approaches to Lowestoft Harbour, including a requirement for the undertaker to carry out  protective works at its own expense; and  (3) The undertaker must carry out any specified work and any protective works required under  sub-paragraph (2)(b) in accordance with the plans approved under sub-paragraph (1) or settled  under article 62 (arbitration).  (4) If the harbour authority fails to express its refusal or approval of any plans or arrangements  within 30 days after they have been delivered to it under sub-paragraph (1) and the harbour  authority has not requested an extension of time to give its consent from the undertaker prior to the  expiration of the 30 days which the undertaker has granted, acting reasonably, it is deemed to have  refused them.  (5) If the harbour authority fails to express its approval of any plans or arrangements delivered  to it under sub-paragraph (1) at the expiration of the extension of time granted by the undertaker  under sub-paragraph (4), such a request is deemed to have been refused by the harbour authority.  57.  The undertaker must at all reasonable times during construction of a specified work allow  the harbour authority, its servants and agents, access to such work and all reasonable facilities for  inspection of any such work subject always to the reasonable stipulations of the undertaker  relating to delay to construction, health, safety, security and confidentiality.  58. —(1) After the purpose of any temporary works has been accomplished the undertaker must  with all reasonable dispatch, or after a reasonable period of notice in writing from the harbour  authority requiring the undertaker so to do, remove any such temporary works or any materials  relating to them which may have been placed on port land or below the level of high water within  Lowestoft Harbour or the approaches to Lowestoft Harbour by or on behalf of the undertaker, and  make good the land upon which the temporary works took place to the reasonable satisfaction of  the harbour authority.  (2) If the undertaker fails to do so within a reasonable period after receiving such notice, the  harbour authority may remove the same and may recover the reasonable costs of doing so from the  undertaker.  59. —(1) If during the construction of a tidal work or after the completion of that work and  wholly or partly in consequence of its construction there is caused or created an accumulation or  erosion the undertaker, if so requested by the harbour authority acting reasonably, must remedy  such accumulation or erosion to the extent attributable to such construction and, if it refuses or  fails to do so as soon as reasonably practicable, the harbour authority may itself cause the work to  be done and may recover the reasonable cost of doing so from the undertaker.  (2) For the purposes of sub-paragraph (1)—  (3) In the event that surveys, inspection, tests and sampling carried out pursuant to paragraph  64(1)(b) establish that such accumulation or erosion would have been caused in any event by  factors other than construction of a tidal work, the undertaker is liable to remedy such  accumulation or erosion only to the extent that the same is attributable to such construction.  60.  The undertaker must pay to the harbour authority the reasonable costs of—  as may be necessary in consequence of the construction of a tidal work.  142 (c) carrying out any dredging operations in relation to sub-paragraphs (a) and (b),  (b) laying down moorings or buoys; or  (a) alterations to aids to navigation (including navigation marks or lights) owned by the  harbour authority;  (b) in the case of erosion, the remedy must be the carrying out of such reconstruction works  and other protective works or measures as the harbour authority reasonably requires.  (a) in the case of an accumulation, the remedy must be its removal; and  (c) must not restrict the powers granted to the undertaker under this Order where such  powers do not affect the harbour authority’s undertaking. 