Each brigade (so 1st Army Tank Brigade in this instance) should have had its own dedicated Field Ambulance which would have been responsible for recovering casualties from the Regimental Aid Post and after triage, backloading the more seriously wounded either to a CCS or direct to a Field Hospital (if urgent surgery was required, a Fd Hosp had better facilities). However I haven't able to discover if this was the case with 1st Army Tank Bde. My understanding is, at that stage in the war, if a casualty was sufficiently badly wounded or ill, he would have been sent back to the BMH in Alexandria for convalescence.
