Removal of Alimak Hoist System

Project Overview

To kick off 2026, our January Featured Lift takes us back to the West Gate Tunnel Project for one of our last tricky lifts on the project, where Premier was engaged to carry out the safe and controlled removal of an Alimak hoist system at the North Portal.

This lift formed a critical part of the project’s transition works, requiring precise execution within a live construction environment.

The task involved removing multiple Alimak components, including the mast sections and cart, while maintaining strict safety controls around personnel, surrounding structures, and ongoing site activities.

With limited space, controlled lift radius, and strict ground pressure requirements, this operation demanded detailed planning, engineered certainty, and disciplined site execution.

Challenges:

Working Within a Live, Constrained Site

The North Portal environment presented tight access, restricted slewing space, and the need to maintain exclusion zones around active work fronts.

Every movement had to be controlled to prevent encroachment into adjacent work areas.

Solution:

• A detailed lift study was developed to define crane positioning, lift radius, and slewing paths.
• Strict barricading and exclusion zones were implemented to control access throughout crane setup and lifting operations.
• Dedicated spotters and clear communication protocols ensured the lift was executed without interference to surrounding works.

Managing Multiple Loads with Different Characteristics

The removal involved lifting Alimak mast sections and the Alimak cart, each with different weights, centres of gravity, and rigging requirements.

Solution:

• Engineered rigging configurations were developed for each component, including multi-leg chain arrangements and controlled lift points.
• Loads were lifted well within chart capacity, maintaining conservative utilisation levels to ensure maximum control and safety.
• Trial positioning and controlled take-up of slack allowed the rigging to be checked and adjusted before each lift commenced.

Ground Conditions and Outrigger Reactions

Operating on prepared surfaces required careful consideration of ground bearing pressures and outrigger reactions to avoid overstressing the supporting ground.

Solution:

• Outrigger deployment and load spreading were planned in accordance with ground pressure calculations.
• Bog mats were used to distribute loads evenly and protect the ground surface.
• Crane configuration was selected to maintain stable operations throughout all lift stages.