 On the afternoon of 3 January , Berryman met with Allen , Jerram and Frowen at Allen 's headquarters at Post 40 to discuss plans for the next day . It was agreed that Allen would advance on Bardia and cut the fortress in two , supported by Frowen 's guns , every available tank , MacArthur @-@ Onslow 's Bren gun carriers and the 2 / 8th Infantry Battalion , which Mackay had recently allocated from reserve . Allen gave orders accordingly . During the afternoon the 6th Cavalry Regiment was pulled back to become the brigade reserve and the 2 / 5th Infantry Battalion relieved the 2 / 2nd to free it to advance the next day . That evening , Berryman came to the conclusion that unless the Italian defence collapsed soon , the 16th and 17th Infantry Brigades would become incapable of further effort and Brigadier Horace Robertson 's 19th Infantry Brigade would be required . Mackay was more sanguine about the situation , and reminded Berryman that his orders had been to capture Bardia with only two brigades . While they were discussing the matter , O 'Connor and Harding arrived at 6th Division headquarters , and O 'Connor readily agreed to the change of plan . 
