Double Duty

15 April 2008

Auxiliary hydraulic lines from the vibratory hammer are plumbed into the front of the machine

Auxiliary hydraulic lines from the vibratory hammer are plumbed into the front of the machine

The biggest single equipment investment made by EE Cruz Co. is a new Liebherr HS 855 HD Litronic duty-cycle crawler crane. With a capacity of 115 tons, the crane is designed primarily for duty-cycle applications, an attribute that fits well into the company's business plan, according to Jefirey Cruz, vice president.

“The purchase of the new Liebherr crane is commensurate with our philosophy and business direction of pursuing niche construction markets that demand specialized equipment for out-of-the-ordinary projects,” says Cruz. “Th is crane will further separate our company from the more traditional construction contractor by enabling us to take on serious work requiring a serious duty-cycle crane. We have found that the more we concentrate on specialized construction services, fewer contractors can compete for the same construction projects.”

While the company seeks out specialized projects, thus narrowing the landscape of competitors, it works to diversify its services. Traditionally, the company has rented cranes (usually with operators supplied by the crane rental company) on a job-by-job basis. Although Cruz continues to rent cranes on an as-needed basis, a large-scale construction contract precipitated the purchase of the Liebherr HS 855 HD.

The project is the $138 million Rahway Valley Sewerage Authority Plant Upgrade which will increase the plant's 40 MGD (million-gallon-per-day) capacity to 105 MGD. Cruz needed a crane capable of driving sheet piles and one with good reach for lift activities on the project that will span some three and a half years.

Drive on

Because it is an existing sewage treatment plant, the company first had to drive sheet pile walls with the HS 855 and vibratory hammer before they could excavate for the new treatment tanks, otherwise the foundations of the existing ones would fall in. Th ey then used excavators while the HS 855 drove sheets for the next tank. When this is complete, they may use the crane to handle a concrete bucket or place the new heavy pumps. When the tank is finished, the HS 855 will be employed to use the vibratory hammer to pull the sheets back out.

Best buy

Rui Andre, Cruz's equipment manager, says he investigated the pros and cons of renting a crane, a power-pack and a sheet hammer and the purchase of the equipment. He says, “After Jeff, Joe Malandro, and I [the crane purchasing team] compared the costs of the two options, we concluded buying a crane was the better choice of the two.”

While many on the staff at Cruz have had experience in working closely with both crane rental houses’ and subcontractors’ cranes on construction projects, they sought advice on which crane might best fit the project. Th e knowledge needed to temporarily rent a crane and the expertise required to purchase one are two different things, Andre says.

“We extensively examined different make cranes to be certain we chose one that would bring the most return on its investment,” says Cruz. “A crane is viewed as just another piece of equipment in our fleet, so it is the return on its investment that we hold as most important when purchasing one.”

Liebherr's Scott Moreland also provided information to Cruz. “Th ey were extremely thorough and well educated in machinery, and I made many trips to answer questions, and it seemed that almost every option that I brought up developed new questions,” says Moreland. “Th e main things they were interested in were what the machine was capable of, specific options for their current and future applications, such as the control systems for the vibratory hammer, max flows at pressure to size, how large of a vibratory hammer, lead system controls, slurry wall bucket control systems, data logging, and the like.”

The Cruz team compared attributes and evaluated three makes of crane, deciding on the Liebherr. Cruz says, “Th e Liebherr is a true duty-cycle crane. Th e features needed for our requirements - both duty-cycle and lift - are found on the Liebherr. We intend to do more and more projects where a well-designed duty-cycle crane will be needed.”

They purchased the HS 855 with the optional auxiliary hydraulic kit, which is powered by the crane's single 600 hp Tier 3 engine. Th is auxiliary hydraulic system is the power source for powering various tools, such as casing oscillators, VM vibrators, hydraulic impact hammers, hydraulic grabs and spotters for fixed leads. With this option installed, the cost of a separate power pack was eliminated.

Cruz control

Cruz says the built-in power supply system offers advantages over the conventional separate power pack. A separate oiler-operator is not required to oversee and maintain the separate power pack because it is accomplished with the crane's oiler. Controlling the built-in power supply is done by the operator from the operator's cab.

The HS 855 doesn't require additional work space aside from the crane's footprint, and there are no hoses running over ground for connecting a separate power pack to the crane, nor the unsafe practice of hanging the power pack from the rear of the machine, Cruz explains.

More than a year after putting the crane to work, the Cruz team is happy with its decision to purchase its own crane as opposed to renting one. Andre says the long-term rent quoted to him for a lift crane, combined with the rent of a power pack, came to more than $30,000 per month. Since a crane will be operated for at least 30 months at the project, the rental costs would reach $750,000 to $900,000, depending on how long the additional power pack is needed.

“[Our] crane is also acceptable for making lifts required on our type construction projects,” says Cruz. “We bought 164 feet of boom [maximum available is 223 feet] so there is plenty of reach for making the necessary lifts. We made the right choice since the crane will be used for both duty-cycle work, such as driving sheet piles and lift work, such as pouring ready-mix concrete and placing other construction materials.”

Cruz says the company hopes to venture into slurry-wall work when this project is complete.


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