View Full Version : A question on structure size

02-23-2011, 08:53 AM
Okay this is a question that has really being bugging me, we've all seen them, those MASSIVE fortresses and palaces that are just so epic that they scream high fantasy. However, I can't look at them without questioning would they even be able to stand up in real life, and as my understanding of physics is somewhat limited I through the question over to the learned members of the guild. Would it be possible to build structures like this that bound by the laws of real world physics?

I ask because I want to have some sort of massive, ornate and iconic structure at the heart of the Dal capital and I won't know what my size limits would be; if it helps the Dal mainly use brick and heavy wooden beams in construction with large stone blocks being used as foundations or in defensive structures. I provided some examples below that I have found while wandering around the net. I remember it being mentioned somewhere that structures made of stone are limited in how big they can be become because the stone would begin to sink, is there a way around this? I suppose a simple solution be to simply carve it out of a mountain, like Tolkien's Minas Tirath, as the mountain itself would act as a solid foundation but what if I wanted to build from the ground up?

It's not a major question, just a question I would greatly appreciate some insight on. Please remove this thread if it's innappropriate for this forum.


02-23-2011, 09:10 AM
Well, some of those would be feasible in stone - if they were mostly solid stone. Think Japanese castles, which are mostly a massive stone block wall backed with rubble and fill, and a wood-and-plaster fairytale castle built on the resulting platform(s). A lot of European gunpowder-era forts have the same principle. So your fantasy fortress would be mainly solid for most of the lower portion, with the exception of a few staircases and tunnels, perhaps.

They only sink into the ground if there is nothing solid under the foundations, you would want to build all of those on solid bedrock.

02-23-2011, 09:59 AM
As Vile said, all of these are actually possible given solid foundation support. The only one that I can see that might not be(easily) possible without magic is the last one. Either the far side has series of switch backs to ascend(or this side are so small we can't see them), the mesa has a ramp or switchbacks inside a partially hollow interior base, or the building materials were moved up magically.

02-23-2011, 10:46 AM
As Vile said, all of these are actually possible given solid foundation support. The only one that I can see that might not be(easily) possible without magic is the last one. Either the far side has series of switch backs to ascend(or this side are so small we can't see them), the mesa has a ramp or switchbacks inside a partially hollow interior base, or the building materials were moved up magically.

Maybe the building materials were made in situ when they stripmined the top of the mountain?
They'd still have to get there of course.

02-23-2011, 11:34 AM
I think if you look at real buildings like Westminster Abbey, you'll see that quite large buildings can be constructed. Keeping in mind the Westminster has very tall walls with very little inside for strength, which is why it has all the flying butresses. If you were to add floors some additional supports and outbuildings connected by raised walkways that structure could easily rival most fantasy buildings.

The thing that always holds me back is.. why would you need a building that large, what do you do with all the rooms, what purpose is it being built for?
Then even less important for mapping but really important for gaming, is how would this really large building work in a game situation?

02-23-2011, 11:35 AM
They'd still have to get there of course.

Heh.... my brain is sitting here thinking of a REALLY long rope ladder...It would tend to discourage unwanted visitors... :twisted:

02-23-2011, 11:42 AM
This a wikipedia link, so take or leave it, but there's a section in the Tower of Babel entry concerning the height of the tower (http://en.wikipedia.org/wiki/Tower_of_babel#Height_of_the_tower), where it quotes a book that has some info on how tall the tower could have been before the weight of the stones above would have simply crushed the stones below.

02-23-2011, 12:15 PM
This is worth a watch: http://www.youtube.com/watch?v=lXt2-xi2yLc

I saw the whole programme over Christmas, he was saying that one of the problems with stone is that the higher you went, the larger the base had to be to stop the whole thing toppling over. Hence the design of the pyramids and the flying buttresses (which are base extensions) to ensure that the whole structure was kept under compression (stone is no good under tension).

I love those massive fantasy buildings. I guess we all have our 'credulity breaking point' and on this subject mine is beyond Pluto. Give me cities with populations of millions and just one field, give me 600 foot high statutes! Give me vast populations living in underground caverns with no natural light! (Tolkien's dwarves must have all had rickets)! I love it all!!

02-23-2011, 12:31 PM
This is an interesting read (http://www.laphamsquarterly.org/roundtable/roundtable/skyscrapers-of-the-dead.php): Skyscraper Necropoleis of the future! That would make a really cool addition to a fantasy city (and would make sense). In fact.....I think I will put one in the city I'm building at the moment! Thanks LoneW!

And at the 2006 Venice Bienniale (http://archinect.com/features/article.php?id=45668_0_23_0_M), South Korean architect Chanjoong Kim recently proposed “The Last House,” a skyscraper cemetery where a cell phone call could light up the specific receptacle of your loved one’s remains, so you could view them from a distance.

02-23-2011, 01:11 PM
The first one appears questionable, but not completely impossible.

The second one appears completely impossible. Those spires are way too thin and way too tall. Shrink most of it down a fair bit, and it should be fine, if still a rather questionable layout.

The third is one I can't really decide on. There isn't much detail to suggest how big it is actually suppose to be. But if it really is at the closest point it could be, then it appears feasible.

The fourth looks completely reasonable, except for the main gates, which I would have expected to be smaller. (It appears reasonable as it appears to simply be carved out of a hill. The upper dome would be hard to construct in that fashion, as I would have expected more support on the outer wall, but it would hold if the interior was suitably columned.)

The last isn't going to happen. Two main things are wrong with it: 1 the base doesn't look like anything I've seen in natural stone, it looks like a tree. 2, it is way too tall for its height, running on rough guesses, I can't see something like that forming in nature beyond 1/3 of its height. The sides are far too vertical, and it would shear off at the first seismic event. (If not a strong wind)

02-23-2011, 01:49 PM
have you ever been to St.Peters cathedral? I went in side and could not think of how its still standing -- with some clever building anything is possible i guess XD

Photo's dont really do it justice but I could see those crazy castles standing ( or just go ahead an say Magic holds them up)

02-23-2011, 04:39 PM
That last one may indeed be technically impossible, but it's my favorite of all of them. I'd give it the magic excuse and keep it anyway just for sheer cool factor.

02-23-2011, 05:11 PM
Remember this: until the Eiffel Tower came along, the pyramids were the tallest man-made things on earth. So I say it depends on the tech level of your world. If you're using true medieval technology then you need buttresses on the outside and vaulted ceilings with columns on the inside for anything over 50 feet, or so, or else the curtain walls fall over and the roof collapses. On the other hand, the temple of Solomon is purported to have foundation stones larger and heavier than the pyramid stones (but I don't know how tall it was supposed to have been). But since no one can really prove that it becomes a matter of faith and if you choose to believe then I'd say anything is possible with large enough and strong enough material at the base. If they can build Machu Pichu then I say that last one is feasible as well, though the stone formation looks totally implausible it could have been "shaved"...kinda stupid to do that but it looks cool and history is full of egomaniacs who want cool-looking stuff and don't know jack about engineering. The Romans had that volcanic ash concrete, which is stronger than normal concrete and actually hardens under water, so substitute magic for volcanic ash or have titanium quartz in your granite and truly anything is possible. I like the 3rd and 4th as the most plausible here because they're all built on a hill so you can tunnel into the hill and have all sorts of extra room (just don't collapse the hill on yourself). My personal faves are the throne rooms in God of War.

02-24-2011, 04:49 AM
all great looking buildings, and in my world I don't care about arcitectonical possible but about cool ... the rest is magic ;)

and concerning - WHY one would build those huge buildling and what the space is used for - don't underestimate the intimidation factor of those impressive buildings - showing off your nations power :)

02-25-2011, 10:16 AM
Wow, i didn't expect so many responses so quickly 0.0 . Thanks for all the input, i now have a better idea of how my structure is going to be limited physically.


02-26-2011, 06:41 AM
Ascension, I never got why the pyramids always get that title. Some church-towers in Europe are taller than the pyramids. And at least eight of those pre-date the Eiffel tower. HOWEVER, many of those collapsed due to catastrophes, like storms or lightning-strikes, and are either lower nowadays, or no longer exist. The pyramids are solid structures however, they do not have much internal usable volume. Most of it is structural. Building very tall free-standing structures in the middle ages certainly was possible. That makes the pyramids VERY durable. However, for free-standing structures, many churches and cathedrals are also quite impressive. Many churches also reach ages up to 900 years by now. Which is quite durable in my humble opinion.

The addition of magic or semi-magic would in fact make it quite possible to build buildings which are much bigger than that. You may want to read up a bit on arches and vaults and so forth, it really helps understand how to make a building look believable.

On the topic's pictures:
1: Looks very well possible with the addition of a little magic, however I find the walls a bit too tall to be one surface, unless it gradually decreases in width along it's height.
2: Looks like it would collapse, especially those super-tall free standing towers. The big statue seems quite unwise... those wings must catch a lot of wind... Certainly an impressive drawing, but it doesn't really work for me.
3: Not much detail. Seems like it has a bit too many single elements comprising it's height. Also, the shape of the tall structure looks like it doesn't belong in that city.
4: The gate is a bit overdone, but otherwise this looks quite believable. I would avoid square shapes (windows) as much as possible though.
5: The gods of that world must have been drunk when they created that mountain.

Note, most of these buildings probably would collapse in reality, but in fantasy, we only have to have it LOOK like it wouldn't collapse. ;)

Zevious Zoquis
02-26-2011, 08:08 AM
I wouldn't want to be the guy that had to climb the stairs to the top of those needles in number 2... :)

02-26-2011, 07:47 PM
A couple of other factors to consider about structure.

At ten stories buidlings have the same frequency as earthquakes. So they are the first structures to topple. Unless they have anti vibration dampening.

Another factor with tall structures is wind load. The more surface area and the higher it is really affects if it is able to withstand those forces. A tall skinny structure doesn't have the internal structure to withstand it. Tapered structures are more readily able to deflect the wind load. Wider towers have more sidestructure to absorb the wind load.

03-03-2011, 09:14 AM
Okay, thanks for all the input and since this thread is still sort of recent I hope you don't mind me running ideas past you. All of these ideas relate to the architecture of the Dal and mostly relating to the Great Palace of the Dal'Jha'N. As this is a cartography site I will understand if this thread gets closed down, itís just that Iíve found this site to be a valuable trove of knowledge.

Okay, the ideas. The Great Palace is a work of art in itself, it has never been destroyed since it was first erected almost 1200 years before the current date and has constantly been improved upon and has always served as the Dal central seat of government and culture and home of the DalíJhaíN (Dal equivalent of royalty). Some ideas I wonít to try and logically (i.e. with minimal magickal contribution) include in the design of the palace are grand structure sizes, refrigeration and food storage, non-combustible internal heating, spectacular gardens and some form of plumbing. Iím still studying structure sizes, thanks for all the info, gardens I can do because I know that it is possible with good soil and sufficient irrigation and Iím basing the technology of ancient refrigeration on info I have found on Persian Yahk-Chals.

Hereís my idea for internal heating, itís based somewhat on Korean onsons and Roman hypocausts (check spelling) so I know itís possible my question is would it be possible on the scale Iím thinking. The Palace is actually built on the remains of two extinct volcanos (one rose up inside the remains of the other), certain areas of the still fissured rocks and caverns are quite hot so the Dal thought of diverting water into these hot spots to create steam, some areas already converted underground streams into steam, the Dal just upped the scale. The steam and hot air is diverted into shafts and hollows that are built into the walls of the palace. The hollows heat up and the heat is transferred into the room keeping the palace warm all year round. Flaps and slides in key shafts and junctions allow the hot air and steam to be diverted to certain parts of the palace. In the warmer seasons all of the shafts are blocked off and an entirely separate shaft system is opened up to divert the steam and hot air away from the palace and out through vents in a nearby hill, most of the water channels leading into the hotspots are also sealed. Would such a system theoretically work, or do you need more info? If you need a base idea of how big the palace is it has a footprint the size of the Forbidden City and its highest point is at least eleven stories, research into Chinese architecture (specifically pagodas) have confirmed that the size/height can get bigger than this.

My other ideas are based somewhat on this system so I need to know your thoughts on this before proceeding.


03-03-2011, 07:33 PM
The heating with steam would be pretty difficult.

#1 Some volcanic steam is poisonous, but that is a minor issue.

#2 Condensation. The heated steam will start to condense as it transfers all the heat to where it is needed. So the system would have to be designed to allow the water to run-off somewhere.

#3 Airflow. The whole system has to be able to breathe. I.E. needs to have constant flow. The shafts have to be voluminous at the start and slowly reduce as they branch off. Also they have to exhaust. If the mass of air cannot exit, there will be no air movement. The "chimneys" have to be able to allow lots of exiting air to keep air flow at a good speed.

#4 You can also have some areas of the palace use heat transference where the steam can heat the stone and the stone radiates the heat outwards. This is especially effective in large areas.

Hope these give you some more ideas on what is feasible.