The main types of cable trays used in power, industrial and commercial projects are ladder, angular ladder, perforated and solid bottom. They differ in how the base under the cables is built: open rungs, rungs on steel angle runners, a slotted sheet or a closed sheet. That construction decides how much support, ventilation and protection the cables get.
In short: ladder trays carry heavy power cables over long spans. Angular ladder trays are a heavier ladder construction for harsh, heavy-duty routes. Perforated trays give mixed power, control and instrumentation cables continuous support with airflow. Solid bottom trays protect sensitive cables from dust and debris.
This guide explains each cable tray type and compares all four side by side. It also separates tray types from the materials, finishes and trade names that are often mistaken for them, then ends with a checklist for choosing the right type.
A cable tray is a rigid support system that carries insulated cables along a route: across ceilings, along walls, up vertical risers and through plant areas. It is the open, accessible part of a building’s cable management system, alongside enclosed options such as trunking, raceways and conduit. Cables are laid into a tray rather than pulled through it, so they can be added, inspected and replaced without dismantling the run.
The table summarises the four cable tray types. A detailed comparison follows the individual sections.
| Type | How it is built | Cable support | Best suited to |
|---|---|---|---|
| Ladder | Two side rails (runners) joined by rungs | At each rung | Heavy power cables, long spans, vertical risers |
| Angular ladder | Steel angle runners joined by flat-bar rungs | At each rung | Heavy-duty and harsh-environment routes |
| Perforated | Continuous sheet base punched with slots | Continuous | Mixed power, control and instrumentation cables |
| Solid bottom | Continuous sheet base with no openings | Continuous | Sensitive cables, dusty or debris-prone areas |
A ladder cable tray consists of two longitudinal side rails, called runners, joined by transverse rungs. Cables rest on the rungs, and the open space between rungs leaves the underside of every cable exposed to air.
How it works: the side rails carry the load between supports, so a ladder tray is the usual choice where supports are far apart and cables are large and heavy. Cables can be tied to the rungs and brought out between any two of them.
Best for: large power cables and main feeders, power plants and substations, outdoor pipe racks and vertical risers, where weight, span and heat are the main concerns.
Ladder trays are built in two ways. In a welded rung ladder, the rungs are welded to the side collar of the runners to form one rigid unit. In a bolt-fitted rung ladder, the rungs are bolted in place, so they can be fitted or adjusted at site. Aparna Rollform manufactures both, with rungs spaced 250–300 mm apart.
An angular ladder cable tray is a heavier form of ladder tray. Its runners are mild steel angle sections, and its rungs are steel flats fixed between them. Aparna Rollform makes it from mild steel (IS 2062) in 3 mm and thicker sections.
How it works: the angle sections give the runners a stiff, robust profile, so the tray holds its shape on heavy-duty routes. Like any ladder, it leaves cables open to the air and accessible along the run.
Best for: power distribution, telecommunications and manufacturing installations in factories, power plants and commercial buildings. It also suits harsh conditions, such as oil and gas and marine settings, where cables face extreme temperatures, humidity and corrosive elements. Aparna Rollform supplies it hot-dip galvanised, powder coated or in red oxide paint.
A perforated cable tray has a continuous sheet-steel base punched with rows of slots, with side flanges formed from the same sheet. It is also called a ventilated or slotted cable tray. Aparna Rollform’s perforated trays use a 20 × 10 mm slot pattern.
How it works: the base supports the cables along their whole length, while the slots let heat and water escape and give convenient tie-down points.
Best for: general-purpose routes in commercial buildings and industrial plants: control, instrumentation, lighting and small-to-medium power cables. It suits applications that need moderate ventilation and cable visibility, and routes where small and large cables share a tray.
A solid bottom cable tray has a continuous base with no openings. Indian suppliers often list it as a box type or closed type cable tray, especially when it is supplied with a cover.
How it works: the base and side walls support the cables fully and shield them from below. With a cable tray cover fitted, the run is enclosed on all sides.
Best for: sensitive signal, control and data cables; dusty or debris-prone areas such as cement and material-handling plants; exposed runs where cables need protection from knocks.
The biggest practical difference between the four types is how the cable is supported, because that drives heat, span and protection. The construction, material and finish rows reflect Aparna Rollform’s range.
| Factor | Ladder | Angular ladder | Perforated | Solid bottom |
|---|---|---|---|---|
| Construction | Runners with welded or bolt-fitted rungs at 250–300 mm | Mild steel angle runners with flat-bar rungs | Slotted sheet base with side flanges | Closed sheet base with side walls |
| How cables are supported | At each rung | At each rung | Continuously, on a slotted base | Continuously, on a closed base |
| Small or flexible cables | Can sag between rungs | Can sag between rungs | Fully supported | Fully supported |
| Ventilation and heat | Best | Best | Good | Poorest |
| Distance between supports | Usually chosen for longer spans | Heavy-duty routes | Usually shorter spans | Usually shorter spans |
| Protection from dust and falling objects | Low | Low | Moderate | High, especially with a cover |
| Water | Falls through | Falls through | Drains through the slots | Can collect unless drained |
| Cable exits | Between any two rungs | Between any two rungs | Through a fitting or a cut opening | Through a fitting or a cut opening |
| Material (Aparna Rollform) | Mild steel, stainless steel 304/316, aluminium | Mild steel (IS 2062) | Mild steel, stainless steel 304/316L, aluminium | GI sheet, aluminium |
| Finishes (Aparna Rollform) | Pre-galvanised, hot-dip galvanised, powder coated, painted | Hot-dip galvanised, powder coated, red oxide paint | Hot-dip galvanised, pre-galvanised, powder coated | Galvanised sheet, hot-dip galvanised, powder coated |
| Typical settings | Power plants, substations, risers, outdoor racks | Factories, power plants, oil and gas, marine | Commercial and industrial general use, instrumentation | Control rooms, dusty plants, sensitive circuits |
Many projects use several types: ladder or angular ladder on the main power routes, perforated for control and lighting, and solid bottom where cables need protection. For a detailed head-to-head of the two most compared types.
Search results and catalogues often list “GI”, “stainless steel”, “trunking” or “with cover” as types of cable trays. They are not. A type describes how the tray is built; material, finish, cover, fittings, supports and size are separate choices made after it. Mixing them up is how a specification ends up asking for a “GI type” tray without saying whether it should be ladder or perforated.
| What is being described | What it means | Examples | Decided by |
|---|---|---|---|
| Type | How the tray is built | Ladder, angular ladder, perforated, solid bottom | Cables, heat, span and protection needed |
| Material | What the tray is made of | Mild steel, stainless steel (304, 316, 316L), aluminium | Environment, weight, chemical exposure |
| Finish | How the steel is protected from corrosion | Pre-galvanised, hot-dip galvanised, powder coated, painted | Indoor or outdoor exposure, humidity, chemicals |
| Fitting | Pieces that change direction, level or width | Bends, tees, crosses, reducers | Route geometry |
| Cover | A lid over the tray | Flat, hut (peaked), U-type | Dust, falling objects, sunlight, access |
| Support | What holds the tray up | Wall brackets, cantilever arms, trapeze hangers | Building structure and support span |
| Size | The tray’s dimensions | Width, side height, sheet thickness, length | Number and size of cables |
A complete description combines them. For example: “perforated cable tray, mild steel, hot-dip galvanised, with hut-type cover”. That names the type, material, finish and cover, and leaves the size to the cable schedule.
Cable tray type names vary between markets and suppliers, so the same tray can appear under several labels. This table maps the common names to the construction they usually describe.
| Name you may see | Usually means | Check before ordering |
|---|---|---|
| Ventilated tray, slotted tray | Perforated tray | Slot pattern and sheet thickness |
| Ventilated trough (US usage) | Perforated tray | Imperial sizes; convert to metric |
| Trough, trough type | A tray with a continuous base and side walls; can be solid or perforated | Whether a solid or a perforated base is intended |
| Box type, closed type | Solid bottom tray, usually with a cover; sometimes enclosed trunking | Whether a cover is included, and how it is fixed |
| Cable ladder, ladder rack | Ladder tray | Welded or bolted rungs; rung spacing |
| Angle ladder | Angular ladder tray | Angle section and finish |
In tender documents, name the construction explicitly rather than relying on a trade name.
Trunking, ducts and raceways are enclosed systems: cables run inside a closed body with a cover. They are covered by a separate IEC standard series (IEC 61084, cable trunking and ducting systems), and IEC 61537 excludes them from its scope. Junction boxes are enclosures at branch points, while covers, fittings and supports are accessories. Catalogues often group them with cable trays because they are sold together, but in a specification they are separate items.
These are common patterns, not rules. The cable schedule, load and environment of each project decide the final choice.
| Setting | Common cable tray type | Why |
|---|---|---|
| Power plants, substations, main feeders | Ladder; angular ladder for heavy-duty routes | Heavy cables, long spans, heat dissipation |
| Oil and gas, marine and other harsh environments | Angular ladder, hot-dip galvanised | Robust construction; finish chosen for humidity and corrosion |
| Commercial buildings, offices, hospitals | Perforated | Mixed services that need continuous support and neat runs |
| Process plants: instrumentation and control | Perforated; solid bottom for sensitive signal cables | Small cables need continuous support |
| Cement, steel and material-handling plants | Solid bottom with a cover | Keeps dust and debris off the cables |
| Data centres and IT rooms | Perforated for data and control; ladder for power | Continuous support for small cables, airflow for power |
| Vertical risers in tall buildings | Ladder | Cables can be tied to rungs over the full height |
| Coastal, chemical or outdoor areas | Any type in a suitable material and finish | Corrosion is decided by material and finish, not type |
Whether you are comparing electrical cable tray types for a commercial building or an industrial plant, work through these six points in order. The first three decide the type; the last three refine it.
Tray width, side height and thickness come last, once the type is fixed and the cable quantity is known.
Aparna Rollform, the roll-forming division of Aparna Enterprises Limited, manufactures all four cable tray types at its plant in Patancheru, Telangana: perforated, ladder with welded or bolted rungs, angular ladder and solid bottom. The trays are made on high-speed cold roll-forming mills that punch, bend and cut in a single line.
Finishes include pre-galvanised, hot-dip galvanised, powder coated and painted, with stainless steel and aluminium versions for perforated and ladder trays. The cable trays comply with IEC 61537, and hot-dip galvanising follows IS 2629, IS 2633, IS 4759 and IS 6745 in a seven-tank process.
Matching flat, hut and U-type covers and a range of bends, tees, crosses and reducers complete each system. The division’s quality system is certified to ISO 9001:2015.
To discuss which cable tray type suits your project, contact the Aparna Rollform team or browse the full cable tray range.
Ladder, perforated, angular, and solid bottom. Ladder trays have rungs between two side rails and suit heavy power cables. Perforated trays have a slotted base that supports cables continuously with ventilation. Solid bottom trays have a closed base for the most protection. Angular ladder trays are a heavier ladder construction used on heavy-duty and harsh-environment routes.
In standards language, a cable ladder is built from rungs fixed between side members, while a cable tray has a base, which can be solid or perforated. IEC 61537 covers both under “cable tray systems and cable ladder systems”. In everyday Indian usage, “cable tray” is the umbrella term and the ladder is one type of it.
No. A tray cable, such as Type TC under the US National Electrical Code, is a cable construction rated for installation in cable trays. A cable tray is the support system the cables lie on. Searches for “types of tray cable” are about cable insulation and ratings, not tray construction.
The type does not decide corrosion resistance; the material and finish do. Any of the four types can be used outdoors if it is hot-dip galvanised, stainless steel or aluminium, with stainless steel grade 316/316L preferred for coastal or chemical exposure. For heavy-duty outdoor routes, Aparna Rollform supplies angular ladder trays hot-dip galvanised.
Yes, and most large projects do: ladder or angular ladder trays on main power routes and risers, perforated trays for control and lighting circuits, and solid bottom sections where cables need protection. Keep finishes consistent where trays meet, and maintain electrical continuity across joints if the tray forms part of the earthing and bonding arrangement.
Choosing a cable tray starts with the cables, their load and the installation environment. Ladder trays give an open construction for heavy power routes and long spans, and angular ladder trays add a more robust build for heavy-duty and harsh conditions. Perforated trays balance continuous support with ventilation, and solid bottom trays put protection first with a closed base.
Select the construction from the cable arrangement, loading, support spacing and protection required. Then confirm the material, finish, dimensions, fittings and accessories against the project specification.
Aparna Rollform is a cable tray manufacturer in India, producing perforated, ladder, solid-bottom and raceway cable trays in galvanised and powder-coated finishes. Explore the range or request a quote.
Aparna Rollform is a cable tray manufacturer in India, producing perforated, ladder, solid-bottom and raceway cable trays in galvanised and powder-coated finishes. Explore the range or request a quote.
Aparna Rollform is a cable tray manufacturer in India, producing perforated, ladder, solid-bottom and raceway cable trays in galvanised and powder-coated finishes. Explore the range or request a quote.
