My Wrekin

Legendary size

Hercules™ D400 manhole covers

Our Hercules range has been designed as the ideal solution when a very large manhole cover is required for a D400 Group 4 environment.

The products have been designed and manufactured to meet the requirements of BS EN 124:2015. Additionally, the covers include features designed to provide both greater operator safety and operational longevity.

Hercules manhole cover render

Large chambers are commonly covered with steel access covers. But when the chamber is located in a Group 4 trafficked environment, steel rarely provides the solution. That’s where Hercules comes in, providing a durable, ductile iron solution to clear openings up to 1.2m x 1.2m.

Manufactured for highways ironwork projects in D400 Group 4 environments, it has been specially designed to meet rigorous specification standards. The range includes a number of features benefitting the contractor, including:

  • The double triangular covers are indexed to ensure correct orientation when fitting
  • The cover has a small and secure window, allowing for easy inspection, preventing the need to remove covers
  • A threaded lifting eye can be secured to allow for mechanical lifting - making it easier and safer to move and inspect
  • Anti-flex covers prevent seating wear, eliminating excessive noise and catastrophic failure
  • Enlarged frame corners help to dissipate load, minimising bearing pressures
  • Suits large chambers - up to 1.2m clear opening
  • UKAS-accredited third-party certification (70+PSVR tested)


  • 70+ PSRV tested at top surface of chequer by UKAS accredited 3rd party.

    PSRV tested
  • The covers feature a universal beam (also known as an I beam) providing significant improvements to rigidity, reducing seat wear for an enhanced service life.

    Universal beam icon
  • The high seating position ensures that forces are transmitted more directly downwards, meaning conversion of traffic loads into mortar-compatible compression forces.

    Cover support geometry
  • The enlarged frame corners help to dissipate loads onto the foundation, providing a longer service life and increased reliability.

    Enlarged frame corners
  • Indexed corners ensure correct orientation first time, every time.

    Indexed corners
  • Inspection window allows safe and easy view into chamber.

    Inspection window

Square or rectangular manhole covers

Stock code Range Clear opening
Overall frame
Frame depth
Options My Wrekin
DMT0D6/1212/4 Hercules 1,200 x 1,200 1,385 x 1,385 150

Available options and accessories


  • Ventilation holes
  • Alternative badging
  • Sealing plate
  • Safety grille
  • Locking
  • M16 x 50mm Lifting Eyebolts


Additional M16 lifting points are present on Hercules cover sizes exceeding 1200×1200 Clear Opening in lieu of BS7903 Lifting Keyways, for alternative methods of mechanical cover lift. The Hercules 1,200 x 1,200 mm cover is the only cover in the range to have keyholes for manual lifting.