My Wrekin

Compliant and trusted

TriStar D400 Manhole covers

Tristar D400 ductile iron access covers fully comply with BS EN 124:2015 and carry the BSI Kitemark. Tristar contains innovative design features that mark it out from the competition.

TriStar manhole cover D400 render
Tristar enlarged frame corners
Enlarged frame corners

Spread the load

Traffic sends vibrations through every installation, this vibration will transfer to the foundations, potentially eroding them.

Enlarged frame corners help to disperse the energy and minimise damage. They provide a larger surface area for the energy to transfer through. This helps provide your installation with the longest life possible.

We designed our Tristar D400 manhole covers to last. All rectangular covers in the range have enlarged frame corners.

Other features

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

    PSRV tested
  • Indexed corners ensure correct orientation first time, every time.

    Indexed corners
  • Safety keyway prevents accidental disengagement of the lifting key during the handling process.

    Safety keyway
  • 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

Square or rectangular manhole covers

Stock code Range Clear opening
Overall frame
Frame depth
Options My Wrekin
DMT0D4/6045/KT Tristar 600 x 450 750 x 600 100
DMT0D4/6060/KT Tristar 600 x 600 760 x 760 100
DMT0D4/6767/KT Tristar 675 x 675 830 x 830 100
DMT0D6/6060/KT Tristar 600 x 600 760 x 760 150
DMT0D6/6767/KT Tristar 675 x 675 830 x 830 150

Square to round manhole covers

Stock code Range Clear opening
Overall frame
Frame depth
Options My Wrekin
DMS1D4/60D/KTSF Tristar Ø 600 780 x 780 100

Circular manhole covers

Stock code Range Overall frame
Clear opening
Frame depth
Options My Wrekin
DMS1D4/45D/KT Tristar Ø 620 Ø 450 100
DMS1D4/60D/KT Tristar Ø 770 Ø 600 100
heavy traffic moving at speed on UK motorway in England at sunset

Do you need to upgrade to a CD 534 v0.1.0 compliant access cover?

National Highways CD 534 specification has been updated v0.1.0 and comes with new requirements.

Over 1,500 Annual Average Daily Traffic

E600 manhole covers are to be installed in place of D400 covers where the Annual Average Daily Traffic (AADT) of light goods vehicles travelled on a road is greater than 1,500 in each direction. Check your road traffic stats

600x600mm & 675x675mm covers

Following the regulation changes, a lower limit of frame mass has been specified to ensure frames are stiff enough to resist the loads on National Highways managed roads.

Alongside this, a frame depth of 150mm is now required on all installations on motorways, and all-purpose trunk roads.

ClickLift being installed
Rapid frame raising system


ClickLift eliminates the time and resources required to dig out and reinstall frames to suit the final adoptable surface. This eliminates the potential damage to manhole covers during construction and removes the potential for residents' claims for damage to their vehicles and massively reduces disruption. ClickLift provides housing developers with huge savings in terms of time, money and hassle. Allowing whole estates to have their covers raised to the final surfacing level, in as little as a few hours.

Armadillo manhole cover protector shell installed
The hard hat for your ironwork


Armadillo is a complete range of protector shells, designed to be placed over manhole covers and gully grates to provide enhanced protection during the construction phase.

Armadillo provides protection from construction site traffic, including tracked vehicles, and can be easily removed when the final surfacing is completed. This ensures manhole covers and gully grates can start their service life in ‘as new’ condition to optimise longevity.

Related case studies

Related case study

Scotland’s first ever ClickLift installations

Wrekin has successfully completed five ClickLift™ installations as part of trials for two separate housing developments in Scotland, marking the first time the product has been used outside England. ClickLift™ raises Wrekin Highway and TriStar frames to suit the final surface layer without the need for digging out and re-installing.

Campion Homes, Tough Construction, Dawn Homes
Campion Homes, Tough Construction, Dawn Homes
Read more