Stainless Steel Cable Trays

From tunnels and skyscrapers to factories and homes, cable trays support and protect the cables that power modern life from damage, contamination, and disruption. Cable trays range from basic configurations to custom installations that stretch tens of thousands of meters, ensuring safe and reliable functionality. They come in a variety of designs, such as fully covered solid trays, ladder trays for heavy-duty installations, and open grid trays designed for increased airflow. While aluminum and galvanized steel are the most commonly used cable tray materials, there are applications where these materials are unable to cope and stainless steel excels.

Where is stainless steel cable tray critical?

Corrosive environments

Maintenance of offshore oil and gas platforms and offshore wind power generation platforms is challenging and costly. Cable trays secure and organize cable routing in tight spaces, preventing the risk of loose cables, while operating reliably in adverse conditions such as high winds. They also reduce the need for maintenance in hard-to-reach areas. Molybdenum-containing stainless steels were chosen to meet these challenges because they offer excellent resistance to seawater and salt spray corrosion, reducing the need for frequent maintenance.

While coated carbon steel components are still commonly used on these platforms, molybdenum-containing stainless steels are preferred for superior durability and lower lifecycle costs in more corrosive environments. 316 stainless steel with 2% molybdenum is often used for the upper cable trays of offshore platforms. In a five-year exposure test in Brest, on the Atlantic coast of France, 316 stainless steel outperformed economical duplex stainless steels with lower molybdenum content. 2205 duplex stainless steel with 3% molybdenum showed even better performance, which was also confirmed in a four-year seaside exposure test in Dubai. Only 2507 super duplex stainless steel with 3.5% molybdenum remained completely rust-free at all times, demonstrating its unparalleled corrosion resistance.

High temperature environments

High temperature environments, such as those near boilers, furnaces or heat exchangers, require materials that remain stable and resist aging. Stainless steel performs well in such environments, especially grades containing molybdenum, making it the most durable cable tray material for applications with high heat loads.

Although all materials lose strength at high temperatures, stainless steel retains its strength even in the event of a fire. At 400°C, stainless steel is still stronger than mild steel at room temperature, and 316 stainless steel outperforms 304 stainless steel, which does not contain molybdenum, at higher temperatures. These properties make stainless steel essential in high temperature and fire-prone environments where safety and durability are critical.

Hygienic applications

Stainless steel is essential in the food and beverage industry because its smooth, non-porous surface inhibits bacterial growth and ensures that it can be thoroughly cleaned. It is durable and easy to disinfect, making it ideal for applications with strict hygiene requirements. 304 stainless steel is widely used, while 316 stainless steel is more suitable for corrosive environments such as the production of ketchup, soy sauce or pickled products. Components such as salts and acids from the production process can become airborne and deposit on cable trays, increasing the risk of corrosion.

Cable trays in these environments are also often exposed to corrosive cleaning agents (flushing or spraying). Cleaning agents often contain chlorides or acids, which can attack less resistant materials. As global hygiene standards increase, stainless steel cable trays are becoming increasingly indispensable in applications such as food production and pharmaceutical and healthcare facilities that require high sterility.

The open wire mesh cable trays in breweries allow for air circulation, reducing the opportunity for bacterial growth.

Powering the world's most challenging rail tunnels

Tunnels for car and train traffic are another important application area for molybdenum-containing stainless steel cable trays, which can reduce the risks of moisture, fire and limited maintenance in these hard-to-reach places. Tunnels are often high enough for corrosion to become a serious problem. For example, humidity levels in Switzerland's Mont Blanc Tunnel range from 40% to 95%, far above the critical value at which most salts in the environment begin to corrode. Despite the high humidity levels, tunnels present a significant fire risk due to the presence of flammable materials, confined spaces and poor ventilation. Although fires are rare, they can be devastating: a fire in the Mont Blanc Tunnel in 1999 killed 29 people and cost €450 million to repair.

The fire resistance of 316 stainless steel is well documented, reducing the risk of falling debris and structural collapse in the event of a fire. It was for this reason that 316 stainless steel cable ducts and handrail support components were installed along the emergency evacuation route of the Gotthard Base Tunnel in Switzerland, the world's longest and deepest railway tunnel. In 2016, more than 8,000 meters of cable ducts and 60,000 support components were installed. Tunnels are difficult to maintain, especially in remote mountainous areas or areas with high traffic volume. Closing a tunnel for maintenance disrupts normal operations, which highlights the importance of durable and low-maintenance materials such as stainless steel.

Stainless steel cable channels in the Gotthard Base Tunnel carry wiring and support composite emergency handrails

316 stainless steel cable trays will also be used in one of the world’s most challenging tunnel projects: the Udhampur-Srinagar-Baramulla Railway Link (USBRL) in the Indian Himalayas. The railway includes more than 100 kilometers of tunnels, connecting Jammu and Kashmir, opening a passage through rugged, mountainous and sparsely populated areas. Not only is maintenance work extremely difficult, but there is also a serious risk of corrosion caused by humidity and industrial exhaust gases. Based on the advantages of stainless steel's good corrosion resistance, long service life and low maintenance requirements, approximately 6,000 tons of cold-rolled 316 stainless steel cable tray with a thickness of 2 mm and a 2B surface were used. It will become an integral part of India's longest traffic tunnel, which is due to open in 2025.

Newly installed 316 stainless steel cable tray in the USBRL railway tunnel

Stainless steel cable trays are indispensable in applications where reliability and durability are critical due to their excellent corrosion resistance, high temperature stability and hygienic properties. From tunnels and offshore platforms to pharmaceutical and sanitary facilities, stainless steel cable trays ensure safety and performance in demanding conditions where failure is not an option. (KW)