Operation Distant Plain

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title: "Operation Distant Plain" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["explosions-in-1966", "explosions-in-1967", "1966-in-canada", "1967-in-canada", "projects-established-in-1966", "1966-in-military-history", "1967-in-military-history", "military-projects-of-the-united-states", "code-names", "science-and-technology-in-alberta", "organized-events-in-alberta", "drdc-suffield", "explosions-in-canada"] description: "Series of non-nuclear explosive and detonable gas tests" topic_path: "history" source: "https://en.wikipedia.org/wiki/Operation_Distant_Plain" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Series of non-nuclear explosive and detonable gas tests ::

::data[format=table title="Infobox high explosive test"]

Field	Value
name	Operation Distant Plain
image	DistantPlainGasHemisphere.jpg
image_size	300px
caption	125 foot 20 ST propane-oxygen hemisphere is prepared for detonation as Event 2A. The striped poles carry instrumentation equipment and a human figure can be seen in the lower right.
country	Canada
test_site	{{plainlist
date	July 7, 1966 – August, 1967
agency	Defence Research Board, TTCP
number_of_tests	8
explosive	TNT, Detonable Gas
configuration	{{plainlist
max_yield	100 tonTNT
previous_test	Operation Sailor Hat
next_test	Operation Prairie Flat
::

| name = Operation Distant Plain | image = DistantPlainGasHemisphere.jpg | image_size = 300px | caption = 125 foot 20 ST propane-oxygen hemisphere is prepared for detonation as Event 2A. The striped poles carry instrumentation equipment and a human figure can be seen in the lower right. | country = Canada | test_site = {{plainlist|

• Suffield Experimental Station, Alberta
• Hinton, Alberta}} | date = July 7, 1966 – August, 1967 | agency = Defence Research Board, TTCP | number_of_tests = 8 | explosive = TNT, Detonable Gas | configuration = {{plainlist|
• Stacked Sphere (Tower, Buried)
• Stacked Hemisphere
• Gas Balloon
• Gas Hemisphere}} | max_yield = 100 tonTNT | previous_test = Operation Sailor Hat | next_test = Operation Prairie Flat

Operation Distant Plain was a series of non-nuclear explosive and detonable gas tests performed on test sites in Alberta, Canada, during the course of 1966 and 1967. Their purpose was to provide airblast, cratering, and ground shock data in summer and winter conditions for testing new prototype equipment, military targets and coniferous forest blowdown, and defoliation.

Participants included Canada, the United Kingdom, Australia, and the United States under the Tripartite Technical Cooperation Program. Detonable gas balloons were used in this operation in an attempt to find an economical substitute for TNT as well as for the fact that they could be placed at desired heights without a heavy support structure or towers. In addition, they were more adaptable to airblast phenomena and produced a well defined blast wave without perturbation or ejecta; they also produced no crater. However, it was found that they lacked the high pressure associated with high explosives, and difficulties were encountered as the 20-ton gas balloon ruptured and another detonated unexpectedly during inflation. Ultimately ANFO was elected as a lower cost alternative to TNT for non-nuclear explosives tests.

Tests

The following table summarizes the events that took place during the operation in chronological order.

::data[format=table] | | Event | | Date | | Charge | | Yield (short tons) | | Height of Burst (feet) | | Location | | Notes | |---|---|---|---|---|---|---| | 1 | 7 July 1966 | TNT sphere, tower | 20 | 85 | Drowning Ford Test Range, SES | Airblast and induced ground motions | | 2 | July 1966 | 125 foot methane-oxygen balloon | 20 | 85 | Drowning Ford Test Range, SES | Cancelled, balloon ruptured during inflation | | 2A | 22 July 1966 | 125 foot propane-oxygen hemisphere | 20 | 0 | Drowning Ford Test Range, SES | Test feasibility of detonable gas, compare with 20 ton TNT events | | 3 | 27 July 1966 | TNT sphere, half buried | 20 | 0 | Drowning Ford Test Range, SES | Normal environment control for Event 5 | | 4 | 16 August 1966 | TNT Hemisphere | 50 | 0 | Edson Forest, 10 miles northwest of Hinton | Coniferous forest blowdown test | | 2B | October 1966 | 125 foot methane-oxygen balloon | 18.6 | 63 | Drowning Ford Test Range, SES | Rescheduled Event 2, detonated unexpectedly during inflation on ground | | 5 | 9 February, 1967 | TNT sphere, half buried | 20 | 0 | Drowning Ford Test Range, SES | Frozen ground test | | 6 | 26 July 1967 | TNT sphere, supported | 100 | 0 | Watchdog Hill Blast Range, SES | Nuclear weapon surface burst simulation | | 1A | 18 August 1967 | TNT sphere, tower | 20 | 30 | Watchdog Hill Blast Range, SES | Airblast and induced ground motions, repeat of event 1 | ::

File:DistantPlainGasDetonation.jpg|Detonation of 20 tons of propane-oxygen hemisphere in Event 2A. The blast wave can be seen affecting the smoke trails.

References

References

1. (1 May 1971). "Operation Distant Plain, Events 1, 2A, 3, 4, and 5: Project 3.02A, Earth Motion and Stress Measurements".
2. (1 January 1966}}{{dead link). "Operation Distant Plain. United States Participation With Canada, Australia, And Great Britain In a Non-Nuclear Experimental Test Series".
3. (1 July 1971}}{{dead link). "Air Blast Measurements from the Detonation of an Explosive Gas Contained in a Hemispherical Balloon (Operation Distant Plain, Event 2a)".

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::