2nd learning journey

July 24, 2007

The Palace of Knossos

Filed under: Architecture — 2ndlearningjourney @ 7:35 am

Dated about 1900 BC, destroyed and rebuilt around 1450 BC. Discovered by Sir Arthur Evans 1900 AD.

There is little in the book on the world history of architecture that I didn’t know about Knossos, still, it was an enjoyable read.

Knossos, a Minoan ruin, stands in Crete, an island off the coast of Greece. Revered by most Eurocentric historians as the starting civilisation of magnificent Greece, Ponting in his World History is quick to point out that this probably isn’t the case and the Cretan civilisation might have been but a spin-off caused by migrants / indigenous (?) – anyway, people – who emulated the styles of more glorious civilisations of that time: Egypt, Mesopotamia, but gradually came up with their own.

The Palace of Knossos, so dubbed by Evans and the rest that follow him, might not actually be a palace in the real sense of the word. Historical debate has provided an alternative reading for the possible function of this complex, it could have been religious, since there is little to suggest residential use by monarchs but is full of rooms built for ceremonial purposes, like rooms made for storing religious ware. There is a throne room, but it is structured with a lustral-basin (depressed pool) which gives rise to speculation about whether the room could have used for ceremonial functions. In fact the name ‘throne room’ was only given because of an elaborate alabaster seat found there.

The art at Knossos was also more naturalistic than that of contemporary Egypt. It depicted youths in some ritual involving bulls, natural living things like fishes, plants etc. It seemed to emphasize movement, or at any rate gave more free rein to movement than Egyptian art. The bull imagery was probably due to a cult at Knossos that held the bull sacred. To me it sort of links with the bull mania in Spain: is this a possible predecessor? Rather unlikely connection though. It is more likely to have some links with the myth of King Minos and the minotaur.

An interesting thing about Knossos was that the whole complex was not fortified at all, by defensive walls or moats or whatever. So what exactly was the function of the place? The palace was also constructed in a labyrinthine model, which is questionable since who with proper town planning ideas would do that? And knowing that, as the myth goes, the minotaur was kept in a labyrinth, to what end was the complex constructed? Did the complex precede the myth, or vice versa?

Back to what is of architectural interest, the complex at Knossos had very exceptional water supply and drainage standards for those times. Terracotta pipes carried water in to the complex to supply baths, and sanitary sewers carried off waste water from basins and water closets. Although there was one place that had to be emptied by bailing though, a tub in a room called the Queen’s Megaron.

Besides the naturalistic frescoes, Minoan art at Knossos appeals to me as it strikes me as elegantly simple and rather ‘modern’… In particular the columns of the Minoan order. They are ‘downward-tapering shaft(s) with… bulbous torus ring(s) and abacus block capital(s)’.

Columns at Knossos

(From http://www.bsa.ac.uk/knosos/index.htm?vrtour)
I wish to add that the above site, the British School of Athens’ page on Knossos, also offers a very interesting 3D virtual reality tour of Knossos. I found it pretty tiring to navigate the site after a while though, but for the patient, it could be most enjoyable! Also worth a look is http://www.dilos.com/location/13370 which is a Dilos Holiday World introduction to Knossos, Crete. Don’t be deceived – it actually has very extensive and informative write-ups on Knossos and the Minoan Civilisation! I was very amazed.

July 16, 2007

Structural Systems, continued

Filed under: Architecture — 2ndlearningjourney @ 6:49 am

Post and Lintel (Column and beam):

Stonehenge

Perhaps the simplest and most memorable example of post and lintel construction – Stonehenge. Post and lintel means two vertical forms supporting a horizontal on the top. Certain ancient Greek buildings were constructed this way too, think Greek columns with a ‘bar’ (beam?) on top. When loaded, the beams deflect downward, compressing the fibres of the first half of the columns and stretching (or putting in tension) the lower half. The book apparently says that wood, steel and reinforced concrete are most popular for this kind of structure since the materials employed must be equally strong in tension and compression. But stonehenge is made of stone??? Perhaps that’s the astonishing fact of it. Anyway it might also account for why the horizontal stones are not as broad as the vertical ones, since the weight might be too heavy to be supported in this way.

Corbel and Cantilever
Because of stone’s weakness in tension, civilisations past used corbelling to work around it. Corbelling consists of trying to make a stone arch by piling stone blocks projecting a little further than the previous one that it stood on, so that gradually one makes a triangular arch:

Corbelled arch

(As the pics here are really not my own I think I should acknowledge that this one came from what looks like a very informative site on corbelling – www.stoneshelter.org/stone/construction.htm)

In cantilever construction, where beam(s) protrude over the structure supporting them, the same concept is applied. Think Fallingwater:

Frank Lloyd Wright’s Fallingwater

Yes that part protruding is cantilevered. Frank Lloyd Wright’s genius…

Arch and Vault!
My favourite! It ‘blows my mind’, to borrow a phrase someone I knew keeps using.
Masonry (stone) arches and vaults were created in a dry stone walling system (without mortar!) in the past. Wedge shaped stones called voussoirs form the arch. The amazing effect of stones appearing to stay in position ‘floating’ in the air is due to forces. The arch exerts, not only a downward thrust, but also a lateral thrust which must be counteracted by other forces if the stones that form it are to stay in place. So during construction a temporary framework, called centering, must be used to support the entire arch, until all the stones are fitted in place and compress each other (all the countermanding forces keeping the stones in place). I think it’s pretty neat.

Barrel Vault
Barrel Vault, from www.thefreedictionary.com/barrel+vault

Centering
The centering is the wooden framework in the middle on which the stones of the would-be arch are placed. From www.uky.edu/Classes/A-H/323/restricted/terms.htm.

Truss and Space Frame
The trussing method of spanning space is found in cases where wooden or metal elements are connected in geometrical configurations (the most popular seem to be triangular). If this definition confuses you, think of bridges like the one below:

Example of a Warren Truss bridge

In this typical example, the bridge is a space frame that is created through steel bars connected in an equilateral triangle configuration. This equilateral triangle config has been patented and is known as the Warren Truss.

When looking for pictures I came accross wikipedia! http://en.wikipedia.org/wiki/Space_frame Looks pretty informative esp on how the trussing method has been used to give very interesting results in architecture.

Tension
Some structures are built largely on tension, and tension features pretty much in modern architecture. I personally think it’s a pretty cool concept – entire bridges can be held up by suspension cords! Which is why bridges hold some fascination for me… Architecture based largely on tension is probably mostly modern because of rapid advancements in these modern times that have brought the birth of iron bars and steel strands turned cable that can hold up massive structures! Whereas what can one do with vines and sisal…

Now let my bit of ‘nationalistic’ pride get in the way as I present the world’s largest span suspension bridge!

Tsing Ma Bridge

Tsing Ma Bridge, Hong Kong.

July 15, 2007

Firmitas, Utilitas, Venustas – Architecture!

Filed under: Architecture — 2ndlearningjourney @ 3:11 pm

The built environment has fascinated me since I was 11 years old.
My blog entries on architecture, for this time, will be from a book entitled A World History of Architecture. The book starts off with a few ‘basic’ concepts.
The above is a quote from the Roman architect Vitruvius, on what he considered the essentials of architecture. Usually translated firmness, commodity and delight.
Firmness: structural stability
Commodity: meeting of functional requirements
Venustas: beauty. which is subjective and hard to define.

On to a very fascinating thing about architecture, materials define architectural character more than I imagined. There are two ‘forces’ apparent in considering materials, as the book puts it, ’structural materials can be classified according to the way they accept loads: in tension or compression, or a combination of the two’. Compression: press ‘em together. Tension: pull them apart. Stone, brick and concrete are strong in compression but not in tension (which is why you’d never see a wire made of stone, what can it hold?), wood is strong in both tension and compression, as is iron, but iron is brittle. Reinforced concrete combines ‘the compressive strength of concrete with the tensile strength of embedded steel’, which is why it is strong in both.

Structural systems can be classified into 5 categories depending on the geometric configuration of their members and the way loads are carried:
– post and lintel (column and beam)
– corbel and cantilever
– arch and vault
– truss and space frame
– tensile

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