This D400 square‑frame manhole cover is BS EN 124:2015 Class D400 certified (400 kN load), featuring a hinged ductile‑iron cover and frame with an automatic slam‑lock system that secures the cover upon closure and a 90° safety block to prevent accidental dropping during maintenance. The square‑to‑round frame accommodates a clear opening of Ø 600 mm within an 850 × 850 mm footprint and a 100 mm frame depth, ensuring a flush, non‑rock installation in trafficked areas such as highways, car parks, and pedestrian zones. Manufactured from EN GJS‑400‑15 spheroidal graphite cast iron with an anti‑slip tread and continuous EPDM gasket, it delivers decades of low‑maintenance reliability and enhanced safety.

Overview

The D400 class manhole cover and frame are tested to BS EN 124:2015 Group 4 standards, sustaining wheel loads up to 400 kN (40 tonnes) for carriageways and heavy‑traffic environments. Its square “square‑to‑round” frame design (850 × 850 mm outer dimensions) disperses loads evenly into the substrate, minimizing point stresses and preventing rocking in use. The Ø 600 mm clear opening provides ample access for inspection and servicing, while the 100 mm deep drop‑in frame self‑aligns flush into a prepared recess for rapid, accurate installation.

Key Features

• BS EN 124:2015 Class D400 Certification: Verified to withstand 400 kN static and dynamic wheel loads per Group 4 requirements.

• Square‑to‑Round Frame: 850 × 850 mm square frame encases a Ø 600 mm circular opening, combining compatibility with standard tooling and efficient load distribution.

• Hinged Cover with Slam‑Lock: Self‑engaging slam‑lock mechanism automatically secures the cover when closed, streamlining operations and eliminating unsecured covers.

• 90° Safety Block: Integrated latch holds the cover open at 90°, preventing accidental closure and enhancing operator safety during maintenance.

• High‑Strength Ductile Iron: EN GJS‑400‑15 spheroidal graphite cast iron offers superior tensile strength and impact resistance for heavy‑duty applications.

• Anti‑Slip Tread Pattern: Raised chequered surface exceeds PSRV 70 standards, maintaining traction under wet or oily conditions.

• Continuous EPDM Gasket: Neoprene or EPDM seal minimizes noise, odours, and water ingress, ensuring environmental protection.

• Optional Security Bolting: Cam or keyed locks available to deter theft and unauthorized access, complementing the slam‑lock system.

Technical Specifications

Benefits for End Users

The robust ductile‑iron construction and anti‑rock frame design ensure over 30 years of service life with minimal deformation or corrosion in harsh traffic environments. The slam‑lock mechanism and safety block reduce maintenance risks and liability by preventing unexpected cover movement, while optional bolting deters theft and vandalism. The anti‑slip pattern and gasket seal maintain safety and environmental hygiene, making it ideal for urban and highway installations.

Installation & Maintenance

Simply drop the square frame into a compacted bedding layer, ensuring it sits flush. The slam‑lock engages automatically when the cover is closed, eliminating additional locking steps. Routine checks involve inspecting the hinge, lubricating the slam‑lock, and clearing debris from the tread and gasket, tasks that can be completed in minutes to minimize downtime.

Compliance & Quality Assurance

Manufactured in ISO 9001‑certified foundries and BSI Kitemark certified for BS EN 124 compliance. Third‑party testing covers load, slip, and fatigue performance, and the product carries full CE marking for use across Europe.