Calculating load capacity ensures steel shelving and longspan bays operate safely without collapse risks or inefficiencies. Understanding UDL, beam capacities, and safety factors helps you select the right system for your needs, using real figures from systems like Widespan.
What is UDL in Steel Shelving?
Uniformly Distributed Load (UDL) measures the maximum weight spread evenly across an entire shelf, preventing sagging or failure from point loads. For standard steel shelving, UDL typically ranges from 150-500kg per level on light-duty bays, rising to 750kg+ on heavy industrial models. Always check manufacturer specs, uneven loading halves effective capacity, stressing uprights and beams.Beam Capacities for Longspan Shelving
Beams in longspan shelving like Widespan support wider spans (up to 2.7m) with UDLs of 500-1000kg per level, depending on beam length and steel gauge. Shorter beams (e.g., 1.8m) handle higher loads like 850kg UDL, while longer ones drop to 450kg to account for deflection. Multiply beam UDL by bay levels for total upright capacity, never exceeding frame limits.Applying Safety Factors Correctly
Designs incorporate a 1.3-2.0 safety factor, meaning tested UDL already builds in overload protection—don’t add extra. For a Widespan bay with 5 levels at 600kg UDL per beam, total capacity hits 3000kg, but derate 20% for dynamic use like forklifts nearby. Industrial shelving uprights often cap at 10,000-15,000kg overall.Quick Calculation Steps
- Weigh heaviest average load per shelf, add 10-20% buffer.
- Confirm UDL matches shelf width/depth from spec sheet.
- Sum levels × beam UDL ≤ upright rating.
- Example: Widespan longspan shelving, 2m beam at 700kg UDL × 4 levels = 2800kg bay total (safety-checked).