& “= e@ Blast Mtg Notes, 29 Dec 51 large The station between Engebi and Bogon was included to bridge the gap between the 20 and 50 psi regions. A platform of some type ts visualized, and Malik may also have 7(t) instrumentation there. It was agreed not to attempt to instrument for asymmetries because of the complexities of recording from stations west of Elugelab. Bogallua was suggested, but Ogle thought the presence of trees there might give assymmetries which were not due to the blast. B. Underwater Overpressures SC Two types of set-ups were originally proposed: 6 gauges in the lagoon with wires running back to the same kind of recorders as used for the air pressures studies, and 6 gauges on buoys in the ocean, with the possi- bility of Since the could not agreed to a self-recording device. The buoys would have to be anchored, and ocean is quite deep off Eniwetok, it was felt that their position be known accurately enough for good measurements. It was, therefore, have gauges only in the lagoon. The number of stations was also ‘ cut to 3, positioned as shown in Table I, since the group agreed that while _ this will be interesting data, it is doubtful just what one can apply it to-a Super will probably never be detonated for tactical purposes in this fashion in a lagoon. The gauges used will be waterproof, of the Wiancko type to measure pressure-time, There is a considerable uncertainty in the range of pressures to be expected. The gauges will normally cover a renge of 25:1. Sandia is thinking of using 2 gauges with different sensitivities, so that they will be able to cover a range of roughly 150:1. C. "SOFAR" Channel Transmission NEL (A UnZTp, ) This entails nothing but alerting the Naval Electronic Laboratory to request operation of the SOFAR station. Sandia Laboratory will do so, through BuShips. D. Wind Associated with Super-Bomb Shot This measurement is related to structural damage studies, and also to understanding bomb theory. Sandia proposed to instrument two stations in the high overpressure region to measure afterwinds only. (Watt pointed out that the radius of the fireball is likely to be 3,000 ft, so that to go in closer than 6,000 ft would probably do no good.) From the 80-psi region on out to Parry, Sandia would attempt to measure both the winds in connection with the pressure wave and the afterwinds. In order to do this and to get direction will require from 3 to 5 recording channels per station, depending SNL