This is a practice ADSID (Air Delivered Seismic Intrusion Detector. The ones that were actually used in Vietnam were painted camouflage.
How these things worked was that they had a seismic detecting device and sending unit inside the hollow bottom portion of the device with an outside antennae. These came in different sizes and I think that this is the largest. The fins on the bottom folded upward for easy storage . The long pointed metal shaft is solid steel so as to plant it’s self into the ground The devices were dropped from either helicopter, transport planes or fighter planes along the Ho Chi Minh Trail to detect troop or vehicle movement through acoustic and seismic signatures. Relay aircraft were used to capture the info from the devices and sent to an infiltration surveillance center.The surveillance line was nicknamed the McNamara Line after Secretary of Defense Robert McNamara code name Igloo White. This was in 1966.
Now my question.
I believe that by looking at the under layers of paint that at one time this thing was painted florescent orange so that it could be seen for retrieval. So should I leave it the way it is or repaint to original color?
I do remember seeing ADSID at EOD at Pendleton http://www.bocn.co.uk/vbforum/threads/98320-EOD-facility-Camp-Pendleton-CA and asking them about it.
These were not only dropped along the Ho Chi Minh trail but throughout suspected travel corridors throughout RVN, The “rocket belt” around Danang, along the DMZ, hwy 9 from the coastal area west to Khe Sahn. After they were dropped local Marine and Army units running combat patrols in the vicinity accompanied by tech type people would locate the sensors and then artillery coordinates would be registered and a WP round or two would be fired to verify . They did work as we sometimes had to run patrols after a fire mission that was triggered by the sensor to see what the results were. Not all were seismic sensors. Never saw any that were orange.
This I was told was a practice device. Thanks for the added info.
Orange color in US submunitions usually is indicating “inert” dummy material.
An interesting view of this seismic device being dropped by a helicopter is in the movie:-
Kong: Skull Island (2017).
I just watched it on TV and recognised the item, even if in a Hollywood fantasy movie.
Dropped when the copters reach Skull Island and the noise attracts Kong.
The movie was OK but I expected better.