Operation Arbor Explained

Operation Arbor
Country:	United States
Test Site:	NTS Area 12, Rainier Mesa NTS, Areas 1–4, 6–10, Yucca Flat
Period:	1973–1974
Number Of Tests:	18
Test Type:	underground shaft, tunnel
Max Yield:	150ktTNT
Next Series:	Operation Bedrock

The United States's Arbor nuclear test series was a group of 18 nuclear tests conducted in 1973–1974. These tests^[1] followed the Operation Toggle series and preceded the Operation Bedrock series.

United States' Arbor series tests and detonations
- !style="background:#ffdead;"	Name^[2] !style="background:#efefef;"	Date time (UT) !style="background:#ffdead;"	Local time zone^[3] ^[4] !style="background:#efefef;"	Location^[5] !style="background:#ffdead;"	Elevation + height^[6] !style="background:#efefef;"	Delivery^[7] Purpose^[8] !style="background:#efefef;"	Device^[9] !style="background:#ffdead;"	Yield^[10] !style="background:#efefef;" class="unsortable"	Fallout^[11] !style="background:#ffdead;" class="unsortable"	References !style="background:#efefef;" class="unsortable"	Notes	- ! Polygonum	14:30:00.166	PST (–8 hrs)	NTS Area U2by 37.159°N -116.0741°W	1304m (4,278feet) – 213.36m (700feet)	underground shaft, weapons development						- ! Waller	15:15:00.164	PST (–8 hrs)	NTS Area U2bz 37.1539°N -116.0686°W	1294m (4,245feet) – 310.9m (1,020feet)	underground shaft, weapons development			Venting detected, 3Ci			- ! Husky Ace	17:00:00.08	PST (–8 hrs)	NTS Area U12n.07 37.2003°N -116.204°W	2238m (7,343feet) – 415.66m (1,363.71feet)	tunnel, weapon effect						- ! Bernal	15:30:00.08	PST (–8 hrs)	NTS Area U3jy 37.011°N -116.0252°W	1183m (3,881feet) – 285.29m (935.99feet)	underground shaft, weapons development			Venting detected, 0.1Ci			- ! Pajara	19:00:00.1	PST (–8 hrs)	NTS Area U3ji 36.9915°N -116.0251°W	1175m (3,855feet) – 278.17m (912.63feet)	underground shaft, weapons development			Venting detected, 5Ci			- ! Seafoam	15:17:00.17	PST (–8 hrs)	NTS Area U2ea 37.1614°N -116.0739°W	1306m (4,285feet) – 198.12m (650feet)	underground shaft, weapons development			Venting detected, 5Ci			- ! Spar	18:30:00.04	PST (–8 hrs)	NTS Area U3jr 37.0058°N -116.0196°W	1180m (3,870feet) – 148.43m (486.98feet)	underground shaft, safety experiment						- ! Elida	19:16:00.11	PST (–8 hrs)	NTS Area U3hy 37.0011°N -116.0323°W	1178m (3,865feet) – 381.42m (1,251.38feet)	underground shaft, weapons development			Venting detected, 0.8Ci			- ! Pinedrops-Bayou - 2	15:38:00.17	PST (–8 hrs)	NTS Area U10as 37.1741°N -116.0517°W	1283m (4,209feet) – 343m (1,125feet)	underground shaft, weapons development			Venting detected, 6Ci		Simultaneous, same hole.	- ! Pinedrops-Sloat - 1	15:38:00.17	PST (–8 hrs)	NTS Area U10as 37.1741°N -116.0517°W	1283m (4,209feet) – 342.9m (1,125feet)	underground shaft, weapons development					Simultaneous, same hole.	- ! Pinedrops-Tawny - 3	15:38:00.17	PST (–8 hrs)	NTS Area U10as 37.1741°N -116.0517°W	1283m (4,209feet) +	underground shaft, weapons development					Simultaneous, same hole.	- ! Latir	17:00:00.09	PST (–8 hrs)	NTS Area U4d 37.1044°N -116.054°W	1243m (4,078feet) – 640.77m (2,102.26feet)	underground shaft, weapons development						- ! Hulsea	17:00:00.166	PST (–8 hrs)	NTS Area U2bx 37.1551°N -116.065°W	1289m (4,229feet) – 195.07m (639.99feet)	underground shaft, weapons development			Venting detected, 67Ci			- ! Sapello	15:15:00.08	PST (–8 hrs)	NTS Area U3ge 37.0149°N -116.045°W	1189m (3,901feet) – 180.74m (592.98feet)	underground shaft, weapons development						- ! Portrero	15:13:00.161	PST (–8 hrs)	NTS Area U2eb 37.16°N -116.0774°W	1310m (4,300feet) – 210.31m (689.99feet)	underground shaft, weapons development						- ! Plomo	14:02:00.21	PST (–8 hrs)	NTS Area U3ff 37.0311°N -115.9863°W	1227m (4,026feet) – 149.35m (489.99feet)	underground shaft, weapons development						- ! Jib	16:55:00.085	PST (–8 hrs)	NTS Area U3hb 37.001°N -116.0023°W	1177m (3,862feet) – 180.44m (591.99feet)	underground shaft, weapons development						- ! Grove	14:15:00.169	PST (–8 hrs)	NTS Area U2ds 37.1149°N -116.0754°W	1264m (4,147feet) – 313.94m (1,029.99feet)	underground shaft, weapons development			Venting detected, 26Ci			- ! Jara	14:40:00.08	PST (–8 hrs)	NTS Area U3hp 37.0038°N -116.0243°W	1180m (3,870feet) – 378.06m (1,240.35feet)	underground shaft, weapons development			Venting detected			- ! Ming Blade	16:00:00.084	PST (–8 hrs)	NTS Area U12n.08 37.2103°N -116.2081°W	2212m (7,257feet) – 387.65m (1,271.82feet)	tunnel, weapon effect

Notes and References

A bomb test may be a salvo test, defined as two or more explosions "where a period of time between successive individual explosions does not exceed 5 seconds and where the burial points of all explosive devices can be connected by segments of straight lines, each of them connecting two burial points and does not exceed 40 kilometers in length".Web site: V. N.. Mikhailov. Catalog of World Wide Nuclear Testing. Begell-Atom. dead. https://web.archive.org/web/20140426102201/http://www.iss-atom.ru/ksenia/catal_nt/1.htm. April 26, 2014.
The US, France and Great Britain have code-named their test events, while the USSR and China did not, and therefore have only test numbers (with some exceptions - Soviet peaceful explosions were named). Word translations into English in parentheses unless the name is a proper noun. A dash followed by a number indicates a member of a salvo event. The US also sometimes named the individual explosions in such a salvo test, which results in "name1 - 1(with name2)". If test is canceled or aborted, then the row data like date and location discloses the intended plans, where known.
To convert the UT time into standard local, add the number of hours in parentheses to the UT time; for local daylight saving time, add one additional hour. If the result is earlier than 00:00, add 24 hours and subtract 1 from the day; if it is 24:00 or later, subtract 24 hours and add 1 to the day. Historical time zone data obtained from the IANA time zone database.
Web site: Time Zone Historical Database. iana.com. March 8, 2014.
Rough place name and a latitude/longitude reference; for rocket-carried tests, the launch location is specified before the detonation location, if known. Some locations are extremely accurate; others (like airdrops and space blasts) may be quite inaccurate. "~" indicates a likely pro-forma rough location, shared with other tests in that same area.
Elevation is the ground level at the point directly below the explosion relative to sea level; height is the additional distance added or subtracted by tower, balloon, shaft, tunnel, air drop or other contrivance. For rocket bursts the ground level is "N/A". In some cases it is not clear if the height is absolute or relative to ground, for example, Plumbbob/John. No number or units indicates the value is unknown, while "0" means zero. Sorting on this column is by elevation and height added together.
Atmospheric, airdrop, balloon, gun, cruise missile, rocket, surface, tower, and barge are all disallowed by the Partial Nuclear Test Ban Treaty. Sealed shaft and tunnel are underground, and remained useful under the PTBT. Intentional cratering tests are borderline; they occurred under the treaty, were sometimes protested, and generally overlooked if the test was declared to be a peaceful use.
Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
Designations for test items where known, "?" indicates some uncertainty about the preceding value, nicknames for particular devices in quotes. This category of information is often not officially disclosed.
Estimated energy yield in tons, kilotons, and megatons. A ton of TNT equivalent is defined as 4.184 gigajoules (1 gigacalorie).
Radioactive emission to the atmosphere aside from prompt neutrons, where known. The measured species is only iodine-131 if mentioned, otherwise it is all species. No entry means unknown, probably none if underground and "all" if not; otherwise notation for whether measured on the site only or off the site, where known, and the measured amount of radioactivity released.