referred to in column (1) of the table below, where the extent of permitted downwards  deviation for each such part is set out in the corresponding entry in column (3) of that  table.  (10) In this article, references to—  (9) Without limitation on the scope of paragraphs (2) to (7) in constructing or maintaining the  authorised development the undertaker may—  unless the undertaker has demonstrated to the MMO and the MMO has agreed in writing that  dredging to a depth lower than those set out in sub-paragraphs (a) and (b) would not give rise to  any materially new or materially different environmental effects than those assessed in the  environmental statement.  (8) The undertaker must not undertake any capital dredge to a depth lower than—  (7) Paragraph (6)(b)—  (a) “linear works” are references to any works shown on the works plans by way of centre  lines; and  (b) deviate from the design of the new bridge or bridge structure shown on the engineering  section drawings and plans, provided that any such deviation is in accordance with the  final version of the design guidance manual approved under paragraph 3(2) of Schedule  2.  (a) deviate by up to 3 metres from the points of commencement and termination of any of the  linear works, except in the case of the coterminous point of termination and  commencement of Work Nos 1A and 1B, from which the undertaker may deviate by up  to 10 metres in a north-easterly direction following the centreline of Work No. 1A, and by  up to 3 metres in a south-westerly direction following the centreline of Work No. 1B; and  (b) 3m below chart datum in respect of Work No.7,  (a) 6.4m below chart datum in respect of works in Lake Lothing except Work No.7; and  (d) does not permit the undertaker in constructing the bridge deck comprising part of Work  No. 1B, to deviate downwards to a level which provides less than 4.9 metres headroom  above the running rail of the railway.  (c) does not prevent the undertaker, in constructing the lifting elements of the superstructure  of the new bridge, comprising part of Work No. 1D, from deviating by up to 2.5 metres  above the levels shown on the engineering section drawings and plans (mainline long  section sheet 2 of 2), and to any extent downwards as the undertaker considers to be  necessary or convenient; and  (b) does not permit the undertaker in constructing the bridge deck between piers within Lake  Lothing, comprising part of Work No. 1D, to deviate downwards to a level which is less  than 12 metres above Highest Astronomical Tide;  (a) does not prevent the undertaker, in constructing the piles comprising part of each of Work  Nos. 1B, 1C, 1D and 1E, from deviating to any extent downwards as the undertaker  considers to be necessary or convenient;  (1)  Numbered Work  (2)  Upwards vertical limit of  deviation  (3)  Downwards vertical limit of  deviation  Work No. 1A  1 metre  1.5 metres  Work No. 1B  1 metre  2.3 metres  Work No. 1C  1 metre  4 metres  Work No. 1D  1 metre  2.5 metres  Work No. 1E  1 metre  1.1 metres  Work No. 5  1.5 metres  -  Work No. 6  5 metres  2.5 metres  12