Illustrations

Payload vs. Range Graph

Improvised Rocket Motor.

Loading Technique for improvised Rocket Motor .

Improvised Rocket Motor Missions . iy

‘Typical Multiple Round Launching Seheme . ..

Ignition Methods... 0... ce cc cee eens

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I, Introduction

Improvised rocket motors provide @ simple means for irregular forces to deliver military payloads to ranges beyond individual hand weapons without complicated Iaunch means, Improvised rocket techniques can be exploited to increase the firepower and effectivencss of guertillatype 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 mens are restricted to that common to the area of opera- tions,

‘Phe advantages of an improvised rocket munition are: A, Revoilless operation, }, Simplified launching techniques and apparatus,

(A mound of dirt may suffice in Lhe simplest ease.) C. High degree of mobility, (Only the payloud, motor

and ignition device need to be carried.) D, Munitions can be fabricated from materials available

from lbe environment or the local economy E. Unskilled labor can be used for manufacturing

operations. The identity of the manufacturing effort can be easily concealed.

This report will investigate a system using and providing the following features:

ts

A. Use of common materials for construction (pipe, pipe caps and nipples; saltpeter and sugar; wooden dowel, et cetera).

B, Recoilless, flashless performance €. Adaptubilily lo a wide spectrum of payloads and

ranges, 1, Suilable for a variety of ignition means incuding

powder train, hot wire, blasting fuse or homemade fuse,

E, Capability of being fired remotely or with a minimum. of 20 seconds delay for operalor security

F, Capability for instantaneous firing of multiple round salvos or single younds (for harassment or ranging)

CG, Exablishment of a relslively “standard” rocket camier design, determined from the materials avail able in the particular area, (This will simplify the allistics and provide the forces with a predictable weapon.)

Section IL, “Technical Diseussion”, describes the analysis and design approach Lo be used in providing the improvised hardware, (L also outlines the problem areas and consider- ations in providing reasonably useful munitions in a surrept.- tious fabricalion situation where quality control and mans. faclusing processes must be accomplished without tools other

than common hand tools and “eye hall” instrumentation.

I. Technical Discussion

A. BACKGROUND

In the period 1947 t6 1957, a large number of amateur rockel experimenters were engaged in the manufacture and testing of mdimentary rockets. By 1947, the information from the World War I rocket gechnology begin to become jocumented and disseminited, catching the imagination and

interest of many young experimenters. These persors, work ing alone or banding into groups, produved many hazaniaus and even lethal, rocket propelled missiles, Uinforlunately, the haaarous nature of be propellants selected, such as autel heads, shotgun shell powder. and home-brewed mixtures of volatile and inflammable uterials, proved more dangerous in the basement or garage laboratory than on the firing range ‘The “are number Of injuries from the uncontralled experi- mentation led to many local ordinances and Jaws prohibiting Lhe sale of certiin materials and alse restricting the firing avtivities to areas where adequate supervision could ve provided. ‘Ihis general awareness of the hazards of rocke experiments began about 1937, evidenced by the American Rocket Sovivty adopting an official organizational position opposing amatcur experimentation outside of qualified supervision, In xpile of the tustrictions, Lhe experimenters still found common materials which could he adapted to produce rocket. hardware

During the decade of more or less widespread amateur experimentation in rocketry, many combinations of propel- lant formulations were made and tested. Ingenious experi- menters devised wavs of extracting nitrates from the cheap and readily available fertilizers having this compound. Mixing this source of oxygen with various fucly provided very adequate rocket propellants. One of the materials found to

he readily accessible was sugar, A sucrose-potassium nitrate larmutution provides a specific impulse: fay derived from haliisie bomb dati) of akoul 130 - 140 seconds, In actual rocker? molor performance oo the oxder of 103 seconds is readily attainable. This compares with an I, of 200 for M7 propellant, currently in wide use in military Toekets

In preparing tnis book sever: pipe rockets were assem- bled and iested against wooden targets at sbost range, de- monstrating the feasibility of the propellant and body stractuse,

‘This study proposes sucrose-potassium nitrate for the im. provised rocket pyopellans, Both Ibex materials can be obtained in most of the world. particitarly in those areas where insurgency uperations are must probable. These designs for an improvised rocket. wii concentrate on this propellant aviature as the "stunelaed

In providing am improvised munilion of this type, this study will give alzention Lo ube following areas:

A. Propellant vin formulation and configuration 8. Grain installation in rocke hody for integrity” in

rough handling, storage life expectancy and reli- ability tn handling.

(, Assossment of environmentat effects such as opera- ting Lemperature ranges for vurions possible geo. graphical arcas. humidity and fungus

D. Safety E ‘Yraining. &, Effects of variations in materials of construction

on safety and performance security Aspects

Means should be provided to conceal the true nature of the items being fabricated.

HL. Launching preparation should be simple allowing. rapid setup and firing

1. Signature effects al the taunch site should be mini- mum

J. High reliability of operation should he 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 guerrillatype forces,

B. Generalized design guidance for instruction of guer villa personnel in the construction of improvised rock- ets, including safety precautions,

C. Descriptions of firing procedures, including rudi- mentary ballistics and fixe control under probable conditions of use,

D. Investigation of reliable ignition methods. Also, means for ignition of the improvised rockets for firing individual rounds and salvo or ripple firings of multi- ple rounds,

F, 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, DESIGN CONSIDERATIONS

This study’s proposed design will be based upon rockets using materials obtained from normal agricultural, con- struction or commercial sources. Referting 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 (4 to % inch water pipe bodies) to militarily useful diameters {minimum of 2 inches). ‘These include:

A. Length to Diameter (12:1) Raties A cerlain maximum (1./D) ratio cannot be execeded withoul genvralion of excessive chamber pressures, which ean rapture Ube chaniber wall,

B, Propellant “Watering” A certain content of water is necessary for efficient performance, Phis bas been reterred 10 as an “aid For compaction” by some ateateur groups, but the real mechanism affecting performance must be deter mined

©. Port Diameter to Nozzle Diamever ‘he usual rule, Ubat Lhe pore area must be two to three times tbe nozzle area does nol seem to bold rigorously for the rather soft, erodible grain fovmed by KNOgisugar, "This should be investigated

D, blfechive Burning Area Vo Throat Arca (Ky) Altemprs haye heen marke by the: amateurs to correl- me various working geometnes by Kp. Attempts indicated that a wrobable rass-action or permeable buming effect mary this relationship not whalzy straightforward, ‘This will bave wo be definitized before matoxs Larger than two inches ean We designed

Data is on hand trom the firings of over a thousand rockets assembled and <ired by a group of privale experi mentors comprising a rocket resnarch association, now dis bancled. This group, although using rudimentary materials for construction, maintained their records of fabrication and losting in a profess'onal manner and in sufficient detail to reproduce sheiv designs, ‘the bulk of the (ntore thin Shou sand) units prepared by this group were rockets fashioned

ou: stundanl 2 inch and % inch pipe. It is believed that similar designs can be sealed upward to provide rockets of two inch diameter having a maximum range of 4,000 melets carrying a one pound payioad, or correspondingly sioroer ranges Fir ercater sized payloads:

C, DESIGN CONFIGURATION AND PERFORMANCE

A “62 standard” (.62” is the inner diameter of common ¥ inch water pipe) motor has been fabricated and test. units fired with piezo-cleciric: 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 agtee quite well, On the hasis of these tests, a set of curves was draw to show payload delivery capabilities for the “.62 standard” and also 4 “.82" motor (% inch pipe), These curves are shown in Figure 1.#

A one pound payload, as an example, can be projected to 600 feet with » 62 motor and more than 1,500 feet with 4 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 concepls outlined in this proposal is shown in Figure 2.

Figure 3 shows the procedure for loading KNOg/sucrose propellant. After compacting. the grain with the hollow tamper, the mandrel (dowel) is removed to toave the perfor- ated grain,

D, DEVELOPMENT PROGRAM

In providing ap 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 sealing laws.

+ Although pipe sizes in a given area of employment may not be identical with standard U.S. pipe dimensions, performance should be comparable.

Curves are computed from the equation given in Paragraph E with the total impulse obtained from actual rocket tests.

PAY . 4sooh LOAD vs. RANGE

4000 5,

3500

3000 +-

2500 3/4 in, (.82) pipe 1/2 in. (62) pipe

2000

1500

1000|—

500}

RANGE (FEET) AT 45° LAUNCH ELEVATION

PAYLOAD WEIGHT (POUNDS)

Figure 1

ICTR TUB:

IMPROVISED ROCKET MOTOR

Figure 2

LOADING TECHNIQUE C. Design and development of a typical improvised For Improvised Rocket Motor rocket motor suiteble for construction by unskilled = : personnel using commonly available materials and ©} y tools. D. Fabrication of 85 cach proiniype pipe-hodied rockets _ teen (all loaded with KNOgisugar propellant), of the “ following pipe sizes:

Test firing of the above units, expending 25 of each type in static tests for characterization 40 euch in payload versus range tents, with 1/2 1a pound inert

ce tan heads. Impact pattern data will also be collected for bees an indication of dispersion F. Preparation and submittal of a final report describing

the designs, fabrication procedures for ficld accom plishment, firing and launching procedures, safety measures and the program activity accomplished eavcine during the program. A supplement will be prepared for the improvised weapons handbooks for each size rocket motor tested and ranye tables provided,

in addition Lo the basic rocket carrier, it is proposed that: a study be made of lhe employment of the rockwt.as a pructi- cal weapon, including possible payloads and the implications and interface considerations between the payloads and the rocket. The effort will include:

c 1/2 inch 3/4 inch

1-4/2 inch ‘\ 2inch

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 utlachment, arming and activation, performance characteristics and modi-

Figure 3 fications required to adapl rocket and payload.

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&, PERFORMANCE OF POTASSIUM NITRATE/SUGAR PROPELLANT

A composition of 70% Potassium Nitrate Technival Grade, 100 0 mesh (Tylerr with 30% suerore, commercial grade, crystalline, plus 3-5% water lo ad in compaction for grain fabrication (interna! burner only) has beep (ested in ballistiv bombs, providing the following data:

Assuming 2 molecular weigh! (MW) = 30 Ratio of specific heats () = 1.21 Tempernare of vomiuslon (Ty) ~ 2640°R Gives n specific impalse (1) = 137 see (500 psi > 15 psi Ina purvicular motor, the following determinations were

made: Characteristic exhauss velocity (c*) = 3080 fps

'y = 105 see With a thrust coefficient (Cp) 110 ALa propellant density = 0.08 Ibsin

Burning rave (r}) = 0.28 inixee (at 800 psi)

Lower limit, combustion chamber pressure (Pp) ~ about 100 psi

Upper limit, Py = more than 7300 psi

+ Although commercial purity materials may not be avail able to field forces, standord materials are cited here for reference and later comparison with uetual results ob- jained. The degradation of performance froin the use of “field grade” purity compositions will be investigated. Ht is possible, however, that materials can be obtained in pure form, thereby achieving optimum performance.

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a Sek ==,

-_——

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:

2

1 Ire Range at 45° clevation =| -— | ——————___—— & wnt Wyte

2

Where: § = gravitational acceleration 32.2 ftjsec®

fy = total impulse, Ibs = specific impulse x nant weight

Wm" weight of motor. Ibs Wp ~ weight of payload, Ibs w = weight of propetlant, Ibs

F, PAYLOADS AND MISSIONS FOR IMPROVISED ROCKETS Z

Once the basic propulsion unit is available, only the inge- nuity of the guerrilla personnel Limits the possitle mission for the rockeis, 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 paylouds such as incendiary mix- tures and biological materials which can be put together quickly by the guenilla 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 und bolts could be prepared for delivery with the

improvised rocket.

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IMPROVISED ROCKET MOTOR MISSIONS.

SUPPORT MISSIONS

OFFENSIVE OPERATIONS

Line Throwing

Antipersonnel

Access across obstacles

|, concussion, tear gas)

Granade throwing (shrup!

Projection of telephone wires

Antivehicular

between two friendly positions

Shaped charge

Signaling

Antistructural

Projection of flares and smoke

Shaped charge

Projection of message containers

Antiaircraft Ripple firings or simultaneous launch of rockets. carrying aloft trailing wires

Sabotage Remote firing of pre-positioned and concealed units into a secured area Projection of conductors over high tension lines or into transformer stations to short out service circuit

Figure 4

It is aasumed thay the guerrilis forces wall be armed te some degree with conventional weapons, parcielladly aand guns and grenades, ‘he most rffeet vr mayiond Zoe che Impro- vised rocket is the grenade: Lhe proposal primary mission ix as a grenade thiower, Available it: sw varecy of PTlings, lhe grenade provides a reliable, sell-comained unit wasity al fixed to the improvised racket carrier hy imervion in ay open ended can Iastened to the racket hesel can, ut would he of @ size to allow pulling of the erenade safely pir wh restraining the hand safety clip of the Us. type 4 Air drag during flight can fe used Lo seputette hee grenade from the can, or the grenade eam br amaryl co wepnrale {and arm) at ground impact, Other arming muuvations ean

eruades

be devised for friction mateh ¢pull typer gurers af some Foreign grenades.

Fhe improvised woeket’s yr. advan ix that i enn be made in moderate numbers quickly wish ordinary hand tools, oF its parts cian be pre-fabricated vid stored its partially finished stock, presenting the appearancr uf some ustespi« cious commercial product, When nevded, the unity can be loaded rapidly and assembled into the Lact ical von figuration, Paylouds can be affixed and even final asembly: ean be accomplished under cover or concen.ment st or near the auinch ste, Components can be brouulul, ine Lae assembly area hy separate persons for security uf"the operation and Personnel, A typical launch xrea sclap showing @ powder train ‘gnition method is depicted in Figure, The circular launch configuration and the venwal ormin for powder trains to each rocker allows ripple firings without one rocket exhanst extinguishing the powder wain of adjacent. rockets Vhe launch support shown in Figure 3 as a sunple forked stick cut lo a size to allow the 45° launch angle. ‘This ig acvomplished by providing the vertical beight of the support lo je 7/10¢h of the length of the rocket hody Lo Lhe point of support

In aldition to liek supports, mounds of dirt, convenient emixuikments, drain pipe or stove pipe, wooden Lroughs or a variely af other maaterrals as available in dhe area vay be usec fer reeked pest ioniny-nnl nuvi dareetional conteul

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LAUNCHING SCHEME

2 Zz 2, ° c w 2 e 2 2 =

4 2 = > e

Figure 5

Figure 6 shows examples of ignition means which can be used for fitings of individual or multiple rounds.

G. ‘PACTICAL FMPLOVMENT

Although the improvised rockets are of relulively snuall size, they can be used for projecting xelatively heavy payloads for shor. distances, For example, they mighl. he used as anti- vehicular or even antitank weapons, In suvi use, the rockel would be pre-positioned with its warhead and ignited yemote'y. A typical emplacement mighl be m an enubankiment Tlank’ng a defile or road traveled by vehicles, A very large warhead could be projected on a relatively Chu rajcetory for a range of 10-30 meters.

Ihe fabrication of shaped chast§ devices ist readily accomplished in the field. For example. the hottom config: usation of many wine hottles Corms an execllontly configured mold and Kner for a shaped charge. It is also possible to improvise an impact initiator using sodium chlorste, sugar and sulphuric avid (car batvery acid)

The possible use of the improvised rockely as antial craft. weapons should not be discounted, Ateanged in an under the approach or take-off pattems of airpoyus, oF pve: positionwd in prohable Landing areas (tyr aircraft ‘or heli- copwers, Ube improvised rocket cou.d prove 4 reasonably effective one time weapon. Tt would als br possible Lo use the rockets for air defense of an area by taunching salvos against pre-selected points in the alespuce over the ucrrill position, firing the rockets upon the approach and pussage through the airspace hy the target aircraft

An interesting mission for individual rackets is in the throwing of lines. A large variety of uses is possible here, In acls of sabotage, conductive wires cam be projected over high Leosion lines or into transformer stations to shor! out ciren'ts ef the electrical supply. Since critical electrival favilinies ate likely le be under close security guard or surveilluser, an ability to reach thr installation by rocket Tinwl from ic seem polish outsiele Ube securily area provide ances whirl might otherwise be impossible for che saboteurs

7

we | wee The same wire pulling technique can he used for friendly & 225 ee og eee ig support purposes — to interconnect two positions with tele: - 3 (gee 2 phone cable or to place alead line across an obstacle to draw e 3 qo 3 across a heavier interconnection for Turlher access across the

3 2 obstacte. ‘the improvised rocket would he best employed with pay

loads and missions which explost the haste features of the improvised device. These missions ire

A. Grenade throwing for antipersonnel and limi structural damage.

a

B, Line throwing for acess ince scoured areas or a spanning obstacles.

‘The guerrilla force) having a rpcker capabiity will find iliaking tie AF eexplayeeny i Mw iene cin aching in ther envitonment. They will use both individual vockels to solve specilie access problems and multiple round firings for their defensive and offensive operations, The iumprovised Torkel will add a shock and surprise capability to insurgent operations. It will give the ugents not only grewler slriking opportunity but better security and abilicy to escape after actions, Ones used by the guerrilla force, rockets will expand the opposition’s manpower requived for uhe security of vital inskallations, making the counter-tsurgency effort more burdensome and costly

The improvised rocked will add « dimension to guerilla operations impacling both the tacticat and_ psychological areas of the insurgency cituslion, The rocket capability will strengthen the effectiveness and morale of the guerrilla force, while presenting the opposing authority with a new and unexpected problem, Inctensed suppressive effort. over larger areas rust be applied Lo counter the suddenly incteased vulnerability of his installations, equipment and personnel At a very low cust lo the guerrilla io time and effort, his harassment value will be enhanced significantly dhrough addition of the improvised rocket to his “rgenal”,

Figure 6 J 9 =

i |

IGNITION METHODS

a e 5

tran wis wy

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APPENDIX

Table J, following. gives che results of more than 1,000 test firings of polassium nitratessuerose propclied 10 Is using w propellant formulation ay deseribed in Paragraph Section II, “Technical Discussion", Tests were conducted during the period 1917-50, Nowlion wed on Table | follows the conventions outlined in the seeiiom following Ihe Table “Simple Expressions For Quick Look KsLmations of Sold Propeilan!. Rocket. Motor Performance"

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te L

te] ze

foo | zz

° ov |

vee vontionied

; s

fae | estes]

az |

o | ov |

vee weneiaieg

aie een

sel 1

y [oo |

ce |

ce [attha)

vee napa

; vei

| oe |

uw |

se | co

vonnioyeg ;

Taiopa vezi |

s [ari |

see |vaa| ae | s |

sev |

zz imonng -

- isms

weet |

ot | ort |

see loen|

az |

2 | seer |

ceo eas oi |

os [om |

st |leon| ov | se | ze eee

: : Taped coer |

1

[or] se

fev] oer |

se |

zee oe

Tai Sears

= s

v et

el ssopag

on) St

payolysey

eam |HioNa1 8

zuusar |

sen |

oy) |

saa |

we cn | eee

an

Nivao.

ANV113d0Ud JSOHINS/EOND

H.LIM S1S3L YOLOW L3NDOH

4O ANVWANS

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CLOSED BOMB DEVERMINATION OF SPECIFIC IMPULSE:

z@| 2 8 é i Bomb Volume = V, ce

" Propellant Weight — w.gm fe

as S 7 Maximum Pressure ~ P, Ibjin2 2 a ge Ze Impetus = Fimp ttlbsb

cE F 2 ae a] 2 im Sa qe 2 ° Wy ge 4 ae as & aé ky ~ 2,307 (covolume and dimensionless 3 : unit conversion factor) o2 | z * ka (Pimp) 2 Be * 2 ale ‘ > kg (Pimp) oe é 8 3s fe " ar = 7,72 (unit conversion fie 88 " $ Lo ae (unit sion factor)

ae gigia* 8 4 1 bo. z a 3 ga = Ele 4a é B ge = a ky ~ 0.240 (dimensionless factor) aS eaeear 3 gz giizja- 8 15 ~ ky (Fimp) 1:2 aa! 0 2 3 a B 3 1,000 psi 2G “ Be 3s % is mt io. ky = 0.879 (unit conversion factor)

=< ig |g8 28 3 ee Zz NOTE: Constants kj, kg, kg and ky above are empitically a 1 e 3 derived factors which give approximations Lo the quantities 3 3 3. expressed for quick Jook evaluations of the proposed solid 3 gar propellant rockets as derived Irom amateur group experi- Bu » Se» D8 ae ments

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