Medieval foundations...

[Externet]

Those medieval castles with massive stone walls and in general, huge loads on soils, how were their foundations 'calculated', in ages with little tools, expertise, no reinforcing bars, portland cement, soils testing and engineering ?

 

Many still standing, built with handcrafted and selected stones, erected with great efforts. Building sites mostly on solid grounds, but not all of them.

Deterioration trough 4-5-6+ centuries show above ground, but, how good are their foundations after time elapsed ? How was that success achieved then ?

 

The names and techniques of the engineers forgotten, the owners are the famous.

 

----> https://duckduckgo.com/?q=medieval+castle&t=canonical&iax=1&ia=images

 

One at random ----> http://www.topcastles.com/kastelen.php?SubMenu=main&SelCastle=foixs&Language=en

Edited January 15, 2015 by Externet

[studiot]

It is always tempting to say

 

Look how clever builders, writers, painters etc were in the past.

 

But remember all we see today of their output are the successes.

The mediochre to failures have long crumbled away and been lost or discarded.

 

Many cathedrals today have history displays and it is suprising how many of them fell down (at least in part) in construction.

The same is true of many bridges.

 

So I expect castles were little different.

 

The only other comment I have about the foundations is that they tended to be built on raised ground (like Edinburgh Castel) for military reasons.

And often the ground is raised because it is harder/stronger than the ground around it (Edinburgh is famous for the volcanic rock it is built on).

[imatfaal]

As Studiot says the absolute preference would be to build on rock - this not only allayed fears of peacetime collapse it made the possibility of being undermined very remote. And castles, cathedrals and towers did sink, tumble and distort.

 

There is a superb (and well researched) fictional account of the building of these medieval skyscrapers in "The Spire" by William Golding; it is the story of Dean Jocelyn during the construction of the main spire at Salisbury Cathedral - which I believe was one of the tallest buildings in the world at the time and for many centuries later

[Enthalpy]

The Strasburg cathedral was built on timber, which sufficed as long as ground water was high enough to keep the wood damp. Or Venezia, where some buildings are tall.

 

"in ages with little tools, expertise, [technical means]"

 

With fewer tools and materials and computation means than now, but with very much expertise, and quite a few tools too. They did it as any engineer still does, as a mix of prediction and experience, and being strongly aware of what can be predicted and how safely.

 

Still now, we have no model of how most shells buckle. Spheres under hydrostatic pressure, cylinders under axial or hydrostatic pressure... All models are optimistic by a factor of 2 to 6, oops. How do we manage that? We have to know that models in textbooks are wrong, know where to find good data, and apply rules of thumb and curves with corrective factors learned from experiment. Middle-age engineers probably did the same.

 

Or think of music instruments. We have presently a very limited understanding of what makes them good or bad, to put it mildly. So makers (who are often experts in acoustics, sometimes better than academics) make hypothesis, trials, observations - and most time they stick to what has worked.

 

When you look at how a music instrument is built, it's impressive. The part of it we understand through acoustics tells that it's a fabulously good design - "improvements" suggested by non-makers use to fail whatever the academic knowledge. And then there's all that we know that we don't understand, and the part we even ignore that we don't understand.

 

So having no formal theory is not a definite obstacle to building excellent objects.

[overtone]

The first attempt at building a stone pyramid with smooth sides, instead of the traditional steps of Imhotep's design, collapsed near completion. http://en.wikipedia.org/wiki/Meidum

 

Subsequent attempts were successful, and stand yet thousands of years later - lessons learned. They are not built on sand, for example, and the smooth facing is better fit and supported.

 

Similar events and accounts doubtless precede all great and enduring human achievements in construction.

 

btw: The names of the engineers/architects (often the same guy, in the old days) are not always lost - we do know the name of the inventor of the Egyptian stone pyramid, for example (Imhotep), and many of the designers/engineers of things like domes (Brunelleschi, Michelangelo, et al) and the official histories of the Mughal Empire list a couple of dozen recognized designers and engineers who are thought to have collaborated on the Taj Mahal - they were there, available, at any rate, and their names recorded.

[imatfaal]

The Strasburg cathedral was built on timber, which sufficed as long as ground water was high enough to keep the wood damp. Or Venezia, where some buildings are tall.

 

snip snip...

 

Strasbourg - ie the French one in Alsace (France). Spelling it with the German spelling Straßburg or Strasburg is a little indelicate. It has been named in many different ways over the last 1000 years or so (and the Germanic/Allemanic may be more historically accurate) but bearing in mind its pretty dreadful recent history I think the modern French spelling is desirable.

 

Sorry - minor point aside - it is fascinating about the foundations being giant wooden piles. I will have to look into Salisbury - it seems very similar as both are 12/13/14th century cathedrals not built in the most auspicious geographical position. Here is a wonderful view of salisbury cathedral showing the proximity of the water plain (and a good excuse to show one of England's great landscape artists) - John Constable

 

 

So having no formal theory is not a definite obstacle to building excellent objects.

 

Agree.

[michel123456]

One should note that ancient thick fortresses walls are not made of the same stone inside out, in all civilizations as far as I know.

 

I already mentionned that in some old post here

 

http://www.scienceforums.net/topic/59024-nazca-civilisation-peru/?p=622545

[imatfaal]

That was a great series of posts - I actually had occasion to look it up a few months ago to prove a point.

 

Although I was at a place built by the Romans a few years ago where the blocks were just big - the trilithons at Baalbek are reckoned to the largest stones every quarried. I cannot find a decent picture of them in situ - but there is a famous one still at the quarry (slightly bigger than normal and the largest dressed/quarried rock)

 

 

[studiot]

I remember working on the underpinning and strengthening of The Handle House, built across the river Biss between an ancient pack horse bridge and a later brick arch.

 

We came across more ancient timber (possibly Roman) foundations beneath the pack horse bridge.

 

They were more difficult to break out than the masonry.

[imatfaal]

A very strange building and possibly unique

 

 

[studiot]

Not sure where your photo came from, imatfaal, it's 20 years and more since I've been there.

[imatfaal]

Not sure where your photo came from, imatfaal, it's 20 years and more since I've been there.

 

a random blogger

 

http://devizesdays.blogspot.co.uk/2015/01/walking-trowbridge-town-trail.html

 

It is such a strange building that I thought a picture should be posted

[studiot]

The history is interesting.

Especially as there is one known Handle House left in Somerset in very poor condition and this one in Wiltshire.

So there are probably only two left in the World.

 

A river Biss crossing was strategically important since early times and the Romans probably were the first to bridge it, hence the timber foundations.

 

In later times that part of the country became a centre for the wool trade and a masonry pack horse bridge was built across the river (we now know on the old Roman foundations).

 

A particular type of thistle (teazle) grows naturally along the river here, more were probably planted.

The thistle head has curved hooks.

'Handles', like clothes brushes with thistles instead of bristles were employed to 'raise the knapp' on the woollen cloth.

 

This process was carried out wet and the hooks straightened with the moisture so the 'handles' were hung up to dry in drying sheds to recurve the hooks.

These drying sheds were called handle houses and were once common in the Cotswolds and Mendips.

 

In the Victorian era business boomed even more and brick sheds were built using the perforated brickwork to allow free airflow to promote the drying.

(In bricklaying terms this is called rat-trap bond and was also used in other places to allow airflow such as under timber ground floors.)

 

The Trowbridge Handle House is such a building. It was quite fun to lift it up and rebuild the river channel underneath.

Edited January 30, 2015 by studiot

[imatfaal]

...

In the Victorian era business boomed even more and brick sheds were built using the perforated brickwork to allow free airflow to promote the drying.

(In bricklaying terms this is called rat-trap bond and was also used in other places to allow airflow such as under timber ground floors.)

 

 

 

That's where I had seen it before - under timber ground floors! Thanks

[studiot]

 

That's where I had seen it before - under timber ground floors! Thanks

 

 

My house was built with a timber ground floor suspended 2' 6" above formation by rat trap sleeper walls in 1938.

The timber was fine until the early 1970's when central heating (radiators) was installed.

This led the timbers to rot within 20 years in the resulting damp.

An unfortunate example of an unintended consequence due to an engineering change.

Edited January 30, 2015 by studiot

[michel123456]

The history is interesting.

Especially as there is one known Handle House left in Somerset in very poor condition and this one in Wiltshire.

So there are probably only two left in the World.

 

A river Biss crossing was strategically important since early times and the Romans probably were the first to bridge it, hence the timber foundations.

 

In later times that part of the country became a centre for the wool trade and a masonry pack horse bridge was built across the river (we now know on the old Roman foundations).

 

A particular type of thistle (teazle) grows naturally along the river here, more were probably planted.

The thistle head has curved hooks.

'Handles', like clothes brushes with thistles instead of bristles were employed to 'raise the knapp' on the woollen cloth.

 

This process was carried out wet and the hooks straightened with the moisture so the 'handles' were hung up to dry in drying sheds to recurve the hooks.

These drying sheds were called handle houses and were once common in the Cotswolds and Mendips.

 

In the Victorian era business boomed even more and brick sheds were built using the perforated brickwork to allow free airflow to promote the drying.

(In bricklaying terms this is called rat-trap bond and was also used in other places to allow airflow such as under timber ground floors.)

 

The Trowbridge Handle House is such a building. It was quite fun to lift it up and rebuild the river channel underneath.

Excellent.

There are a lot of peculiar buidings around that sometimes you don't recognize. Many of them are buidings that act as a machine.

perforated buildings like this one were also used for drying tobacco or other stuff. Mainly build in wood.

http://drjohnejones.com/Penna%20Elder%20Trains/Pa%20Trains%20(123).JPG

Other kind of "machine-buildings*" are the mills, wind mills or water mills. There are other examples I cannot remember right now, but even the shape & structure of a medieval fortress can be understood as a war-machine.

Other kind of perforated buildings are sometimes dovecoats like this one very characteristic of south France.

 

 

*When I say "machine-building" I mean a building that acts as a tool, not a building that covers a machine.

Edited January 31, 2015 by michel123456

[StringJunky]

...*When I say "machine-building" I mean a building that acts as a tool, not a building that covers a machine.

It's interesting how ideas translate from other languages. I've never thought of a 'machine-building'.

[studiot]

How far do you wish to take the concept of a machine?

 

So how about a greenhouse as a machine-building that concentrates solar energy?

If you accept this what about modern energy recovery installations or older north light roofs?

 

And what do you mean by a building?

 

Does a wave-wall count in flood defence work?

 

Scientific instruments also come to mind,

The camera obscura of old and the modern telescope like Palomar.

[michel123456]

How far do you wish to take the concept of a machine?

 

So how about a greenhouse as a machine-building that concentrates solar energy?

If you accept this what about modern energy recovery installations or older north light roofs?

 

And what do you mean by a building?

 

Does a wave-wall count in flood defence work?

 

Scientific instruments also come to mind,

The camera obscura of old and the modern telescope like Palomar.

O.K. googling "machine-building" does not give significant results. Maybe there is a more specific term, I don't know.

 

Another example that comes to mind is a lighthouse.

I think windmills are beautiful examples

http://en.wikipedia.org/wiki/Windmill#mediaviewer/File:Goliath_Poldermolen.jpg

These are machines.

---------------------

I don't know if Chand Baori could be relevant, but anyway it is so beautiful i wanted to mention it here.

http://pendarama.com/story/chand-baori-the-step-well

[Wolfhnd]

I was surprised nobody mentioned that engineering is largely about efficiency. Almost every project has a life expectancy. There are various reason why modern structures are not designed to last as long as castles or roman aqueducts. One is the higher cost of labor but more importantly I think society doesn't plan ahead for prosperity. We don't expect what we build to carry our names into the indefinite future nor do we believe in the possibility of a future without change.