|History of the Snark Missile|
|USAF Nuclear Weapons Specialist Home Page|
|Copyright 2002 by Jim Oskins|
| The SM-62 Snark had the dubious honor of being the United States Air Force's only Intercontinental Cruise Missile (ICM). Powered by a single Pratt and Whitney J-57 turbojet engine, assisted by two booster rockets for launch, the Snark was designed to cruise at 45,000 feet at .9 mach until approximately 50 miles from target when it would increase speed to .94 mach and climb to 52,000 feet.
Once over the target the entire nose of the missile with the warhead would separate from the main body and impact the target. We were told that the internal celestial guidance system could be programmed to make up to eight 90 degree turns per flight.
Twice during flight, shutters would open on the top of the missile and allow three telescopes to check stars to determine if the missile was on course. If the missile was within 75 miles of either side of it's flight path, the guidance system would bring it back on course.
This performance, plus a range of 5,500 nautical miles while carrying a W39 warhead with a 3.9 MT yield, gave the Snark an impressive appearance on paper. In spite of these doubts the Snark was rushed into operational service to meet the supposed "missile gap" created by Russian successes in space in 1957 and 1958.
|W39 warhead on lift trailer|
| Originally, the Snark was to be mounted on a highly mobile launcher and was to be dispersed over a wide area and moved from location to location. However, the Air Force felt cost, security, and the urgency to get the system deployed ruled this out and in 1957 selected Presque Isle, Maine as the location for the 702nd Strategic Missile Wing (ICM-Snark).
As an Air Defense Command (ADC) base fighter-interceptor squadrons were operated at Presque Isle AFB from 1951 to 1957. With the transition from fighters to missiles came an almost complete remodeling of base facilities, including construction of the missile area.
The missile area contained 6 large unhardened corrugated steel missile buildings, approximately 150 by 30 yards, with two 40 yard diameter launch pads per missile building. We were told that since the Air Force had not planned to site the missiles at one location they had to adapt a missile building originally designd for the Navajo missile. The missile area also contained a jet engine run-up building, the warhead maintenance and inspection building, missile maintenance and guidance lab, and a few miscellaneous small buildings. Most of these buildings are still intact and can be viewed on Terraserver.
Each missile building contained 5 missiles, sitting on their launch trailers, one behind the other. The missile crew sat not in a blockhouse, but on a balcony overlooking each missile. Missile number 1 with tow vehicle attached was on countdown hold at T minus 15 minutes; missile number 2 with tow vehicle attached was holding at T minus 30 minutes and missile number 3 was at T minus 180 minutes. Missiles 4 and 5 were in maintenance generation with number 4 being 3 days from launch and number 5 being five days from launch. After a given period of time, missile number 1 was taken off alert and towed to position 5, number 2 was moved into position 1 and placed on 15 minute hold, missle 3 was moved into position 2, etc.
The Snark could not be launched from inside the missile building. In order to launch it was necessary to 1- Start the generator on the tow vehicle, 2- Open the building doors, 3- Transfer power from building to generator power, 4- Disconnect the building-to-missile cables, 5. Tow missile to launch pad, 6. Connect the missile cables to the pad, 7. Start and run-up the jet engine to full military power, and 8. Launch the missile. This could be done within 15 minutes with a lot of hustle on the part of the launch crew.
At launch the Snark had more thrust at 270,000 pounds than an Atlas missile. That is until the booster rockets, which burned for only four seconds, fell free of the missile. There was a farm house in line with some of the launch pads at Presque Isle and we always wondered if it would catch some of the burned out booster rockets. Fortunately we never found out.
Safety was a major issue with the Snark. Along with a fully manned crash truck, each missile building contained a large tank that was capable of flooding the entire building with a 12 foot deep blanket of CO2. These precautions were necessary due to the Snark, sitting on alert, having two solid propellant booster rockets (130,000 pounds thrust each), two black powder igniters in the booster rocket, high explosives in the warhead, explosive squibs for nose separation, and JP-4. I think having all this inside a building with 20 to 30 people violated every safety regulation the Air Force ever wrote. To help insure safety no matches or lighters were allowed in the missile area.
The 331X0 duties associated with the Snark were maintenance of the arming and fusing system and warhead, as well as mating the warhead to the missile. Training consisted of 30 days at Lowry AFB, Colorado for the arming and fusing system followed by 60 days of launch crew (countdown) training at Cape Canaveral, Florida. Warhead mating training was conducted after arrival at Presque Isle AFB.
The 331X0 function on the launch crew was to set the cams and timers in the arming and fusing system and to electrically connect the warhead. This was done at the very beginning of the countdown at T minus 180 minutes and took approximately 15 minutes to complete. Each class session ran for six hours, so in theory two complete countdowns could be completed. However, with maintenance holds the first countdown always took close to six hours to get the missile to T minus 15 minutes. The meant the 331X0's had nothing to do for the remainder of the class session, other than disconnecting the warhead when the countdown was completed, so the next class could connect it. Most of this "nothing to do" time was spent watching other missiles launch and blow up.
During our training at the Cape we got a chance to watch the scheduled launch of a Snark test vehicle. However, at launch only one of the two booster rockets fired. This gave the missile enough thrust to get off the launch trailer but when the booster rocket burned out after four seconds, the missle did have the air speed to continue flying. The result was a very large fire on the beach and some unimpressed personnel.
The arming and fusing system of the Snark consisted of an aircraft gyrocompass, two sets of cams and timers, baros, proximity fuses, batteries, etc., and was contained in the nose of the missile along with the warhead. The cams slaved to the gyrocompass and were checked twice during flight by the missle guidance system. If the cams were not in the proper on course position the warhead would not arm. Access to the arming and fusing components and the warhead connections was through a 18"x24" hatch in the bottom of the missile's nose section. Work was done while standing on a mainenance stand and with the upper part of your body inside the missile completely filling the hatch. This made enforcement of the "Two Man Concept" very difficult. The second man could not see what the first man was doing (setting the cams and timers, connecting and safety wiring the warhead cables) and could only check the completed work; but then the first man couldn't see what the second was doing.
The W39 warhead was a Mk39 minus the afterbody and normal nose cap. A special nose cap was installed to hold a crossbar that was used to secure the front of the warhead in the missile. The aft end of the warhead was covered with a bathtub like cover containing the electrical connections. A single suspension point was mounted on the top of the warhead/bathtub flange and was used to secure the aft end of the warhead to the missile. Maintenance of the warhead was limited to paint touch up and electrical checks using the T-304C. The warhead was not operational long enough to require any LLC exchanges.
The warhead was mounted into the missile in a back to front position and mating was normally done in position 4 in the missile building by a team of four or five 331X0's. An electrically powered hydraulic trailer was used. One team member rode on each side of the trailer as the warhead was raised into the missile, checking clearance, and locking the ends of the crossbar into the missile fittings. The remaining mounting point was then secured, the trailer removed, and the two large doors covering the warhead bay were installed. The warhead was not electrically connected until sometime later, at the beginning of the countdown.
From the 331X0 standpoint the Snark was relatively trouble free. The main problem was the gyrocompass in the arming and fusing system. These were standard aircraft gyro's that were designed to operate for 10-12 hours at a time, not 4-6 weeks straight while the missile sat on alert. After 2-3 alerts the bearings would fail on the gyro and it would make the entire forward section of the missile jump up and down 6-8 inches. This would, of course, mean the missile would have to be taken off alert and the compass replaced. Safety procedures, with any missile problem, dictated the warhead be electrically disconnected immediately.
This meant disconnecting the warhead with the missile bouncing around and the compass threatening to come apart six inches from your back. Then there was a 3 or 4 hour wait, while the gyro wound down, before it was safe to change the compass. To complicate matters the launch officer was alway pushing to get the missile back on alert and it was sometimes necessary to point out we were working with a nuclear weapon ("You wouldn't want us to make a mistake, do you?"). This always resulted in the launch officer backing off and letting us work at our pace.
The 331's worked a rotating shift that required a minimum of two personnel on duty at all time. The day shift worked eight hours and the night shift worked sixteen hours. The night shift personnel (2) could sleep in the bunks that were provided, however they were required to respond to the priority missile within five minutes of the klaxon sounding. This meant sleeping fully clothed, including shoes, since in five minutes you had to wake up, start the truck (clean off the snow in winter), and drive to the missile building which could be as far as 1/2 mile away. In the winter this could be brutal, going from a sound sleep out into -35 degree temps and hoping the truck would start (if it didn't, you jogged).
The Snark probably holds the AF record for the shortest operational deployment of any weapons system. The first Snark went on alert on 18 March 1960, SAC declared the 702nd SMW operational in February 1961, however one month later President John F. Kennedy directed the phase out of the missile because it was "obsolete and of marginal military value". Shortly thereafter SAC ordered the close out of the 702nd SMW.
Unlike today's base closures which take years, the de-militarization of the Snark and the closure of Presque Isle AFB was very rapid. Within a couple of months all the missiles were taken off alert and all explosives, fuel, booster rockets, jet engines, and anything else of value were removed. The 331's removed the warhead, gyrocompass, and part of the arming and fusing system. The warhead and compasses were sent back to depot for overhaul and reuse while the arming and fusing components were broken up and sent to salvage. The missile's themselves were taken to salvage, forklift truck tangs driven through them, and then sold as scrap. With all the missiles gone and most of the personnel transferred, the 702nd SMW was deactivated in June 1961 and the base was turned over to the city of Presque Isle shortly thereafter.
|For the Snark picture gallery on the Air Force Museum web site|