Hydraulic gantries: above and beyond
By Christian Shelton21 August 2017
PSC in the USA using a 700 tonne capacity J&R Engineering telescopic hydraulic gantry lifting system
The hydraulic gantry lifting system has become standard equipment in the lifting business today because of its cost effectiveness and project versatility. They can be used to lift and position heavy loads in applications where traditional cranes will not fit and where permanent overhead structures for jib cranes are not an option. In addition, they can be integrated with rail systems. According to Kevin Johnston, president of J&R Engineering, a US manufacturer of specialized lifting equipment, “our Lift-N-Lock hydraulic boom gantries, with their increased height capabilities and safety features, require considerably less of an investment than mobile or overhead cranes and can perform many of the same tasks. Gantries can also work in confined spaces or low overhead areas while remaining mobile and easily transportable.”
The following high-profile case study from one of J&R’s clients – Ohio, USA-based PSC Crane & Rigging (PSC) – illustrates some of the advantages of using a telescopic hydraulic lifting gantry for a challenging job:
PSC was commissioned for a heavy lift and transportation job as part of the Dugway Storage Tunnel project in North East Ohio. The Dugway Storage Tunnel will be 4.5 km long, with a diameter of 8 metres. It is designed to collect, store and treat wastewater and rainwater with the objective of reducing the level of environmental pollution in Lake Erie. The work called for PSC’s assistance in the set up and assembly of a 27 foot (8.2 metre) diameter tunnel boring machine (TBM). PSC was tasked with loading the TBM components onto 20 lines of self-propelled modular transporter (SPMT) and transporting them approximately half-a-mile from the TBM equipment staging laydown yard to the location of the installation shaft.
The main TBM component weighed 450 tonnes. Once the TBM components had been transported to the installation shaft, PSC then offloaded them from the SPMT lines using a 700 ton hydraulic gantry system from J&R Engineering as a lift tower. The hydraulic gantry system was used in conjunction with an 800 tonne Enerpac strand-jack system atop 80 foot (24 metre) girder beams. These spanned a shaft that was 50 ft (15 m) wide and 200 ft (61m) deep. The TBM components were then lowered into position. There were six main components that had to be lowered into position and the total assembled weight was 609 tonnes. PSC then skidded the TBM assembly components laterally into a starter tunnel by approximately 300 ft (91m) by utilising its 1000 ton hydraulic ‘Up & Go’ skidding system from Hydra-Slide.
Although highly complex and potentially dangerous work, the job went smoothly and safely. This was, in part, thanks to the Lift-N-Lock cam locking technology which is integrated into all of J&R Engineering’s full-size gantry systems. “The Lift-N-Lock system was developed in 1989; the particular model used in this job, the T1402-4-39, was developed in 1998 and has many years of proven field service,” states Johnston. “The model is very popular and its usage spans many industries, including automotive, power generation, machinery moving, etc. All J&R Engineering full-size gantries feature our exclusive Lift-N-Lock cam locking technology, which provides true continual load protection throughout the duration of the lift. In the unlikely event that a lift cylinder or lock valve loses pressure or otherwise fails, our system will immediately engage to hold the load in place. We believe that this technology is far superior to other methods of load protection. The Lift-N-Lock Cam Lock System is automatically applied by a spring, which engages the cams each time hydraulic pressure is reduced in the system – thus the load on the gantry boom can never be inadvertently lowered or dropped. When normal gantry boom lifting operations resume, the cams are automatically opened by a small hydraulic cylinder.”
The integration of the Enerpac strand jack was also straightforward. “Strand jacks are often used with Lift-N-Lock hydraulic boom gantries without the need for any modifications,” qualifies Johnston. With the J&R Engineering hydraulic gantry, SPMT, and Enerpac strand jack combination, lifting, moving, lowering and skidding were all achieved with maximum efficiency.
The Enerpac SL300
Enerpac doesn’t just manufacture strand jacks; it produces a range of high pressure hydraulic tools, controlled force products, and solutions for the precise positioning of heavy loads, including telescopic hydraulic lifting gantries. Its newest product is the SL300 telescopic hydraulic gantry. According to Enerpac, the system has two stage lifting cylinders for loads up to 3,000 kN and it runs on a 61 cm gauge track. Enerpac states that the SL300 is designed to meet stringent safety requirements and complies with the safety standards set by ASME B30.1-2015. At 2,705mm retracted height, the SL300 has a lift capacity of 3,000 kN, using four legs; at stage 1 capacity is 750 kN at 4,605 mm; and at stage 2 the lift capacity is 500 kN at 6,700 mm maximum height. Each gantry is tested to 125 percent of capacity at full extension and witness-tested by a qualified, third-party organisation, says Enerpac. It adds that the SL300 is also CE-compliant.
“Providing a more advanced solution than standard lifting systems, the SL300 hydraulic gantry offers industry leading features such as a wireless control system and an integrated self-propelled drive system,” comments Peter Crisci, global business development leader at Enerpac. “It is the highest capacity gantry on our 61 cm track gauge. These features, combined with safe, reliable performance, allow our customers to satisfy their complicated lifting applications.”
Like Enerpac’s other gantries, the SL300 has self-contained hydraulics, electronic controls and an Intellilift wireless control system. The control systems allow users to operate the lift locally at each leg or use the Intellilift remote control for unobstructed views of the load. Enerpac says Intellilift provides the operator with information about the stroke, lift and load per unit and automatically corrects any unsynchronised motion of the individual units. The Intelli-Lift wireless system ensures automatic synchronization of lifting with accuracy of 24 mm (0.95 inches) and automatic synchronization of travel with an accuracy of 15 mm (0.60 inches), Enerpac claims.
For enhanced durability, the SL300 has a sturdy, weather-resistant base frame. It can also have a powered side shift for easy operation. Optional gantry accessories include skid tracks, header beams, powered side shift, lifting lugs, slings and shackles, and a tarpaulin cover.
According to Enerpac, another benefit of using telescopic hydraulic lifting gantry cranes is that lifts are less affected by wind speeds than those using cranes. This is particularly useful for rail construction projects to help avoid unscheduled disruptions to train and passenger services. Enerpac says a gantry can be used at up to four times the wind speed permissible with a crane. The company also claims a gantry can be used in areas where crane access is impractical and it allows a continuous lift onto SPMT that is more efficient and safer than traditional jack and pack methods used with smaller bridge decks. For example, an Enerpac SBL900 gantry was recently used by lifting specialist Osprey Heavy Lift to prepare a replacement bridge section on a railway line near Chester, UK. “The Enerpac gantry was the ideal lifting system for this bridge deck replacement project,” said Nigel Fletcher, managing director at Osprey Heavy Lift. “Working at ground level and the ease of lifting the deck onto a SPMT made for a smooth installation of the new bridge deck.” Enerpac provides two types of hydraulic gantry systems for rail construction: the Super Lift (SL) series for lifts up to 400 metric tonnes (mT); and Super Boom Lift (SBL) series up to 1100 mT.
Enerpac claims hydraulic gantries are cost-effective to mobilise, too. The gantry’s telescopic leg can be folded down for ease of transportation, either on a flatbed trailer or in a container. Once on site, the gantry allows the new deck to be completely constructed on site at ground level, avoiding the need for working at height requirements.
Lift and rotate
Enerpac has also developed a 450 ton, lift and rotation strand jack gantry. The company claims it is the first of its kind to feature a rotating unit, enabling the lift and rotation of large turbine equipment during power plant installation. According to Enerpac, the main challenge for logistics companies in the power generation sector is the installation of new equipment. Loads are typically transported on trailers positioned parallel to the power plant; however, the equipment needs to be lifted and installed perpendicular to the trailer. Enerpac’s solution is a strand jack gantry with lift and rotate capabilities for loads up to 450 tons to a height of up to 15 metres.
The Enerpac strand jack gantry comprises four modular support legs supporting an overhead skid track for an Enerpac SBL1100 gantry. Two 200 ton strand jacks are positioned on each gantry beam. The strand jacks are, in turn, connected by steel strands to a centrally suspended, custom-made rotation unit and lifting beam. The lifting beam allows the load to be rotated by 90°. Enerpac says this is a unique feature for a gantry. “The strand jack gantry design combines the strength of strand jack lifting with the flexibility of a hydraulic gantry, and an innovative load rotation capability, to provide a highly capable lifting system for heavy loads,” says Enerpac director, Jeroen Naalden.
The Enerpac heavy lift, 450 ton, lift and rotation gantry is designed such that the entire gantry can be transported in multiple standard containers for ease of deployment at port logistics centres and power plants. It was developed and manufactured at Enerpac’s Integrated Solutions facility in Hengelo in The Netherlands.
Looking to the future, Enerpac plans to launch a number of accessories for its newly redesigned gantry side shift systems that it claims will provide added functionality. The new gantry side shift designs are modular, allowing them to be scaled to fit a variety of gantry sizes. For example, Sling Tool is a steel structure which can be placed on the anchor block for direct sling attachment with radius. In addition, Enerpac will include a storage frame with each set of side shifts. We will, of course, bring you all the details as and when they are released.