March 2015

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Page 43 of 59

he continued. "It's much better than a traditional crane with a hammer." From the clockwork-like handling of the sheets to the speed with which they enter the sand, it's clear that the RTG pile drivers with high-frequency vibration enabled this level of production. Raysik chimes in, adding that a suspended hammer relies on the weight of the hammer, whereas high-frequency vibration capitalizes on both downward force and vibration. Keeping Piles Plumb Himborg seems to know the operation as well as his machin- ery as he rattles off specs. He says the RTG pile drivers feature an Automatic Self Leveling function to ensure that sheets are plumb, which is mandatory on this project. "During the driving process, the mast is being monitored," he explained. "When the mast goes a bit off of being plum, it automatically comes back." A ground man with a hand level verifies plumb- ness as the pile vibrates into the sand. Steel I-beams pinned in the sand serve as falsework to ensure the plumbness of incoming piles. Serpe explains that keeping the sheets straight is critical to ensuring that the bent plate cap fits on top properly – and it's a rare feat. "Most people that come out here and see a cold rolled sheet installed this straight want to go and shake the foreman's hand," he said. Tight Working Space e worksite, framed by a towering dune and stockpiled steel sheets, is not much wider than a couple bowling alley lanes. Just above the dune, a curious neighbor watches the pile-driving operation from his deck as the RG 21 T vibrates a sheet into the sand. e vibration, powdery consistency of the sand, and gravity constantly work to level the material, further narrow- ing the channel. A small fleet of excavators and bulldozers worked ahead of the pile driving operation to maintain the right-of-way. "In this area, you can't get any more of an easement or you'll be in someone's living room," Serpe says with a laugh. e wall was designed to follow the easement between the shoreline and the dunes, while adhering to residential property line setbacks, and tying into the future beachfill project. is required close coordination with the USACE and the NJDEP. Working in the Sand Working on the beach presents unusual challenges, including wear and tear on the equipment. While gravity returns much of the fine white sand to the beach, it sticks to lubricated areas such as joints and within the tracks of the pile drivers. e resulting friction can be damaging, according to ECA's Raysik, who works to eliminate any downtime associated with the RTG pile drivers. e salty air can also increase corrosion. Another challenge is the constant clogging of air filters by airborne sand, which reduces the performance of the equipment. EIC's full-time maintenance crew fought this battle by blowing them out biweekly. Mobility was the next challenge since wheels and tracks slide in so sand. EIC increased traction along the work corridor with a geotextile fabric base topped off with crushed stone. "It's an incredible amount of effort just to get the steel where you need to install it," says Serpe of the sandy site. He attributes much of the credit to EIC's skilled operators. e steel sheets – 45 feet long by 4.9 foot wide – tip the scales at 7,000 pounds. Each pile was dragged by a bulldozer from a nearby staging area to its final destination. e geotechnical aspect of this project is intriguing for anyone who has tried to drive a beach umbrella into so sand. e surface layer is fine beach sand, but below is a layer of black sand, clay, and an additional layer of fine sand. Himborg explains the science as the operation unfolds. "It's all about friction," he explained, indicating that the high water table is helpful. "When you come to a water-saturated area, it acts like a lubricant and facilitates the penetration process." e steel sheets essentially displace the sand as they are driven. e RTG pile drivers feature an active push system, according to Himborg, which allows the machine to plow through dense materials such as clay. e sand on this project was obviously no match for the RTGs. While EIC occasion- ally encountered clay at the tip elevation, the pile drivers were met with little resistance. Drive time hovered between two and three minutes 95 percent of the time. He describes the situation as "putting the brakes on the hammer" when the sheet breaks through the clay below and needs to be stopped by the rig. Serpe indicates that the power of the RTGs was the defining factor in punching through the heavy layer of clay beneath the beach. When all is said and done, Mantoloking will return to the bucolic island atmosphere that residents have traditionally enjoyed. But it will be stronger. is wall of steel will be a distant memory, disguised by dunes. "You're never going to see this wall," said Serpe as waves crash gently nearby, "and it's the last line of defense if, God forbid, the big storm ever comes again." It seems like a small price to pay. n ("Pile Drivers Shore Up New Jersey's Superstorm Defense" continued from page 41) 42 | www.cedmag.com | Construction Equipment Distribution | March 2015 >> DEALER IN THE TRENCHES BRIAN FRALEY is the principal of AEC Solutions, LLC. He can be reached at bmfraley@fraleysolutions.com, 610-906-7275. TIME OUT FOR A SHIPWRECK In early October, EIC attracted national media atten- tion by unearthing a 19th Century shipwreck while driving piles with an RTG piling rig. A cease and desist order was issued to allow archaeologists and shipwreck historians to determine the identity of the old wooden vessel. At the time of this writing, it is believed this could be a Scottish ship known as the Ayrshire, which was carrying Irish and English immigrants to America. Two-hundred passengers were on the ship and all but one were rescued. e investigation and further excava- tion on this portion of the jobsite continued alongside of the construction.

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