Commentary on Sections Part 1 – Works Section 4 – Permitted deviation within limits
26.Section 4 allows for a degree of flexibility within the defined limits. It permits movement or variance from the precise lines and sections shown on the Parliamentary plans and sections. In the Act this is described as “deviation”.
27.The Parliamentary plans show the centre lines of the works and also show limits of deviation around those centre lines. Section 2 specifically states that the authorised works are situated within the limits of deviation. The Act will not accordingly permit the construction of those works outside these lateral limits.
28.The Parliamentary sections show the vertical dimensions and situation of the proposed works. The Act authorises the works in accordance with those dimensions and levels, subject to the flexibility permitted by section 4.
29.Section 4 provides that every work as constructed or maintained may deviate laterally within the limits of deviation, and vertically by up to 3 metres upwards and to any extent downwards. This reflects the outline nature of the authorisation being given by the Act. The works are not being authorised in the fine detail which will be formulated at a later stage when the railway is finally designed. The permission to deviate therefore allows for the normal design process.
30.The ability to deviate vertically to any extent downwards that may be necessary or expedient enables the authorised undertaker to construct the works at whatever depth is needed to achieve stability. It also allows for e.g. the undertaking of ground stabilisation works in the event of mine workings or other geological conditions.