Home
My Wrekin

Are all D400 manhole covers appropriate for highway use?

CD 534 v0.1.0

National Highways has updated CD 534, a significant set of its requirements for manhole covers and gully grates installed on their road network. First released in February 2020 and updated to version 0.1.0 as of May 2022.

These updated requirements now state "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 road traffic statistics

Read further details on CD 534 v0.1.0

BS EN 124:2015

BS EN 124:2015 is the key standard for access covers and gully grates. It categorises the various places where they may be installed; from Group 1, the least demanding environment, through to Group 6, where the highest wheel loads are expected. The standard provides guidance on the minimum class to be used against each installation group.

It states that anywhere on a road is a ‘Group 4’ location; ‘carriageways of roads (including pedestrian streets), hard shoulders and parking areas, for all types of road vehicles’ and requires a minimum of D400 class products.

Some manufacturers of popular D400 products state on their websites and documents that their covers are ‘not suitable for carriageway use’ or are for installation only in ‘low-risk areas’. In doing so, this transfers undue responsibility onto installers to understand the complexity of the manufacturer’s product range and ensure safe products are selected.

Should a cover fail under the rigours of a busy carriageway or in an area with heavy traffic braking and accelerating, the cost of lane closures and rework can be significant.

It’s vital to remember manhole covers and gully grates are safety-critical products; using covers deemed not suitable for carriageway use could cost far more if damage or injuries are caused as a result of failure.

When selecting a BS EN 124:2015 conforming D400 cover and frame, every customer has the right to assume it is fit for carriageway use.

A Water Research Centre study

A study by the Water Research Centre (WRc) (CP373 Street Ironwork – Effective Management) concluded that structural bedding failure contributed to the failure of at least 30% of installed manhole cover and frame failures.

Products which fulfil the requirements of CD 534 v0.1.0, therefore, are required to exert less pressure on the bedding material and have features to keep the covers secure within the frame.

Read further details on CD 534 v0.1.0

Related products

Stock code Range Clear opening
(mm)
Overall frame
(mm)
Frame depth
(mm)
Options My Wrekin
DMH0D4/1361/K Vault 1,300 x 610 1,490 x 810 100
DMH0D4/1383/K Vault 1,300 x 850 1,490 x 1,050 100
DMH0D4/7567/K Vault 750 x 675 950 x 875 100
DMH0D4/9045/K Vault 900 x 450 1,090 x 650 100
DMH0D4/9060/K Vault 900 x 600 1,090 x 800 100
DMHT0D4/6045/KH Highway 600 x 450 810 x 660 100
DMHT0D4/6060/KH Highway 600 x 600 815 x 815 100
DMHT0D4/6767/KH Highway 675 x 675 890 x 890 100
DMHT0D4/7560/KH Highway 750 x 600 960 x 810 100
DMHT0D4/7575/KH Highway 750 x 750 960 x 960 100
DMHT0D4/9060/KH Highway 900 x 600 1,110 x 810 100
DMHT0D6/6060/KH Highway 600 x 600 815 x 815 150
DMHT0D6/6767/KH Highway 675 x 675 890 x 890 150
DMHT0D6/9060/KH Highway 900 x 600 1,110 x 810 150
DMT0D4/1267/KH Highway 1,220 x 675 1,460 x 895 100
DMT0D4/4545/KH Highway 450 x 450 665 x 665 100
DMT0D4/6045/KH Highway 600 x 450 815 x 665 100
DMT0D4/6045/KT Tristar 600 x 450 750 x 600 100
DMT0D4/6060/KH Highway 600 x 600 820 x 820 100
DMT0D4/6060/KT Tristar 600 x 600 760 x 760 100
DMT0D4/6060/KU Unite 600 x 600 810 x 810 110
DMT0D4/6767/KH Highway 675 x 675 885 x 885 100
DMT0D4/6767/KT Tristar 675 x 675 830 x 830 100
DMT0D4/6767/KU Unite 675 x 675 885 x 885 110
DMT0D4/7560/KH Highway 750 x 600 965 x 815 100
DMT0D4/7575/KH Highway 750 x 750 965 x 965 100
DMT0D4/9060/KH Highway 900 x 600 1,115 x 815 100
DMT0D4/9090/KH Highway 900 x 900 1,130 x 1,130 100
DMT0D6/1212/4 Hercules 1,200 x 1,200 1,385 x 1,385 150
DMT0D6/1267/KH Highway 1,220 x 675 1,460 x 895 150
DMT0D6/1267/KU Unite 1,220 x 675 1,465 x 920 150
DMT0D6/1867/KU Unite 1,830 x 675 2,075 x 920 150
DMT0D6/4545/KH Highway 450 x 450 665 x 665 150
DMT0D6/6045/KH Highway 600 x 450 815 x 665 150
DMT0D6/6060/KH Highway 600 x 600 810 x 810 150
DMT0D6/6060/KT Tristar 600 x 600 760 x 760 150
DMT0D6/6060/KUE Unite 600 x 600 820 x 820 150
DMT0D6/6767/KH Highway 675 x 675 895 x 895 150
DMT0D6/6767/KT Tristar 675 x 675 830 x 830 150
DMT0D6/6767/KU Unite 675 x 675 885 x 885 150
DMT0D6/7560/KH Highway 750 x 600 965 x 815 150
DMT0D6/7575/KH Highway 750 x 750 965 x 965 150
DMT0D6/9060/KH Highway 900 x 600 1,115 x 815 150
DMT0D6/9090/KH Highway 900 x 900 1,130 x 1,130 150

Stock code Range Clear opening
(mm)
Overall frame
(mm)
Frame depth
(mm)
Options My Wrekin
DMS1D4/60D/KTSF Tristar Ø 600 780 x 780 100
DMS1D4/60D/KUSF Force Ø 610 850 x 850 100
DMT0D4/4545/KHSQR Highway Ø 450 660 x 660 100

Stock code Range Overall frame
(mm)
Clear opening
(mm)
Frame depth
(mm)
Options My Wrekin
DMS1D4/45D/KT Tristar Ø 620 Ø 450 100
DMS1D4/60D/KT Tristar Ø 770 Ø 600 100
DMS1D4/60D/KU Force Ø 850 Ø 610 100