Operation Esso is remembered because of mines. throughout the length and breath of AO (Area of Operations) Aldgate the enemy used M16 Mines taken from the barrier mine field laid between the Horseshoe Hill and Lang Phouc Hai on the coast. The Viet Cong used mines extensively in that, in most cases, they were placed not as an obstacle to protect his bases, but to slow down, disrupt and discourage allied operations in the district.
The mines were placed on tracks, in likely ambush positions, in likely harbour positions, around houses in the villages, in short, anywhere where our troops were likely to move.

Prior to relieving 9RAR in the AO, and while there 5RAR took all possible precautions to minimize the danger and effect of mines. Special training was done; all vehicle floors were sandbagged; flack jackets and steel helmets were worn whenever possible; mine detectors were used by all patrols; and all routes or worksites were cleared prior to use. Despite these elaborate precautions seven soldiers were killed and forty three were wounded by mines.

Fire Base Thrust, some six hundred yards south of Hoi My received twelve 82mm mortar rounds at six minutes past midnight on 8 July. Three soldiers were slightly wounded in this attack and very little damage was done. In fact, some people in the base, being so used to the battery firing harassment missions during the night, did not even wake up!

Under operational control of 5RAR during this operation, was a troop of engineers and elements of the plant troop of 1 Field Squadron. Two infantry companies were involved throughout the operation protecting this Land Clearing Team and the team constructing the defensive bunkers around Dat Do village.

The Dat Do District was previously dominated by the VC from their sanctuary in the Long Hai Mountains. Because of inadequate leadership, training and material, the local Regional and Popular Force soldiers were largely ineffective. The population contained a high percentage of VC families, infrastructure and sympathisers and was consequently prepared to live in co-existence with the VC. During Esso, 5RAR placed small training teams in military posts throughout the district and encouraged more offensive operations by the local forces. Government agencies were urged to police the rice control programme and to man checkpoints on the main entry/exit points around Dat Do.

1ATF forces in the area over a period of months produced a real and significant result in the pacification programme. Captured documents revealed that the enemy infra-structure could not function properly because of the Allied ambushing at night. Rice control also forced the price of rice on the black market to be raised by one third.