Heavy Engineering: Cranes, Lifting Equipment and Welded Structures

High loads demand calculations you can audit

In heavy engineering a design error is not a rework item; it is a safety incident. Cranes, lifting equipment, heavy fabrications and pressure parts need load cases, safety factors and weld details that are calculated, written down and checkable by a third party. LTM provides heavy engineering design with that transparency, for manufacturers, fabricators and EPC contractors.

Heavy equipment we design

• Knuckle boom cranes, hook loaders and roll loaders
• Jib cranes, lifting beams, spreader beams and lifting fixtures
• Heavy welded frames, skids and equipment bases
• Pressure parts such as valve bodies and coil assemblies, sized to the relevant code
• Heavy handling fixtures, turning and tilting equipment
• Pipe welding machines and positioners for pipeline work

Load cases come first

Most heavy equipment failures trace back to a load case that was missed rather than a calculation error. A crane boom may be checked for the rated lift but not for the dynamic factor when the load is snatched from the ground. A lifting beam may be checked in bending but not for lateral torsional buckling. A heavy frame may be strong enough statically but crack at welds under cyclic loading.

Every LTM heavy engineering design begins with a written load case table, listing rated loads, self weight, dynamic factors, wind, impact, test loads and cyclic loading, agreed with you before sizing starts. The calculation report then traces each member and weld back to that table, so anyone reviewing the design can see exactly what it was designed for and what it was not.

How heavy structures are checked

Each design starts with a defined load case: rated load, self weight, dynamic factors for lifting and travel, and any wind or impact loads. Members are checked for bending, shear, combined stress, deflection and buckling, and every weld is sized for throat stress and, where loads cycle, fatigue detail category. Bolted joints are checked for preload, slip and separation. Hydraulic cylinders, slew drives and pins are sized from the same load case so the whole load path is consistent. FEA is used for complex nodes and cross-checked by hand calculation.

Experience

Designs include a hook loader and roll loader knuckle boom crane for fast loading and unloading of containers and bins, an internal pipe welding machine for onshore pipeline joints in 12 to 14 inch pipe, valve automation and coil assemblies. Calculation reports and drawings are prepared so that your fabricator, inspector and certifying authority can follow every assumption.

Quick checks

Use our free bending stress calculator for heavy beams, the beam deflection calculator for spans and the bolt torque calculator for structural bolting. The steel weight calculator gives self weight for load cases.