Colwall Green Railway Bridge

Questions and Answers

 

Q Is there is a significant difference between the planned layout and the actual layout of the existing safe route over the bridge?

A No, the alignment of the route was checked twice by an engineer from the design team. Since then the alignment has been inspected again and the position relative to the beams checked. On all occasions the route (including the barriers) has been found to be correctly aligned. The survey work was undertaken by two separate teams each adopting a different methodology for the survey in order to eliminate, as far as possible, the potential for systematic errors.

The original preliminary design has been adjusted and takes account of the actual size of the barriers. However the angles to the corners cannot be made less acute or the barriers moved apart because of the need to prevent additional loading of the weaker beams below the carriageway. The route alignment remains suitable for a 3.5 tonne van though the weight restriction is 3 tonnes.

Q All railway bridges are controlled by government legislation under The Railway Act and there are deposited plans for every bridge in the country which guarantee & protect the integrity of bridges’ load-bearing, carriage width & other factors as & when said bridges require repair or replacement as in Colwall. Please can you explain how the proposed plan for a one-lane bridge instead of the deposited plan for a two-lane bridge can possibly be reconciled with existing legislation? 

A In this instance the legislation and documents referred to give an overall width as not less than the adjoining highway (the current bridge and proposed bridge is approximately 30 foot). The load carrying capacity is set by the Transport Act 1968 and associated legislation.  The division between carriageway for motor vehicles and pedestrians is entirely in the remit of the Highway Authority.

Put simply Network Rail are complying with their obligations for providing a route over the railway and the council is exercising its right to determine the width of the highway.

Q Please give us the reasons why the present scheme for the new bridge is being proposed. Why is it deemed sensible to have a single lane, the existing bridge has two, so why change it?

A For two way traffic the new bridge would need to be widened as the current width of the eastern footpath on the existing bridge is too narrow (for both safe and practical use) and does not comply with current standards. The council would not be fulfilling its legal duty of care if the footpath was not widened, particularly with the close proximity of two schools.

If we widen the bridge to take two way traffic with reasonable width footways  there is significantly more design work (for example the existing abutments supporting the bridge deck would need widening) plus there would be other preparatory work. It is understood that an early opening of the bridge is important to Colwall. To achieve this early opening there is a need to minimise design and construction processes.  It is the minimisation of design and construction processes to meet the primary needs of Colwall that dictates the single way traffic. 

Q Could there be two 1.5m wide footways and a 6.2m wide carriageway with guardrails to protect pedestrians all within the existing highway width?

A No, the guardrails need to be set back from the edge of the kerb by around half a metre. Therefore the footways would only be one metre wide if this approach was adopted.

Q If the bridge was widened would additional land be required?

A Yes if we widened the bridge we would need to gain access rights over land and this would probably require compulsory purchase order procedures. It is also expected that planning permission would be required. This work would significantly extend the time to complete the new bridge deck.

 

30th April 2008