(4) When signifying his approval of the plans the engineer may specify any protective works (whether temporary or permanent) which in the engineer’s opinion must be carried out before the commencement of the construction of a specified work to ensure the safety or stability of railway property or the continuation of safe and efficient operation of the railways of Network Rail or the services of operators using those railways (including any relocation, decommissioning and removal of works, apparatus and equipment necessitated by a specified work and the comfort and safety of passengers who may be affected by the specified works), and such protective works as may be reasonably necessary for those purposes must be constructed by Network Rail or by the undertaker, if Network Rail so desires, and such protective works must be carried out at the expense of the undertaker in either case without unnecessary delay and the undertaker must not commence the construction of the specified works until the engineer has notified the undertaker that the protective works have been completed to his reasonable satisfaction. 

36. —(1) Any specified work and any protective works to be constructed by virtue of paragraph 35(4) must, when commenced, be constructed— 

(a) without unnecessary delay in accordance with the plans approved or deemed to have been approved or settled under paragraph 35; 

(b) under the supervision (where appropriate and if given) and to the reasonable satisfaction of the engineer; 

(c) in such manner as to cause as little damage as is possible to railway property; and 

(d) so far as is reasonably practicable, so as not to interfere with or obstruct the free, uninterrupted and safe use of any railway of Network Rail or the traffic on it and the use by passengers of railway property. 

(2) If any damage to railway property or any such interference or obstruction is caused by the carrying out of, or in consequence of the construction of a specified work or a protective work, the undertaker must, regardless any such approval, make good such damage and must pay to Network Rail all reasonable expenses to which Network Rail may be put and compensation for any loss which it may sustain by reason of any such damage, interference or obstruction. 

(3) Nothing in this Part of this Schedule imposes any liability on the undertaker with respect to any damage, costs, expenses or loss attributable to the negligence of Network Rail or its servants, contractors or agents or any liability on Network Rail with respect to any damage, costs, expenses or loss attributable to the negligence of the undertaker or its servants, contractors or agents. 

37.  The undertaker must— 

(a) at all times afford reasonable facilities to the engineer for access to a specified work or a protective work during its construction; and 

(b) supply the engineer with all such information as the engineer may reasonably require with regard to a specified work or a protective work or the method of constructing it. 

38.  Network Rail must at all times afford reasonable facilities to the undertaker and its agents for access to any works carried out by Network Rail under this Part of this Schedule during their construction and must supply the undertaker with such information as it may reasonably require with regard to such works or the method of constructing them. 

39. —(1) If any permanent or temporary alterations or additions to railway property are reasonably necessary in consequence of the construction of a specified work or a protective work, or during a period of 24 months after the completion of that work in order to ensure the safety of railway property or the continued safe operation of the railways of Network Rail, such alterations and additions may be carried out by Network Rail and if Network Rail gives to the undertaker reasonable notice of its intention to carry out such alterations or additions (which must be specified in the notice), the undertaker must pay to Network Rail the reasonable cost of those alterations or additions including, in respect of any such alterations and additions as are to be permanent, a capitalised sum representing the increase of the costs which may be expected to be reasonably incurred by Network Rail in maintaining, working and, when necessary, renewing any such alterations or additions. 

