[AtE] Postapoc parkour, and it's management

[thrash]

Originally Posted by Luke Bunyip

Small areas of total devastation, surrounded by areas of unmaintained concrete towers sporting broken windows, water damage, etc. Some buildings are maintained at a rudimentary level, whilst others occasionally suffer structural failure and partially or totally collapse.

There are a couple of rules of thumb that might be helpful:

• Any building too tall to be evacuated by hook and ladder truck is a high-rise, with very expensive additional code requirements. In my jurisdiction, this is defined as a height to the lowest occupied floor (i.e., not including roof-top equipment or towers) of 74 feet. The only place it makes sense to construct high-rises, therefore, is in the central business district (or similar corridors leading to it) where land is at an even higher premium.
• You won't have high-rises on the approach and departure paths to the airport, for obvious reasons.
• Buildings over four stories usually require an elevator, which is another expensive item. Most non-high-rise buildings will therefore be limited to four stories or less. This is a relatively recent (~1970's?) change, though, so (e.g.) eight- or ten-story walk ups may still exist in older parts of a city.
• Floor-to-floor heights vary, from as little as 9 feet (which doesn't leave much room for overhead ducting, wiring, etc.) to 16 feet or more. These may vary in a single building, with (say) 16' heights on the first floor for retail space, and cheaper 9' office floors above.
• Modern buildings often have a relatively thin skin over a structure of steel or concrete. This will be the first thing to go, leaving something that looks like a huge parking garage (but without the ramps).
• Office and apartment buildings will frequently be designed around a standard floor plate, with columns on a regular grid (usually 30x30', but could be 25x35' or whatever).
• Any open area that spans more than about 35' requires extra beams under the concrete slab ceiling (at additional cost), and so will be limited to special areas -- lobbies, auditoriums, etc.
• Modern buildings are also designed with shear walls, to resist lateral forces. These are usually combined with stairwells and elevator shafts (which have higher structural and fire code requirements). This combination of features is probably the last thing left standing as the rest of the structure crumbles.
• Shopping malls, with their acres of surface parking, are mostly a suburban phenomenon. If you want a big, open, varied space for combat but you want to stay close to the downtown high-rise district, a convention center may be the way to go. As a bonus, many convention centers post their floor plans online for event planners (e.g., Phoenix Convention Center).

Here's a link to the construction site camera for a high-rise we're building in downtown Phoenix. If you click on the date, you should be able to go back to the early days of the project (e.g., March 2020) and see some of the features I'm talking about as they went in. You should also be able to zoom in on any part of the picture, including several other construction projects going up in the same area.

[Luke Bunyip]

Originally Posted by thrash

On the other hand, since urban combat is frequently lethal to infantry in the open, creating "mouse holes" connecting interior spaces and using them for concealed movement is quite common. These can run vertically as well as horizontally.

I'd considered lift wells, air conditioning ducting, power and data trunking, and plumbing voids in multi-story buildings, but you've got me thinking.

A series of holes in a number of floors, with improvised ladders built between each floor, or something similar. The holes don't have to align, but they have to go from a discrete room to another corresponding room above or below. Could require transit across a floor to get to the next ladder.

[Luke Bunyip]

Originally Posted by thrash

There are a couple of rules of thumb that might be helpful:

<snipped useful stuff>

Originally Posted by thrash

• If you want a big, open, varied space for combat but you want to stay close to the downtown high-rise district, a convention center may be the way to go. As a bonus, many convention centers post their floor plans online for event planners (e.g., Phoenix Convention Center).

Cool. Ta muchly.

[dcarson]

Here is a diagram form a WW II manual on prepping a house for urban combat https://imgur.com/gallery/3VJhI3v

[Luke Bunyip]

Noice. Just the ticket...

[Michele]

Originally Posted by dcarson

Here is a diagram form a WW II manual on prepping a house for urban combat https://imgur.com/gallery/3VJhI3v

Hmm. Note the photo caption mentions cellars, which aren't present in the drawing. Those are of capital importance if we're talking about a firefight (possibly, in an all-out war setting, accompanied by artillery shelling too) and not about a martial-arts parkour fight.

[Anaraxes]

Originally Posted by Michele

s cellars, which aren't present in the drawing.

Right hand side, bottom most picture (with the "remove the stairs" callout).

[Michele]

Originally Posted by Anaraxes

Right hand side, bottom most picture (with the "remove the stairs" callout).

If that's the cellar, then it fails to point out the main advantages of it. Most such cellars weren't entirely under ground. They often had low, narrow windows close to the ground, the sort of thing that strongly reminds a bunker's firing slit. Yes, a first-floor window had a more commanding view - and it also was an obvious target. A low basement window with a MG could swipe a street clean and not even be located by the enemy.
If the cellar is windowless, but isn't entirely under ground, you'd better punch a firing slit there than on the first floor, to serve the same purpose of such a cellar window.

Also, if the enemy is going to use artillery, all that work on the first floor will quickly go. You'd better use any beams you have to reinforce the cellar's ceiling. Once the house is so much rubble because of the artillery barrage, you get out of the cellar to use the rubble as a hardened trench, and you still have the cellar as a bunker if the enemy artillery fires again.
That's what both the Soviets and the Germans did in Stalingrad. They also linked up the basements of adjoining buildings in a block to form a network, and linked that up, in turn, with the sewers.

Again, as I mentioned, this depends on how much true firepower is going to count. If this post-apocalypse setting is 300 years after the end, then probably nobody has serious artillery any more, and maybe not even small arms. That's why I asked.

[Luke Bunyip]

I'm not factoring in any large scale conventional military action in the setting. There will be some historical blast and fire damage, as well as the occasional partial or complete building collapse.

Given that I'm basing it on the CBD and inner suburbs of Sydney, Australia, there will not be a large volume of legacy firearms or ammunition stocks, as compared to other potential locales.

Building fortification will be in response to defending a group's safe haven from potential threats, which will be either other survivor groups or the mutated wildlife and vegetation. Things like a trebuchet or a megafaunal goanna, rather than artillery or AFVs.

[Michele]

Originally Posted by Luke Bunyip

I'm not factoring in any large scale conventional military action in the setting. There will be some historical blast and fire damage, as well as the occasional partial or complete building collapse.

Given that I'm basing it on the CBD and inner suburbs of Sydney, Australia, there will not be a large volume of legacy firearms or ammunition stocks, as compared to other potential locales.

Building fortification will be in response to defending a group's safe haven from potential threats, which will be either other survivor groups or the mutated wildlife and vegetation. Things like a trebuchet or a megafaunal goanna, rather than artillery or AFVs.

Fine, then industrial RC buildings can be your setting's medieval castles. Nobody's going to bring them down in two minutes with large-caliber direct HE fire.

Now, if firearms are in serious shortage, what about bows and crossbows (maybe made out of recycled equipment springs)? If these do not exist or are rare, then most of the considerations linked to fields of fire, which dictate the organization of MOUT with small arms and heavier infantry weapons, could be ignored.