EX1200 Loads Trucks Every 80 Seconds at Quarry in Oahu

Wed July 29, 2009
Aggregate Equipment Guide

Fifty-ton (45 t) haul trucks scurry about the new quarry being established by Grace Pacific Corporation on the Hawaiian island of Oahu. Like ants from a pile of honey they scurry from the Hitachi EX1200, one every minute and 20 seconds, their beds heaped high.

Bob Singlehurst, project manager of this huge venture, looks down on the activity from his lofty vantage point with a knowing smile.

“We have 6 million cubic yards of material to move to get this site ready,” said Singlehurst. “The production we’re getting from the EX1200 is keeping us on schedule.”

The EX1200’s 6.9-cu.-yd. (5.3 cu m) bucket fills quickly as 115,081 lbs. (52,200 kg) of digging force rips through the volcanic material, cycle after cycle.

So what’s the hurry?

Time is money. The owners want the prep work done before the necessary operating permits arrive. Overburden must be removed, haul roads cut into the walls of the quarry, and berms built to shield the 35-acre (14 ha) project from view. Once in operation, more than 1 million cu. yd. (764,555 cu m) of rock a year will be mined for the next 25 years. It’s a big job, one of the largest this 69-year-old-veteran of the quarry business has had in his storied career.

“The company has an enormous investment here. We need to be ready to produce as soon as those permits arrive.”

The EX1200 is Singlehurst’s first Hitachi, and he has been pleased with its performance.

“We have liked it from the beginning. Now that it’s been on the job a while, I would honestly say the EX1200 has exceeded our expectations in every way.”

Dealer’s Duty

Singlehurst said a dealer plays an important role in the selection of equipment.

“A good dealer is particularly important when you’re dealing with a high-production machine like the EX1200. If it goes down, the job and all of the men and equipment working with it go down, too.”

He noted that costs soar far higher than the repair bill itself. Dealers need to have competent technicians and well-stocked parts departments.

“We’ve had virtually no downtime with the EX1200, but when there’s an issue, the repair truck is here in an hour or less. And there has been nothing that has stumped the technician. He’s been able to get us going fast.”

Singlehurst alluded to one instance when the machine was down for a day. A tooth ripped off the bucket, and to get it welded correctly just took time.

The importance of a competent dealer, particularly when working in a remote location like Hawaii, can cause difficulties when parts are needed fast. Singlehurst said that this hasn’t been a problem.

“American Machinery has had any part we’ve needed in stock.”

He also pointed out that with today’s airfreight, parts can arrive in a couple of days.

Creature Comforts

Operator comfort, particularly in a high-production machine like the EX1200, can help an operator work at peak efficiency for long shifts, and this machine stands tall on this measure, too, according to Singlehurst. Large tinted-glass panels provide a clear view, 360 degrees around. An adjustable suspension seat molds to the operator’s body for comfort, and the cab is heated, air conditioned and fully pressurized to keep dust out.

“I’d have to fight to get that machine away from our operator, and I’m not sure I would win.”

He pointed to another area where a happy operator pays big dividends — the way the machine is operated and taken care of. He noted that pride can go a long way in increasing production and reducing abuse of the machine.

About Grace Pacific Corporation

This 75-year-old company has constructed and maintained many roads and highways that are an integral part of Hawaii’s infrastructure. It is a large supplier of concrete, asphalt and aggregate, and its 500 employees also provide prestressed and precast concrete products, metal framing systems for construction, and traffic and highway safety products.

This story was reprinted from Hitachi Breakout magazine, Second Issue 2009. CEG

This story also appears on Truck and Trailer Guide.