Tool arrangement for compacting a composite preform assembly comprising a support structure preform and an array of component preforms each extending from the support structure preform and spaced apart along the support structure preform. The tool arrangement comprises a support tool defining a lay-up surface for laying up the support structure preform; a plurality of component moulds, each component mould comprising a pair of blocks configured to cooperate with one another to receive and compact a respective component preform extending from the support structure therebetween, each block having a compaction surface for engaging the component preform and a driving surface.