Covers for joint boxes and manholes were made in different materials.  The footway covers were generally made of concrete, with steel or cast iron reinforcing around the edges and the carriageway covers made of cast iron.  The covers fit in a frame and just lift off, as the weight keeps them in place.

Carriageway covers in the early days were a cast lattice with wooden blocks forced in the spaces.

Footway covers were fitted on Channels, Joint box whilst most covers for carriageways were fitted in a frame.

Covers, Joint Box were later renamed as Covers, Footway.

Covers, Driveway were introduced circa 1983.

Certain covers can be supplied with ventilators or locks fitted.

The type number, date and manufacturer can be identified as they covers will be marked.  Most footway covers are labelled by a plate embedded in the concrete face, whilst others are marked underneath, on the casting. Click here for more information.

All these covers are extremely heavy and after a period of time in situ they tend to jam in the frame due to grit or dirt ingress.  Special keys are provided and each cover has a correct way to remove it.  Due to back injuries sustained by staff working with these covers, the GPO spent a long time testing different mechanical lifting devices but most were not up to the job.

The measurements below are for the cover only and do not include the frame.

Click here for pictorial identification of covers

Click here for pictorial identification of non-GPO/PO/BT covers

List of Joint Boxes (as 1970) - A2G0101

Surface Joint Boxes - A2G0153

Joint Box No. 23 - A2G0161


  Type Length Breadth Date of information
Cover, Box Joint        
21 Concrete 1' 1.9" 0' 9.9" 1950
22 Concrete     1950
23 Grey Iron - FUW Box, Joint No. 23 478mm 238mm 1974
24 Grey Iron - FUW Box, Joint No. 24 378mm diameter   1974
25 Steel framed concrete - FUW Box, Joint No. 25 533mm 293mm 1974
Cover, Carriageway        
1 Triangular (used in pairs) - Silent Knight 846mm 367mm 1983
2 Triangular (used in pairs) - BS497 - Grade D 1030mm 686mm 1982
3 Triangular (used in pairs) - BS497 - Grade D 1830mm 686mm  
4 Steel framed concrete 1002mm 547mm 1968
Cover, Driveway        
2C Steel framed concrete 808mm 338mm 1982
4C Steel framed concrete 1000mm 530mm 1981
5C Steel framed concrete (Marked with T symbol) 695mm 695mm 1982
10C Steel framed concrete 824mm 800mm 1981
11C Steel framed concrete 795mm 595mm 1982
Cover, Joint box / Footway        
1 Distribution 1' 6.75" 1' 0.75" 1928
2 Cast Iron framed concrete 2' 8.75" 1' 2.25" 1928
2B Steel framed concrete (Marked with T symbol) 857mm 388mm 1987
2C Steel framed concrete 2' 7.75" 1' 1.25" 1969
3 Cast Iron framed concrete 3' 2.5" 1' 5.4" 1904
4 Cast Iron framed concrete 3' 3.5" 1' 8.75" 1928
4A Cast Iron framed concrete (Marked BT in 1982) 3' 3.5" 1' 8.75" 1970
4C Steel framed concrete 3' 3.5" 1' 8.75" 1969
5 Junction (cast iron) 2' 3.75" 2' 3.75" 1922
5A Cast Iron framed concrete 2' 3.75" 2' 3.75" 1983
5B Steel framed concrete (Marked with T symbol) 737mm 737mm 1987
5C Steel framed concrete 2' 3.75" 2' 3.75" 1969
10C Steel framed concrete - 6 key holes 2' 8.5" 2' 7.5" 1969
11C Steel framed concrete 2' 7.3" 1' 11.5" 1969
Cover, Jointing Pit        
2 Carriageway, Oval 3' 1.75" 2' 1.75" 1907
Cover, Manhole        
2 Roadway (cast iron) slated 2' 1.5" diameter   1933
3 Roadway (cast iron) slated 2' 2.5" diameter   1933
4 Roadway (cast iron) 2' 1.75" diameter   1928
5 Roadway (cast iron) 2' 6.25 diameter   1919
6 Footway (cast iron surround) 2'  6" 2'  6" 1928
7 Roadway (cast iron) 2' 8.75 diameter   1928
Cover, Unit Type (Light)        
Cover, Unit Type Fits Frames and Covers, Unit Type A, B and C 1'  11" 2'  8" 1956
Cover, Unit Type (Light) Fits Frames and Covers, Unit Type A, B and C 1'  11" 2'  8" 1956

Covers, Jointing Pit No.2, and Covers, Manhole No's 3, 4, 5 and 7 were fitted with wooden blocks.
Covers, Manhole No. 6 was fitted with 4 artificial stones.
Type C covers are for driveways.
Covers, Footway No. 5 can be of a ventilated type (grill in centre).
Covers, Manhole No's 4, 5, 6 & 7 can be of a ventilated type.

Cover, Unit Type and Cover, Unit Type (Light) are used on Frames & Covers, Unit Type and Frames & Covers, Unit Type (Light).  These frames are modular and supplied in three types: A, B and C.  The type A has a single cover, with two type B's being used to make a two cover installation and the type C being an intermediate frame that when used with  two type B frames producing a three cover installation. 
The Light variant is not as deep as the standard type and are only used grass verges, crossovers, lay-bys and service roads.  Originally called Frames and Covers, Unit Type 1, 2 3 and 4, they were renamed to Frames and Covers, Unit Type A, B and C.  Click here for more information

Covers, Manhole were superseded by Covers, Carriageway.

Some covers were also produced with locks and ventilation holes.



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Last revised: February 01, 2024