Richard,
Corio Air Engineers = manufacturer. Not sure about the number they built under contract, as it appears they may have commenced chassis numbers at 1,000. Seems to be about 500 trailers, which would be about right for the Aust army requirements at the time.
U/L C of G: Unladen Centre of Gravity, which is about the same as Keefy said. In other words, the plate marks the CofG point when the trailer is unladen.
5434 and the 'pyramid' above the 'roo: Embarcation code for the Unit, in both numerals (5434) and colour bars, above the Australian National Symbol. No, it does not mean the unit/trailer went overseas.
100849: the Australian Army registration number. This would have been carried on an AMF number plate affixed to the rear/number plate bracket. Black plate, white numbers, letters 'AMF' above in the centre.
3 in yellow: Bridging Plate. The Bridge to be passed over must have that number or higher before the trailer can be taken over that bridge. '3' denotes that the GROSS (fully laden) WEIGHT may be up to 3 tonnes, but that does not mean that the gross laden weight of this trailer is 3 tonnes, just that it doesn't exceed that weight. Gross weight for this trailer would be 1650 pounds plus 2,240 pounds = 3890 pounds = 1.763 tons
50 = Tactical sign of the 1970/80s of 16 Air Defence Regiment, based at Woodside South Australia. They were armed with RBS70 VLLADS and Rapier missile systems at that stage. Also carried by 16 AD Regt Workshop RAEME, so could be configured as serving with either.
Pic 3: a sub-unit sign. Only a former member of 16 AD can tell you what it might be! Whatever 'it' is might be cradling/holding a spanner (ie workshop) or a missile (ie the Regt itself): who knows!
C104356: Commonwealth Contract Demand/Contract number against the manufacturer for the supply of the trailers.
Chassis 1356: manufacturers number. In this case, it corresponds to ARN 100849.
Unladen weight: According to the listed data, 1650 pounds (in unmodified form. A proportion of these trailers were modified with wider wheel rims and mudguards which may alter the weight slightly upwards).
Nomenclature: 'Trailer, 1 ton, Cargo, (Aust) No.1 Mk.1' but changed in late 1959 to:
'Trailer, Cargo, 1 Ton, Aust. No.1 Mk.1'
Acquisition: 1959-1960
Disposals: Mostly 1970s and 1980s.
Regards
Mike C
