Crawler cranes: chart configuration, support reactions and planned load travel
Crawler cranes require the actual boom, jib, counterweight and track configuration to be matched to the load, working radius and support conditions. Tracks do not establish safe ground or unrestricted travel with a suspended load. Liebherr’s LTR 1060 is a telescopic crawler with a 60 t maximum load capacity and a 40 m telescopic boom; those separate headline figures do not promise 60 t at 40 m. Its charts and permitted configurations govern the lift. An expressly assumed uniform 200 kN support reaction divided by 4 m² effective area gives 50 kPa average pressure, but neither input comes from a generic crawler designation and the result is not a ground design. Confirm the actual reactions, effective support and ground assessment, then plan assembly, load travel and transport as distinct operations. US construction-crane rules also impose specific support and travel conditions where they apply.
Crawler cranes need a chart for the actual boom and load position
What should determine a crawler-crane comparison?
Define the required load and radius, lifting height, site geometry and permitted crane setup, then identify the applicable chart. Keep the boom and jib combination, counterweight, track spread, reeving and lifting point with the figures. A crawler label or maximum-capacity number cannot establish that the proposed arrangement can perform the particular lift or reach its position safely.
Must every crawler crane have a lattice boom?
Liebherr’s LTR 1060 reference identifies a telescopic crawler, with 60 t maximum capacity and a 40 m telescopic boom. Crawler running gear can support a telescopic boom. A lattice-boom crane uses its own approved sections and rigging; neither design category provides a universal capacity, assembly time or transport requirement.
Does 60 t capacity with a 40 m boom mean 60 t at that reach?
Capacity and boom length are separate limits. Capacity depends on the applicable chart at the actual radius, boom arrangement and support configuration, with the chart’s required deductions. Treating maximum capacity and maximum boom length as one operating point can assign a load the manufacturer has never rated, even though both individual numbers appear on the product page.
Retain configuration and lifting-equipment conditions
Can added counterweight or wider tracks independently increase capacity?
Use only configurations and ratings supported by the actual manufacturer documentation and procedure. Use the chart for the approved configuration.
Identify installed counterweight and track position. Confirm chart applicability, limits and required checks before planning the lift.
Which lifting equipment must remain in the chart calculation?
Follow the specific chart notes for hook blocks, lifting tackle, attachments and any other stated deductions or conditions. Count the complete suspended arrangement. A nominal item mass is not necessarily the complete demand on the crane, and subtracting a generic allowance cannot replace the actual weights and rules for the planned lift.
Establish effective support rather than a nominal footprint
| Input or result | Explicit example |
|---|---|
| Assumed uniform reaction | 200 kN |
| Assumed effective support area | 4 m² |
| Calculated average pressure | 50 kPa |
What does the assumed ground-pressure calculation establish?
An expressly assumed 200 kN reaction spread uniformly over 4 m² effective area gives 50 kPa average pressure. The inputs are assumed, not manufacturer reactions. The actual crane orientation, load distribution, ground layers, edges, voids and support stiffness may make an assumed uniform area inappropriate for the operation.
Can the whole outer area of a mat always be credited?
Effective support depends on the mat’s strength, stiffness, load transfer and support beneath it, as well as the actual reaction. Mat footprint cannot establish effective support area.
Obtain a support assessment and ground information. Increasing a nominal area cannot prove uniform load transfer.
What does the US construction-crane ground rule require?
For covered operations, OSHA 1926.1402 addresses ground sufficiently firm, drained and graded, with supporting materials as needed to meet the equipment manufacturer’s support and level requirements. Crawler cranes remain within the rule’s scope.
Identify site conditions and support responsibilities. Tracks and mats alone cannot prove compliance.
Plan permitted load travel, mobilisation and inspection
Is traveling with a load automatically permitted on crawlers?
OSHA 1926.1417(u) prohibits load travel when the manufacturer prohibits it and sets conditions for covered permitted travel, including competent supervision and assessment of relevant movement conditions. Pick-and-carry capability remains configuration-specific.
Check capacity, boom position, route and travel procedure. Crawler running gear cannot authorize unrestricted load travel.
Why are assembly and mobilisation separate planning tasks?
Identify the crane’s permitted travel or transport arrangement and every component moved separately, including its actual weight and handling points. Establish trailers, route requirements, assembly area and the supported assembly method. Some operations need additional equipment or space, but a universal claim that every crawler needs the same dismantling sequence or assist crane ignores the actual crane and plan.
What should a used crawler-crane inspection cover?
Use the applicable inspection and condition criteria for structure, boom components, ropes, mechanisms, rigging and running gear, with the machine identity and records. Price the inspection findings and required repairs. A single successful lift, engine-hour figure or apparently sound track cannot establish all structural, control and lifting-system conditions or select the most expensive likely repair for every machine.
What makes crawler-crane quotations comparable?
Require the same load positions, configuration, lifting equipment, support assumptions and scope for transport, assembly, inspection and operation. Keep chart capability separate from assumed scheduling costs.
Compare mobile cranes, material handlers and crane setup and ground support. Return to machine classes.
Define the lift and the site installation together
List the required pickup and placement positions, the load and complete lifting equipment, then identify the boom, jib, counterweight and track arrangement supported for that work. A lattice boom uses its approved section combinations; a telescopic arrangement has its own deployment and configuration conditions. Neither design supplies a capacity at an unverified radius.
Check the chart's load basis and required deductions with the rigging and hook equipment. Retain the actual boom length, radius, operating sector and support conditions. A headline maximum is a product reference rather than approval for the planned movement, and additional counterweight must belong to an approved configuration.
Prepare the support and movement plan
Obtain the relevant reactions and ground assessment for the setup and work. Track contact length and nominal area cannot establish uniform bearing pressure or identify a weak underlying layer. Supporting mats need the appropriate strength, stiffness and load-transfer assessment as well as sufficient effective area.
If travel with a load is proposed, establish that the manufacturer permits it for the actual configuration and use the applicable travel procedure and requirements. Include the route, support, load position and required supervision. Tracks alone do not make a suspended load safe to carry or remove the need to assess changing ground conditions.
Quote mobilisation as a separate part of the job
Identify the components that remain assembled and those carried separately, with their weights, handling points and transport arrangements. Establish the required assembly area, equipment, responsible personnel and sequence before delivery. An assist crane or a particular dismantling arrangement is a planning question for the identified crane rather than a universal requirement.
Keep the applicable inspection and service records for the boom, ropes, mechanisms and running gear with condition findings and repair quotations. Price transport, assembly, support preparation and operation on the same scope when comparing offers. A good engine reading or one successful pick cannot establish the condition of every lifting and structural component.