L. J. DWYER, J. H. MARTIN AND E. W. TITTERTON 



open-pot fiill-out sampling methods have also been described previously, and 

 some of the radio-iodine data have been discussed. It remains to consider 

 the measurements from Operation 'Antler', and to outline the ^"Sr pro- 

 gramme, the first stage of which is now nearing completion. 



OPERATION 'antler' 



This test series, the second to be conducted at the Maralinga site, was held 

 during September and October 1957. Three nuclear weapons were deto- 

 nated, the first two from towers and the third suspended above the ground 

 from balloons. 



^^^""^ 



Round 3 





7\. .r- Round 2 



r u 



Figure 1. The cloud trajectories for the three nuclear weapons exploded at 

 the Maralinga site (Operation 'Antler') 



This balloon technique was used for the first time in Australia. The 

 arrangement was designed to hold the weapon, complete with its instru- 

 mentation and cabling, much higher above the ground than conventional 

 towers. It has been known for some time that fall-out levels would be 

 greatly reduced with explosions under these circumstances but much 

 difficulty has been experienced in the past in positioning the device with 

 sufficient precision. Many of these difficulties have now been overcome and 

 the whole exercise was carried out most successfully. It is noteworthy that 

 the United States Atomic Energy Commission in its most recent test series 

 at the Nevada site made extensive use of this technique. 



139 



