The fourth bridge was built by Middlesex County Council in 1953 immediately alongside the Old Walton Bridge. It is a proprietary 'Callender Hamilton' bridge, intended to be put up quickly as a temporary measure.
Responsibility for the bridge passed to Surrey County Council following local government re-organisation in 1964.
It is believed that the parts for the construction of the Callender-Hamilton Bridge may have been taken from wartime stock that had been stored to replace a damaged bridge during the war, but which had never been used.
The 'Callender Hamilton' bridge can be seen on the right in the aerial photograph.
The bridge was not painted when it was erected, and due to modifications that were carried out at that time, it was not subsequently possible to paint some of the steel beams. Also, there was no waterproof layer between the road surface and the steel supporting plates. Joints in the road surface had also deteriorated resulting in leakage.
At the same as the demolition of the third bridge in 1985, the fourth bridge was given a thorough inspection and assessment which led to the first weight limit of 24.5 tonnes.
Maintenance work continued to keep the bridge safely in use until a permanent replacement could be constructed, but inspection and re-assessment in 1993 led to a reduction of the weight limit to 17 tonnes.
Following the annual assessment in 1996, the inspection interval was reduced to six monthly. The inspection in June 1998 showed the need for further strengthening works, but it was still necessary to reduce the weight limit to 7.5 tonnes. This weight limit stayed in place until December 1999, when the fifth bridge was opened to traffic.
This photograph shows the extent of corrosion of the supporting columns that was uncovered during the 1998 inspection.