View Full Version : Road/ford building
craigepo
02-13-2011, 18:15
Engineer question:
I built a ford on my farm, complete with culverts, across a fairly steep wet-weather creek. Culvert and large rock, then covered with sandbags.
I will be crossing the ford with UTVs, horses, as well as using the ford for my trail runs. I am looking for something to cover the sandbags with, as they will wear out relatively quickly with wheeled traffic.
I'm curious as to whether there might be a military surplus covering I could throw over this ford. Also, is there a military road-building FM?
Engineer question:
I built a ford on my farm, complete with culverts, across a fairly steep wet-weather creek. Culvert and large rock, then covered with sandbags........
Did you improve a fording area or make a low water bridge? Sounds like you made a low water bridge - something that with heavy rains the stream would overflow the roadway. A little higher and you'd have a dry road bed but also the chance of a dam - with only one culvert.
Yes there are FMs - IIRC the old one was titled Roads and Airfields and covered basic T/O construction for both. Bridging also had chapters on low tech T/O bridges. I'd have to dig out my old FM 5-34 (edited to add Chapters 7 & 8) as that had a little bit of everything in it. (Edited to add Non-standard Bridging TM 5-312)
But how high and how long? I've seen some pretty nice back woods bridges built with scrap steel I beams, cement footings and wood planks- plus a portable welding rig.
craigepo
02-13-2011, 18:56
It's about 12 feet by 8 feet. I think that the structure is sound enough to hold the weight I will be putting on it; my issue is covering the sandbags with something that will take the wear of the traffic.
I watched a show recently, which showed how military engineers built WWII runways with this huge metal type of covering. I am curious as to whether the army would have a similar covering or idea for a much smaller area.
Peregrino
02-13-2011, 19:13
I think what you're looking for is PSP - Perforated Steel Planking.
http://en.wikipedia.org/wiki/Marsden_Matting
Go Devil
02-13-2011, 20:08
Marzden Matting
http://en.wikipedia.org/wiki/Marsden_Matting
I saw a bit of it around Benning, Bragg, and Knox for holding back earth.
I suppose it would be easier to obtain in Europe, or the pacific.
I've seen it used on expeditions in desert regions to self extract trucks from sand.
PSP, PAP or the Russian equivalent.
It's all surplus.
http://www.calumetindustries.com/?cat=34
But you don't have that big an area. 12 x 8 is pretty small - deck size. I would think some pressure treated 4x4s used as sleepers - long metal drift pins hammered into the roadway to hold them in place. Some more 4x4s as stringers and then 2x's as decking. If you have access to a scrap lumber pile somewhere it should be pretty inexpensive.
Redneck decking? I've seen bags of quickcrete laid out where folks want them and then hosed down. Disclaimer - it does not mix well or set up well and crumbles to worse than gravel.
But if your existing roadway is firm - since you have a stream - you can put some 4x4s along the edge of the roadway, take the same bags of cement, hand mix them and pour them between the 4x4s. Some old wire fencing would be a nice addition in the middle of the cement.
All depends on how much you want to spend - or what you have at hand or scrap in the local area.
I would cover the sandbags with rip rap. You see it along the roadways everywhere.
Check here (http://en.wikipedia.org/wiki/Riprap)
If you can't find the FMs, send me a PM. I maybe able to help you out.
But if your existing roadway is firm - since you have a stream - you can put some 4x4s along the edge of the roadway, take the same bags of cement, hand mix them and pour them between the 4x4s. Some old wire fencing would be a nice addition in the middle of the cement..Old railroad ties, if you can get them cheaply...coated with creosote, they might lasts forever...old power/phone poles, cut to length could help build a corduroy road...if you had some cable, drilled holes through the 4x4/railroad ties/powerpoles, anchored with a dead man at either end, you should have a pretty substantial ford...and if you can find a pre-70s FM 5-34, some of this stuff should be in there...there is also an FM on Roads and Airfields, FM 5-430...should be something for that in the subject area of Theater of Operations Construction...FM 5-280...
And wikipedia is occassionally useful...
http://en.wikipedia.org/wiki/Corduroy_road
The Reaper
02-14-2011, 19:18
I would just add that if you try to obstruct the flow of the stream, it will win, eventually.
The culvert may be inadequate for the stream when it is at flood stage, and when that limit is reached, anything you put there is going to wind up downstream.
Sounds like all you want is a shallow ford, and the sandbags are fine for that.
TR
If you really want to determine if the culvert you placed is adequate, do some tinkering with Talbot's formula (http://ow.ly/3X0T2). If you need some watershed calculations, PM me. A vented ford is what I have seen installed in streams where there is potential for flooding but you still want an economical way of traversing the stream.
Golf1echo
02-15-2011, 17:08
As Pete said FM5-34, sections 7 and 8, also sec.9 as it has culvert design, expedient surfaces to include Chesaling mat roads and Corduroy details.
Just South of you a bit (WNC) the old timers used alternating logs covered with earth to make small bridges over creeks since they did not have culvert materials. Yellow Locust trees!! would be a good material to use as they will "last longer than the holes you put them in", I suppose a corduroy made with them would be quite workable for horses, tracks and wheels.
You will find metal landing mats in sec.9 too. Depending on your grade, I do not like the metal so well as tracked equipment can slide if not done appropriately.
The USFS will use nonwoven mat material either to take traffic or to allow the vegetation to come back but depending on use it might not be sufficient? If you can get a blast mat (rubber material built into a mat, used for placing over charges) that might do it but would possibly be detrimental to water quality?
Below is a picture of a concrete/rock surface seen in the Cherokee Indian Village, it is probably a third the dimensions you mentioned and I would arrange to rocks differently or not use them at all for the uses you mentioned ( Possibly use wire reinforcements in about a 6" slab unless you expect heavy traffic.)
Edit: 2nd image is an example of what TR said, when water did come it took the stone with it. ( Greenway trail )