Dickinson & Sons’ 218 HSL proves to be perfect fit

“The way this 218 HSL crane is set up gives the contractor both the vertical height and horizontal reach that is needed. It acts like a flattop tower crane without the logistical problems of putting down a base foundation which would encounter a whole mess of underground utility lines,” said Don Dickinson, the president of I.B. Dickinson & Sons, Inc.

The requirement for this type of crane was brought about by the uniqueness of the type of structure and the extreme space limitations involved. The South and Spring Street Parking Garage, now under construction in downtown Harrisburg, Pennsylvania, will be a 12 story, 755 vehicle parking garage with speed ramps for egress and exit. This is a difficult construction project for a number of reasons. Not the least of these is the limitation of space. There simply is no place for onsite storage, not even a laydown area to shake out materials.

“We were able to reach a satisfactory arrangement for a long term rental with I B Dickinson & Sons, Inc. from Reading, PA.,” said construction manager, Gary Snyder. “The 110 ton capacity machine was rented with fully qualified and experienced union operators who are responsible for the crane’s day to day maintenance. Dickinson is also accountable for performing the factory specified routine hourly service."

“Essentially we are a crane rental house serving central and eastern Pennsylvania,” said Don Dickinson, the president of I.B. Dickinson & Sons, Inc. “The company was founded by my father, Irvin, 58 years ago. Now my son, Jeremy, is also in the business, making us a three generation family-run company. The smallest rental machine that we have in our inventory is a six-ton boom truck and our largest is a 300-ton capacity hydraulic crane. We have worked with this contractor several times in the past and that makes it a lot easier.”

“A very important part of our service is in supplying qualified operators with our rental cranes. We rely on Local 542 of the Operating Engineers for this and they have really upgraded their operator training program lately,” added Don Dickinson.

“When the determination was made to go with this crane, the availability of the luffing jib was a major consideration. It would be very difficult to do this job as easily any other way. The 218 HSL Link-Belt equipped in this luffer configuration is proving to be just what we needed,” concluded Construction Manager Gary Snyder.

The consensus is that if a contractor had to design a crane specifically for a job like this, they probably couldn’t do a better job than Link-Belt has already done. The 218HSL, in the luffer configuration, is a compact, maneuverable machine with a small footprint, stability, reach and lift.

To cope with space limitations and crane capacity, the 218 HSL is equipped with a total of 84,940 pounds of counterweight, including 11,100 pounds of sidetrack counterweight on each track.

“The Link-Belt crawler crane is outfitted in the luffer configuration because of the new garage’s unique placement. It is essentially an “infill” structure being built on a vacant space surrounded by other high rise structures. Space limitations ruled out the use of a larger conventional or fixed mount tower crane. Fifteen foot wide alleys are adjacent to the new building being built in the shadow of the magnificent state capitol building. The parking structure is also situated over Spring St. which is a point of entrance and exit to the garage,” said Project Superintendent Jim Kellum for Pyramid Construction.

In the age of prefabrication and precast concrete lift panel buildings, the new parking garage is primarily a cast-in-place concrete structure. The foundation and lower floors are built relying on pumped concrete placement. The columns and horizontal box beams on the upper floors are all being placed using the tried and proven crane and bucket technology.

A total of about 10,000 cu yds of cast-in-place concrete is required for the overall project. The majority of this is 5,000 psi mix with a 7 day cure time. The exception here is that the post tensioning for all the floors must be completed within the first 96 hours of the pour. Concrete is being furnished by Pennsy Supply of Harrisburg and trucked to the site on a carefully scheduled time basis to prevent a traffic logjam in the downtown area. The Link Belt crane will be using a 1 cu. yd. GarBro bucket for the crane and bucket pours.

Space limitations also preclude the use, delivery and storage of precast concrete panels or any other construction materials. The overall site is bounded by Second Street, one of the busiest thoroughfares in this, the state capital, as well as South Street and Susquehanna Streets.

“Traffic flow, including twice a day rush hours morning and night, precludes our bringing in a series of trailers with precast concrete panels. There simply is no space to park them, even on a temporary basis. And just bringing in ready mix concrete trucks, one at a time to the concrete pump, is a logistical nightmare.

“The crane is outfitted with a 130’ main mast and a 140’ luffer jib. It was imperative that the crane have a level surface for the limited area of travel available to it. For this we opted to bring in special 3-inch thick, lightweight Dura Base composite mats manufactured by The Loma Company of Carencro, LA. rather than use the heavier, more massive, conventional timber mats. We also added a layer of stone dust under the mats and the results have worked well,” said Construction Manager Gary Snyder.

“The new technology today demands a new type of operator. While it is true that we still have the older printed capacity load charts, the computers have significantly reduced our absolute dependence on them. The new versions simply will not let you override them, assuming that you were foolish enough to try. These are second and third generation computers, much advanced and far more dependable than the first computers that appeared in cranes. Don’t misunderstand me; we still refer to the load charts, especially in the planning stages. But we are in a totally different world today and Link Belt has been at the forefront of this,” said operator Joe Mihalik.

“As might be expected, weather is also an important consideration. The job commenced in April 2006 and completion is scheduled for around July 2007. That allows for only a couple of snow days and maybe a couple for the traditional Pennsylvania deer hunters. It’s a real tight schedule. Since we are doing the bulk of our construction during the winter months, ambient temperature is always a consideration and with cast in place concrete pours, winter cures will be a problem. We’ll have to tent the pour and heat it during the process. Once the pour is finished we will employ a chemical cure to complete the job.

“And, because of the crane’s configuration, winter wind is another significant consideration. Strong gusty winter winds whip through the alleys like a wind tunnel. We can only have the boom in the air when the winds are less than 25 miles an hour. To cope with this limitation we have installed a Hirschman PRS-80EZ wireless anemometer wind speed sensor with an in-cab readout. The transmitter unit is mounted on the knuckle between the vertical mast and the luffer boom. We have already encountered this situation and that is when you know for sure that you have a skilled operator. When he can safely lower the mast and boom without damage when a high wind suddenly whips up, as Joe Mihalik did, it’s a very comforting feeling,” continued Snyder.

The 218 HSL is also used to “fly” the plywood forms between floors before and after the concrete is cured and the forms are stripped by the carpenters. The largest forms are 56’ X 4’ square box beam forms. These weigh 7,600 pounds each. The heaviest single pick (lift), at over 10,000 pounds, will be the precast concrete stair sections.

During one major lift of four 20’ X 8’ plywood panel forms with 12” wood braces, the 218HSL was lifting about 5,000 pounds at that time. The tower boom was set in 80 degrees with the luffer at 45 degrees. It set the forms at a 130’ radius at the opposite end of the garage from the crane.