Complex sentence: Operation was initially by RTs, but as with other services that crossed the London border it was quick to succumb to conversion to One Person Operation (OPO) which was implemented from 14 June 1969 using single-deck MB class AEC Merlins.
Split into simpler sentences: Operation was initially by RTs, but as with other services that crossed the London border it was quick to convert to One Person Operation (OPO). This was implemented from 14 June 1969 using single-deck MB class AEC Merlins.