The Suburban Rail Loop is a major infrastructure project in Melbourne, Victoria, Australia, designed to transform the city’s public transport network by delivering a 26-kilometre orbital rail corridor connecting key suburban areas from Cheltenham to Box Hill. This underground rail line will provide high-capacity transport that bypasses the central business district, improving connectivity and reducing congestion across Melbourne’s growing suburbs. The project involves extensive tunnelling works, with Tunnel Boring Machines (TBMs) playing a critical role in excavating the twin tunnels that will accommodate the rail system. These TBMs are specifically designed to operate in a range of ground conditions, including soft soils and groundwater-affected strata, while minimising surface disruption.
A critical component of the TBM launch is the Eye Seal System, which includes the Eye Seal Ring, Eye Seal System Bracing, and Eye Seal Support Leg. The Eye Seal Ring provides a watertight and ground-tight interface between the TBM shield and the launch shaft, preventing groundwater ingress and soil migration during TBM breakout and initial advance. The Eye Seal Bracing supports and stabilises the seal ring under the significant thrust forces and external pressures generated during launch, while the Eye Seal Support Leg provides additional vertical and lateral structural support, ensuring alignment and stability of the entire assembly. Together, these elements are essential for a safe, controlled, and stable TBM launch, supporting uninterrupted tunnelling operations.
The Project was awarded to Revision Zero on May 2025 to deliver 3D modelling services and the preparation of structural steel drawings, specifically for the TBM launch eye seal system. The scope included the detailed steel design for the Eye Seal Ring, Eye Seal Bracing, and Eye Seal Support Leg, covering approximately 101.67 tonnes of structural steel. These works ensure that the eye seal assembly is accurately detailed, structurally sound, and constructible, forming a fundamental part of the TBM launch preparation in the SRL project.
