Australian Military Vehicles Research

The Army Headquarters (AHQ) Belly Uparmouring Project by Shane Lovell

Commencing 15 August 1970, all Australian M113A1s in South Vietnam were progressively fitted with four modifications under the AHQ Belly Uparmouring Project. Fitting of the modifications was primarily undertaken by 106^th Field Workshop, Royal Australia Electrical and Mechanical Engineer at Nui Dat.

The project involved the fitting of hull length belly armour, a collapsible drivers footrest, right hand sponson armour (left hand sponson armour had been fitted to all M113A1 from mid 1969) and repositioning of the drivers hatch.

The project was undertaken as a high priority to decrease vehicle and personnel casualties suffered from Viet Cong anti vehicle mines.

The M113A1 variants in service in South Vietnam when the project occurred were M113A1 Armoured Personnel Carriers APC, M125A1 81mm mortar vehicles APC(M), M113A1 Fitters vehicles APC(F) AND M577A1 Armoured Command Vehicles ACV.

The project was completed in early November 1970. Subsequently, the modifications were also fitted to all replacement vehicles, including Fire Support Vehicles (FSV) prior to their issue to combat units.

The following tables identify the majority of M113A1s modified between August and November 1970

Headquarters, 1^st Australian Task Force (Note 1)

A Squadron, 1^st Armoured Regiment

106 Field Workshop, Royal Australian Electrical and Mechanical Engineers

Unknown Unit (Possibly the theatre reserve held by 2^nd Advance Ordnance Depot)

 1^st Field Squadron, Royal Australian Engineers (Note 2)

B Squadron, 3^rd Cavalry Regiment

Note 1:
The Armoured Command Vehicles allowed HQ 1 ATF to deploy into the field from Nui Dat as required. Each vehicle had a specific function:

 Note 2:
The table for 1 Field Squadron, Royal Australian Engineers does not include ARNs 134267 and 134226 as these vehicles were not officially issued to the unit. These were diverted to 1 Fd Sqn instead of returning to Australia after being declared ‘beyond local repair’. They were modified for use as improvised mine clearing vehicles.

Communications Equipment
46  -  AN/VRC 46 (1 X RT 524)

49  -  AN/VRC 49 (2 X RT 524)

106  -  AN/GRC 106

125  -  AN/GRC 125

Vehicle Armament

GPMG General Purpose Machine Gun M60 7.62 mm
.50 M2 HB .50 calibre machine gun on a pintle mount with a gun shield
50/30 M2 HB .50 calibre machine gun and L3A3 .30 machine gun within a T50 turret
30/30 Two L3A3 .30 calibre machine gun within a T50 turret

It was common for the L3A3 .30 calibre machine gun to be mounted on the T50 roof on an improvised mounting.