dead weight

An oppressive burden or heavy responsibility. The physical attributes of such a weight were noted early on, but the figurative use of the expression dates from the early eighteenth century. The English philosopher Lord Shaftesbury (the third Earl) wrote (1711), “Pedantry and Bigotry are millstones  able  to  sink  the  best  Book, which  carries  the  least  part  of  their dead weight.”