Marston Mat Mudway

Marston Mats, aka perforated steel planking (PSP), were developed by the U.S. before World War II. The idea was to quickly build temporary runways and landing strips. They were first used at Camp Mackall airfield near Marston, North Carolina, in the U.S.

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A Curtiss P-40 Warhawk on a Marston Mat runway at Milne Bay, Papua New Guinea in September, 1942. – public domain

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I honestly don’t remember where or when I acquired four of these heavy metal planks, probably saw them advertised somewhere. I know I didn’t pay much for them. The idea at the time was to see about using them for my bridge deck. I wasn’t able to acquire any more at the time, so opted for the wood deck you see in the photos. One of these days I’ll replace that deck with something metal. I like that the perforations would let air flow through so the bridge would not be as vulnerable to high wind gusts.

Meanwhile during our rainy season, areas where we like to walk get more than a little muddy. The small creeks flood and send water everywhere. I’m always digging ditches to try to control the flow somewhat, but this particular area is low, so it’s always a mucky mess.

mats
So I installed some 2×10 planks I had as well as the four Marston Mats. Nothing much to it, other than first setting out short cross members for everything to rest on. While you could just toss the planks into the mud, raising them up a bit makes them more effective, and you can get them level to some extent. I screwed down the wooden planks, but the mats were heavy enough to be stable without reinforcement.

jeepmud
When finished with the project, we noticed that Jeep the dog appreciated the wooden planks, but not so much the mats. He proved the point that the Marston Mats would not be the best material for a bridge, assuming you want to allow your four legged friends to come across with you. We’ll be watching for other options.

Thanks for stopping by! Be sure to check out our suspension bridge book. Here is the link:

Building a Small Cable Suspension Bridge with the Cable Locking System

Images, diagrams, and text copyright 2013-2016 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

Habitat for Pond Turtles: Turtle Sofas!

There’s a stream that runs through our property and into Wildcat Creek, close to where our bridge resides. Though the stream is officially nameless, we’ve always called it Phillips Creek, because it ran through the Phillip’s place; Belle’s Creek, because our neighbor’s dog loved to play in it; and Penn Creek, so named by the ODFW who showed up (without notice) to count fish one day. Whatever the name, the stream tended to cause flooding in the pasture in winter, so we put in a pond. How that was done is a blog for another day.

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buddy

At first the pond dried out in summer, but once the beavers noticed it, they routed more of Phillips Creek so that it flowed into the pond year-round. We installed a bigger culvert along with a fence to keep the beavers from clogging it up, and had ourselves a nice pond we called Buddy’s Lake, after our beloved Swamp Puppy, Buddy.

We had seen pond turtles in various wetland areas on our property, but were amazed at how fast they discovered Buddy’s Lake. They first appeared on a log that we’d left out, sunning themselves in the spring chill. When that log began to sink, as logs are often prone to do, we decide to make turtle sofas.

turtlemom-baby

Previously we milled up a few logs for various projects and had kept the sides for benches or whatever. So why not a turtle sofa? And to keep our sofas from sinking, we screwed on strips of rigid insulation we also had left over after building our house. The material isn’t toxic for the watershed.

turtlesofa11After launching the first sofa, we noticed that it tended to hang out close to the shore where a turtle might feel vulnerable to land animals, especially the two-legged variety.

turtlesofa12

This turtle is game to try anything new!

So we tied an anchor to a rope attached to the sofa and tossed it out so the log would float more in the middle. We also roped the sofa to a tree on shore so we could haul it back in if need be. And, we added measuring sticks as a fun way to see how big the turtles were. A full grown pond turtle gets to be 6-7 inches long.

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Jeep, Buddy’s predecessor, wonders why we threw such a big stick for him to fetch.

windjammers

We added windjammers to a couple of sofas to help stabilize them. Probably not necessary unless you have beavers who like to knock them over and use for their dam.

turtlesofa1

This is a turtle favorite, probably because of the moss that has grown on it. Without the foam underneath, this old log would have sunk by now.

turtlebunch

Six is not a crowd!

We’ve seen up to nine pond turtles at once on Buddy’s Lake. We’re happy that our turtle sofas are a preferred place for them to hang out. Or do whatever it is turtles do.

turtlelovecard

A Simple Swamp Bridge

We continue to expand the trail system on our property in the Great Northwet, and that’s not a spelling error. Here in western Oregon many areas that are passable in summer become higher-than-boots water in winter. One spot we have is a small wetland that is fed by a stream that runs year-round, just not as torrential during the dry months. I decided it would be a good place to put a small stump-and-plank bridge so that we could connect two trails we like to use.
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swampbridge3
I had some 20 inch diameter cedar posts that would work well for the bases. Planted in water and being cedar, they would not rot anytime soon. I cut them with a chain saw and then the fun part began – digging holes in deep mud, in water. Even in summer, it is a very boggy area. My goal was to dig until I hit more solid ground, but of course the sludge would just pour back into the hole as I shoveled. I dammed up in front of each hole as I dug to divert some of the water, and that helped. Mostly it just took persistence and a bit of mind over matter.
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swampbridge2
I set the posts 10 feet apart for my 2×10 planks. If you use something smaller for planks, it is probably best to space the posts closer together. I cut the planks so that they centered on the posts and screwed them down. Then I used metal strapping to tie them together. I could add another deck using smaller dimension lumber to really beef it up, which I’ve done for other bridges on the property (more on them later!), but after walking across this bridge every day for several months now, it seems to be all we need for such a short span – about 40 feet. I might punch some metal posts on each end and the center and add a rope railing for balance. In any case, it’s not a bridge for the non-sober!
finishedbridge
Thanks for stopping by! Be sure to check out our suspension bridge book. Here is the link:

Building a Small Cable Suspension Bridge with the Cable Locking System

Images, diagrams, and text copyright 2013-2014 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

Copper Pipe Shelf System

Here’s a shelf system I designed for a friend who was going to build something similar using galvanized pipe. I thought copper was a better idea because there would be no need to thread the pipe ends.
Copper Shelf Unit
The drawing shows a single tower. Several towers can be built and connected together. To make the tower assembly you could either screw or solder the joints.

Thanks for stopping by! Be sure to check out our bridge book. Amazon has the book on sale for about $12.00 right now. Here is the link:

Building a Small Cable Suspension Bridge with the Cable Locking System

Images, diagrams, and text copyright 2013-2014 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

Zip Line!

When I created this blog I promised something would be posted about zip lines aka ziplines. So, here is the first post about all that.

I visited Costa Rica a few years ago and rode on my first wild zip line. That is, it wasn’t a carnival ride or a rope in someone’s yard. It was down a mountain, in the rainforest, and attached to trees, and pretty freeking amazing. When I got home, my spousal unit said, “You’re going to build one of these, aren’t you?” And I said “Of course!”

I set up a a 420 foot zipline on our property. So far I’ve built the tower and ladder, which is a great treehouse getaway:
ZipBuilder

and I built the lower platform:
ZipLanding

and have installed and tested a temporary (smaller diameter) cable. Here is a fun movie of a sandbag wearing my spousal unit’s blouse slamming into the platform:
Zip Line Test with Fake Spousal Unit Getting Seriously Hurt.

While I was pleased at the 32 MPH speed, this test proved that I need to raise the final cable a bit on the tower tree and on the base post as well when I finalize everything.

There are more photos of the building process on my website: Zipline Photos.

The full size cable is up on the hill ready to install but at this point the path down the mountain needs to be cleared (again) before we continue with the construction. For now, I’m working to finish building our house, so this project is on hold for the moment, but will be completed at some point.

What’s funny about this particular project is that when my spousal unit’s elderly relative heard about it, she wrote us out of her will, telling another relative in private (which of course didn’t remain private) that “Building a zip line is pure Tom Foolery! These people have time to burn!” Well, building a zip line is what I do on the weekends rather than watch football. Just don’t call me Tom.

Thanks for stopping by! Be sure to check out my book about building a bridge. It includes some cool ideas that apply to other projects, like how to put a really tall post into a deep hole when you aren’t that tall. Amazon has the book on sale for about $12.00 right now. Here is the link:

Building a Small Cable Suspension Bridge with the Cable Locking System

Images, diagrams, and text copyright 2013 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

Repurposing Old Stuff – DIY Shelf Unit

This was actually my partner’s idea, but since I’m the one who put it to use I will take the credit: a shelf made from an old ladder!

laddershelves

This shelf was made using an old beat up aluminum ladder that I cut in half for the task and 3/4″ plywood for the shelves. I used 2×10 blocks for the middle supports, but they didn’t need to be that serious, I just had scraps around.

True, ladders have been used as shelves in other applications, but I haven’t seen them set up in this way. So there you go – something cool to do with an old ladder or two. We might build something like this inside our house.

Or maybe not.

Be sure to check out my book about building a bridge. It includes some cool ideas that apply to other projects, like how to put a really tall post into a deep hole when you aren’t that tall. Amazon has the book on sale for about $14.50 right now. Here is the link:

Building a Small Cable Suspenion Bridge with the Cable Locking System

Images, diagrams, and text copyright 2013 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.