The Spanish Civil War - pg. 59

The anarchists, who knew very well what awaited them if
the army seized the city, decided not to leave their fate in
the hands of politicians. During that night the CNT local
defence committees went ahead with full preparations
for war. Isolated armouries were seized (a couple with the
active assistance of sympathetic NCOs) and weapons were
taken from four ships in the harbour. Even the rusting hulk of
the prison ship Uruguay was stormed, so as to take
the warders' weapons. The UGT dockers' union knew of a
shipment of dynamite in the port, and once that was seized,
home-made grenades were manufactured all through the night.
Every gun shop in the city was stripped bare. Cars and lorries
were requisitioned and metal workers fixed crude armour
plating while sandbags were piled behind truck cabs.