The Ultra Trifecta

Enlarge Image Image 1: JLG's 1250 AJP features 125-foot platform height.

 November 3, 2004—The articulating “mega boom” concept was first successfully marketed by Grove Manlift after introducing its popular AMZ131XT in the fall of 1994. While the numbers aren't for certain, it's a good estimate to say the unchallenged AMZ131XT's production had grown to more than 100 units annually before JLG Industries, McConnellsburg, Pa., offered a competitive machine a decade later with this year's 1250AJP introduction. Timing couldn't have been better for JLG. By late 2003, it became clear that Manlift was going nowhere, and this growing market would become JLG's by default.

JLG's first venture into the mega articulating boom market was back in the 1980s with the 150HAX. This had limited market acceptance because of its 11'6" stowed width, 56,000-pound weight, and price tag of $322,000 net.

Recognizing the need for a more affordable product that's more sensitive to transportability issues, JLG responded by developing the 1250AJP articulating mega boom, the company's third model in its Ultra Boom Series. The extremely successful Ultra Boom Series also consists of the 1200SJP and 1350SJP straight boom lifts.

Enlarge Image Image 2: An override button allows the jib to be rotated back against the main boom for reduced transport length.

The JLG 1250AJP's nomenclature reflects its 125-foot platform height; A is for articulating boom; and JP signifies that the unit is fitted with the JibPLUS™ feature. The rotating jib has a dual purpose. It can be rotated back 180° for shipping, and when the jib is stored this way, the overall length of the unit is less than 38 feet. The extendable axles can be quickly retracted from the 12'6" operating position to an 8'2" stowed position by returning the boom assembly to the prescribed stowed position and then driving the unit while depressing the platform axle switch. I needed about 30 feet of travel on a clean asphalt surface to accomplish this task. Combine all these capabilities with its approximate 44,000 GVW (depending on option choices), and you have a unit that can be towed without the need for special permits or equipment, which is truly an amazing accomplishment for a machine of these capabilities.



Key designs
From my perspective, two design factors are essential to the success of the 1250AJP. First was JLG's decision to move forward with the Ultra Boom Series. These units share a tremendous amount of design technology: They all ride on the same chassis and utilize the same operating, power, and drive systems. With the exception of the boom configuration, there isn't much difference between them.

The second key development factor is dependent on the unit's coordinated elevating boom design. Simply put, the lower and upper boom assemblies are automatically synchronized as they lift and lower to optimize the balance between forward and rear stability. This system is an integral part of keeping the overall weight of the machine down.

With three lower and two upper articulating boom sections, there is a lot to keep coordinated. To manage it all, the boom controls use a variety of sensors that not only enhance the stability of the machine and provide features not otherwise possible. The key is the JLG-developed EPBC (Engine Powered Boom Control) microprocessor control system, which results in simple and speedy operation, smooth control, and added versatility as exhibited with the dual-capacity control system.

The most notable feature is the tower/main boom control system, which simultaneously controls the telescope in/out and lift up/down actuators of the tower boom to follow a predetermined motion path. At the same time, the system controls the lift up/down actuator of the main (top) boom, allowing it to maintain a relative angle to the horizon. This gives you the sense that you are always moving in the right direction — Up! The end result is the operator has only one function switch to deploy the tower boom, making it a simple and speedy operation to control, eliminating the need to manually sequence the tower (lower) while deploying the upper boom.

One very important and fascinating link in this chain of monitors is the load sensing, main boom pivot pin. This “smart” pin incorporates an internal dual axis strain gauge and microprocessor, and it's able to read bending, or straining, in both directions. Whether it's in normal operation or back-up mode, the control system continually evaluates the appropriate functionality.



The Sky's the limit
Considering its reach and load capabilities, 44,000-pound GVW is a pretty light machine. A dual capacity work envelope available on this unit expands its overall working range, featuring an up-and-over height of 60'6" (18.44 m) and horizontal outreach of 63'2" (19.25 m). A cursory look at the reach chart indicates the unit is able to safely utilize its 1,000-pound capacity in about 75 percent of the total work range. [Insert IMG3_9340_gate.jpg) Image 3: The SkyGlazer option benefits greatly from the side-mounted entry gate.

Enlarge Image Image 3: The SkyGlazer option benefits greatly from the side-mounted entry gate.

JLG's Workstation in the Sky™ brand of attachments includes specific task-related systems that add to the productivity and utility of its products. On all Ultra Boom products, the SkyPower™ package is standard equipment. It consists of a self-contained 7,500-watt, 240/120-volt single phase, 240-volt three-phase generator and power line with outlets at both the base and in the work platform. They also run a 1/2-inch air line from the base to the platform. The unit I tested also was equipped with the SkyGlazer™ package. For an extra $800, this option includes a caddy mounted on the leading edge of the work platform. However, use of the SkyGlazer wouldn't be possible without the side-mounted, inward swinging entry gate.

The 1250 AJP carries a net price of $160,000. For that tidy sum, you get just about everything you could possibly need: four-wheel drive and steering, traction and power to go any place you would ever need to; plenty of on-board energy for just about any power tool; a jib with unparalleled reach capabilities; and the exclusive dual-load capacity.

As the market matures, demand for products with greater reach capabilities will expand. The 1250AJP is a manifestation of that maturity. Watch next issue for my hands-on evaluation of the 1250 AJP.

While JLG currently has the corner on this market since the departure of the demand-creating Grove machine, their exclusivity will be short-lived. Genie's new taller Z135/70, scheduled for introduction in the first quarter of 2005, will pose a formidable challenge.