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REPORT 6 Daylighting Assignment Canary Wharf Underground Station, London

SanamMulani

Daylighting Assignment Case study: Canary Wharf Tube Station 1 | P a g e

DAYLIGHTING ASSIGNMENT ESSAY

Name: SanamMulani

Course Year 2011-2012

Project:Canary Wharf Underground Station

London, UK, 1991-1999

SanamMulani


TABLE OF CONTENTS

1. INTRODUCTION.............................................................................................................................

2. PROJECT......................................................................................................................................

3. SITE LOCATION AND TOPOGRAPHY..............................................................................................

4. ROOF BASED DAYLIGHTING, SHADING STRATEGIES AND USER INTERACTION...............................

a) DAYLIGHTING STRATEGY IN PLANNING, ORIENTATION AND DESIGN

b) USER INTERACTION

c) ROLE OF MATERIAL IN DAYLIGHTING

5. POTENTIAL AREAS WHERE IMPROVEMENTS COULD HAVE BEEN MADE TO IMPROVE BOTH THE

LEVELS OF DAYLIGHT AND IT'S UNIFORMITY.....................................................................................

6. BIBLIOGRAPHY AND REFERENCES..................................................................................................

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INTRODUCTION

In the metro cities, due to rarity in space, underground spaces are becoming more sought after.

Underground spaces can give users a feeling of seclusion if they are not naturally lit. So in such

places day lighting becomes an important factor. Architect David J. Bennett designed many

underground buildings .While designing underground spaces Bennett had faced many controversies

and different opinions about underground spaces. "Underground is in many cultures a metaphor for

a virtual host of negative associations: death, darkness, cold, dampness, deceit, anti-

establishmentarianism, and, not least, evil. This [preconception] is almost universal worldwide. It is

deeply embedded in the psychology of most people", Bennett told this to writer Loretta Hall of

SubsurfaceBuildings.com in 2002(Hall, 2000-2011).To battle this, in 1973 he came up with new

innovative concepts and techniques for dragging daylight in the underground building.

Architect Bennett used few

techniques to draw daylight

in underground spaces such

as designing spaces with

Recessed courtyards, use of

Large windows around

sunken courtyard to transmit

the sunlight into the

underground interior, use of

angled windows at 45

degrees, roof lighting, sky

light, use of mirrors on glass-

cupola. “Bennett also used an even more imaginative daylighting

scheme for the visitor centre at historic Fort Snelling in Minneapolis.

Windows along a shallow, recessed courtyard provided natural light

and exterior views to rooms on the first subsurface level of this

building. One floor below, office workers could enjoy sunshine and

scenery through a simulated window. Long, angled mirrors at the top

and bottom of a vertical shaft essentially created a wide periscope. The

angles of the mirrors allowed them to function well for workers seated

at their desks, but the view was less realistic when viewed from a

standing position.”(Hall, 2000-2011)

Fig 1:Use of reflective surfaces (Source: http://www.subsurfacebuildings.com)

Fig 2: Glass cupola with mirrors

(Source: http://www.subsurfacebuildings.com)

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PROJECT BACKGROUND: CANARY WHARF UNDERGROUND STATION LONDON, UK Client: Jubilee Line Extension Project (JLEP) Consultants: Ove Arup & Partners, Davis Langdon & Everest, JLEP, Claude Engle, PosfordDuvivier Architect: Sir Norman Foster Canary wharf tube station is one of the underground stations of London on the Jubilee Line. This station is located between Canada Water and North Greenwich.Canary Wharf station is one of the busiest stations on London underground after central London with over 40 million people using this station. The construction started in 1990. “It was constructed, by a Tarmac Construction / Bachy UK Joint Venture, in a drained arm of the former dock, using a simple "cut and cover" method to excavate an enormous pit 24 metres (78 ft) deep and 300 metres long. The size of the interior has led to it being compared to a cathedral, and it has even been used to celebrate a wedding. However, the main reason for the station's enormous dimensions was the great number of passengers predicted; as many as 50,000 daily. These predictions have been outgrown, with as many as 69,759 on weekdays recorded in 2006.”(Magoni, 2011)

SITE LOCATION AND TOPOGRAPHY

Fig 3:Site map of location/latitude (Source: Google earth)

The station is oriented on east west axis with all high-rise buildings located on the north and south

side of the underground station. Station entrances are located on the east and west ends which are

covered with curved glass canopies. There is no obstruction on east and west side, so daylight enters

from the glass canopies. As per the article (Grignaffini, 2001), the fully overcast CIE luminance

distribution comes from the zenith area of the sky. Therefore,the influence of the obstructions did

not much affect the light entering from the canopies as the day on which project was studied there

was overcast sky.These glass canopies are the only visible station elements at the ground level which

can be seen from the top. Between these two entrances a landscaped public park is created above

the underground station which is used as Canary Wharf's principal public recreation space. The

SUN PATH

N

CANARY WHARF TUBE

STATION

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station has three entrance canopies where there are two main canopies and the third one is a small

entrance which is known as ‘Fosterito’. “At 300 metres in length it is as long as Canary Wharf Tower

is tall. The robust aesthetic is achieved by a simple palette of hard-wearing materials that create the

dramatic atmosphere.” (Foster, 1999).

ROOF BASED DAYLIGHTING, SHADING STRATEGIES AND USER INTERACTION

a) Daylighting strategy in planning, orientation and design: Elongated, narrow planning. Glass

canopiesare the main structural element of the station. The building is designed in two levels,

namely, platform level and ticket hall level with mezzanine concourse floor. Space planning is very

clear with direct passenger routing and easily understood as the main concourse is free from

administrative offices and ticket hall.

Concept of refraction and reflection of light is adopted for this particular station building. According

to architect Norman Foster’s design concept (Bennett, 2004) , orientation of glass canopies is

planned in such a way that natural light has been concentrated at these entrances which also

reduces directional signage requirement. With an overcast sky, glass canopies draw sufficient

daylight into the large interior space of the tube station. Each of the two domes measure twenty

meters and are integrated into the sloping grass banks at both the ends of the park. There are two

main entrance canopies that are a development of the Fosteritos which are located at ground level

to reproduce bright light underground. The canopies reflect the light directly downwards by

refraction. To go with the main concept of bringing natural light inwards, the roof constructed with

insitu concrete also helps to reflect light. “Within the long box structure it was aimed to give the

traveller a direct smooth progression from street level down to the ticket hall, then down again to

the trains.”(Bennett, 2004)

Glass canopy Dimly lit area Glass canopy Glass canopy

Low daylight/area

with artificial lighting

Fig 4: Ticket hall level plan and platform level plan (Source: http://www.archsociety.com/archimg/canarywharf/section1.jpg )

http://www.archsociety.com/archimg/canarywharf/section1.jpg

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Lighting Concept of Canary wharf tube station:

Fig 6: Uplighting study (Source: (Bennett, 2004))

“Claude Engle, an international lighting consultant, was responsible for all lighting that you see at

Canary Wharf Station. His idea was to create an artificial sky on the ceiling of the roof, which would

throw light down onto the ticket hall to create a well-lit space by day and night. Daylight from the

entrance canopy will not be quite such a blinding contrast on entering the ticket hall and on gloomy

overcast days the spread of reflected light will be a bonus”.(Bennett, 2004)

Fig 5: Longitudinal section (Source: http://www.archsociety.com/archimg/canarywharf/section1.jpg )


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Fig 7: Sketch Development of station box by Sir Norman Foster (Source: (Bennett, 2004))

The increasing population has to be taken into consideration while constructing a station. The future

generations will have to experience the inevitable growth in the passenger density. To do away with

overcrowding and eventually the feelings of congestion or claustrophobia, Canary Wharf has been

created with soaring volumes of space within the station. That is how Canary Wharf is so

strategically important to London.

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Glazed canopy (roof light) details: The curved canopy is made up of toughened glass, manufactured

by an Italian company called ‘Isiglass’, which is double laminated and in 3m x 1m panels to withstand

vehicle impact. Special bending machines were used to curve the panels in longitudinal plane. The

execution of the panels comprised of special spider connections that sprung from the thin blade

beams arching from the concrete base. Each of the 76 panels is unique having different longitudinal

curvature and having an exact point on the canopy to be fitted.(Bennett, 2004)

Fig 8: Transversal cross-section (Source:

http://www.archsociety.com/archimg/canarywharf/section1.jpg)

Fig 9: glazed canopy (photographed by SanamMulani on 20th

January 2012 at 11.30 am)

Concrete base

Thin blade beams arching

from the concrete base

Toughened glass, doubly

laminated panels

Fig 10 & 11: glazed canopy (photographed by SanamMulani on 20th January 2012 at 11.30 am)


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b) User interaction: According to one of the working staff at the station, building is visually comfortable

in most of the climates .Glare coming from glazed canopies is reduced by integrating artificial lights

at the centre of the building where daylight is dim, which helps to smoothen the transition in

luminance .This way the user does not experience the sudden change from full daylight to lower

lighting levels. Overall environment of the station is appropriate, pleasing and comfortable with

efficient visual performance.

Fig 12: Central area between two canopies which are sometimes dimly lit so artificial light is provided (photographed by SanamMulani on 20th January 2012 at 11.30 am)

Sometimes when outside climate is rainy, uniformity is dull which can lead to tiredness and lack of attention.

c) Role of material in daylighting:

“Priority was given to providing those elements that can never be introduced once a station is built,

rather than elaborate finishes. Indeed, instruction was given to leave the civil work exposed

wherever possible, to un-decorate rather than decorate the station.”(Bennett, 2004). Fair –faced

concrete walls are left exposed which give a sturdy and robust look to the tube station which has

about 30% light reflectance, which was achieved, by testing the conventional concrete in different

types of shutters.

The important features of the station is emphasized by using a sixteen century painting technique,

which helped in brightening and highlighting them, thus bringing them in foreground. Light coloured

Materials such as glass and stainless steel are used on foreground and other dark coloured materials

fade into the background. Using this painting technique a hierarchy of light and darkness for surfaces

is achieved for this particular project. The roof of the station is supported by large columns which

have high stainless steel skirting. Pre-cast concrete pavers are used on the floor.

Visibility and natural light are not the only factors for choosing glass cladding to the ticket hall cabin

and the entrance bubbles, but also for its resistance to minor vandalism. To avoid vandalism and to

increase user comfort glazed lifts are used.

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POTENTIAL AREAS WHERE IMPROVEMENTS COULD HAVE BEEN MADE TO IMPROVE BOTH THE LEVELS OF DAYLIGHT AND IT'S UNIFORMITY.

Glare:

During summer there is a possibility of more glares which can cause excessive brightness in the

underground building, which can be reduced by using shading devices around the canopy and by

increasing contrast through artificial light in central area between two entrances.

Uniformity:

Even though the circulation area is artificially lit to guide people, the user sometimes experiences dull uniformity in the tube station. Also on the platform level no sufficient daylight is provided. So the following techniques could have helped:

On the upper level, skylights could have been fixed for lighting the central dimly lit area. Active skylights with mirror system can perform well by drawing sunlight through skylight into the interiors. Tubular daylight devices are the other option which can be used for top lighting. “Some of these systems also attempt to reduce the daylight ingress in the summer months, balancing daylighting with cooling loads. Tubular daylight devices are another type of top lighting device. These devices employ a highly reflective film on the interior of a tube to channel light from a lens at the roof, to a lens at the ceiling plane. Tubular daylight devices tend to be much smaller than a typical skylight, yet still deliver sufficient daylight for the purpose of dimming the electric lighting.” (Gregg D. Ander, 2011)

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Bibliography

London Editions. (2007). Retrieved January 30, 2012, from www.londoneditions.com:

http://www.londoneditions.com/product_368_48.htm

B. Bouchet, M. F. (1996). Day-lighting of underground spaces: design rules. Energy and Buildings 23 ,

293-298.

Bennet, D. J. (n.d.). DJB Architects limited. Retrieved January 30, 2012, from

www.davidjbennettarchitect.net:

http://davidjbennettarchitect.net/sustainableundergoundbase.htm

Bennett, D. (2004). the architecture of the jubilee line extention. London: Thomas Telford.

Claire. (2010, April 23). The digital Iris. Retrieved January 30, 2012, from www.thedigitaliris.net:

http://www.thedigitaliris.net/2010_04_01_archive.html

Foster and Partners. (2012, January 10). Canary Wharf Underground Station. Retrieved January 30,

2012, from www.openbuildings.com: http://openbuildings.com/buildings/canary-wharf-

underground-station-profile-42764

Foster, S. N. (1999). Foster and Partners. Retrieved January 20th, 2012, from

http://www.fosterandpartners.com/Projects/0579/Default.aspx

Gregg D. Ander, F. (2011). WBDG. Retrieved january 25th, 2012, from Whole building design guide:

http://www.wbdg.org/resources/daylighting.php

Grignaffini, F. G. (2001). Shafts for daylighting underground spaces: sizing guidelines. Lighting

Research and Technology(33), 183.

Hall, L. (2000-2011). "Building Underground with a Light Touch". Retrieved January 22, 2012, from

SubsurfaceBuildings:

http://www.subsurfacebuildings.com/BuildingUndergroundwithaLightTouch.html

Hopkinson, R., Petherbridge, P., & Longmore, J. (1966). Daylighting. Bath: Heinemann.

Magoni, F. (2011, december). flickr. Retrieved January 22nd, 2012, from

http://www.flickr.com/photos/fabriziomagoni/6472927431/

Note:Cover page photographs by Sanam Mulani

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