Connecting East & West Under The Mississippi

Dual River Crossings Connect Separate Water Systems For St. Charles Parish
By Jeff Griffin, Senior Editor | May 2009 Vol. 64 No. 5

Owner of the projects was the St. Charles Parish Department of Waterworks; the consulting engineering firm was Shread Kuyrkendall & Associates, Baton Rouge; and the contractor for both river bores was Ranger Field Services, Broussard, LA, a Quanta Services company.

A Vermeer 330x500 directional drilling rig was used to make both crossings. The machine develops 330,000 pounds of pullback, maximum spindle speeds of 50,000 pounds and speeds to 88 rpm.

The second crossing was 3,000 feet long at a maximum depth of 165 feet and was completed on the last day of February after 22 work days, said Boyd Simon, P.E., Ranger Field Services division manager.

Set up for the installation was near the town of Luling and included clearing trees for a 150 by 300 foot area on the entry (West Bank) side of the river and a 150 by 200 foot area on the opposite side at the exit point in the town of Destrehan. Four hundred twenty five yards of fill dirt was hauled to the exit area to provide firmer ground.

The 8 inch pilot hole was launched from the surface and required three days, averaging 1,000 feet per day. The maximum 165 foot depth was achieved at the 1,007 feet point of the bore. For the pilot hole, an 8 inch mill tooth bit was used. One backreaming pass was made with a 24 inch fly cutter reamer and a second with a 36 inch fly cutter tool. Backreaming required 14 days with pullback completed in eight hours.

Earlier bore

The first bore was completed in December 2007 and new line was fully operational in December 2008.

A 200 by 300 foot launch area was prepared and 650 yards of fill brought in for the drill rig set up. Simon said the 3,300 foot long bore path contained a compound curve of 6 degrees to the left and 9 degrees to the right. This was necessary to stay within boundaries of acquired right of way.

The 8 inch pilot hole, also surface launched, required four and a half days, averaging 733 feet per day. Maximum depth of 150 feet was achieved at the 901 foot mark. The same type of bits and backreamers as used on the second installations were used on this installation. Backreaming was completed in 16 days with one backreaming pass made with each size reamer. Pullback was completed in 10 hours.

Sixty six joints of pipe were fused along State Highway 3160 which, along with State Highway 18, was closed for a short period during construction.