(K, = 220) for 30 tower shots with A 2 100. line A represents The horizontal part of the mean K-factor (Ky = 25) of 40 airbursts. There is a substantial difference between detonations on steel towers and those that are air burst. We consider a burst on a building to be comparable to a burst on a massive steel or concrete tower; similarly a treetop burst is comparable to an airburst. The most critical point for establishing the dependence of K-factor on building height appears to be the Trinity shot, analogous to one megaton on a 30-story building. If wooden towers can be considered analogous to treetop-burst conditions, several points in the two figures are analogous to treetop bursts. The only well-established ones are those for Smallboy and the two Little Fellers. For lower elevations we have Koon, whose suspension does not fit these categories, and Coulomb B, burst on a wooden tower but with a poorly documented fallout pattern. For air and treetop bursts, the Subcommittee recommends using line A in Figures 1 and 2, which amounts to a factor of about 0.45 for a scaled burst height, 1, of 10. This is uncertain to the extent represented by the spread in the Small Boy data. As for bursts on buildings, the available data indicate that line B should be used, which is to say a height-of-burst correction of only 0.87 at a scaled height of burst of } = 10. This effect cannot reduce the K-factor below about 220 no matter how tall the building. As in Chapter 1, DCPA needs a K-factor (K,) that does not reflect reductions for instrument response or ground roughness. On this basis, the minimum K-factor (K,) for bursts on buildings is es pS » ra pi ik Le rs r4 &E roan zx r4 about 390,