| Pedestrian zones with no routine vehicle access | A 15 | 15 kN | Footpaths, pedestrian plazas, landscaped areas, and bicycle paths where vehicles are excluded | Lightweight solid or recessed cover; slip-resistant surface; locking device where unauthorized access is a concern | Use a clear opening suited to maintenance equipment. For surface drainage, provide a separate gully or a ventilated/grated design where permitted by the drainage plan. | Ductile iron or other approved structural material with a corrosion-resistant coating; polymer or composite options may be suitable where permitted by local standards | Confirm that bollards, barriers, or traffic controls prevent accidental vehicle loading. Check trip hazards, cover stability, and accessibility requirements. |
| Footways and residential driveways with occasional light vehicles | B 125 | 125 kN | Footways, pedestrian areas, residential parking, and private driveways subject to occasional car traffic | Hinged or captive cover with a stable seating frame; anti-slip pattern; locking or tamper-resistant hardware for public locations | Use a sealed cover where the chamber must resist surface-water entry. Use drainage slots only when the chamber and surrounding soil can safely receive the water. | Ductile iron or reinforced composite construction; select a coating appropriate for moisture, de-icing salts, and soil exposure | Check wheel-path exposure, frame support, bedding, and the finished level. Avoid placing a B 125 cover where delivery or emergency vehicles may routinely pass. |
| Kerbside areas and parking lanes with slow-moving vehicles | C 250 | 250 kN | Kerbside channels, road margins, parking areas, and hard shoulders outside the main wheel track | Recessed or solid cover with a robust frame; anti-rocking seating; lockable design where covers are exposed to theft or vandalism | For drainage inlets, use a hydraulically sized grate or combination cover. Keep grate openings aligned with the flow path and avoid openings that can trap bicycle wheels. | Ductile iron is commonly selected for impact and fatigue resistance; use a suitable coating or corrosion allowance in aggressive environments | Verify that the installation remains outside normal wheel paths. Coordinate the frame with kerb geometry, paving levels, and road-resurfacing thickness. |
| Urban roads and streets carrying regular passenger vehicles | D 400 | 400 kN | Carriageways, traffic lanes, hard shoulders, and areas accessible to normal road traffic | Heavy-duty hinged or captive cover; anti-rocking seating; secure locking system; non-slip surface; controlled opening angle for safer maintenance | Use a solid sealed cover for access chambers unless drainage is required. For drainage points, size the inlet using rainfall intensity, catchment area, slope, and allowable surface ponding. | Ductile iron or an engineered equivalent complying with the specified local standard; protect against road salt, hydrocarbons, and cyclic wetting | Check the complete assembly, not only the lid: frame stiffness, bedding, concrete surround, load transfer, level tolerance, and resistance to dynamic traffic impact. |
| Industrial yards with frequent heavy trucks and forklifts | E 600 | 600 kN | Industrial areas, ports, freight yards, loading zones, and sites exposed to concentrated wheel loads | Heavy-duty captive cover with reinforced frame; anti-slip finish; positive locking; lifting points designed for the cover mass and maintenance procedure | Use sealed covers where spills or contaminated runoff could enter the chamber. If drainage is required, provide a load-rated grate and a controlled oil or sediment management system. | High-strength ductile iron or another specifically engineered load-rated material; specify coating and chemical resistance for the site environment | Assess axle loads, wheel loads, turning forces, braking forces, forklift traffic, and the possibility of impact from trailers or container-handling equipment. |
| Airside or exceptionally heavy-duty transport areas | F 900 | 900 kN | Aircraft movement areas and other locations subject to exceptionally high wheel loads, only where required by the project design | Specially engineered, captive, anti-rocking assembly with secure locking and a surface compatible with aircraft or heavy-vehicle operations | Coordinate the cover with airfield drainage calculations, rapid runoff requirements, debris control, and restrictions on loose or projecting components. | Engineered ductile iron or approved equivalent designed for the specified loading, fatigue, corrosion, and maintenance conditions | Obtain project-specific structural calculations and approval. Confirm compatibility with pavement design, aircraft loads, inspection rules, and emergency access requirements. |
| Flood-prone sites, high groundwater, or areas with surcharge risk | Use the traffic class required by the location, commonly D 400 or higher | Based on the selected EN 124 load class | Low-lying roads, coastal areas, floodplains, groundwater-sensitive chambers, and combined sewer locations | Sealed or gasketed cover with secure locking; anti-float features where buoyancy could lift the cover; robust frame anchorage | Check external hydrostatic pressure, surcharge, inflow, outflow, and possible reverse flow. A sealed cover may reduce inflow but does not replace a properly designed flood-control system. | Corrosion-resistant ductile iron or engineered material; specify elastomeric seals compatible with hydrocarbons, wastewater, temperature, and cleaning chemicals | Confirm chamber buoyancy, frame anchorage, gasket compression, venting requirements, and safe pressure equalization before opening. |
| Coastal, de-icing-salt, wastewater, or chemically aggressive environments | Use the traffic class required by the location; environmental exposure does not reduce the structural class | Based on the selected EN 124 load class | Coastal roads, winter-service routes, wastewater plants, treatment facilities, and industrial process areas | Sealed, lockable, anti-rocking cover with replaceable gasket where repeated maintenance is expected; avoid details that trap standing water | Separate hydraulic design from corrosion selection. Consider chloride exposure, hydrogen sulfide, acidic wastewater, abrasive solids, and cleaning chemicals. | Specify coating system, corrosion allowance, stainless or protected hardware, and gasket compatibility according to the exposure assessment | Review coating thickness, coating repair procedures, galvanic compatibility, drainage of the frame pocket, and expected inspection intervals. |
