740 
Sielie 
directly to the spacer cable. Two gauges were mounted face-on parallel with 
the spacer cable with the center of each gauge 1-1/8 in. from the cable. The 
side-on gauges were mounted near the end of this block so that their axes 
were perpendicular to the spacer cable. The weight of the small block and 
the gauges was 5 lb (Fig. 26). A blook with the gauges mounted in identical 
positions but of greater length was also constructed so that the total weight 
was 22 lb (Fig. 25). The ratio of the damage as measured by the side-on 
gauges to that measured by the face-on gauges was 0.95, The difference in 
the mass of the backing had no effect on absolute damage or scatter. Since 
in previous tests on the momentum-gauge mount, the side-on gauges had show 
greater deformation than the face~on gauges, it was thought that there might 
be an effect due to the close proximity of the spacer cable to the face-on 
gauges. 
Another type of mount was built with the centers of the face-on gauges 
9 in. from the spacer cable and those of the side-on gauges about 12 in. 
from the cable. These mounts were built in models of two different weights; 
one weighed Fear 1b (including zauges ) and the second 23 lb. Using these 
mounts the ratio of the side-on gauge readings to the face-on gauge readings 
was about 1.0). No difference in absolute magnitude or scatter resulted 
from the difference between the masses of the two gauge mounts. 
(iv) Quadrilateral ball-crusher side-on mount. As a result of the 
above tests, an extremely compact mount, holding four gauges side-on toward 
the charge (perpendicular to the spacer line) and easily moved from one posi- 
tion to another along the spacer line, was constructed. This mount (Fig. 3A) 
consisted of a square of 1=1/2 in. stcel plate 2-1/2 x 2~1/2 ine, with the 
four bali-crusher gauges screwed into the four rectangular sides of this 
plate. _The steel plate was divided diagonally to allow it to slip over the 
spacer cable, and this diagonal cut was notched to receive the cable. By 
loosening the screws holding the two halves of the plate together this mount 
could be slid along the cable to any desired position. The faces of the 
ball-crusher gauges in this mount were 3 in. from the spacer cable, This 
type of block was used for mounting crusher gauges after shot RE-155 and 
proved very satisfactory. 
(a) Momentum— and Hilliar-gauge mounts, -- The first Hilliar—gauge 
mounts were made by placing a cross bar at right angles to the spacer line 
and fastening the gauges at the end of this cross bar. This would not with- 
stand the explosion and had to be repaired or renewed aftor each shot. Con- 
sequently a triangular suspension frame was constructed, which mounted five 
Hilliar- or momentum gauges and four ball-crusher gauges. later on this frame 
was replaced by the cross trussed rectangular frame as shown in Fig, 30. 
This frame would mount four momentum or Hilliar gauges at the four corners 
plus one at the intersection of the cross truss, and proved to be exception- 
ally sturdy in use. Bridlcs were used to keep all of these frames hori- 
zontal so that the gauges were always face downwards. 
(e) Piezoelectric-gauge mounts. — (i) H-frames. Piezoelectric 
gauges were normally mounted on an H-frame, the cross bar of which was 
attached at mid—point to the spacer cable. Two piczoelectric gauges were 
