Drainage grates to state road-authority drawings

What it is

Australian state road authorities publish standard drawings for the drainage grates and frames used on their networks and on many council and developer roads that follow them. Examples are the standard drawings of Transport for NSW, the Department of Transport and Planning in Victoria, the Department of Transport and Main Roads in Queensland and Main Roads Western Australia. A project specification will typically name the drawing number and revision for each pit type – kerb inlet, gully or field inlet – and leave the contractor to source a grate that matches.

World Steel fabricates these grates and frames as a build-to-print service: we take the drawing named in your specification, fabricate exactly to its dimensions, materials and coating requirements, and document what we did. This is the custom counterpart to our standard steel drainage grates and heavy-duty road grates.

World Steel is not prequalified or approved by any road authority, and fabricating to an authority drawing is not a claim of agency approval. Where the client or authority requires prequalified suppliers, type testing or product registration, confirm this before ordering.

Types and options

Grates are generally welded steel bar construction in a galvanised angle or flat bar frame. Hinged grates, locking bolts and anti-theft details are made only where the drawing or specification shows them.

Design and compliance

Because the design belongs to the road authority, World Steel does not redesign the grate: the drawing fixes the bar size, pitch, frame section and seating. We check that the drawing revision is current at the time of order, raise any dimensional ambiguity before cutting, and record the revision on every inspection document. Load performance is defined by the drawing and by AS 3996-2019 – usually class C or D for trafficked locations – and any type-test requirement is the client's to confirm.

Bicycle-safe grates follow the bar orientation and slot limits shown by the authority. For projects outside Australia, the same build-to-print service applies to EN 124 or AASHTO-based drawings. See the pit cover page for covers designed by World Steel rather than to an authority drawing.

Fabrication and finishing at World Steel

Bars and frame members are cut on saws and CNC plasma, assembled in jigs made for each drawing so that every grate is interchangeable in its frame, and welded to qualified procedures under ISO 3834-2 and AS/NZS 5131. First-article inspection checks every dimension on the drawing before the batch proceeds; batches are then sampled for dimensions, weld size and flatness, and grates are trial-fitted in frames.

All items are hot-dip galvanised by qualified galvanisers to AS/NZS 4680 (or the coating named on the drawing). Grates are banded on pallets with their frames and shipped in containers with the rest of the export package.

Installation and specifying

• Set frames to the pavement or kerb level shown on the drawing and bed them fully before placing the grates.
• Check that bicycle-safe grates are orientated as drawn – bars across the direction of travel.
• Fit locking bolts where required and touch up any coating damage with zinc-rich paint.
• When ordering, name the authority, drawing number and revision for each pit type, and the quantity per type.