Ben Forster from USA-based Lift Systems talks telescopic gantries

By Euan Youdale09 August 2011

A 44A gantry leg with the new fork pockets and ladder designs as well as a new power unit with enclo

A 44A gantry leg with the new fork pockets and ladder designs as well as a new power unit with enclosures

USA-based Lift Systems, Inc. and Riggers Manufacturing Company have been busy with product refinement, compliance, upgrades and retrofits, as well as higher capacity models. The companies' president Ben Forster told IC all about it

What advances have been made to existing lines?

At Lift Systems we have taken a serious look at our Power Tower line of boom style gantries as well as our Model 44A and 48A gantries. Refinement was the goal with an eye for detail and user friendly improvements. All Power Tower models, the 44A, and the 48A gantry legs, now come with OSHA compliant ladders with large work platforms and multiple certified tie-off points. The benefit of this improvement is for easier header beam attachment as well as safer pinning operations during a Power Tower lift. More work is being performed above ground level, thereby making the OSHA compliant ladders a welcome addition. Existing units in the field were not forgotten during the engineering process, as ladder kits can be purchased and field-installed by existing owners of Lift Systems' gantries. Large fork handling pockets as well as multiple lifting lugs are now standard on all power units and gantry legs. This makes for faster jobsite setup and de-mobilisation, and provides adaptability whether forklifts or cranes are used for erection and disassembly.

Complying with CE standards, complete, lockable enclosures are now the norm for all Lift Systems gantry power units. Noise reduction and operator protection are the key benefits to this refinement as well as the satisfaction of a more polished looking end product. Several panel designs have been tested to strike a balance between noise reduction, serviceability, and engine heat factors.

What are the latest innovations?

The Power Tower line of gantry systems has received a number of other improvements over previous generations. Our new, patent-pending, hydraulic wedgelock design is now field proven and requires less maintenance, is field serviceable, and does not require a factory technician for replacement or adjustment. Along with cleaner looks, the new hydraulic wedge design incorporates the hydraulics of the redundant safety system directly in the wedges themselves. With this, the elimination of 350 mechanical parts and linkages was possible on a four leg gantry system. Retrofits are also available for the new hydraulic wedgelock system for existing equipment owners.

What other challenges have you faced?

A common concern for gantries with continuous drive systems is that when they are in freewheel mode, they are not truly free to move due to oil still needing to circulate through a closed hydraulic circuit. We solved that by developing a complete mechanical disengagement of the drives when not in use, during setup, or during an initial lift of an object for when it is critical that the gantry legs freely move to centre themselves under the load. Our new system can physically lock the drive into freewheel mode. Once re-engaged and hydraulic pressure is applied to the system, the drives will automatically revert to drive mode.

The key advantage over the 'freewheel valve' method of drive disengagement is that the hydraulic oil no longer has to cycle though a closed hydraulic loop 'freewheel mode', which is sometimes difficult to do when manually pushing the gantry leg down a runway track during setup, and during initial lifting operations. This also allows for an internal brake to be incorporated into the drive motor so that the drive will remain static when no hydraulic pressure is acting on the system.

How is the development of your control system coming along?

Our CARL Control System remains to be a hit with clients as they discover the powerful capabilities of our synchronised control system, which allows for both synchronisation of lift and travel. With three tare modes, off-set setups are possible with full synchronised control even with offset loads and with the cylinders between leg pairs in different stages. When demonstrated, clients are always impressed that two legs with no load will seamlessly synchronise extension, retraction, and travel with two legs fully loaded. Our multilingual platform has been a hit with our international customers as they can now operate equipment in their native and even corporate languages. We are currently in the process of further refining our control system to be more user friendly, as well as incorporating universal symbols in lieu of words whenever possible.

Are there any new products in your range?

New gantry models of note are the new massive 1,400 US ton (1,270 tonne) capacity 34PT14080WT Power Tower which boasts lifting capacities of 1,400 US tons to over 35 feet (10.6m) and 892 US tons (809 tonnes) to 46 feet (14 m). In the EZ Lifter line of gantries, Riggers Manufacturing used the popular EZ600-33 platform as a jumping off point in the development of the EZ600-40, which is the first EZ Lifter to extend to 40 feet (12.2 m), yet it retains the standard 4 foot (1.22 m) base width.

New gantry attachments include the 550 US ton (499 tonne) Rotation Station, which is a hydraulically powered continuous 360 degree rotation platform. Versatility was the key in the final design for the Rotation Station which allows for use at ground level with an object on top of the platform, or with the load suspended in the air from underneath the station. Loads can also be rotated on top of the station in the air.

Lift Systems has also developed a dual power option for gantry power units that incorporates an electric motor and an internal combustion engine in the same enclosure and hydraulic circuit. This feature allows the user to use fuel when electricity is not present, eliminating the need to rent a generator on an outdoor project, and provides a no-emissions solution when working indoors. Simplicity was paramount in the design - if the key is turned, the internal combustion engine will operate the system. If hooked up to electric power, the unit will operate once the start button is pressed. No alterations, adjustments, preparations, or installations are required for power unit setup - the unit will operate in either mode as-is.

What about the mobile line?

The mobile line of product from both companies received extensive refinement. Meshing the best features of the Riggers TriLifter and Lift Systems' MobiLifts and TwinLifts, the 110 US ton (100 tonne) capacity version of each was developed. The 110 ton line has several impressive features, including 90 degree steering, lower ground bearing pressure than the previous 75 US ton (68 tonne) versions, and a common direct drive system. Both the 110 US ton Mobilift and 110 US ton TwinLift have been produced to date. The 110 US ton TriLifter is designed and ready to build with the first order. In addition, the 110 US ton capacity, model TL220BW TriLifter can be used as a 100 US ton (91 tonne) forklift as well as with multiple other methods of load attachment. During the development of the 110 US ton line, the 75 US ton versions received a new drive system allowing maximum ground bearing pressures to be reduced by a significant 50%.

Implementing the CARL Control System platform in the mobile line has allowed for complete joystick drive, steering, and function control, as well as radio remote control, however, a steering wheel can still be ordered as an option. The now standard CARL platform enables fuel-saving engine control in addition to an easy to disseminate, machine and lift data, and an onboard diagnostics screen. The TriLifter line also received a new attachment - a hydraulic riggers boom, making the TriLifter now capable of lifting 25 US tons (23 tonnes) to 35 feet (10.6m). Riggers booms can now be installed as an aftermarket attachment on all existing TriLifters.

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