Shah Jahan Mosque

Presented To: Sir Usman

By: Asma Chaudary

Hermain Anees

Narmeen Khalid

Mahnoor, Syed

Bilal Ahmed

Haseeb Saleem

LOCATION

• The Shah Jahan Mosque is located in Thatta, Sindh province,

Pakistan. It was built during the reign of Mughal emperor Shah

Jahan.

HISTORY

• The mosque was built in 1647, during the reign of Mughal King

Shah Jahan, as a gift to the people of Sindh for their hospitality. It

has been on the tentative UNESCO World Heritage list since 1993.

• The mosque had undergone several renovations. More recently, the

mosque was restored during the 1960s and 70s.

• This Mosque is called with many names like Jama Masjid

Thatta, Shahjahani Mosque and Badshahi Mosque Thatta.

PLAN

PLAN DETAILS

• The mosque, a heavy brick structure of simple construction built

upon a stone plinth, with heavy square pillars and massive walls, is

centered around a courtyard 169' X 97'. The prayer chamber is of a

similar size. Both are covered by large domes. On the north and

south two aisled galleries open by means of arcades onto the

courtyard. Ninety three domes cover the entire structure.

• The mosque is spread over an area of 51,850 square feet. The main

entrance of the mosque has a central domed chamber. The mosque

has an open central courtyard of about 15,900 square feet.

• The abulation pond is located on a central courtyard located within

the eastern portion of the mosque.

• The main quality of the Mosque is that it has no minarets. Instead of

the typical three domes, there is only one main dome in the prayer

hall. Its 93 domes and 33 arches with varying sizes add to their

architectural beauty. It is world's largest mosque having such number

of domes.

• More than 20000 people can pray in the mosque.

ARCHITECTURE

• The mosque is built with red bricks with blue colored glaze tiles

probably imported from the town of Haala, Sindh.

• It is laid out in the usual quadrilateral arrangement with a large (52 x

30 meter) courtyard at its center. The arcades around the courtyard

are covered with 93 domes of varying size.

• Architectural styles: Islamic architecture, Mughal architecture.

• The two main chambers are entirely covered with blue gazed tiles.

Their domes have been laid with a mosaic of radiating blue and

white tiles.

• Floral patterns, akin the Kashi work of Iran, decorate the spandrels

of the main arches and elsewhere geometrical designs on square

tiles are disposed in a series of panels.

• The mosque has also a ventilation system and during hot summer

months one feels comfortable enough.

• A little niche is built in on either side of the prayer niche (mihrab) in

the qibla wall of the mosque and helps let in both light and fresh air

into the chamber.

• The slanted passageways are a peculiarity of

architectural design in the mosque.

• It has been built keeping acoustics in mind. A person speaking

inside one end of the dome can be heard at the other end when the

speech exceeds 100 decibels.

• Ninety three domes cover the entire structure, and are probably the

cause of a remarkable echo, which enables the prayers in front of

the Mihrab to be heard in any part of the building.

ACOUSTICS

• Acoustics is a science that deals with the production, control,

transmission, reception and effects of sound.

• Acoustics is classically divided into sound and vibration. Sound

refers to waveforms traveling through a fluid medium such as air,

while vibration describes energy transmitted through denser

materials such as wood, steel, drywall or anything besides a fluid. It

is not heard as much as felt, due to its extremely low frequency,

which is below the range of most human hearing.

DOMES

• Domes are inherently echo chambers.

• In a spherical geometry, rays are concentrated at focus point, with a

uniform distribution, where propagation distances of sound paths

are described as equal depend on the particular point the speaker

takes.

• The ideal dome with a steady state high sound concentration in a

small area and uneven sound distribution across the entire audience

area, and a deflected dome with a centre of sphere to an elliptical

shape, which shows level variations across the audience area as

smaller, thus providing a better coverage of the entire audience area

– a better acoustic performance.

DOMES

• In the deflected dome, an overall increase in speech intelligibility as

well as an even distribution of sound level across the audience area

can be seen. Furthermore, this shape supports even distribution of

reflections across the audience area.

• By bringing the back wall closer to the performer, useful reflections

arriving at an early stage aid in raising the speech intelligibility

across the audience area.

• The structural deflection of original spherical geometry and resulting

sound reflection in relation to curvature of the space enhances the

acoustic performance of the space.

DOMES

• Most modern domes are built from thin aluminium sections with ribs

providing a supporting structure behind. The use of aluminium

makes it easy to perforate the dome with thousands of tiny holes.

This reduces the reflectivity of sound back to the audience

(providing better acoustic characteristics) and allows air circulation

through the projection surface for climate control.

• The sound is carried by waves that travel around the circumference

clinging to the walls.

• When a visitor stands at one focus and whispers, the line of sound

emanating from this focus reflects directly to the focus at the other

end where the whispers may be heard.

DOMES

• The adapting heights, varying position of centre points, varying

dimensions and curvature of domes are the cause of echo produced

throughout the mosque.

REVERBERATION

• Reverberation is the persistence of sound after a sound is

produced. A reverberation is created when a sound is reflected

causing a large no. of reflections to build up and then decay as the

sound is absorbed by the surfaces of objects in the space.

Reverberation is frequency dependent.

• Reverberation is a statistical process not relying on specific room

shape and sound propagation paths. Reverberation decay sounds

even and consistent to the human listener. The spaces are made

less reverberant and more absorptive. The reflections contribute to

sound buildup rather than to sound decay.

ECHOES

• Echoes are reflections that can be heard distinctly and separately

from the early reflected and reverberant sound.

• Echoes are normally heard due to intense reflections arriving later

after the direct sound signal has reached the listener.

• Echoes are based on the sound level of reflections and their delay

after the direct sound.

SLANTED WALLS

• Slanted walls may eliminate some periodic modes of flutter echoes,

but then may allow some more hidden ones. A hard plane wall act

like an acoustic mirror so that reflections from the wall can be

explained as coming from an image room behind the wall. Two walls

meeting at a right angle will create three image rooms from where

reflections appear to come from.

• The flutter-echo can be explained as plane-wave reflections

between two parallel surfaces in a cluster of image rooms.

SLANTED WALLS

• It is useful to utilize angled walls as reducing the number of parallel

surfaces in the room minimizes acoustic problems such as standing

waves. Perfectly square rooms are the most difficult spaces to treat

as they are prone to every acoustical issue.

• The elimination of parallel wall surfaces also eliminates standing

waves that cause certain frequencies to resonate as they echo back

and forth between two walls or between the ceiling and floor.

SLANTED WALLS

• By introducing angles to the walls, side-to-side or front-to-back

sound waves cannot sustain themselves. These angled walls create

opportunities to introduce large bass traps into the design and

because the size gradually changes, they naturally deliver

broadband absorption.

• They can be used in the form of absorptive panels, diffusers or a

combination of the two.

• They can certainly minimize instances of flutter echo (higher

frequencies).

SLANTED WALLS

• Slanted passageways used in the mosque reduces the flutter echo

and thus enhances the clarity of the sound being reflected.

GEOMETRICAL DESIGNS

• The manner in which sound reflects depend upon the shape, texture

and material of the space boundary. For a surface to be a good

reflector of sound, its dimension should be at least one wavelength

or larger than the lowest frequency being reflected. Reflected sound

plays a critical role in maximizing loudness levels to the audience.

• Sound can also reflect in a diffuse manner. The reflection is

fragmented into many reflections having less intensity, which are

scattered over a wide angle creating a uniform sound field. Three

dimensional surfaces such as columns, ornamentation serve as

diffusing elements and were used as an integral to the acoustics in

19th century spaces.

SUMMARY

Following elements play an important role in the acoustics of the

Shah Jahan Mosque.

• Domes (supports even distribution of the sound and increases

sound intelligibility)

• Slanted walls (decreases the echo of the sound produced and

increases the audibility of the sound)

• Geometrical designs (increases the reflection of the direct sound

and thus increases the audibility)

THANK YOU

THE END