HOWTO dig a kids' pirate cave

This 1929 Modern Mechanics HOWTO explains to young people how they can dig their own pirate's cave, complete with working fireplace. The author explains that mothers can allow their sons (yes, it was all pretty gendered back then in 1929-land) to build such a clubhouse without fear, because the design will prevent cave-ins. Articles like this fill me with sorrow and delight: sorrow because you couldn't include such a place in a work of fiction (letalone a factual article aimed at children) today; delight at the adventure that those who followed these directions back in the 20s and 30s must have had.

Save all the flat stones for the fireplace, unless bricks are available. The latter will make a better fireplace, however, without mortar. The roof or ceiling joists should extend at least a foot on each side of the excavation. The ridge support is made up of two two-by-fours laid one on top of the other, as shown in the diagram. The roof boards should be covered with tar paper or old canvas, or in a pinch, several layers of newspapers. At one end of the roof, tack heavy wire screen under the gable, and further protect this with a row of slats set at an angle. These are to partially support large stones placed against them to conceal the vent. If the stones are big enough they will not impede air circulation to any great extent. A trench is dug for the stove-pipe and, when this is laid, covered over again with dirt. Of course, it will be an advantage to have the chimney as far away from the cave as your supply of stove-pipe will permit. However, be sure that the top of the chimney is one or two feet higher than the stove. Otherwise your draft will be sluggish. Stones should be piled around the chimney to hide it, and it wouldn't be a bad idea to throw over the chimney itself some old junk, such as rusty washboilers, etc., that will not interfere with draft. In case a potential enemy sees smoke rising he naturally would assume it to be a rubbish fire.

Digging a Pirate's Cave

I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.

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Donald Petersen

Hmph. Kids just aren’t allowed to perish in interesting ways anymore. Thanks to the inevitable triumph of the busybodies who filled in the cave forts, dismantled the tree houses, intervened in the dirt-clod wars, fenced off the drainage culverts, developed the hillsides, diverted the streams underground, drained the ol’ swimmin’ holes, and paved over the abandoned mineshafts, it’s no wonder kids just play videogames all day.

You can’t get useful statistics anymore simply because nobody’s allowed to do those “insanely dangerous” things anymore, but it would have been interesting to compare the rates of death and/or serious injury from accidental burial in a cave fort, or putting someone’s eye out with a BB gun, or falling out of a treehouse, or tumbling into a well, or drowning in the sewers, or blowing one’s hand off with a firecracker, or any other childish pastime of the last century, in comparison to just the car accidents and intramural sports injuries of today.

My kids can climb trees and dig holes until they collapse from exhaustion, but just watch what resistance they’ll meet if they ever ask me if they can play high school football.
andyhavens

Reminds me of one of the great kid-built houses from my favorite kid’s picture book of all time, “Andrew Henry’s Meadow.”

http://www.worldcat.org/title/andrew-henrys-meadow/oclc/61261880?referer=di&ht=edition

Great book, great pictures, a set (of 9 or 10, I think) of kid-built houses that appeal to whatever each kid is into: a tree-house for the bird-watching girl, an underground house for the kid who has mice and a mole, etc.

Should be a Free Range Kid Book Club selection for sure.
Anonymous

I am 53 and for many years have done a pirate treasure hunt for young people – of all ages. It was my sister and her best friend who in their teens dug an enormous fort out in the woods. To my parents the credit for encouraging immagination and countering gender steriotypes.
Gavin Rondeau

Am I the only one who thinks there are far too few anthropomorphic muskrats in fiction? Also, the pirate cave clearly has instructions on how to set up a chimney for your roaring fire in an enclosed space, thus ameliorating the risk of death by CO.
Anonymous

I’m immediately reminded of the American Boy’s Hogan (chapter XXIV) of D.C. Beard’s Shelters, Shacks, and Shanties.
http://www.gutenberg.org/files/28255/28255-h/28255-h.htm
pjcamp

Where’s the door?

It’s like the Pirate’s Tell Tale Heart.
Ferntree

There’s a beautiful but unfortunately long out of print book from the 70s called Huts and Hideaways that details grown-up plans like this. Fortunately, the author David Stiles seems to have released a number of modern versions. I can’t vouch for the newer ones, but if they’re anything like his original, they’re definitely worth checking out.
Modusoperandi

Oh, sure, it seems like a good idea now. Then you come home to find the DEA busting down the door of Junior’s camouflaged underground meth lab!
Ingmar

There’s a downside, of course: you’ll have to wear a tie on the playground.
frankieboy

I see mothers actually driving their kids to the bus stop! They sit there idling in an SUV or van until the bus comes.
It’s not below freezing, the stop is not far from their house, the neighborhood is safe as can be, thankfully.
The moms just mollycoddle the kids.
Allow the kids out of their sight long enough to build an underground pirate fort? Not in a million years.

When I was a kid, a neighborhood gang dug out an underground series of tunnels, that over a dozen kids could get into. The ground was very clayey, and it was little tunnels with small rooms, each enough for 3 or so kids to huddle in.
When the dads found out, they understandably freaked out, and a couple of them used dynamite to destroy it. Now when I think about it I shudder.
The next project was a tree fort so big we got a full sized couch up there! That was OK. A broken arm, not so bad; suffocating in a collapsed underground fort, quite another story.
Godfree

My sorrow is that it’s likely most of the kids today who are the age the article is talking to (the boy in the article looks about 12) don’t have the vocabulary to understand it. “What’s a latter?”
Jake0748

We made cave hideouts like this when I was a kid. Of course not so elaborate. We’d usually just pile a bunch of dirt on top of a sheet of plywood for the roof. A stove would have been cool.
- Anonymous
  
  Me too!
  
  Of course, it’s a different story in Central Florida with it’s sandy soil and high water table.
  
  I gave up on the underground hideout in my backyard after the snakes moved in, anyway.
Anonymous

Plywood and 2×4′s? When I was a kid in the 1980′s we just used logs. Dig a huge pit. Cover with logs. Pile dirt over the logs.
Hans

It reminds me rather of the warnings we got when I was a young’un in Minnesota. The snow plow would leave massive piles of snow at the ends of the street, and all the parents would warn us to never tunnel through it. Seems those were liable to collapse and kill us.

Of course, we did tunnel through them all the time, and they did collapse regularly. But we’d dig each other out and “*shhh* don’t tell mom, she’ll just worry.”

Good times.
- Jardine
  
  The snow plow would leave massive piles of snow at the ends of the street, and all the parents would warn us to never tunnel through it. Seems those were liable to collapse and kill us.
  
  My dad is a snowplow driver. One of his fears is that some kids will decide to play in the snow at the side of the road. If they’re tunneling away, there’s no way to see them and some days there is a lot of snow moving quite quickly. There’s enough force to take out a mailbox, I imagine it wouldn’t be a good day for a kid.
Anonymous

Given:
-above diagram
Assumptions:
-Based on the date I’m using true 2″x4″ boards (not modern skinny ones)
-3 pixlels per inch vertically and horizontally
-Diagram is reasonably to scale
-no ingress or egress is shown, so assumption is that viewing end is open like a dugout. Excavation probably doesn’t extend more than 8′ into hillside. Most likely this dimension os much smaller.

Measurements:
-depth=165px=54.999″=4’7″
-base=189px=62.999=5’3″
-width at ground level (truss width or span?)=298px=99.333″=8’3″ (10′ board would work well here, based on description)
-height of truss structure=35px=11.655″=11-5/8″ (12.75″ would make sense based on materiuals shown)
-depth soil on top=23px=7.6659=7-5/8″
-slope of walls 1:3 or 3 rise for every 1 run

All you engineers out there stop being laywers and run calcs. Make an assumption on soil type and summer time moisture level. Something from the midwest sounds good to me. Run the numbers and let us know what you find. I’d play in it.
- CANTFIGHTTHEDITE
  
  That’s fair, but I’m not a geotechnical engineer, so I can’t comment on the sloped soil walls. I can due some truss calcs to calculate the maximum loading on the roof, so stay tuned.
  - Anonymous
    
    So while we are waiting for structural calcs on the roof and a geotech to comment on the pit I thought I’d be an amatuer.
    Trench Safety PDF
- CANTFIGHTTHEDITE
  
  Keeping the load calcs simple, for time, I’ve calculated that each truss should support 71 kg. With a safety factor of 2, that would limit us to 35.5 kg per truss. With 9 trusses for a 14 foot span, and all of the dimensions from anon that I’m replying to, the truss structure should support 28.8 kg/m^2. With the depth of soil 7.625″, that would mean the soil could have a maximum density of 149 kg/m^3. It’s my understanding that most wet soils have a greater density than this. To reiterate, I’ve simplified the calculations significantly, so I could be underestimating or overestimating the loading capacity of this roofing design. Sorry in advance for the bold text, but…
  
  THIS COMMENT IS IN NO WAY TO BE CONSTRUED AS AN ENGINEERING CALCULATION, OR AS AN ENGINEERING APPROVAL OF THIS DESIGN. THIS IS NOT TO BE USED FOR CONSTRUCTION.
CANTFIGHTTHEDITE

Those walls look a bit steep to me. Depending on local soil condtions, this could be subject to sloughing. I wouldn’t enter something like this until a geotechnical engineer signed off on its design, I had sample data on the soil, and compaction tests of the walls. Also, overland flow could flood this in a hurry, so you’d want to know the relative elevations of the surrounding areas. As harmless as this might seem to the layman, it screams “death-trap” to an engineer.
- Chaoss Control
  
  If you’re being serious, and I suspect you are, as you seem completely oblivious to the fact that you just LOVE to throw technical terms around (we get it, you’re an engineer…yay! good for you!), then you’ve proudly contributed to the ongoing wussification of America. Congratulations. If our children are slaughtered like cattle in the upcoming apocalypse for fear of digging a hole in the ground, you, sir, will be partially to blame.
  - CANTFIGHTTHEDITE
    
    Just to address my apparent “wussification” of America, or at least Canada… nope. I’m not saying kids shouldn’t have underground forts, only that they should be taught about the dangers of excavations before they jump in one, as well as how to properly build a safe structure. The attitude of “I don’t need to prove that something is safe for human occupancy, that’s for wusses” is a negligent and ignorant one. Guess I should tell the people repairing watermains in excavations that shoring is for wusses, and that they’re hurting America.
    
    A safe underground fort is easy enough to design and build, if you’re willing to put the effort into doing it right.
    - jasonq
      
      I ain’t no engineer, but it seems to me that a 14′Lx7′W hole, 4 feet deep, is far less likely to collapse and lethally bury a kid than a 8′Dx4′W utility trench. Also, wouldn’t the sloped walls help prevent such a collapse?
      
      As for someone else’s concern water tables rising and inundating the hole, drowning the occupants…really? Seems pretty unlikely, and the instructions to site the clubhouse in a high spot and dig drainage trenches around would further ameliorate the possibility.
      - CANTFIGHTTHEDITE
        
        Less likely, yes, but it’s entirely dependent on the type of soil. Sloped walls help, but anything as steep as in the picture would have a negligible effect on sloughing. Anything over the kids’ heads would make me uncomfortable, so as long as that wasn’t the case I’d be willing to consider it.
        
        As for the water table, it could be a serious concern depending on the location. Sure, you’d keep your kids out of it during a rainstorm, but the water table could stay high for a few days or longer depending on a few variables.
        
        I missed the detail about the high spot, that would definitely help, but they should take care to define what they mean by that because it’s fairly open to interpretation. Wouldn’t need to be legalese, just a short list of defining characteristics. I would advocate against the drainage ditches, and instead recommend a sloped impermiable barrier around the edges of the roof to 24 inches horizontally outward, which you could cover in debris or what-have-you.
        
        The fireplace seems like a very bad idea due to the difficulty in achieving proper ventilation on your first attempt at it. You’d need a fair bit of trial and error to get it right, and then take care to keep ventilation paths clear of accidental obstructions.
        
        All these things are possible for some kids with a little bit of adult supervision to double-check their design and construction work. Would you let your kid(s) hang out in a tree-house if you didn’t at least have look at it to make sure it’s built right?
      - Art
        
        I’m guessing you draft “studies” for a living. You know, those things that municipalities pay a fortune for every year.
        
        Am I close?
      - CANTFIGHTTHEDITE
        
        Nope, I provide engineering support to operational staff in the water department of a major municipality, focusing on sanitary and stormwater lift stations.
        
        Now back to the load calcs.
  - Anonymous
    
    General note: civilizations have collapsed on a number of occasions throughout history. Even so, nearly everyone who spent their time preparing to survive alone in a post-apocalyptic world was wasting it.
- holtt
  
  Keeping the functional in fun there, eh CANTFIGHTTHEDITE?
Anonymous

Been there, done that . . . actually ours wasn’t quite(NEARLY) as fancy.
chgoliz

In case a potential enemy sees smoke rising he naturally would assume it to be a rubbish fire.

Remember rubbish fires? *cough* *cough*

There have been losses for children in what they’re now exposed to, but also gains.
feralman

Cory is a renowned writer who publishes through large companies who have attorneys vet his books. Those who care to publish their own work, or work with smaller houses without the same sort of legal worries, are not bothered about publishing stories about, say, a kid’s pirate cave.
MonsterMan

I just made one of these in Minecraft. Except a LOT bigger. And with a lava moat around it.
Skep

“Articles like this fill me with sorrow and delight: sorrow because you couldn’t include such a place in a work of fiction (letalone a factual article aimed at children) today”

So I guess that new YA authors couldn’t write about a group of three kids who create a secret underground lair under a huge junk pile at a junk yard, as in Robert Arthur’s Three Investigators mysteries from the 60′s. I loved those a a kid. The secret lair was a big part of the attraction, but I was never motivated by the books to try to create a secret junk yard lair under mounds heavy scrap metal.
- embryoconcepts
  
  I was a big fan of that series, as well as one called something like “The Mad Scientists Club”. They had a super-secret lair that required an obstacle course to enter, as well their own sub-powered Loch Ness monster, from what I recall….
  - Chris Tucker
    
    For those interested, the Mad Scientist’s Club books have all been reprinted.
    
    After you get them, good luck in finding the author’s Other famous book, “Rocket Manual for Amateurs”. Long out of print.
    
    Why? Well, consider. You’re the lawyer for a publisher. Here’s a book that tells you how to make all kinds of rocket fuel. Except, that if you put that rocket fuel in a pipe capped at both ends, you just made a seriously badass pipe bomb.
    
    That, and there’s a section of the book that describes “Treatment for belly wounds.”
    
    At which point, you, the lawyer have just wet yourself and fallen over backwards at the thought of the liability lawsuits.
- Elijah
  
  !! I had completely forgotten about that series, which is odd as I read every one I could get my grubby little digits on. The fort was _awesome_.
  
  “but I was never motivated by the books to try to create a secret junk yard lair under mounds heavy scrap metal.”
  
  Oh, I was, and I would’ve done it in a New York minute if only I had a access to such a wondrous place as a scrapyard. As it turns out, an old barn full of haybales provides some suitable design alternatives, though not necessarily much safer.
  
  Thanks for the nostalgia moment!
Anonymous

I guess back then, carbon monoxide didn’t kill kids like it does today. Only explanation that I can conceive of some idiot putting a stove inside without ventilation.
thephil

this reminds me of one of my favorite books as a kid, The Secret Hide-Out. http://www.amazon.com/Secret-Hide-Out-John-Peterson/dp/0590001191

Now i need to find the local chapter of the Viking club.
- Anonymous
  
  Coolest book ever! My brother and I made the paper bag masks and the broom stick spear thing.
holtt

sorrow because you couldn’t include such a place in a work of fiction

I’m really confused by this statement. Who is the “they” that says you can’t do this?
- BookGuy
  
  I was wondering the same thing. It seems to me that if some of the most wildly popular YA books are about wizardry, vampires, and children fighting to the death for the entertainment of a post-apocalyptic world, certainly a pirate cave wouldn’t be so objectionable as to make a book unpublishable.
- RedBaron
  
  I think Cory’s point was that readers wouldn’t believe it. Families don’t do that kind of thing… (thus the sorrow)
  - holtt
    
    Getting people to believe what they read in works of fiction is definitely a tough challenge for authors.
Rich Keller

I vaguely remember reading a story when I was in grade school about some kids in Saskatchewan who found a shelter similar to this. One of their dads checked to see if it was safe for them. Was that a Farley Mowat story?
Anonymous

It looks like an exact replica of the “bad place” in Peter Jackson’s The Lovely Bones. I do not want to go in there.
- Anonymous
  
  That’s what I thought, too. Don’t you think just picturing it encourages a serial killer somewhere?
  eeeew!
Baron Karza

WOW, the Viking Club! That brings back some memories. My brother and I did all of the crafts in that book, especially the slit-paper “tweeter” signals. Still very annoying today! Perhaps I’ll try one in the office today.
Angryjim

if I have a kid Im totally gonna help him (or her) build one of these. Then Im going to play in it long after they get bored with it and go off to play whatever sort of video game they normally plug into their brains.
traalfaz

Hm, I’ve been thinking about digging a root cellar this summer to store tubers and apples and flower bulbs. Maybe I can expand the nature of the project a bit…
Anonymous

Reminds me of http://www.cp-tel.net/pasqualy/hole/index.html
Anonymous

“The author explains that mothers can allow their sons (yes, it was all pretty gendered back then in 1929-land)”

If you don’t think that things are still gendered this way now, you aren’t paying attention.
Anonymous

Where’s the exit?
Stefan Jones

There’s a TOTALLY COOL backyard pirate cave app coming out.
Maggie Koerth-Baker

I think “The Lovely Bones” may have ruined the awesomeness of this for me, at least somewhat. Just one more reason to hate “The Lovely Bones”.
Bart

To fix the walls scavenge some 4×4 boards, sink them two feet, spaced 18″ apart. On the outside lay 2 sheets of pbx slightly overlapping. every three feet up, place another 4×4 horizontally between the vertical supports. This will make it stronger than most OSHA approved scaffolds. Backfill between the dirt and the pbx with sand and pea gravel. As for flooding? Be an adult and don’t let it get built in a ditch. Or be creative and put a sump pump in there. There was also an above ground earthen shed in “Mother Earth News” last year, I could see it being a hobbitesque playhouse.
playswithknives

when i was a kid in the 60s, my neighborhood switched over from septic tank systems to a proper sewer system. when people started filling their old septic tanks with dirt, all of a sudden there were lots of 6′ diameter steel caps for the taking. we kids used them for the tops of out cave forts. since we were in south louisiana, we had the added attraction of snakes and giant spiders in our caves.
AirPillo

I don’t see why you couldn’t build this for a kid today.

Legally you’d need a permit for the structure and the fireplace, and I’m honestly not sure if the design would meet any sort of building code.

However, since when do most parents bother getting permits to build a playhouse? Just don’t build it in sandy or other mudslide-prone soil, and don’t let the kids in it during rains. I wouldn’t even worry about the fireplace. Teach your kids fire safety at a young age like you’re supposed to anyways.

Worst thing that could possibly happen is you do something that needs a building inspector some day, and they notice the playhouse and tell you to take it down.
- Brainspore
  
  I don’t see why you couldn’t build this for a kid today.
  
  Yes, build for a kid. Maybe build with a kid. But encouraging them to build themselves? Probably not a good idea.
  
  My dad built us some pretty cool play structures when my siblings and I were young, he even let us help. But he didn’t hand us a blowtorch and nail gun and wish us well on our multistory jungle palace.
Amelia_G

The quote reads a bit like “Two Little Savages”! Haven’t thought about that in a while. Thanks, Cory.
jdk998

I must be getting old. All I can think about is the potential for CO poisoning.
Tavie

Add me to the list of those who would’ve been delighted by this before “The Lovely Bones”. thanks a lot, Alice Sebold.
cmpalmer

My cousins and their friends dug a fort almost exactly like this one in Pensacola, Florida sometime in the 1970′s. They finished it the week we were there on vacation and I got to visit it. I was pretty young at the time, but it was one of my favorite memories of visiting them.

It was about 12′x14′ and maybe 8-10′ deep. It had a gently trussed roof and a side tunnel to crawl down into it. It didn’t have a fireplace and I don’t remember how it was ventilated (but it was since they would spend the night in it and no one suffocated).

They built it in an empty lot where people used to dump stuff, so they camouflaged the top with junk (just like the Three Investigators and I was a big fan of those books).

A few weeks after I visited, a concerned parent (not my aunt and uncle) made them tear it down and fill it in.
allfortruth

As a six year-old living in a rural area in the prairies of central Alberta, I attempted to construct such a den, based on a somewhat similar plan I found in Richards Topical Encyclopedia. I staked out a 6′ by 8′ boundary and began to excavate with a long handled spade. I dug persistently and vigorously and in the first day had removed about three inches of soil from the area. Next day, another three inches came off. Then, on the third day, I ran into thick, heavy clay at about eight inches. I struggled with that for two more days before I finally gave up after clearing about ten or eleven inches of earth/clay out of the hole. Based on my experience, I’d recommend either that any aspiring pirate kid pick his spot carefully or that he build an above-ground lair with tree branches and lumber scraps. Otherwise, like me, he might end up a bitter, disappointed failure, albeit one who didn’t drown or suffocate in an inundated or collapsed cave.
bfiggins

Am I the only one worried about encouraging a roaring fire in an enclosed space?
planettom

This reminds me of a book I had as a kid (And still have), HARVEY’S HIDEOUT, by Russell and Lillian Hoban, about an anthropomorphic muskrat who builds an underground fort: http://www.amazon.com/Harveys-Hideout-Russell-Hoban/dp/0590077678
h4wk

We used to build underground forts when I was a kid. They were nowhere nearly as elaborate or well roofed as this one. We’d just dig a huge hole, borrow some plywood from a nearby house under construction, then throw in some chairs and such. Now, being older and also being trained in trench rescue, I can see where this isn’t the best idea in the world unless you really know what you are doing.
Antinous / Moderator

Pirate fort? Here in the desert, we call that a scorpion farm. Or a pool pit.
5ynic

@CANTFIGHTTHETIDE
I was gonna wade in on your comments, then I read further down the thread where u basically say “lose the fireplace and design it so there’s no soil gonna be above the kids heads in a collapse, and I’d consider it…”
I think you’re right there. I’m hoping when my brood are a bit older we can do a project like this, and I’ll add your 2 provisos to the checklist. Looking forward to load calcs – Cheers.
Anonymous

I’ve had some exposure to civil and geological engineering in pursuit of my doctoral degree. From what little I know, that diagram is scary. One of those things that’s perfectly safe most of the time. However, some times and in some places, I smell a premature burial.

Dig a big hole about 6 feet deep. Then it rains alot and the water table rises up. The walls could collapse.
Brainspore

Hope there was a followup article on “HOWTO dig your kids’ suffocated corpses out of a pirate cave.”
Robert

When I was a wee lad living in Brooklyn, we didn’t have any dirt to dig in. So we took some 4×8 sheets of wood and some concrete bricks, stood the sheets up with the bricks, built a little maze, and piled more sheets on top to make a sort of pirate shanty.

The wind had a tendency to knock the whole thing over, to our eternal delight.
Taniwha

and another explaining that CO2 is heavier than air and that lighting a fire in a hole in the ground probably wasn’t such a good idea ….
Anonymous

Am I the only person who is instantly reminded of the Loser’s clubhouse in It?
AGC

At least the article didn’t start off by saying you need to by x for your kids or you’re a bad parent.
Anonymous

When I was young we had a fort in a neighbour’s back yard, it was pretty much a shed, which we filled with old cushions which smelt of cigarette smoke. This got me in trouble. I also tried to dig a hole in out backyard to make an underground fort, but the soil was solid clay and I got about a metre and a half and stopped.

I think its sad that Cory feels he can’t even write about underground forts without getting in trouble, though its sensible to get a parent to help out if you are digging holes and then putting a roof on them. It could be a fun project to do with a parent or two.