National Grid’s (NG) proposed transmission line number E-21 replacement crossing beneath Stuyvesant Brook in Stuyvesant, New York, proposed for the installation by horizontal directional drilling (HDD) a 1,700 feet of 12-inch steel gas main.
The crossing site is located in Columbia County, just east of the Stuyvesant, New York along the County Road 26A. NG’s existing 10-inch pipeline crosses Stuyvesant Brook multiple times over distance of approximately 600 feet. The existing line is exposed in the southern most channel and had to be replaced with a 12-inch steel gas main.
Workspace available on the north side of the crossing was very limited and required the 12-inch pull section be fabricated in a single segment, which will minimize downtime associated tie-in welds during pullback. Careful and creative planning had to be implemented to make best use of the limited available space to the west of the exit point.
The geotechnical borings at two locations indicated the existence of Shale bedrock, which is generally fair quality as indicated by the average of the all the Rock quality designation (RQD) values.
Because of the subsurface condition, length of the bore, the required bore depth and existence of sensitive environmental conditions, Turner Underground Installation Inc. (TUGI) decided to utilize its newly acquired American Auger 440T Maxi Rig and MCS 1000 Reclaimer.
The general contractor (GC) was J. Mullen & Sons. The GC did an outstanding job in providing access to the treacherous drill site and by applying timber decked work platform for the drilling operation. The GC’s welding crew was very efficient and cooperative during the pipe pulling process.
TUGI’s thorough planning, drill crew’s wealth of experience and the GC’s unconditional support helped complete this 1,700 feet, 12 inch steel safely, on time and as planned.