results in Figure 2 show an example of the extent of water delivery drift for a

longi-tudinal ventilation system. In this example, activation of both the FFFS zone where the fire is located and one zone upstream mitigates drift effects. Careful zone ac-tivation can mitigate the effect of drift and provide as-surance that water will reach the target. Jet fans near the FFFS zone should be activated only if necessary. In the region near a jet fan’s outlet there will be high velocity relative to the average velocity of the tunnel, which will exacerbate the water delivery drift.

Egress Provisions

Egress points (e.g., exit doors to escape passages) are generally positioned equidistant from each other along the tunnel and should be placed at the ends of the FFFS zones and not within active FFFS zones where egress may be hindered by visibility reduction, noise (the active FFFS is in fact very loud), physical restric-tion, and psychological stress. Placing egress points at the ends of a FFFS zone contributes to more stream-lined egress. Firefighters using these egress points to enter the tunnel could experience significant disorien-tation if entering an active FFFS zone, thereby slowing their subsequent response.

Drainage

Drainage is another aspect to consider when installing an FFFS. In some systems, the very large flow rates of water mean that not all of the FFFS water will be cap-tured at the drains within the zone of discharge, and practically there may be few design options to achieve this. The travelling fuel can create a risk of fire spread since the water can transport the fuel away from the

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Figure 2 – Example of FFFS and tunnel ventilation integration-CFD results

Extra water due to zone overlap Application criterion is 8 kg/ m2 _{in one minute} 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00

Airfl ow is right to left

Jet fans Jet fans

FFFS Zone

Water overshooting zone of application (overshoot by up to 15m)

Water not reaching entire zone of application (up to 5m of a zone missed) Plan view of tunnel water

accumulation at roadway level

FFFS Zone

30m (100 ft.) 30m (100 ft.)

AIRFLOW

Fire and Life Safety

fire site. The fuel draining away from the fire site would be unshielded by vehicles and so it will typically be sup-pressed, if it is burning, prior to exiting the FFFS zone. Flame traps in the drainage system are sometimes used to prevent a secondary fire moving through the drain pipe network.

Fire Alarm Systems, Control Systems, and Heat Detection

Road tunnels can be fitted with automatic and/or manu-ally activated FFFS. In a manumanu-ally operated system, op-erators are provided with a CCTV system to identify the fire location, so that they are able to activate the FFFS in the appropriate zone(s), as described above. In some instances a back-up automatic activation system is pro-vided. This system typically uses a linear heat detector (LHD) to identify the fire location. Once the LHD signal is received at the control panel, a countdown timer activates. If no response is made by the operator within the allotted time, the FFFS is deployed.

The LHD is an addressable sensing cable which can de-tect absolute temperature or rate-of-rise, with each detec-tion zone coincident with a specific FFFS zone. In the case of an automated response, the following items support good system integration:

• FFFS and LHD zones are to be coincident.

• The FFFS should activate in the first LHD zone to detect

heat and the adjacent zone upstream.

• Any further LHD activations must not trigger any

addi-tional FFFS zone activations (as explained below).

The system must be programmed such that the opera-tor can override an automated response if necessary. Automated systems are capable of executing ineffective responses, so it is up to the operator to make the final operational decisions. For example, in a tunnel, heat will travel over a large number of FFFS zones and trip the LHD

in zones remote from the incident. If all of these zones were to discharge water, there may not be enough water capacity available in the incident zone to suppress the fire (a FFFS can be feasibly designed with enough water supply capacity to feed two or three zones). Conversely, the fire can propagate or the operator may need to correct their choice, which means the operator needs to have the abil-ity to shut zones off and start others.

Traffic and Operations

After a fire is identified, traffic must no longer be allowed to flow into the tunnel. In unidirectional traffic, the vehicles downstream of the fire are expected to exit the tunnel while those upstream are expected to stop (a common assumption in tunnel fire-life safety design).

The system must be designed so that the FFFS is never activated over live traffic. An activated FFFS will reduce motorist visibility and vehicle traction, which increases the chance of a vehicle collision and exacerbates the emergency, or worse still, creates an unsafe situation (see Figure 3).

Conclusion

An FFFS is a useful fire safety tool for a road tunnel. Good integration of the FFFS with other tunnel systems and func-tions, using the principles outlined above, assists in bring-ing to fruition its purported benefits for tunnel fire safety. In addition to the engineered systems, it is important that the tunnel operator is well-trained and that tunnel systems are well-maintained to assure good performance.

Matt Bilson is a Principal Technical Specialist in the field of

tunnel ventilation and fire-life safety in the New York office of Parsons Brinckerhoff.

Sal Marsico is a Mechanical Engineer in the field of tunnel

ventilation and fire-life safety in the New York office of Parsons Brinckerhoff.

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Fire and Life Safety

Fire-Life Safety and System Integration:

The Functional Mode Table

by Matt Bilson, New York, NY, US, +1-212-465-5510, [email protected]; and

Andrew Gouge, New York, NY, US

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Introduction

A fire or other emergency situation in a tunnel environ-ment can be a serious threat to human life and the in-frastructure. One of the main tasks of the fire-life safety (FLS) engineer is to develop a response strategy to manage or prevent such events. The strategy will fre-quently rely on many sub-systems such as ventilation, lighting and signage, traffic management, alarms, op-erator responses and coordination, and communication with emergency services agencies (e.g., the fire depart-ment). The harmonious and correct operation of the sub-systems is essential to protecting life and infrastructure during an incident; clear and concise system integration is needed to achieve this goal.

Integration is not a new concept as exemplified by the “V” diagram (see Figure 1) which is a well-known con-cept in systems engineering. However, FLS relies on more than just systems integration; it is also necessary to combine the emergency incident plans with the de-sign concepts and operator training. The concept of the

Functional Mode Table (FMT) is proposed herein as a tool to assist in this exercise.

The FMT, in principle, is a high-level computer program for tunnel operation during a given emergency scenario. It is a matrix of instructions that spells out in a detail how each sub-system must respond for a given emergency incident. It is based on an incident type, the means of detection, and the sub-sys-tem responses required (see Figure 2).

The goal of the FMT is to assure that all major players in the tunnel’s fire-life safety – the FLS engineer, the imple-mentation engineers, the operator, and emergency services workers – will work to a common framework, thereby improving implementation, commis-sioning, training, thereby maximizing the probability of a favorable outcome if an emergency occurs. Subsequent system responses for an incident can be pre-programmed using the FMT, reducing the complexity and burden placed on the tunnel operator.

Figure 1 – The “V” diagram and the Functional Mode Table relationship

Time

Detail

The functional mode table is set out between Concept and Requirements/Architecture phases.

It is then used at every level of the process.

Implementation

Operation and Maintenance System Verifi cation

and Validation Integration Test and Verifi cation Concept Requirements and Architecture Detailed Design INCIDENT AND MODE ID DETECTION METHODS AND LOCATION SUB-SYSTEM RESPONSES Manual Automatic Escalation Modes Traffi c Devices Communications Lighting/ Signs Ventilation Fixed Fire Fighting System Incident ID

(as per the operator’s incident response plans)