Mount Pleasant, NY – Cruz Contractors LLC of Holmdel, NJ successfully completed the installation of a 30” steel casing under the Taconic Parkway and Metro North Railway with the assistance of ICON Tunnel Systems and their pilot tube microtunneling technology for the first time.

Cruz is no stranger to microtunneling projects. Since 1951, they have been a major player for infrastructure projects that have included microtunneling throughout New Jersey, New York, New Hampshire, Massachusetts, Delaware, Connecticut, North Carolina and Virginia.

Cruz was subcontracted by Arben Group, LLC of Pleasantville, NY to handle the trenchless portion of the water system distribution improvements. The project called for (1), 210 linear feet of 36” steel casing to be installed under the Taconic Parkway and Metro North Railway. Originally, the project specifications called for a remote-controlled microtunneling machine in order to handle the native soil, which was thought to consist of stones, rocks and large cobles.
However, the soil boring logs did not show this soil condition being present. The logs actually indicated soft sands, traces of small gravel and clay silts. In addition, the work area would be very tight as the jacking pit for the microtunnel would be placed at the edge of a cemetery. Because of this, Cruz felt the remote-controlled microtunneling equipment would not be the solution because of the amount of equipment needed and large jobsite layout required.

Cruz contacted ICON Tunnel Systems for advice and inquired about the Bohrtec Pilot Tube microtunneling system. ICON reviewed the soil reports and determined that pilot tube microtunneling was a feasible alternative to the remote-controlled microtunnel machine specified.

David Crandall, Vice President of ICON Tunnel Systems along with Cruz and Arben worked with engineering firm Malcolm Pirnie, of Fair Lawn, NJ and Westchester County to successfully modify the pipe installation method on the project specification to allow for pilot tube microtunneling.

“We worked closely with all parties in order to properly incorporate the pilot tube microtunneling pipe installation method into the project specification,” says Crandall. “We recommended the BM600LS pilot tube machine for the project due to its powerful 262 tons of jacking force and 22,186.83 ft/lbs of torque in case we encountered any unforeseen difficult soil conditions.”

“Having the specification modified to meet the pilot tube pipe installation method was a huge advantage and saved everyone time and money on the project,” says Dominick Pillari, Chief Project Manager of Cruz Contractors, LLC.

Being heavily involved in rental/sale and lease of trench shoring equipment, ICON also supplied Arben Group, LLC with the required slide rail jacking and receiving pits for the pilot tube microtunneling operation. In addition ICON provided site specific engineering submittals with paper calculations and drawings with a New York P.E. stamp for our slide rail shoring systems used on the project.

The jacking pit size was 20.5’ long x 13.12’ wide and 14’ deep and the receiving pit was 24’ long x 13.12’ wide by 12’ deep. ICON supplied their new Transformer Rails for the side rail system, which are 30-40% stronger than other rail systems and versatile enough to handle three different types of bracing including; fixed rail, roller rail and angled raker bracing.

Andrew Kerry, ICON Tunnel Systems Pilot Tube Operator and Rob Langenbach, Operations Manager for ICON Tunnel Systems were on site to assist with the proper installation of both jacking and receiving pits and worked side by side with Cruz during the pilot tube machine setup and operation.

“ICON worked seamlessly with Arben in setting the shoring for the tunnel access pits and worked carefully with our crew during the pilot tube machine setup and operation, keeping the project on schedule,” says Pillari.

Large double wall pilot tube rods with an outside diameter of 5.5” and a length of 4.92’ were used for the initial pilot bore . “We experienced relatively low jacking and torque pressures while installing the pilot rods,” says Langenbach.

Once the pilot rods were installed on line and grade, Cruz and ICON would attach a steel adapter head to the last pilot rod. The steel adapter head would increase the bore from 5.5” to 36”. Once the adapter head was attached, they attached the first auger and steel casing to the adapter head. “The augers are placed inside the steel casing and can be moved independently from the casing to assist with the material removal process,” says Langenbach.

During the installation of the 36” casing, they encountered several areas with large boulders, some of which were 14” in diameter. “The large opening of the 36” casing allowed the larger material and potential obstructions to enter the casing at which point the augers would pull all of the material back to the jacking pit where it was then removed,” says Langenbach. “We were able to muscle our way through these difficult areas using the sheer power of the BM600LS and successfully install the steel casing on line and grade without disruptions to the highway or Metro North Railway.”

“The pilot tube machine was the perfect fit for this project and has allowed us to expand our services for future short run pipe installations on line and grade,” says Pillari. “ICON was with us every step of the project and really showcased their services from engineering and planning to shoring and tunneling. They made our first pilot tube project a true success.”

Since 1982, ICON has steadily grown in technology and expertise to become a full-service trench shoring and pilot tube guided boring company and industry-leader in underground construction projects. ICON has the in-house resources to handle projects of any size in any location across North America and provide a comprehensive line of services that include consulting, design, engineering, manufacturing and distribution, leasing and equipment rentals.