Engineering Beyond the Standard: Redesigning an Inclined Shaft Trolley System at Snowy Hydro
- richard-norris0
- Jan 24
- 3 min read
In heavy industry and infrastructure, not every engineering problem fits neatly within a single Australian Standard. Some projects sit in the grey space between multiple codes, requiring application of engineering judgement, experience, and defensible design thinking over finding a fit-for-purpose out of the box solution that in many cases, doesn't exist.
A current project for Snowy Hydro is a strong example of this kind of work, and illustrates the type of engineering challenges Black Square Engineering specialises in solving.
The Project in Plain Terms
Snowy Hydro operates an underground shaft on a steep incline, containing large high-voltage power cables running beneath the floor. Historically, access along this incline was provided by a rail-mounted trolley system, winched by cable, which allowed personnel and equipment to move safely through the shaft.
As part of a major cable replacement program, Snowy Hydro required the trolley system to be fit for purpose, compliant with Australian Standards, and suitable for the new replacement methodology.
Black Square Engineering was engaged to assess the existing trolley and determine whether it could be retained or upgraded.
Our conclusion was clear: the existing trolley was unfit for continued service and uneconomical to retrofit. Following this assessment, we were engaged to undertake a full redesign of the trolley and rail system, tailored specifically to the site conditions and operational requirements.
Why This Was Not an “Out-of-the-Box” Job
From an engineering and compliance perspective, this system does not fall cleanly under any single Australian Standard.
It is a textbook example of non-standard plant certification: while the trolley is winched, it is not a crane. While it operates on an incline, it is not a conventional lift. While it carries people and equipment, it is not a standard workbox or monorail system.
Instead, it sits between—and draws from—multiple standards, including those relating to:
Cranes, hoists and winches
Inclined and industrial lift systems
Steel structures and mechanical equipment
Machinery safety and fall-arrest systems
Walkways, access platforms, and rail-based equipment
In practical terms, this required a principles-based approach to create a defensible engineering solution: identifying the intent, safety philosophy, and risk controls embedded across multiple standards, and applying them coherently to a system that does not formally “belong” to any one of them.
The Engineering Challenge
The complexity of the project extended beyond standards interpretation:
Steep underground environment, with confined access and significant electrical hazards
Aging infrastructure, introducing interface risks between new and legacy systems
Remote location, with limited communications and large logistical constraints
High consequence of failure, requiring conservative, well-documented design decisions
Every design choice had to balance safety, constructability, operational practicality, and long-term compliance—while remaining defensible to regulators and stakeholders.
Innovative Use of 3D Scanning
One of the key enablers for the redesign was detailed spatial data.
To support this, Black Square Engineering designed and fabricated a lightweight custom trolley specifically to carry a terrestrial laser scanner through the inclined shaft. This allowed us to complete high-resolution 3D scanning of the tunnel geometry, rail alignment, and surrounding infrastructure.
Both personnel and equipment were mobilised by air via Canberra, underscoring the logistical planning required for work at this site.
The resulting scan data has been central to developing a system design that fits the actual, as-built conditions underground—rather than relying on legacy drawings or assumptions.
Why This Type of Engineering Matters
Projects like this highlight a reality often overlooked outside the engineering profession: standards do not cover every scenario.
When there is no clear-cut standard to follow, or when multiple standards partially apply, the responsibility shifts squarely onto the engineer. This demands:
Deep familiarity with the standards landscape
Understanding of regulatory and legal expectations
Appreciation of client operations and constraints
Clear documentation of assumptions, risks, and decisions
Engineering advice in these contexts requires much more than a 'pure' technical solution - it carries physical, legal, environmental, manufacturing, and operational consequences for the client.
Our Niche: The Hard Jobs
Black Square Engineering specialises in projects where:
The application of standards is ambiguous or overlapping
No single “deemed-to-satisfy” pathway exists
The system is bespoke, legacy, or highly constrained
Clients need solutions that are practical, safe, and defensible
Whether it is underground infrastructure, specialised plant, or legacy systems that no longer align with modern codes, we work with clients to develop functional engineering solutions that stand up to scrutiny.
If your project feels like a square peg in the codes’ round holes, that is often where our work begins.