A few airstrips I visit are having erosion problems, talk is of cutting down the edges to form a (better) crown, but it will take a fair bit of work since most of them are air- or foot-access only. I saw some photos from the Super Cub fly-in with the rubber erosion strips at Soldier Bar and clued in. I had read about them in the Mountain Flying Bible, but I was not looking for solutions to erosion at that time...

Anyways, I was curious if anyone knew what dimensions the rubber strips are - thickness of the rubber, height above ground, amount of material under the surface and/or how they are secured (if more than being buried). Is any specific type of rubber better or worse for this purpose? How far apart they are spaced, or does that vary depending on slope and surface-type?

The other concern some people had was that if some erosion still occurs between strips, does the gravel/dirt tend to build up along the upper side of the rubber strip? Does this ever cause issues with an inflexible or less flexible erosion strip?

The material is potato belt, cut to 8" wide.
You nail the base to a 2x4 laid on a side (or equivalent such as black spruce trunks) and bury across the runway.
Spacing and relief depends on slope, runoff intensity, etc.

The last time I worked with a friend to fix the "Water Bars" on Soldier Bar they were just long beams about 6x6 or 8x8 with rebar driven through holes near each end. We would replace the rebar then shovel some of the dirt that eroded down onto the top side - over to the low side - to mitigate little tires hitting an 8" BUMP on landing and rolling out. Did you ever know that the original runway ran perpendicular - sort of - just below the first rise and ended down hill at a camp with an outhouse.

Cabin Crick has always had the Rubber water bars. If I could find a number for Bart Walsh - I believe - at Henderson Nv.
He should know as he was a major driver for both Wilson Bar and Big Creek. Bart May be working with Lori right now at the McCall Mountain/Canyon flying school. I believe some of that process actually has to start with the Idaho DOT - "Depart. of Transportation. The RAF should have good data also At Cabin Crick

Best I can so under the influence of pain meds at this hour

Most I have written in a long time

Take care FLY SAFE early and late,

STAY Out of the headlines - they will just make you and us look worse.

Straight from the Forest Service:

http://www.fs.fed.us/eng/pubs/html/wr_p/98771804/98771804.htm

Rubber Water Diverters
Rubber skirting or used conveyor belts are utilized to make water diverters. The water diverters direct water off the surface of the road. Like the other cross drains, the skew angle is critical to the function of the water diverter. Rubber diverters require minimal maintenance; however, to reduce possible damage by grading operations, use an object marker to identify location of diverters.

Material

Rubber skirting: 5-ply, 1/2-in thick by 12-in wide by 20-ft long (13-mm by 300-mm by 6-m).
Timber: 4- by 8-in by 20-ft (100- by 200-mm by 6-m) rough sawn No. 2 or better, pressure treated for a design life of 20 years.
Lag screws: 11, 0.375-in by 2-in (9.5-mm by 50.8-mm) with 0.375-in (9.5-mm) washers.
Object marker: 1, type 2A, 6-ft (1.8-m) long.
Construction
Secure the rubber skirting on the 4-in (100-mm) face of the pressure treated timber, using the lag screws and washers. Figure 9 illustrates the construction of the diverter.

An alternate method of construction uses conveyor belting.

Material

Conveyor belt: 0.438- by 12-in wide by 20-ft long (11-mm by 300-mm by 6-m).
Timber: 2-in by 6-in by 20-ft (50-mm by 150-mm by 6-m) rough sawn No. 2 or better, pressure treated for a design life of 20 years.
Construction
The bottom of the conveyor belt is “sandwiched” between the boards.

Installation
Install the rubber diverter with a maximum 60° downslope skew. A trench is dug approximately 36-in (900-mm) wide. The diverter is installed so that approximately 3 to 4 in (75 to 100 mm) is above the road surface. The density of the backfill must equal or exceed the density of the surrounding material. The backfill material must be either the same material as the road or be crushed aggregate. Figure 10 provides installation details.

I never knew about these until landing at Cabin Creek. When I was just about to touch down and saw something across the runway, I thought, here goes the tires but I can't go around.

Note that the below application is for roads.
0.438" thick conveyor belting is too rigid for runway application.
Use 0.14" or so for more flexibility.

Crzyivan13 wrote:Straight from the Forest Service:

http://www.fs.fed.us/eng/pubs/html/wr_p/98771804/98771804.htm

Rubber Water Diverters
Rubber skirting or used conveyor belts are utilized to make water diverters. The water diverters direct water off the surface of the road. Like the other cross drains, the skew angle is critical to the function of the water diverter. Rubber diverters require minimal maintenance; however, to reduce possible damage by grading operations, use an object marker to identify location of diverters.

Material

Rubber skirting: 5-ply, 1/2-in thick by 12-in wide by 20-ft long (13-mm by 300-mm by 6-m).
Timber: 4- by 8-in by 20-ft (100- by 200-mm by 6-m) rough sawn No. 2 or better, pressure treated for a design life of 20 years.
Lag screws: 11, 0.375-in by 2-in (9.5-mm by 50.8-mm) with 0.375-in (9.5-mm) washers.
Object marker: 1, type 2A, 6-ft (1.8-m) long.
Construction
Secure the rubber skirting on the 4-in (100-mm) face of the pressure treated timber, using the lag screws and washers. Figure 9 illustrates the construction of the diverter.

An alternate method of construction uses conveyor belting.

Material

Conveyor belt: 0.438- by 12-in wide by 20-ft long (11-mm by 300-mm by 6-m).
Timber: 2-in by 6-in by 20-ft (50-mm by 150-mm by 6-m) rough sawn No. 2 or better, pressure treated for a design life of 20 years.
Construction
The bottom of the conveyor belt is “sandwiched” between the boards.

Installation
Install the rubber diverter with a maximum 60° downslope skew. A trench is dug approximately 36-in (900-mm) wide. The diverter is installed so that approximately 3 to 4 in (75 to 100 mm) is above the road surface. The density of the backfill must equal or exceed the density of the surrounding material. The backfill material must be either the same material as the road or be crushed aggregate. Figure 10 provides installation details.

Thank you very much! That is exactly what I was looking for. Hopefully this works for the strips so they do not need to be worked on every few months to fix the erosion damage.

Thanks Crazyivan. I was about to post a scan from a USFS print manual and then saw you posted the link.

Cabin Creek used to have wooden water bars/trenches about 30-33 years ago. They packed a wallop when the water went over the top and made a stepped gravelly mess, and the narrow gap filled in anyways. The first time I landed on the rubber was in '87, and I had the same "Oh crap, what now" on short final.

The deeper you can bury them the better. They will float up in saturated soil. Some specifications included using 36" rebar at an angle to tag the PT lumber base into deeper soil. Others included adding .75 cubic foot minimum rocks to anchor them underneath. The hand excavation is quite a chore, requiring yards for each trench. The rubber is surprisingly heavy to haul around, and make sure it is polyester belted or else it will take forever to cut them if you are unfortunate enough to end up with glass belted conveyor belting.