Thompson, CT USA - The largest DTH drilling project since the Alaskan pipeline was recently completed along a 157 mile (253 km) stretch of railway in the Northeastern United States. This major infrastructure project involved drilling 13,000 piles 24" and 34" (610 and 864 mm) in diameter to support an overhead caternary electrical system required by Amtrak's new, state-of-the-art high-speed trains that will go into operation in 1999.

The $321 million dollar project will make high speed travel of up to 150 mph (241 km/h) possible along the heavily traveled route between Washington DC and Boston, MA. This will result in a drastic reduction of overall travel time between the cities making rail travel much more competitive with air and car travel.

The constructed overhead caternary system consists of high tension electrical wires that are supported by 31 ft (9.5 m) high poles spaced at 75 to 220 ft (23-67m) intervals. The piles for the electrical system were drilled by six (6) specially designed drill trains consisting of a railcar mounted Soilmec R-312 drill rig, two (2) 1300 cfm (613 l/sec) compressors, a support crane, drill house and hammer and bit supplies. Contracted as the primary supplier of down hole hammers and bits, Numa provided twelve (12) Numa Champion 240 down hole hammers and two (2) Numa Champion 180 hammer for drilling piles 24" and 34" (610 and 864 mm) in diameter to a depth of 8 to 25 feet (2.44-7.63 m).

Throughout the project, the ground conditions along the tracks proved to be very difficult consisting of rocks, boulders, metal stakes, rip rap and generally unconsolidated formations. To effectively handle these conditions both conventional and under reaming bits were used with the Champion 240 and Champion 180 hammers. The Super Jaws® Under-Reaming Bit, manufactured by Numa under rights from the Tone Corporation, was instrumental in the drilling success due to its special wing bit design. The bit does not require the use of costly replacement ring bits or casing shoes that remain down the hole when drilling is complete. Instead, it is engineered to have wings that extend out further than the casing while in the drill position to allow the casing to be pushed along as drilling is completed. Once drilling is complete, the wings retract back inside the casing and the entire bit is brought to the surface.

With the drilling portion of the Northeast Corridor Electrification Project completed, efforts are now focused on installing the advanced electrical system, finalizing construction of the high-speed American Flyer train sets and reviewing final engineering requirements. The first high-speed train is scheduled to make its initial journey in late 1999 with continued service into the new millennium.

Numa is a major manufacturer of down hole hammers and bits for the international drilling industry. The company designs and builds down hole hammers and bits for drilling vertical and horizontal holes 3-1/2 to 43 inches (89 - 1092 mm) in diameter.