Though not supplied in the Royal Navy, they are used in the Merchant Navy where a double block is required but where there is either insufficient lateral room for the normal type or where it is desired to separate the parts of the fall with which the block is rove.
Nangona zingadluliswa kwiRoyal Navy, zisetyenziswa kwiMerchant Navy apho ibloko eziphindeneyo iyafunekayo kodwa apho kukho indlu engafumanekiyo ukwenzela ulwahlukaniso lwendidi eziwayo apho ibloko ibhadulayo.