Eleven road bridges in Caerphilly county are sub-standard


A review of spending on bridge maintenance has been called for by Colin Mann, the leader of the Plaid Cymru group leader on Caerphilly council.

He made the appeal after a Freedom of Information request revealed that 11 bridges in the county borough were classified as substandard. A list of those bridges has been provided (below).

Caerphilly council said that it would cost an estimated £10m to strengthen or replace defective bridges with 18 structures currently unable to carry 40 tonne vehicles. No money has been set aside in the present financial year specifically to carry out work on the substandard bridges.

Councillor Colin Mann said: “The bridge disaster in Italy and the collapse of a motorway overpass in India this month have put the issue of the safety of structures in the public spotlight.

“It is vital now that there is a review of spending on upgrading bridges so work can be carried out to ensure they meet the standards of the 21st century. The Sirhowy Bridge in Blackwood has been closed and out of action for months with  no indication of  when it might be brought back in use.

“While I accept that some of the sub-standard bridges are small, and may not be used by vast amounts of traffic, I do feel we need to look at this issue much more closely and in a timely fashion. A warning sign has been sounded and the council needs to act.

“The Freedom of Information request also revealed that while general inspections of structures take place every two years with principal inspections only happening every six years, which some people may find too long a gap.”


Thank you for your request for information received on 20th August 2018We have considered your request and enclose the following information:

 (1) How many bridges is the council responsible for maintaining?

 The Authority is responsible for maintaining / inspecting 591 bridges, which can be sub-divided as:

 471 bridges supporting Highway

120 footbridges

 (2) How often are checks made on the condition of bridges?

 Checks for the condition of bridges are undertaken in accordance with Design Manual for Roads and Bridges (DMRB) publication BD63/17 “Inspection of Highway Structures”.

 General Inspections are undertaken on each bridge once every two years.

Where appropriate and subject to funding available, Principal Inspections are undertaken once every six years.

If a structure has an aspect that has been deemed to be sub-standard for the 40 tonne Assessment Live Load, the structure is monitored in accordance with Design Manual for Roads and Bridges (DMRB) publication BD79/13 “The Management of Sub-standard Highway Structures”.  Inspections are then undertaken on a more frequent basis.

(3) How many bridges are classified as substandard and/or with restrictions on weight carried? Where are those bridges?

 11 of the structures are deemed to be substandard in accordance with Design Manual for Roads and Bridges (DMRB) publication BD79/13 “The Management of Sub-standard Highway Structures”.  3 of the 11 structures are maintained by Network Rail.  1 of the 11 structures is maintained by Highways England (Formerly British Rail Board Residuary Ltd).  The locations of these structures are as follows:

Caerphilly Station Road Bridge

Caerphilly Station Road, Caerphilly

Rock & Fountain Riverbridge

Bottom of Park Terrace, Blackwood

Tirphil Station Overbridge

Tirphil railway station

Llwyn Gwyn Culvert

West of Rudry

Lansbury Park Underbridge

Lansbury Park Estate , Caerphilly

Station Road Riverbridge

Station Road, Crumlin

Bedwlwyn Road Underbridge


Penallta Road Bridge

Penallta Road, Ystrad Mynach

Blackvein Riverbridge

Blackvein Road, Crosskeys

Felin Railway Overbridge

South of Pont-y-Felin Bridge, Abertridwr

Forge Riverbridge

Forge Road, Machen

4) What percentage is this of the total number of bridges?

1.9% of total number of bridges ((11 / 591)x100)

 (5) How many bridges are unable to carry lorries of up to 44 tonnes?

18 bridges are unable to carry 40 tonnes Assessment Live Load, albeit:

4 are in areas subject to environmental weight restrictions

2 are canal bridges in rural areas, which are too narrow to convey HGV vehicles and were probably never originally designed to accommodate such loads

5 are located in areas that have approaches that are not conducive to HGV passage   

 (6) How much finance would need to be spent to bring those bridges up to the required standard/clear the backlog and what is the budget for such work in 2018-19?

It is estimated that it would cost approximately £10 million pounds to strengthen or replace the structures to carry the 40 tonne Assessment Live Load albeit no definitive work has been done to date to substantiate this cost.  As stated above, these structures are monitored in accordance with Design Manual for Roads and Bridges (DMRB) publication BD79/13 “The Management of Sub-standard Highway Structures”.  The 2018/19 budget has an overall allowance of £444,000.00 for Bridge Strengthening but this budget is not specifically targeted to addressing the sub-standard structures.