Sec. 8. DISABILITY PENSIONS. Whenever any member of the fire department or police department of any such city or town, and who is a contributor to said fund as provided, shall become so permanently disabled through injury received, or disease contracted, in the line of duty, as to incapacitate him for the performance of duty, or shall for any cause, through no fault of his own, become so permanently disabled as to incapacitate him for the performance of duty, and shall make written application therefor approved by a majority of the board, he shall be retired from service and be entitled to receive from said fund one-half of the monthly salary received by him as a member of either of said departments, at the time he became so disabled, to be paid in regular monthly installments subject to change under the provisions of Section 10A of this Act.