Decision details

Elevated Harrow Road Bridge – Replacement of Cathodic Protection

Decision Maker: Cabinet Member for Environment and City Management

Decision status: Recommendations Approved

Is Key decision?: Yes

Is subject to call in?: Yes


A Cathodic Protection system protects a structural asset from corrosion. The Cathodic Protection system on the Elevated Harrow Road Bridge is life expired and needs replacing



That the Cabinet Member for Environment & City Management approved the detailed proposals to replace the Cathodic Protection on the Elevated Harrow Road Bridge at an estimated gross cost of £2,400,000.


Reasons for Decision

The Elevated Harrow Road Bridge underwent major repairs in 2002/03 because the steel reinforcement in the concrete beams and columns supporting the main bridge deck had corroded so severely that its capacity to carry modern highway loading was at risk. The A40 Westway above, which is supported by the EHR, was also placed at risk. Severe corrosion was noted in the structure in the late1990’s some 25 years after the bridge was opened. The 2002/03 scheme included the installation of the of the first Cathodic Protection system for the bridge.

Cathodic Protection is a controlled electrochemical process explained in more detail in Section 5 of this report. The Cathodic Protection is an essential protective measure for the bridge, the system installed in 2003 has now reached the end of its serviceable and needs replacing.

The existing system has been protecting the bridge for over 15 years, currently there is no evidence of significant corrosion in the bridge suggesting the Cathodic Protection has been fulfilling its function. An upgraded Cathodic Protection system should protect the bridge for another 15 to 20 years thus minimising the requirement of major repairs.


Publication date: 23/08/2018

Date of decision: 26/09/2018

Effective from: 04/10/2018