4N.I.When it is expressed in a deed of charge that any person covenants for payment of the principal sum charged, there shall, unless provision to the contrary is contained in the deed of charge, be implied a covenant by that person with the registered owner for the time being of the charge—
(a)to pay the principal sum charged and interest, if any, at the time and rate specified in the deed of charge; and
(b)if the principal sum, or any part thereof, is unpaid at the time so specified, to pay interest half-yearly at the rate so specified on so much of the principal sum as for the time being remains unpaid.