Saturday, March 17, 2012

12 August 2010 – HARP: A Blast from the Past


On Monday this week, the US Army Legal office, pursuant to a Freedom of Information Act request, released a number of reports from the Technical Library of the Dugway Proving Ground in Utah.  Dugway is of course famous for the “Dugway sheep kill” incident on 17 March 1968, when a wind shift during an aerial nerve agent spraying test, probably with VX (this has never been officially confirmed) killed about 3,800 sheep in the Skull Valley area, 27 miles outside of the perimeter of the facility.  You might remember a similar incident being used to keep Richard Dreyfuss away from an alien landing site in “Close Encounters of the Third Kind”.

One of the reports released this week involves developmental efforts on a balloon-released, controlled-glide cluster bomb for the delivery of biological warfare agents.  I may revisit this one at some point.  From a Canadian perspective, however, the other report is far more interesting.  It concerns HARP - the High Altitude Research Project which saw strong Canada-US defence scientific cooperation aimed at perfecting the gun-based delivery of small payloads into Low Earth Orbit (LEO). 

You probably remember this project mostly due to the fact that it was associated with Canadian ballistics engineer Gerald Bull, a former Defence Research Board employee (and a stability engineer on the AVRO ARROW project) who was one of the driving forces behind the HARP project (and one of its successors, Saddam Hussein’s “Project Babylon” Supergun), and who was assassinated outside his Brussels apartment on 20 March 1990.

The report in question - BRL 1327 “Review of the High Altitude Research Program (HARP)” is co-authored by G.V. Bull and C.H. Murphy, and was published by US Army Material Command in July of 1966 (one wonders whether the release is entirely new; a version of the report may have appeared under the same title in a 1966 edition of the Annals of the New York Academy of Sciences).  It provides an excellent overview of the project, and includes a detailed discussion of the extent and sophistication of Canada’s scientific and defence contribution to the gun-based delivery of space vehicles.  HARP involved guns of many calibres, from 5” and 7” extended-barrel weapons, to massive extended 16” guns capable of launching sub-calibre and full-bore projectiles to heights in excess of 100 miles - the altitude at which LEO is normally understood to begin.

The 16” gun is particularly interesting.  The project had three.  One of these, a horizontal testbed, was built at Highwater, Quebec, a picturesque valley in the Green Mountains, about two miles north of the Vermont border.  The range was used largely for materials and design testing, and incorporated earthen butts capable of absorbing large, high-speed projectiles.  At the time the report was written, the project scientists were investigating the use of the Highwater gun for testing large, hypersonic vehicles to measure heat transfer, surface pressures and dynamic stability of projectiles - all characteristics that would be crucial for the use of guns to deliver functional satellite payloads into LEO.

The other two 16” guns were located at Yuma, Arizona, and Foul Bay, Barbados.  The Barbados gun was purchased, constructed and operated by Canada - in fact, by the Space Research Institute (SRI) at McGill University.  Two US Navy 16” guns were bought, smooth-bored, shipped and assembled in 1962, and firings began in 1963.  After a muzzle extension was added in 1964, the gun managed to loft a 185-pound projectile to an altitude of 430,000 feet.  With modifications to the sabot and the propellant charge, and with the addition of a Mylar muzzle seal and vaccuum evacuation of the barrel prior to firing, this was increased to 468,000 feet in September 1966.

The Barbados gun was quite something.  The barrel was 119’ 5” long and weighed 200 tons.  Stiffening the barrel against droop took another 30 tons of structural steel welded into radial webs and tie-rods.  It took 8 minutes to elevate the barrel from the horizontal position to the firing elevation of 85 degrees.  The gun fired a sub-calibre projectile called the Martlet 2C - a 54” fin-stabilized missile with a maximum body diameter of 5.4” and a weight of 185 pounds.  The missile was held in the barrel by a 225-pound aluminum-and-steel pusher plate with four wooden arms.  The sabot was oversized and had to be forced into the barrel with an hydraulic jack.  A single firing took 980 pounds of webbed M8 propellant, yielding a chamber pressure of 48,000 psi and a muzzle velocity of 6100 FPS.  The Mylar seal and evacuation of the barrel, mentioned above, added 150 FPS to the muzzle velocity, and 20,000’ to the altitude achieved.

By the time the report was released, HARP had begun experimenting with the Martlet 3B subcalibre boosted rocket projectile.  The peak performance of this projectile was an altitude of 800,000 feet (150 miles) with a 35-pound payload.  By the end of 1966, project engineers were planning to test full-bore rocket-assisted projectiles.  These were expected to be able to carry a 600-pound payload to an altitude of more than 400 miles.

The HARP guns naturally invite comparison.  The closest historical analogue to the Barbados gun was the Kaiser Wilhelm Geschütz, known to military historians as “The Paris Gun”.  Although not cost-effective as a military weapon, the Paris Gun had significant psychological value.  It was built, of course, by Krupp, and saw service from March to August of 1918.  A comparison of the characteristics of the two guns follows: 

Paris Gun
w/HE shell
HARP Gun (16”)
w/Martlet 2C projectile
Barrel Length
Length (Calibres)
210 lb shell
33 lbs HE
185 lb projectile
35 lbs instruments
Propellant Charge
396 lbs
980 lbs
Muzzle Velocity
5200 FPS
6100 FPS
Maximum Altitude
Maximum Range
81 miles
Not tested

In a way, the HARP is vaguely reminiscent of the X-series of rocket-propelled space planes.  It represents an attempt to push the envelope of a long-established technology in order to squeeze the last possible ounce of performance out of it - and the effort ended up being overshadowed by the less certain, but much flashier, rocket booster programs for both satellite delivery and manned space flight that emerged as a consequence of the ballistic missile race of the 1950s and 1960s.

HARP also serves as a stellar example of the kinds of things that can be achieved through scientific cooperation with allies, especially those with whom we share long, undefended borders.  Canada has very few allies that would not only permit but actually encourage us to build a 119’-long rocket-firing 16” cannon only three kilometres from their border.  Did I mention that the Highwater gun could only fire towards the south-west?

As for Gerald Bull, his involvement in the Iraqi “Supergun” project has led to much speculation that the Mossad was behind his death.  However, given - as this newly-released report demonstrates - how much of his experience and training were obtained through his work on the Canada-US HARP, one wonders whether there might not be a different explanation.  According to a report of his decision to quit his post at CARDE, the Canadian Armament and Research and Development Establishment at Valcartier, in 1961, Bull had a “tempestuous nature” and a “strong dislike for administration and red tape [that] constantly led him into trouble with senior management.”  That said, he seems to have had no difficulty getting along both with China’s communist government, for whom he worked on howitzer designs, or Saddam Hussein.

The reports, both on the BW glide bomb, and the HARP summary, can be found here [].

Cheers, and many thanks to Neil Chuka for alerting me to the document release.