Illustrations I. Introduction Payload vs. Range Graph 8 Improvised Kockct Motor 9 Loading Technique for improvised Rocket Motor 10 Improvised Rocket Motor Missions 14 Typical Multiple Round Launching Scheme 16 Ignition Methods 18 Improvised rocket motors provide a simple means for irregular forces to deliver military payloads to ranges beyond individual hand weapons without complicated launch means. Improvised rocket techniques can be exploited to increase the firepower and effectiveness of guerrilla-type forces. Having the great advantage of not requiring heavy launching equipment, such as conventional mortars and artillery pieces, rockets are aptly suited to the characteristics of operations and capabilities of irregular units whose weapons must be concealed between use and whose transport and logistics means are restricted to that common to the area of opera- tions. The advantages of an improvised rocket munition are: A . Reco i Hess o per ation , B. Simplified launching techniques and apparatus. (A mound of dirt may suffice in the simplest case.) C. High degree of mobility. (Only the payload, motor and ignition device need to be carried.) D. Munitions can be fabricated from materials available from the environment or the local economy , E. Unskilled labor can he used for manufacturing operations. F. The identity of the manufacturing effort can be easily concealed. This report will investigate a system using and providing the following features: A. Use of common materials for construction (pipe, pipe caps and nipples; saltpeter and sugar; wooden dowel, et cetera) . tv 1 11. Technical Discussion K . R.eC( > il ] e s.x , flash less p e rf orman ce . C. Adaptability to a wide spectrum of payloads and ranges, I). SuiLable for a variety of ignition means including powder train, hot wire, blasting fuse or homemade fuse. E, Capability of being fired remotely or with a minimum of 20 seconds delay for opera l.or security. K. Capability for instantaneous firing of multiple round .salvos or single rounds (for harassment or ranging), O. Establishment of a relatively “standard” rocket carrier design, determined from the materials avail- able in the particular area, (This will simplify the ballistics and provide the forces with a predictable weapon.) Section II, “Technical Discussion ”, describes the analysis and design approach to be used in providing the improvised hardware*. It also outlines the problem areas and consider- ations in providing reasonably useful munitions in a surn-pl.- lious fabrication situation where quality control and manu- facturing processes must lx* accomplished without tools other than common hand tools and “eye hall" insl-ru mentation. A. BACKGROUND In the period 1 i)47 to a large number of nmnlcnr rocket experimenters were engaged in the manufacture and testing of rudimentary rockets. By ltMT, the information from the World War II rocket technology began to become* documented and disseminated, catching Ihc imagination and interest of many young experimenter^. These petrous, work- ing alone or banding into groups, produced many hazardous, and even lethal, rocket propelled missiles. Ijn fori limit ely, the hazardous nature of the propellants selected, such as match heads, shotgun shell powder, and home-brewed mixtures of volatile and inflammable materials, proved more dangerous in the basement- or garage laboratory than on the firing range. The large number of injuries from the uncontrolled experi- mentation led to many local ordinances and laws prohibiting the sale of certain materials anti also restricting t-he firing activities to areas where adequate supervision could oe provided. 'J his general awareness of the hazards of rocket experiments began about- 19o7, evidenced by the American Rocket Society adopting ail official organizational position opposing amateur experimentation outside of qualified supervision, In spin* of the restrictions, Ihc experimenters still found common materials which could be adapted to produce rocker hardware, During the decade of more or less widespread amateur cx peri men mtion in rocketry, many combinations of propel- lant formulations were made and tested, Ingenious experi- menters devised wavs of extracting nitrates from the cheap anil read i I y uvai l ab I < * I'erti I i ze rs h avin g th is co m p ound Mixing this source of oxygen with various fuels provided very* adequate rocket propellants. One of the materials found to 2 3 ?>■' readily accessible was sugar. A >ucro so -potassium nitrate formulation provides a specific: impulse fas derived from ballistic bomb data) of about T ,10 - 1 1 0 seconds, In actual rocket motor performance on the order of 105 seconds is readily attainable. This compares wife an I s of 200 for M-7 propellant, currently in w df u sc ill military rockets. In preparing tin is book several pipe rockets were assem- bled and te.-led against wooden targets at abort range, de- monstrating the feasibility of the [trope llanl- and body struct m't'. ' Fir U slu d y prop o se s su < : ro se -y t o t a ss i 1 1 m nit ra U : fo r th e im - pro vised rocket, propellant. both flies*- materials can be obtained in most os' the world, particularly in those areas where insurgency operations are most probable. These designs for ar, improvised rocket, will concentrate on this propellant mixture as the “standard." In providing an improvised muni Lion of this type, this study will give attention to the following area.-: A. Propel lan I grain formula lion and configuration. li, Grain installation in rocket, hotly for integrity in rough handling, storage life expectancy and reli- ability in handling. C. Assessment of environ mental effects such as opera- ting temperature ranges for various possible geo- graphical areas, humidity and fungus. D. Safety. E. Training. K. Effects of variations in materials of construction or safety and performance . G. Security Aspects Means should he provided to conceal the true nature of the items being fabricated, II. Launching preparation should be simple allowing* rapid setup and firing. 1. Signature effects at the launch site should be mini- mum. J. Iligh reliability of operation should be obtained to avoid problems of disposal of duds. Our effort will provide: A. Specific hardware designs and sample prototype units of rocket motors of simple design constructed from common materials such as would be readily available to guerrilla-type forces. B. Generalized design guidance for instruction of guer- rilla personnel in the construction of improvised rock- ets, including safety precautions. C. Descriptions of firing procedures, including rudi- mentary ballistics and fire control under probable conditions of use. D. Investigation of reliable ignition methods. Also, means for ignition of the improvised rockets for Tiring individual rounds and salvo or ripple firings of multi- ple rounds. K. Report of effects obtainable from the improvised rounds, including: range, payload, probable disper- sions under standard and non-standard conditions and possible type payloads, F. Prediction of degradation in performance from optimum due to fabrication variances, materials impurity, field handling, storage and environmental conditions. B. DKSIGN CONSIDERATIONS This study’s proposed design will be based upon rockets using materials obtained from normal agricultural, con- struction or commercial sources. Referring to the early work done by the amatuer groups in the practical application of rocket design theory to their hardware, their experience indi- cates that some experimental verifications and detailing is required before scale-up of their small diameter rockets (’A to y* inch water pipe bodies) to militarily useful diameters {minimum of 2 inches). These include: 4 5 A. LoiigLh l.o Dinnieier ( l./Dj Ratio A cor Lain maximum { 1,/D) ratio cannot be exceeded with on l genera lion of excessive chamber pressures, which i nn rupture the chamber wall. B. Propellant “Watering” A certain content of water is necessary lor efficient performance. This has been referred lo us an "aid lor compaction'' by some amateur groups, but the real mechanism affecting performance must ho deter- mined , (.' . IT rt Dia m r ter to Nozz] e D i am e le r The usual rule, that the port area must be two to three times tbs- no? do area dues nol. seem l.o bold rigorously tor the rather soft, credible grain formed by K NO;.> /sugar . This should be investigated. D. Effective Burning Aren To Tliroal Area (K n ) Attempts have been made by the amateurs to correl- ate various working geometries by K n . Attempt* indicated that a or u Viable mass -act ion or permeable burning effect make* this relationship not- wholly straight forward, This will have to lie definitized before motors larger than two inches (ran Undesigned. Data is on hand from the firings (if over a thousand rockets assembled and fired by a group of private experi- menters comprising a rocket research association, now dis- bar, ek'd. This group, all hough using rudimentary materials for construction, maintained I heir records of fabrication and Lesiing in a profess’ on al manner and in sufficient detail to reproduce their designs. The bulk of the (more t.h;ui a thou- sand) units prepared by this group were rockets fashioned from >i;uidard .j inch and A inch pipe. Ii is believed that similar designs can be scaled upward to provide rockets of i wo inch diameter having a maximum range of -1,000 mt-ier* carrying a one pound payioad, or correspondingly shorter ranges fov treat cr sized payloads. c. design configuration and performance A ".62 standard" (.62“ is the inner diameter of common V4 inch water pipe) motor has been fabricated and test units fired with piezo -electric gauges attached, burning times are much shorter and thrust levels higher than performance of the propellant in amateur testing has indicated. However, the total impulse seems to agree quite well. On the basis of these tests, a set of curves was drawn to show payload delivery capabilities for the ".62 standard” and also a ".82” motor ( S A inch pipe). These curves are shown in Figure 1,* A one pound payload, as an example, can be projected to 600 feet with a .62 motor and more than 1,500 feel with a .82 motor. Extrapolating to a two inch pipe motor gives a range of nearly 12,000 feet for a one pound payload. A conceptual drawing of an improvised rocket motor embodying the concepts outlined in this proposal is shown in Figure 2. Figure 3 shows the procedure for loading KNOy /sucrose propellant. After compacting the grain with the hollow tamper, the mandrel (dowel) is removed to leave the perfor- ated grain. D. DEVELOPMENT PROGRAM In providing an improvised rocket concept, this study proposes: A, Examination of basic design models to establish definitive criteria involved in predictable scaling of motors to meet variable diameters and character- istics of possible body construction materials. B. Performance of testing to validate and formalize the scaling laws. * Although pipe size s in a given area of employment may not be identical with standard U.S. pipe dimensions, performance should be comparable. 6 7 RANGE (FEET) AT 45° LAUNCH ELEVATION Curves are computed from the equation given in Paragraph E with the total impulse obtained from actual rocket tests. PAYLOAD WEIGHT (POUNDS) Figure 1 8 9 «rtuo«L-t IMPROVISED ROCKET MOTOR , Figure 2 s/ LOADING TECHNIQUE For Improvised Rocket Motor Figure 3 10 C. Design and development of a typical improvised rocket motor suitable for construction by unskilled personnel using commonly available materials and tools. D. Fabrication of 6b each prototype pipe-bodied rockets (all loaded with KN'0 3 /sugar propellant), of lire following pipe sizes: 1/2 inch 3/4 inch 1-1/2 inch 2 inch R. Test firing of the above units, expending 2b of each type in sialic tests for characterizaLion.*nd 40 each in payload versus range tests, with 1/2 i.<>?| pound inert heads. Impact pattern data will also he collected for an indication of dispersion. F. Preparation and submittal of a final report describing the designs, fabrication procedures for field accom- plishment, firing and launching procedures, safety measures and the program activity accomplished during the program. A supplement will be prepared for the improvised weapons handbook, for each size rocket motor tested and range tables provided. In addition to the basic rocket carrier, it is proposed that a study be made of Ihe employment of the rocket as a practi- cal weapon, including possible payloads and the implications and interface considerations between the pnyloj«Js and the rocket. The effort will include: A, Study and design of ignition means for individual and multiple round firings, including delay provisions. B. Payload interface investigations, including recom- mended payloads, methods of attachment, arming and activation, performance characteristics and modi- fications required to adapt rocket and payload. 17 !J. PKRKORMAXCK OF POTASSIUM X IT R ATE/S U 0 A R PROPELLANT A composition <>S 70'" Potassium Kitrate leehnic&l Grade, 100 SO mesh (Tylerj with 30',v sucrose, commercial grade, crystalline, plus 3-5 r * water lo aid in compaction for grain fabrication ( int-ema 1 . burner only) has been tested in ballistic bombs, providing the following data:* Assuming a molecular weigh I (MW) = 30 Ratio of specific heats (k) 11 i.21 Tempers! ture of combust jcm (T t .) - 2(>40°R Gives a specific impulse I k = 137 see (500 psi -> 1 5 psit In a particular motor, the following determinations were made: Characteristic exhaust velocity (c*) >s With a thrust coefficient (Up) At a propellant density Burning rate (r^) Lower limit, combustion chamber pressure (P c ) Upper limit, P t . - 3080 fps = 105 sec - 1.10 = 0.05 lb; in 3 = 0.28 in/sec tat 800 psil ~ about 100 psi - more than 7500 ps* t l I I =i= AH hough commercial purity materials may not be uvaii- rrble to field forces, standard materials ore cited here fr>r reference and later comparison with actual results ob- tained. The degradation of performance from the use of “ field grade" purity compositions will be investigated. It is possible, however, that materials cun be obtained in pu re fo rm , the re by ac h <7? ving optima m perf orma j ice. The performance of this propellant, then, is slightly supe- rior to black powder. The specific impulse derived from motor data was used to compute the range versus payload graph of Figure 1 as follows: Range at 45° elevation - 1 g ii & w m +v V w 2 VVhere: g h' = w m~ w p = gravitational acceleration 32.2 ft/sec^ total impulse, lb-sec^ specific impulse x propellant weight weight of motor, lbs weight of payload, lbs weight of propellant, lbs F. PAY I. CADS AN13 MISSIONS FOR IMPROVISED T>nrvrTC Once the basic propulsion unit is available, only the inge- nuity of the guerrilla personnel limits the possible missions for the rockets. A number of payloads are immediately sug- gested, ranging throughout the spectrum of regular munitions. Possible missions are shown in Figure 4. There are some types of payloads such as incendiary mix- tures and biological materials which can be put together quickly by the guerrilla fighter, for example, the Molotov cocktail mixture. It would be possible to assemble improvised “tomato can” munitions for use with the improvised rocket. High ex- plosive charges, surrounded by available small hardware such as nails and bolts could be prepared for delivery with the improvised rocket. 12 13 Projection of conductors over high tension lines or into transformer stations to short out service circuit It is assumed that the guerrili:! forces w.J] be- armed to some degree with conventional weapons, particularly hand guns and grenades. The most iTIVcIlve nay Load for the impro- vised rocket is the grenade: l.he proposed primary mission is as a grenade thrower. Available j r . a var.e.v of filings, ihe grenade provides a reliable, seJl'-cmr.ahml unit easily affixed to the improvised rocket carrier l>y insertion in an open ended tain fastened to the rocked, head can. The can would be of a size to allow pulling of the grenade snl’eiy p : r while restraining the hand safety dip of i he |i s, type grenades. Air drag during flight cun be used lo separate the grenade from the can, or the grenade can he arranged ■.<> separate {and arm) at ground impact. Other arming mnovaiion.-j can be devised for friction match (pull iypn igm’.crs of some foreign grenades, I b<‘ improvised rocket ’s great udvaiui^ is that it can be made in mode rale numbers quickly with ordinary hand tools, or its parts can be pre- fabricated and stored its partially finished stock, presenting the appearance nf some un. suspi- cious commercial product. When needed, the units can fie loaded rapidly and assembled into the Laclical configuration. Payloads can be affixed and even final assembly can be accomplished under cover or cuneen.ment :ir or near the launch site. Components can be brought. iti:«> the assembly area by separate persons for security i if 'the operation and personnel, A typical launch area setup showing a powder train ignition method is depicted in figure f>, The circular launch configuration and the ecu a' a I origin for powder trains to ear’ll rocket allows ripple firings without one rocket exhaust extinguishing (.hit powder train of adjacent, rockets. The launch support shown in Kigure -j is a simple forked stick cut l.o a size to allow the 45° launch angle. This is accomplished by providing the vertical height ofthe support l.o be 7/] Oth of the length of the rocket body l.o Ihe point of su pport. In addition Lo slick .support, >, mounds of dirt., convenient embankment.-., drain pipe or stove pipe, wooden troughs or a variety of olher materials a.-, available in the area can he used I'U- rn.’kel posil inning and initial dlieel iolial control. lb Figure 6 show* oxamplos of ignition means which can h<* used For firings of individual or multiple rounds. G. TACTICAL EMPLOYMENT Although the improvised rocket* arc of relatively small size, they can be used for projecting relatively heavy payloads for short distance*. For example, they might be used as anti- vehicular or even anti-tank weapons. In such use, the rocket would be p re -positioned with its warhead and ignited remotely. A typical emplacement might be jo an embankment flanking a defile or road traveled by vehicles. A very large warhead could be projected on a relatively flat trajectory for a range of 10 -30 meters. , The fabrication of shaped ehargWV devices is' readily accomplished in the field. For example, the bottom con fig- urn Lion of many wine bottles forms an excellently configured mold and liner for a shaped charge. It is also possible to improvise an impact initiator using sodium chlorate, sugar and sulphuric acid (car battery acid). The possible use of the; improvised rockets as antiair- craft weapons should not be discounted. Arranged in arrays under the approach or take-off patterns of airports, or pro- positioned in probable landing area* (t>r aircraft or heli- copters, the improvised rocket cou.d prove a reasonably effective one time weapon, ft would also be possible to use the rockets for air deftm.se of an art 1 ;] by launching salvos against pre -selected points in the airspace over the guerrilla position, firing the rockets upon the approach and passage through the airspace by the target aircraft. All interesting mission for individual rockets is in the throwing of lines. A large variety of use* is possible here. In acts of sabotage, conductive wires cun he projected over high tension lines or into transformer stations to sborl out. circiiT* of the electrical supply. Since critical eledricul facilities tire likely lo he under close security guard or >i i rvc i I lance, an ability to reach the installation by rocket ruvi| from a M'cinv point outside the security area provides nr< e-.:i which niighl otherwise he impossible for the saboteurs. 16 17 The same wire pulling technique can he used for friendly support purposes — to interconnect two positions with tele- phone cable or to place a lead line across an obstacle to draw across a heavier interconnection for 1'url.hor access across the obstacle. '['he improvised rocket would be best, employed with pay- loads and missions which exploit the ha>ic features of the improvised device. These missions arc-: A. Grenade throwing for ar.t : per>onn<-1 and limited structural damage. Ji, Line throwing for access into secured ureas or in spanning obstacles. The guerrilla force/ having a rocker, capability will find missions for its employment to Jp^fei ninny nreds arising in their environment, they will use both individual rockets to solve specific' access problems mid multiple round firings for their defensive and offensive operations. The improvised rocket will add a shock and surprise capability to insurgent- operations. It will give Lire agents not only greater striking opportunity hut better security and ability to escape after actions. Once used by the guerrilla force, rockets will expand the opposition's manpower required for the security of vital installations, making the counter-fpsiirgeney effort more burdensome and costly, The improvised rocket will add a dimension to guerrilla operations impacting both the tactical and psycho logical areas of the insurgency situation. The rocket capability will strengthen the effectiveness and morale of the guerrilla force, while presenting the opposing authority with a new and unexpected problem. Increased suppressive effort over larger areas must be applied Lo counter the suddenly increased vulnerability of his installations, equipment and personnel. At a very low cost U> the guerrilla in time ami effort, hiss harassment value will be enhanced significantly through addition of the improvised rocket to his “arsenal”. 13 19 APPENDIX TaV>le I. following, gives the results of more than l ,000 lest firings' of potassium nitrate 'sucrose propertied rodrels Utinfe/ a propellant formulation US described in Paragraph. K, Section II. ‘‘Technical Discussion’'. Icsts wm conducted during the period 10-17-50. Notation used on Table 1 f€»lloT¥» the conventions outlined in the see lion following I he 1 able: “Simple Expressions For Quick book h* Lunations of So. id Propellant Rocket- Motor Performance”. 21 22 23 SIMPLE EXPRESSIONS FOR QUICK-LOOK ESTIMATES OK SOLID PROPELLANT ROCKET MOTOR PERFORMANCE 24 1.46 1.56 1.60 1.65 Note : Max Ctt - 2.246 CLOSED BOMB DETERMINATION OK SPECIFIC IMPULSE; Bomb Volume = V, cc Propellant Weight _ w,gm Maximum Pressure - F, lb/iiv^ Impetus = ft-lb/lb ^imp = k| £ w,'\: k| - 2.307 (covolume and dimension legs unit conversion factor) k 2 - 7,72 (uniL conversion factor) T * - KjjCp ( I'impI V2 R - 0.240 (dimensionless factor) I 5 ^4 ^imp) I ,(>00 psi kq - 0.279 (unit conversion factor) NOTE; Constants kj, k. 2 , k 3 and kq above are empirically derived factors which give approximations to the quantities expressed for quick look evaluations of the proposed solid propellant rockets as derived from amateur group experi- ment:.. 25