Vertical Shaft Cable Tray Fabrication

Vertical shafts for cable trays require careful planning, hoisting equipment, and proper cable support to safely install heavy or high-voltage cables.Shaft Design and PreparationVertical shafts must be designed to accommodate the weight and size of the cables, as well as the cable tray system. Materials for cable trays can include steel, aluminum, or stainless steel, chosen based on mechanical strength, corrosion resistance, and environmental conditions . The shaft should allow for rigid or flexible cable installation, with sufficient space for turning wheels, cleats, and traction equipment .Cable Laying MethodsFor large or heavy cables, such as 500kV XLPE or aluminum-sheathed cables, a hoisting-assisted method is recommended. This involves:Erecting a cable reel bracket and chain crane at the shaft opening.Connecting the cable end to a traction rope and a heavy hammer or weight.Lowering the cable gradually through the shaft using the chain crane, with the traction weight guiding the cable past turning wheels .Using upper end fixed wheels and turning wheels to prevent collisions and ensure smooth passage of the cable . This method reduces manual handling and prevents cable damage due to bending or excessive stress.Installation ConfigurationsRigid vertical installation: Cables are supported continuously along the shaft using cleats or brackets. This method is simpler and preferred for straight shafts with minimal bending .Flexible or snaked installation: Cables are allowed to form gentle curves or loops, which can reduce stress on the cable during thermal expansion or contraction. Spring-loaded cleats may be used to maintain position .Safety ConsiderationsVertical shaft installations are high-risk operations. Key safety measures include:Fail-safe mechanisms to prevent cable free-fall in case of rope or grip failure.Proper calculation of cable weight and tensile strength to avoid rupture.Avoiding closed loops of ferromagnetic steel when using metal supports to prevent electromagnetic interference .Professional supervision and adherence to safety protocols, especially for high-voltage or deep shafts .Cable Support and FixationOnce the cable is in place, it must be securely fixed to the shaft structure. This includes:Cleats or brackets spaced according to cable weight and shaft height.Snaking or looping to accommodate thermal expansion.Avoiding sharp bends to prevent insulation damage .SummaryConstructing a vertical shaft for cable trays involves careful shaft design, selection of appropriate cable tray materials, hoisting-assisted cable installation, and secure cable fixation. Both rigid and flexible installation methods are used depending on shaft geometry and cable type. Safety is paramount, requiring fail-safe mechanisms, professional handling, and proper support to prevent cable damage or accidents.