Heavy Lifting, Lowering, & Sliding

STRUCTURAL TECHNOLOGIES serves as a single point of contact for lifting, horizontal jacking, or lowering operations, and the design of the necessary temporary structures.

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Heavy Lifting with VSL Systems

Lowering segmented bridgeSTRUCTURAL TECHNOLOGIES offers custom engineered heavy lifting solutions. Our heavy lifting systems will often provide the most effective solution for projects in which cranes or other conventional handling equipment cannot be used because of excessive weight, dimensions, or space limitations.



  • Economy and efficiency, through custom designed solutions
  • Reliability, based upon sound engineering and three decades of experience
  • The highest level of safety through the use of advanced and reliable hydraulic equipment

STRUCTURAL TECHNOLOGIES serves as the single point-of-contact for lifting, horizontal jacking, or lowering operations, and designs the necessary temporary structures to suit your requirements. Sound engineering, innovative and concise solution building, and years of successful experience guarantees reliable and cost-effective results.

STRUCTURAL TECHNOLOGIES offers a complete range of services for the planning, engineering, equipment supply, and execution of any heavy lifting project. Our approach is flexible and our construction design-build services are tailored to the specific project requirements. Our solutions are provided worldwide and include:

  • Feasibility studies and preliminary consultation for lifting, horizontal jacking and lowering operations
  • Project design and planning, equipment specification, scheduling, budgeting
  • Design, manufacture, and supply of special equipment and temporary structures, if required
  • Leasing and operation of VSL equipment and execution of work planned by STRUCTURAL TECHNOLOGIES or others

The planning of a heavy lifting operation should be started as early as possible. Early involvement of STRUCTURAL TECHNOLOGIES' specialists will result in a handling scheme that optimizes the project's economy, efficiency and schedule.

Heavy Lifting Process

The process of a heavy lift is very well-orchestrated – with all steps and details planned in advance. The lift begins with the lifting unit in an extended position (1), the upper anchorage engaged (2) and the lower anchorage disengaged. At the upper end of the stroke, the piston is retracted and the load is transferred to the lower anchorage while the upper anchorage is disengaged (3). The piston is then lifted for the next lifting step (4).

All steps of the lift are monitored, along with the movement during each lift. Lifting units are operated by VSL operators or training can be provided and trial runs performed to ensure a successful lift.

Type (1) Max. Number
of Strands
Capacity (2)
Cable Diameter
D (inches)
Overall Dimensions
H x W (inches)
Weight (3)
SLU-10 1 23,380 0.6 38.2 7.9 132
SLU-30 3 70,140 2.1 44.5 9.8 265
SLU-40 4 93,521 2.6 50.2 9.8 441
SLU-70 7 163,661 3.2 44.2 15.7 507
SLU-120 12 280,562 4.6 55.1 15.7 948
SLU-220 22 514,363 6.6 82.7 20.5 3351
SLU-330 31 724,784 7.5 84.3 23.6 4012
SLU-440 42 981,965 9.0 80.7 24.0 4894
SLU-580 55 1,285,907 10.0 70.1 31.1 7165

Piston strokes vary between 6.3 inches (160mm) and 21.7 inches (550mm), depending on the type of unit

1. The figures given in the table are also valid for Strand Moving Units of type SMU
2. Capacity is based on grade 270 strands, according to ASTM A 416-90/A and asafety factor of s = 2.5
with respect to the minimum breaking load of the strands.
3. Weights quoted are for the basic version of the lifting units





STRUCTURAL TECHNOLOGIES, a Structural Group company, is the exclusive designer and manufacturer of VSL post-tensioning and  construction systems in the United States. VSL systems have a well-earned reputation for their quality, reliability, and durability - and have been used throughout the world since 1956 to build, repair, and strengthen bridges, buildings, tanks, and special structures. For information on VSL products outside of the United States, visit the VSL International website www.vsl.com.

With companies dating back to 1902, Structural Group is firmly committed to its ongoing mission of making new and existing structures stronger and last longer. Through its companies, Structural Group delivers turnkey solutions that integrate technology, engineering, and construction. Structural Group provides specialty contracting services through our construction companies and state-of-the-art proprietary products and engineering support services through STRUCTURAL TECHNOLOGIES.

Learn more about Structural Group and its member companies.

VSL is the registered trademark of VSL International Ltd.