（a）the permanent use or occupation of land by the works or any part thereof；
（b）the right of the employer to execute the works or any part thereof on， over， under， in or through any land；
（c）injuries or damage to persons or property which are the unavoidable result of the execution or maintenance of the works in accordance with the contract.11 third party insurance
before commencing the execution of the works the contractor， but without limiting his obligations and responsibilities under 10 thereof， shall insure against his liability for any material or physical damage， loss or injury which may occur to any property， including that of the employer， or to any person， including any employee of the employer， by or arising out of the execution of the works or in the carrying out of the contract， otherwise than due to the matters referred to in the provision to 10 hereof.
such insurance shall be effected with an insurer and in terms approved by the employer ，which approval shall not be unreasonably withheld， and for at least the amount of i.
the contractor shall， whenever required， produce the policy or policies of insurance and the receipts for payment of the current premiums.
the terms shall include a provision whereby， in the event of any claim in respect of which the contractor would be entitled to receive indemnity under the policy being brought or made against the employer， the insurer will indemnify the employer against such claims and any costs， charge， and expenses in respect thereof.12 accident of injury to workmen
the employer shall not be liable for or in respect of any damages or compensation payable at law in respect or in consequence of any accident or injury to any workman or other person in the employment of the contractor or any subcontractor， save and except an accident or injury resulting from any act or default of the employer， his agents， pr servants. the contractor shall indemnify and keep indemnified the employer against all suchdamages and compensation， save and except as aforesaid， and a-gainst all claims， proceedings， costs， charges and expenses what - soever in respect thereof or in relation thereto.
the contractor shall insure against such liability with an in- surer approved by the employer， which approval shall not be un - reasonably withheld，and shall continue such insurance during thewhole of the time that any persons are employed by him on theworks and shall， when required， produce such policy of insurance and the receipt for payment of the current premiums.provided always that， in respect of any persons employed by any subcontrac - tor， the contractor'' s obligation to insure as aforesaid under this subshall be satisfied if the subcontractor shall have in - sured against the liability in respect of such persons in such manner that the employer is indemnified under the policy， but the contractor shall require， such sub - contractor to produce， when required， such policy of insurance and the receipt for the payment of the current premium.13 remedy on contractor''s failure to insure