The Swedish Deep-Sea Expedition 
Hans Pettersson 1 
INTRODUCTION 
Cut off from active work at sea during the 
Second World War, Swedish oceanographers de¬ 
voted their efforts largely to improving the 
technique of deep-sea oceanography. The raising 
of long and undisturbed sediment cores from 
great depths appeared to us to be an especially 
desirable development. Very little advance had 
been made in coring methods during the half 
century which elapsed between the cruises of 
the "Challenger” and of the "Meteor.” In the 
mid-thirties C. S. Piggot of the Carnegie Insti¬ 
tution, Washington, D. G, succeeded in obtain¬ 
ing cores between 1 and 3 meters long from 
great depths by firing a coring tube vertically 
downward into the sea bottom with an explod¬ 
ing charge (Piggot, 1936: 207). The chief 
difficulty in this method was the friction be¬ 
tween the column of sediment and the interior 
wall of the coring tube. Recently an attempt 
to overcome this difficulty was made by utilizing 
the high pressure at great depths to operate 
a "vacuum core sampler” (Pettersson and Kul- 
lenberg, 1940, 1941). An undisturbed core 14 
meters in length was raised by means of this 
instrument in the Gullmar Fjord on the west 
coast of Sweden in 1942. Shortly afterward Kul- 
lenberg developed the "piston core sampler,” 
by means of which an undisturbed core 20.3 
meters in length was raised from the Gullmar 
Fjord in 1945 (Kullenberg, 1947). In this 
device, by trigger action, the entire heavy steel 
coring tube with attached weights is auto¬ 
matically released on approaching the bottom 
and sinks down into the sediment. The main 
wire cable from which the coring tube is 
suspended is stopped abruptly as the coring 
tube and weights are released to sink into the 
1 Director, Oceanografiska Institutet, Goteborg, 
Sweden. Manuscript received May 3, 1948; trans¬ 
mitted from the Seychelles. 
D 
sediment. A piston originally at the lower end 
of the coring tube and attached by an internal 
wire to the main cable is kept motionless while 
the coring tube descends around it. Because 
of the high pressure, the immovable piston 
immobilizes the column of sediment beneath 
it as it is cut out by the corer. A view of the 
piston core sampler suspended alongside the 
research vessel is shown in Figure 1. 
In the spring of 1946 the Swedish govern¬ 
ment permitted the research vessel "Skagerak” 
to be used on a trial cruise to the western 
Mediterranean during which the piston core 
sampler proved its worth. Cores 8 to 15 meters 
Fig. 1. The Kullenberg piston core sampler about 
to be hauled aboard the "Albatross.” 
OCT 2 6194® 
