Notes from Windward: #69


Digging a Ditch

Jon describes some infrastructure work

     When I first arrived at Windward I was reminded that so much of the capital investment in the land has taken place underground. There are thousands of feet of potable water pipes, electrical wires, and sewage pipes that provide Windward's main buildings with basic utility services.

getting the ditch ready for the conduit

     One of my first projects when I arrived at Windward was to make a start on digging a 1 foot deep ditch starting from the Dining Hall and heading down the hill. Normally electrical conduit is buried two feet deep, but since this conduit would only carry the Cat-5 cable for our Local Area Network (LAN), there wasn't any need to go deeper.

     Windward uses a satellite dish mounted behind the kitchen to provide Internet service. Currently, there is an above-surface Cat-5 wire that brings our LAN down the hill. The first fifty feet I dug over a couple of weeks using a shovel. The digging was pretty straightforward, and I only dug for an hour or so most days, but I did learn that the real challenge is not how long or how deep you have to dig--rather, the challenge is what you are digging. For example, there was a five foot stretch that took a long time because it was extremely rocky and there were lots of tree roots I had to cut through.

     Other areas needed to be dug by hand because the route crossed over existing water, sewage or power conduits. Also, I was digging during the end of the rainy season so the dirt was still soft. However, if I had to do the digging in August, it would be a much more painfully slow process.

the Ditch Witch takes over the digging

     After I shovel dug the trench past the sensitive area, we switched to the Ditch Witch. It's basically a small tractor with a tail that digs a 4" wide ditch as it slowly moves along. In about an hour, the Ditch Witch was able to dig a ditch three times as long as the ditch that had taken me two weeks to dig! It was a lesson in how one old but well kept machine can save considerable amounts of physical labor. On the other hand, when we hit a patch of cantelope sized rocks, the Ditch Witch wasn't able to work her magic and it was back to hand work again.

     Once the ditch was dug down to its first access point, I cleaned out the ditch and then laid in a run of 1" PVC electrical conduit. With the conduit in place, it was time to backfill the trench with dirt. However, every time it rains the dirt compacts some more, so I add more dirt on top to level it out.

     The next step is to use a shop-vac to suck mason string through the underground electrical wire conduit. Once that's done, I'll use that string to pull the Internet wire through.

     But projects never go as planned...

      When I tried to suck some mason twine through the conduit I found that I was meeting some hidden underground resistance. So I used a plumber snake (a long coiled metal wire) to push through and clear out whatever it was clogging the conduit. With the blockage removed, I was able to get the mason string in and out. The next step is to use the string to pull the Cat 5 Internet cable through the conduit.

Notes From Windward - Index - Vol. 69