FLETCHER Cl

or

REPLY TO: 218 W. CHURCH STREET JACKSONVfLLE, FLORfDA 3:!Z02 .TELEPHONE 354.0922

ACHIEVEHi;liTS Al'Il DgVELOF~Et-rrS

ARTIJOt-1-( F" A R EAST Co., L TO. P. 0. Ou>: 1 201l

CCTOBSR - 1970

ARTUDAR EUROPE N.V. CDDLiliNOCL 57

RnT r c noAM. I COL.1.A.NO

by

Edwin H. Fletcher

Liccrucd Projmiowzl Fllltillfcr . NCW YOrtK. FLOitiDA . J.Otli~I.\ NA . VERMONT

'.

ARTUBAR ACHII::VSJ.ENTS AS OF OC'T03BR 20, 1970

ARTUBAR is nothing IOOre than an articulated tug/barge system for ocean operation.

This ocean-going, push tug system is the accumulation of five years of intensive engineering and research; and represents a remarkable advance~nt in the State of the Art for efficient high-speed, tug/barge operations.

To date ARTt~~ represents ~ analysis of approximately 15,000 ft. of film, 5000 ~ hours of model basin scientists and tecPJdcians,

. and 8000 hours of engineering design and research. Covering, tug and baree de~ign connection syste~~ ie fixed energy, adjustable energy absorption, and free-slot, in addition, variations in spacing between tug and barge v!ere also analyzed.

In reference to all the above, the estimated emottnt. of recorded data, in regard to readings taken, was appi'o:dJr.ately 750,000 readin~s. }bst of these readings were taped and the data computerized.

vndle ARTL~ut is a patented design, it contains no novel or untried eqUipment or principles.

Tugs have been pushine and tmdne barges for years and it is an established fact that pushing is the ~st efficient and safest arrangement of the tug and barge combination.

l "'l'he ecohomcs of push tow has lead to mmy types of tug-barge connec-.tions. All '-!ere developed llith the hope that the tug vroUld be able to rer~n in the push position throughout its voyage.

To date no tug barge combination \dth independent motion \rhich is considered as t\10 distinct vessels each able to operate s eparately has been able to achieve this goal , 'd th the exception of AR'IUBAR.

Tugs pushing barges \od.th or \otithout notch are OO.aicl!lly designed for sn:ooth \:a ter operations; hO\:ever, this can only be achieved W'i th present z:ot.hods in rcn:x::iJ::lum seas of 6 1 - 8 1 cr to 10 1 Hi th larger units -- then the tug I::iUSt corr.e out of the bo..rge stern notch ~d co~e onto the h~~3er. This systGm hus many ve17 serious dis~vanta~s.

First of o.ll, it is bro:lkir..e loose the c01mections to cor~ out of the barge notch, the loosening up of tho cables, setting the adjustabla skegs for towine, etc., can be vc17 do.naerous to

Ed\.r.l..n li. fletcher & Assoc., 218 H. Church Street 1 Jacksonville , Flo..

-2

equiyllnents, and very h!!.zardot~t:J to the safety of cre\..r a:nd tug. In fact, h:o tuas bo:1.ts v!ere lo~t in 1969 - o!"le in the Gulf of l;~:rlco :::.nd one in Va.tlcot.'Ver, Britr..ish Colur.bia, under basically similm c.irc'I..Unsto.ncoes .

The one in the Gulf of }r,;,x:tco we lmow. Yr.ore about. The adjustable skegs we 'tmdersk.r!d \.'~ro not properly set - the bs.ree Rw.me a.round and capsized the tug 'Ji th :-esul tant loss of life o

Dr o E,. C,. D. Corlett,. :i..n his paper on 11 I."1.tt::crrated Cargo Units" showo sor.e various adva.>1taees C'.nd d:i.sadv!!.nt::t~es of o. f ew sys-tcm3.

Hmo~ever, he h!ts rmde no conpa=i;:;on \lith !;.Tt'l'L"TI;.r-:. 't:hi~h - ~gain is even superior to 2-ny he has considered (proven tank tests o.re the basis for this fact). See Page 2a. Dr. 'Corlett's Figure 1 also inclt~~es other concepts which on1y point out the superiority of' the f..RTl!B1~ concept. Tlrl.s superiority is also recorded in tank test results.

~lith .ARTU3!.R there is no such problem as previously noted. There are no acljustable sker5s. l!y p!!.tented '.tine lt.:!ll skegs aro n :most highly efficient ( 11re!:lm'kll.ble 11 ) trncl:i.nB method yet. devised for a barge. The adjective 11rem.;.rkable 11 is not rey uord , but that of f oreiTnst scientists after exter.sive model basin test~ in Et~ope.

The direc-tors and lending scientists at both NSllB and HarnbtU'g ha11e made most favorable re!l"..ark:3 about /JlTtJr:Yill in tbeir report:!, excerpts of ,.,hich are attached. Netherlands Ship lbdcl Basin Ha:,1Ci1ingen Report ~lo. 68 - 103 - m:r Page 3 states as follous:

S!Ui'nY:

nThe '-

C' . v8SSlOn: Integrated C2rgo Units Paper No. 2 / =-/

-J-

\-!hen the .l:..t1TUSA.R concept disconrwcts, it is guided free of the . barge through the o..djoinine par3.llel sm-faces. Froro a pure stand? oint of safety, there c~ be no comparison of present wethods with A.'\TU.?.AR, as .1\RTU3A..~ is for superior.

The evolution of Art'l'ffi");\.-q, as uell as other designs referred to, is . prcdico.t3d on various f~ctors, such as econoi:"d.cs, safety, etc o The tug barge col':'lbinn.tion bas economic advantages in the following ttee.s Hh~m co!:!p3.red to conventional ships:

1. Construction cost

2. H:l.intenance and crew cost

3. Greater cargo capacity

4. Shorter yard ti.Ite for repairs, lm-rer maintenance costs, etc.

~~Tml~ as a tug ~_rge combination has not only the above advantages but also the follol-dng:

1.. H:meuverabili ty .and sea keeping

J. Discormect in any sea. state frotl pilot house or local station.

4. Connect up with up to 18 inches vertical misalignment of pin and bearing.

5. Tug with ~Tua~~ pin, does not have to be considered dedicc.ted as it can tm.,r '-'lith hi~rser or push in conven-tion:D. cable lash up, or the tug can be used as a conventional tug.

6. Barge lvi th l.RTUBAR ster:1 can oo to\Ted rr.ore efficiently by any tur:: and also pushed by conventional tug ldth cable lash up.

7 o ARTUB.~..R units have hieher ::;pecds uhen cor::pared with other designs on instoJ.J.cd horsepmvar m;rr basis.

8 ~ Increased cre\r comfort in all s'=lc. states as pitch is ~ a~d roll is tlut of b.:lrge.

In stnmr.:iU'Y, tho lJ?.'l'lB'\.R system has in its sir.:plicity none of the objectional fc~tures of the other systemso AR'l'UBt .... ~ has had COf.o/lete plan inspeqtion in the United States by ABS ar~ USCG as t~o separate units.

E

Speed Knots

6

7

8

9

10

11

12

13

14

-4-

In reference to safety 1 ono of tho key con3idcrutions is com-so stn.bllity 1 if you ever ~u to use the oorga on the hn.u~er wi.~h another tu!_!. In this reenrdo, the att..1.ched sketch shouine Tv3ta 1 and 11 indicates the e:

lt\

'

..

..

.

TEST I

0

TEST IT

0

COURSE S Tt,BILITY TESTS DRAFT 31 1 -0 ''

TRIMMABIE SECTIONS OF SKEGS SET J,T 27 OUTWARD AFT

.500 M

!RAFT JlY-0 11

+

SPEED = 8 o .5 KNCY.rs 1000 M

lt.'ING WALL SKEGS

c:: ------------

,500 M I

SPEED = 8 . 0 Kriots

1000 M . I

. .. .

1.500 M 2000 M

MAX + :: )2 M MA.X - :: )6 M

2.50

}!AJ. + :: .5 M ~ ... ::r 10 M

-------- --= *==- 3- -=r

. 1.500 M. I

2000 M I

25(

-6-

I have done extreme extensive ~odc1 ~esting - in f~ct, completed nrJ l n::;t tests on September 2, 1970 at Jb.Ir.burc, Gcrm,!:ny. The &'1Tli~~;.n. concept - in all seas tested in every direction - hns never 3Ubmereed at the stern, nor has it ever taken heavy green water ~1er the stern.

Tests to determine seakeeping, tracking and p~n forces have been conducted at St-::vens Institute of Toclmolog:.r, University of lj_chiGan, USl-8,-Ho.eeninccn, r..olland as well as the latest tests at the Ho.mburg H:>del Ba.sin.

?he rco.son for tcstine at so Il1.any recognized tanks l-Ias to have complete comparative data and to utilize all the latest techniques in the marine model test field, as well as the expertise of each major test facility. Phase I Tests

These tests ue::-e coneucted for resistance and tracld.ng character-istics . These tests shmred that the .ARTUBt~...Tt loring \-!all skeg had a reduction in added resis~nc~ of up to 50% as compared with conventional fixed or adjustable skegs, and even more t.rhen compar-ing full ships bows.

Ph-3.se II Tests

Ths Dreyfus tests vrere conducted from the Phase I lines usine a tug and barge to deter~e both forces in reavy sea states and operational characteristics iJ:l extremely heavy seas.

The models used in these tests are 1 to 30 scale, the following is a to.bulation of the tucr and barge particulars:

Ves:;el Data

~trt: t .0 .A . lU.d Beam Hld. Depth Draft

Displace~nt

Propellers to be:

= 126 1-111 31'-10" =

= =

=

20 1-5n (Sta.. Uo. 5) 16 1-611

SlQ ST B-4-44 - 12 1-011 Dia.

Edttin H. Fletcher & Assoc., 218 H. Church St., Jacksonville, Flao

-7- .

12 .ooo nmll'. B,;trr.re L.O.A. - .J95'-0"

-

1-fi.d. Bee.t1 = 70'-011 - la.C. Depth 35 '-O" :

Drnft = 25 1 Displacetr.ent = 1!; .610 ST

16,000 DDH'l'. B~rge

L.O.A. = .468'-9" l~d. Beam = 70 1-011 Hl.d. Depth = 35 1-011 Draf't = 25 ' Displacement = l9~200ST

As the Phase I tests 1.:ere not conducted to record forces, we "Will refer to the se.me tug a..11d barge usin:J the HSH3 test r eports for this inforrration. These \>!ere conducted in sea conditions consider-ably n:ore serioU3 th.an hurricane conditions in the Gulf of ~exico. In fact, the significant "'ave heieht v:a.s 505~ higr.er, of course, resulting in for~es of 50P greater average, and higher peak values.

On any basis of application, hot-:evor, we must first outline the iorcos - loneitudinal is the thrust both positive and neGative as indicated as plus and minus, the positive force acting ahead and the negati'Te acting as reversal force. These forces reached a peak of 770 kips.

The vertical forces are also tabuluted end ~e indicated as plus and minus, or up and do\m forces, all forces independently taken on starboard and port pins. The plus is a vertical force acting up and the minus force is the vertical force acting dol-m. The :m.a.xi.mum forces indicated vertically "totere 3'90 kips. 'l'he e.xia.l forces are those acting on the pin athHartsbip and i'..re indicated also as plus or minus and here the peak force indicated, Has 650 kips.

From these forces, 1-re Hould indicate t!lR. t the forces indicc.ted above, o.re ::;trictly peale forces tha:~ Ir.ight ha~pen o. fet.r times in evory 1 ,000 readings. 'l'hese are of noro~nt?.ry dmt;l.tion, nnd f'or cl.J. pract ical purposes fall under one second periods of actual applied forc'3.

It s hould b0 pointed out ft~ther that they clo not have any allow-ance, wh::ttsoever, for nny absorption due to rub!)er bearines. 'Ihaqe arc str;ctly r--:lt~l to r.-at~J ~or.tr..ct r~::dinr~3 and, t~1ercfore 1 t .he:r 3hould be pror::erly evaluated first "fro::-~ the sU.ndpotnt. that \.re ill"e evaluo.tin~ the nbove peak forces to considP.r th"-l rr.:-.:drnum

Ed.Yin ~lo Fletcher & Assoc., 218 H. Church St., Jucksonvill3, Fla.

-8-

encount.l)rcd stress; secondly, theGc forces c>.le m0r.ent3.!'Y fo!'ctJn; ru-:d. third, \.Je havo tukcn into accou..'lt nn Cv'1SiL~.crnt io!'1 for ennr:! ab"orption. The acJ~ua.l ener~ absorption \d t h th~ A .. k.'iUJ:..l\. rubber bc:o.rinGs is e~rer-Bly hi[!;h as cor.iporeJ to the model results.

The Johnson nubber Cor:T':Xtny has redc the f ollmring speciflc state-ment in referenc/3 to n:otr.entary insta.."ltaneous loudin~, l!e est:L."'1ll.te a n:.:i.nintii!l of 25-35~~ of initial shock load to be absorbed.

You must keep in mind that the tests for Phase II Hero conducted in a sea state condition covering 98:6 of the seas of the \-lorst conditionn betuecn !\0rth .tl.i'ricn and Hort.hern Europe . T!-leB"J tc::;tf: \.'eTe co~(lucted to t he e.bs01ut:3 l:i.~it of the rno(1el b3.sin capc.bili t~.

In reference to forces, they are extremely low in relationship to bearing e.nd structure loading. AllO\:able loading as recom-mended by rn::mufacturi:lr ...,Ti th bull t-in safety factor allo\lance, without grease lubrication consideration is as follous: '

Constant Stationary loading for periods of 20 to 25 seconds 2CO P .s. I. Act.U2..l '\!Oridng area of bearin~s 6000 sq. inches. Allo...,rable loading l2CQx o:- 600 tons. Of course, at sou there can be no consta.."lt loudin~ on a (Stationary) bearinrr area as tho units (Tug-Barge ) mov~ independentl y of ea~h other,-no ~tter hoW SI:'.a.ll e. sea sto.te they operate in. t>SOp in m:td that in hurrico..ne seas operating under tho 1.rorst co:r.di tion.s in ql.IDJ:'ter-ing seas, the averaQS forces are only 94 tons longitudinally, 51 tons vertically and 9 tons ~~ally operating under a hypothetical speed of 10 knots.

Instantaneous allovTable loading is 1500 P.S.I. or 900 lC or 4500 tons.

From the above, we can readily see that the allO\rabl,r lo~ing is sows 4500 ton3 = 2750 per pin and bearing or 2750 = 7 to 1 over recou:.~enda tions, o.nd recor::rr.~nded lo::~.din[;S also have a built-in factor of safety, even bv.sed on h1.rrrica.ne conditions. In ae.di tion, the Dreyfus test forces are t otal. They include but not linited to:

A. Have forces B. Pitch and Roll forces C. Baree & Tug Resis~~nce forces D. Rudder forces --E. P:-opeller thrust forces

It should also be r.oted tho.t these forces r~e registering some 25% to 35% hieher than v!'ill be realized because these are mota.l-to-n:etn.l readin~s, r.;nch hi~hGr th!ln l.:ill bo c:qJeri~nc~Jd Hith the

111 ... t'I.1'U3!.;l.11 rubber bearings, 2lso forces r ecorded a.re point lo!l.din~s in lieu of desiened bce.ring surf~ce loudings so as to record the worst thcoretico..l codition3 .as e.dditional s!lfoty fo.ctor.

Ed"rin 1I. Fletcher & Assoc., 218 H. Church street, Jacksonville, Flo..

..1)-

Again ~..... these forces o.re to"t

-10- , .

pins '\orhich are each 5 ft. 1-onl7 in a bearing uith projected bearing of four by five feet, for n t~t~l contact st~face of (40) sq. ft~, all mou."ltcd in rubber, totally flexible and self-centering. '!hen we consider a tug pushing in the notch, and putting tho rudder ha.rdovor, the structurd of the tug, norlil!llly, comes up against the structure of the barge. These for9es, l.fhich 1Jould be encountered, would be several tilr.es that which lle mve proven here by calcula-tions. The structural analysis of the pin '\.Te have indica ted belm-r. This is a simple single shear calculated evaluation, as the pin itself is so rigid, it will not be put in a. bending posture. You can see the strength of one pin in itself is 5420 tons '\.ti th a. factor of safety of 28 times the total peak force ever recorded on this unit under analysis.

t\n Data .P..TUBAR pin structure connection in the tug. These are tabulated balm::

BARGE TUBS CD - 57.333 in. lD - 54.188 in.

Area ( H3tal) - 300 in2 3 Sect. H:xi. - 20,000 in

See arrangement sketch on follovdng page.

Ed'rtin H. FletchfJr &. Ar.soc., 218 \.J. Chtuch St., Jacksonville , Flo..

-11-

.. .

TYPICAL TUG-3!1.."1GS FIEX IIITEP.FACE CC!mECTION

PL~N VIEH

. ,---~----

BARGE ~ Ii~G \.fALL

--- ~ --

I - !r----et

n 11

PIN

, ____ S'!'3EL PlATE

\'------RUBBEH

Eduin H. Fletcher & ;.ssoc 0 I 21B H 0 Church st. I Jacksonville' Fla 0

-12-

As3uminJ b~rge tube to be a beam fixed both ends (16 ft. long) and the pin inserted 5 ft. acting as a lever to transnut the load (780 YJ.ps). S - J.'~x. lnr-~nt = 5. 9 x 105 1 iiL: 26. PSI

Sect 1:.00. = 2.2 x 10'+

S (compression) - For~o - ?SO.OCO # m22EOO PSI 1-et.?.l Area - .300 in The above do not t~~e into consideration and strensth obtained !'rom franing and plating uhich secures the AR'l'UBAR pin tube to the tug.

The structure in the tug has been hiehlY reinforced to account for any possible eventualities, and allows a tremendous factor of safety. Yet the forces to be experienoed \doth the ARTUBAR connection \d.ll be fzuo less than existing forces no\1 being experienced ui th present tug e-lld bo.rge operations.. The reason is si.Ir.ply the tu3 is being basically held in the proper relation-ship to the bearing surfaces - theoretically floating in rubber -coming up against a parallel contact surface, with the barge, 'Hi th considerable energy beine absorbed in the rubber bearings and Uexiblo be~ing plates.

All of these contact surfaces e.re lubricated \lith Hater and/or grease, thus providing dissip.l.i:.ion of forGes over R le..1ee designed urea. Under present conditions of pushing in the notch, the forces nre highly concentrated, and no provision h..as been Iil!lde on existing tug designs for properly absor!:>ing this ene;gy, although this, no doubt, is probably due to the fact that th3 structure of tugs in general ia extren:ely heavy in regard to actual required norrr.al structural strength.

The subject tug has been heavily constructed - not because it is necessary for the AF.TUTh\R conn0ction - but so this tuf, muy operate as an independent so.lvc.:~-e tug, or for ha'trser tm./ine of deep sea barges, or us a eencral all-around serv:i.co tug. \-!e ho.ve, ther efore, incltrled additional factors of safety far beyond anything !Eaeinable, designe~ t o date.

One . of the points of consideration that should 1~ kept in mind to allevia..t~ a misconception of the mo.gnittrle of force is t o note the tug has a displacor.cnt of approY~r.~tely l/20th of the loo.ded barse. In past discussion!:>, I h3.va had considerable coii:lr.ent on th9 distri-bution of generated forces, e.nd ~ost people have considered this 'b-J comparinG it to vc.rious studies made on ships Hhich 'trere hineed in the middle. For CX!'~le, here \re have n to'.o:boEd"Tin H. !letcher & Assoc., 218 H. Church St . , Jacksonville, Fla.

-13-

1 1000 tons displacement, propelling a baree of approximately 20,000 tons displace~nt. the effect of this force is neglicfble if you '\-rare to compare the ~'lrge as a hin~d unit; pinned at the center .

Here, you are hinging tocether tva areas tot.a.line 20,0CO tons, each unit displacing 10,000 tons each. You initially started off with a tremendous variance due to the difference in flotation, either light or loe.ded. You then encounter t:::-emendous forces due to the len{;th and displacement potentin.l of the ::r.nsses. You Hould have each unit approxirlately (240) ft. long being encotmtered by dif'fer-ent Have for::t::!.tions, different periods of roll, different loading, etc., resulting L~ trcreendous bearing pr~ssures - nod, of course, could only be harnessed b; massive ruu'Cl\~are, the cost and \!eight of same impractical.

llot too long arro on a hineed Unker study, shoHed a connection utilizine t\o~o (2) 20 ft. die.Ireter pins, each pin transmitting shearing forces of apr..roxi.lr.ately 26,000 tons. This Has 1L"1der moderate asstmptions. The hinge i tseJ.f .... rould \reigh appro:ciJr..3. tely 1500 to 2000 tons or nearly double the weight of the tue, giving resultant design with a questionable facto:::- of safety, based on all conditions.

A comparison of the GULF CQ~ST Transit CQ. tests (June, 1968), -

Pn.R __ c:_A_ T . . +.

-14-

""

TESTS Til Ifi.REGULAR SF.AS

Follo\ti."lG tests ~ra in irrocular seas - from o.ll dircctions o Tug is self-propell ed and gyTo controlled.

Tug lhlel is - 6 1-211 L.O.A. Barge lJ:del is - 23 1-011 L. 0 .A.

Calibrated forces und moti ons vmr e tabulated llt the approxilr..:1te rate of 1 r e::>.ding per socond on tape.. Detailed anal ysis of al l readings were checked and computed by the rr~st advanced State-of-the-t~t procedures.

Significa..nt Have !f,')~L crht

5.4 I 5:~ I 5. 7' s.o

10.4'

IR~GULAR HAVE PARTICUL.t\RS

Avg. Period in Seconds

6.9 f.. .. (, 7.2 7.2 s.s

Peak Have Hei rrht in Feet

-

12.0 1 12.4' 1.2.7' 17.8 1 23.1 1

EdHin H. Fletcher & f..ssoc., 218 U. Church St. , Jacksonville, F1.a.

~.

SPEED

-15-

TABLES 11 & 111 "ARTUBAR" Following is explanation of Tables 11 & 111 attached.

WAVE OIR ECTION 2 70 /

/ WAVE DIRECTION

:2-= S A RGE ----3- WAVE DIRECTION ISO= s = 'f = fa= F'4 = f t =

F~ =

" ,

"

"

"

" ,.

Bow Down Roll to Starboard Bow In Bow Down When Force 2 Pushes The Barge Forward When Force 4 pu shes The Barge Forward When Force 1 Moves Stern Of Bargo Upward When Force 3 Moves Stern Of Barge Upward

Echdn Ho Fl ctclwr & Assoc., 218 l!o Church St~, Jacksonville, Fla.

~

~ (b c+ Q ;:r Q ti r.o :> C4 C4 0 Q ..

::::

~ 0

Test No.

8838

8!347

8848

88).3

8845

8853

8835

8844

8836 8246

Revie\or of the Tents

\!o.ve Ch.o.racteristics

Speed After in Body

Knots

~ Ill ~ ~ G) al

~hx. 0 Q) () ~~ ..... ~ ~~ H11ve ..... ~Cl 0 Q) ..-I,. A fb::tn 4l H

..... ~ n Cl ~ >C)~ 0..-1 (/) :X: rt < >l.rt

10.2H lll 180 5.4 6.9 12.0

7.0 1V 180 5.4 6.9 12.0 10.11'-!

" II II

13.2 It n It

7.0 1V 180 8.0 7.2 17oS 10. 4}-! lV 180 R.O 7.2 It u.a II II II II n

6.9l' lll 225 5.7 7.2 12.7 10.0 . II n n n II 13.1 II II n II II

7.1 . 1V 225 5.7 7.2 12.7 10.1M II II II II II .. 13 .0

" n II II It

7 .2!! 1V 225 10.4 8.~ 23.1 7 oH 1ll 270 5.6 6.6 12.4 10:1~! II II II II II

13.1 n It n II II

7.1 1V 270 5.6 6.6 12.4 10:1M II II II II II 13.1 n II II II II

10.1 }~ 111 45 5.7 7.2 12 .7 10.41-! lV 45 5.7 7.2 12.7

Results c.f the Tests ( r-) Loneitudina1 Force Lonffitudina1 Force on Starbno.ro Pin on Port Sido Pin

i

F2 :l n Short Tons Fl in Short Tone

~an HlX ~!lX ~ban t-ax t-nx ~ + - C'C\

-:::-. +

-

~u.. ?11. (.\) tv

.32 104 154 85 '.37 107 142 80

22 9.3 12.3 8.~ 12 91 130 !37 39 88 128 4; 24 82 119 54 58 56 136 21) .37 46 105 38 26 138 19.3 14'7 15 137 198 131 43 145 189 lJ) 25 14? 196 116 66 S9 185 .3:) 40 75 153 58 ].7 329 .358 26:' 22 340 295 302 43 .354 370 266 .38 3M .326 285 60 .36.3 .393 25,i 64 .376 377 275

19 301, 285 25:i 19 .322 290 21,8 .34 .317 .3.35 250 3.3 332 .310 255 57 314 .370 23!i 47 330 326 260

.38 505 760 51,() 8 551 530 660

-2 123 185 18~; 34 132 227 150 13 117 . 200 18~; 54 136 271 140 .39 127 210 17C 74 145 293 llO

5 146 178 17~. 25 139 217 )}..1 18 140 190 160 36 141 230 1?.5 43 150 201 l?C 54 145 271 108

L.6 270 337 18! 27 32.3 27/. 321 54 255 247 21t. 9 281 29!3 ~03

(Forces in Short Tons )

Vertica.l Force on Starboard Pin

F1 in Short Ton~

t-~an t-ax lhx

"" + -

::--?lL l'1

17 38 44 22

13 38 51 32 20 34 54 10 37 .37 64 .. .3

15 69 76 51 23 57 78 35 35 52 79 13

2 70 66 64 1? 72 76 51 .32 76 89 35

ll 85 89 41 21 74 98 19 36 ?1 1CY7 6

21 l t..3 152 ll5

5 39 57 30 16 37 62 19 27 36 75 6

7 50 57 32 17 51 7.3 16 32 56 f)f?. 6

14 54 105 32 26 60 82 25

Verticc.l Force on -Port Side Pin

F'1 1 n Shor t. '1' ons I

lean :-rue ~ax .f.

-

cO :;:-...

lll.. (\)

28 28 53 2

12 29 42 15 1R J1 49 10 .30 .30 6?. ~2

15 41. 5(, 26 26 41, 63 15 .32 1.4 71 4

1P. 47 72 19 32 54 79 8 48 54 97 0

10 .31 1,5 .38 22 31. 56 19 34 )8 6') 9 14 71 113 60

12 37 51 19 26 38 63 2 44 32 68+10

12 37 1.5 38 20 1.1 53 20 3.3 42 u 5 27 ~ 120 53 24 e1 113 38

~ ..c tl)

~ .....

Q)

" ~ d jg f .E g -

!:evic 1 c~ 1 he '!~sts ncm:l t.s ';)-f the 'l'C,!;'t.s (t.mro r.ll ~!ve t::h:-.r~ctr,d~tt~~ Pitch .\rwli!!! Q!' t .hc Dergo P.oll AnlP.S of the !3nr'(: i'.o1~t.ive lhtion of' Per~' f:J.tch Andes of Tu..,

~ Test '>reed :.r~.c r ~ r;o. in ~1] .s:: t : ;:not:: d

o!. ..... :': ::- m-, ;l J: ~ 2. .. ,i!!Jl9T.IO!C!J ~ :J.n De rr.rec s .ii'!..J.'~Ct ~. in D0"'l't!'J!l ~, 1: ~"' cJ o.:. 0 :!t: -1 +' ~3 1-b!xo --. 0 v (.o

-4 Q) Hc.ve 1-~nn lhx. t-:ea."l l-hx. llenn !nx. }ha~ :-ax. ~ 1-l t~ ~rl~ ;!!. ((\ ~ c(\ ~ "' ""' !lt.Ft ,...

-!2 en ~ cC\ :::- ~ en ::- ::-rl c -1 r::: >a>!:: -::::- ::;-.. :;::-... ::;:... > Cl rl U).,-1 ~P....-1 ~3- l9-- ~9- N> 1

In the Dreyfus tent (&o.keepine) in H~.rch 1970, in sienificant. sea. heichts of 15.63 feet nt Beatuort 9 (si~on~ eale forces) the peak wa.vcs genere.ted -...:ere in excess of 25 feet. 'l.'hese seas represent ver;j ~evere conditions. In fact , \-:hen you con::::ider ~o~e ere driving this vessel into quartering bow seas an...4. quartering follouine seas at npploy.in:'\.tely 10 lmots - here n(F..in, see that the Zl.!Jpro~ch has been a most extreme abnorr.al assUli.ption to croate the ultirr.:l.te force which can be experienced, for even ut !'u.l.l poHer, the subject ARTUB:.R concept could hardly n:aintain an estirr.a ted 6-} knots under theso e~e~e conditions.

In addition, in no:rr..el practice, no vessel \.JOuld head into such quartering seas at 45 an~le to cren.te the vlorst motions arxl -...m.ve impact forces. In fact, all vessels under such conditions would norrr.a.lly take the seas basically head-on.

Hov!ever, with all of this, the resultant motion of the barge stern is Ir..oving up and dov.rn approx:i..Ir:ately som 20 ft~ to 25 ft. vrhile the astern motion of the tug is restricted to per~ps three to four feet of actual motion - not accountine for the \lave profile.

This is one. of the m-rmerous a.dvant.~C!es of the 1mTUBl:.R concept. The capability of the tug to remin free frotl being inundated by a rieid connection to the ba.rge, to remain free to seek the most effective point of flotntion , for propulsive efficiency. This restuts in greater comfort for creu - greater propulsive efficiency - and much greater steering capability.

All in all, all photographs and motion pictures are com~lete labora-torv fil f.I.S t.h~t. hq_vc not h~Eln edt t.~d in t'.nv 1o1ev, \:hn.tsc:ever, and

sho~l the ex.:1ct results as they occurred.

Very little uater broke over the tug stern, even in stern quarter-ine seas, with extreme conditions, at a significant wave heights

50~~ hi !!her th~n ht,..r-ric::1ne se:1s in the Gnl f of l~::ico. Also, no uater under any conditions~ broke over the tug bou. . ,~. , -

The results achieved a.re certainly extraordinary uhen compared \lith standard tug and bc.rce operations. Even on a hm-:scr, a tuc operating in these seas could not r:..Llintain stcer::1ge - it \,'ould have to hold to a speed of about 3 knots ll.l1d its deck at the stern l;ould be prac-tically undervratBr both in n quarterine bm1 sea::; and a quartering follo.1ing sea. In fact, in this sea condition created for the Dreyfus tests, it is doubt.f'ul if the tug \lith the bar ge on .:1. ha\oJSer could even rnintain a station:u-y he::1dins \!hich, of course, 1-:ould r esult in the cre,J evcntua.lly cut tine the baree loose, rather than jeopardize the safety of the crevl and tug. I don't believe there is any doubt froo these tests that the results are certainly extraordinc.ry, and Itost successful.

Ed,rln H. Fletcher ~ .As::;oc., 21$ U. Church St., Jacksonville, Fla.

-19-

Hi\.U3UP.G TESTS - Septemb~r 1970

lle now cor.e to the ultilr.ate tests in 4S f't. seas, the results in the larger sea keepin[! tank in lhmburg - allo\-red much greater t.reedolllS in overall seclceep tests.

The. follo\dng do.ta ore laboratory results cor.:pleted in Septcnber 1970 and are direct statem-3nts from the Hrunburg roodel tank, including pertinent ds.ta, o.s folious:

lo

2.

Particul~rs of B!U',e s Tu~ Baree Tug

length PP (Lp~ ) 738 1611 140'0" Brendth mld (B, 106 1011 40 1011 Draft . Forv1ard 15' 15 t

l~an 15' 17 1 Ai't 15' 19'

1-easuri:g ;technigue

The tug model connected to the barge model Has self-propelled and equipped with a steering engine.

The ~TURAJR unit ~as remotely hand-steered from a sub-carriage travelling across the oosin in front. of the main carriage.

The electric current to feed both the propelling motor am the steerine engine H:!.s supplied by metms of e. 11fishine;-llne"

. cable connecting the model Hi th the sub:-carriage. This cable also served to tr~nsmi t the :x:::ee.sured values from the model to the recorder on the c~iage. The man-operated main and sub-carric.ge follm-:ed the model in such a WJ..y that the flexible cable susper~ed perpendicularly to the model to avoid constraint.

The tests ... :ere performed in the folloHinr; irregular sea conditions :

. Sea condition ~

}ban \-lave heicht significant \:ave hei ~ht :mean of the 1/10 h.ichest \:aves mo.xi.Inum \nl.Ve height

mean wave period significs.nt \:ave period mean of the 1/10 zreatezt t-rave periods mnxinn.un \.!D. vc peri od

10.4' 16.5' 21.7 1 25.5'

7.00 s 9.06 D 7.46 s

10.46 s

E

-20-

These sea condition tests uere performed in hoad sca, stern sea and beam sea.

Ses. condition B

:t-han \rave height significant l:av~ height mean of the 1/10 hiehest waves t'll!Ximlllil \rave height

mean wave period significant ~w.ve period mec.n of the 1/10 greatest vre.ve periods ~ wave period

12.6' 20.0' 25.9' 31.0'

8.29 s 9 .75 s

10.62 s 11.20 s

These se~ condition tests were performed in head sea, stern sea ani beam sea, in HSVA Hamburg, Sept. 1970.

Sea. condit.ion C

l~e.n Have height significe.nt l:ave height

..1"11 ' ~ , ... "" ~t:.U OJ. \Jflt:l .J.f.J.V Ul.g.tl~::JIJ \'IQ.V~S maximum vrave height

mean 'Have period significant \!ave period mean of the 1/10 greatest \

-21-

A deli~rate reduction of the propeller speed, as ~y probably be c~ploycd by ship's officer~ in~ heavy se~ to protect the propelling eng-lne, was not t.:!.ken into accotmt durine; the tests.

4e ~e::rults

The speed of this ship ~as depending upon the speed of the c~i~ge lrhich was continuously recorded and of the rr:Odel course.

As propulsion tests lTith unconstrained, i.e. f reely propelled, models are to be carried out ltd thout friction correction and, moreover, the c.ddi tion lrind forces cannot be taken into account, the speed values c~n only be considered as essential valueso

Beca.us~, the \d.r:dforces for the rr.odcl at mean Beaufort numbers are about equal the friction corrections, the difference betl.reeu the InOdel speed and the real speed of the ship is not large.

The follmring page is a photostat reproduction from the Hamburg model ba.sin .- it's con:ments are self-e::q>lane.tory.

Edwin H. Fletcher & ansoc. 1 218 H. Church St., Jacksonvlll13, Fla.

- 2.3 -

I havo J'i'.ade various economic studies on the ARTUB.'\.R concept, ani the rosul ts nhou ARTUBAR f:lr superior to ei thor the tug/b:.tree h3.\7ser and/ or standard oce:mgoing bulk vessels o However, before I be con~idered prejudiced , I quote fr~~ Prof. J. A. Tea~dale, of the University of Net-rcc.stle, U.Ko paper as published in London, October, 1969.

These are nmr un.usual. s t 9. t i stics an::l, of com-se, they are based on European construct;ton. The same relationship holds true for American construction.

TASIE 1 - - QT.Jar::O FROH PROFESSffi TF..ASDALE

Cargo capacity per 151 000 tons component

One way trip time 2 days

Loading time 1 day

~o&Ungtme lday

Operational time per annum .360 days

Annual tonnage transported 1,3501 000 tons

Capital cost of b-:l.I'ges {3) 512501 000 dollars Capital cost of (1) tue 1,ooo,ooo dollars

Capital cost of complete system 6,2501 000 dollars

SHIP

15,000 tons

1 day

1 day

l day

360 days

1,.350,000 .

S, 000,000 dollars

TAB~ 1 shows just the basic cost of a system without .considering '\-rarehouse capabilities, cargo accumulation,

planning, etc.

Eduin H., Fletcher & Assoc., 218 Ho Chttrch Street, J~cksonville, FlR..

-24 -

TABlE lJ. - - OUO!t:O FRON PllOFSSS(R '!'EASDAIZ

1TE1~ !31'~~GE SHIP

N~r of Components 3 burges nt 7,200 t.d.~. in sy:::.teli1.9 & 1 tug a~ 3,500 h.p. 1 ship

Capital cost of (3) barges at 1 .3 m. 3,900,000 dollars dollars

Capital cost of 1 tug 1 1500,000 dollars Capital cost of 1 s~tp

-1o,ooo,ooo dollars

'

Thus capital co3t of transpOl .. t sector 5,4001000 dollars 1o,ooo,ooo dollars

Capital cost of ware-hotl.Se, vrharf & 1,100,000 dollars 3,500,000 doll~s miscellaneous

Thus, overall I capital cost 6,500,000 dollars 13,500,000 dollars TABIE ll shows the same system considering the vrarehousing

function, the time cycle for cargo accufirulation, etc.

Edwin H. Fletcher U. Assoc., 21S H. Clnn-ch Street, Jacksonville, Fla. .

..

. ..

The current status of ARTUR~~ as of October, 1970 is as follows:

1. Ni1 o &.rr;e Lines

Request for con=;truction bids for J.6,ooo mrr Barge and 126 foot twin screu tug are \rith u.s. shipyards at present.

DESIGNS

O..mer. Barge Dimen:;tons 12ill1! IYPE T'Gc;} DIN,

Nassau Towing 610xll2Y.4 7 u,ooo Salf unloading JSOy4Qx22 '-O"

Nilo 468x70x35 16,000 Bulk ~x20'-5 Olin l'.athieson 570x80-~ - 47,500 Bulk J26xJ3x2QY5 i'-Gul.fcoast Transit 545-85-45'3 29,500 Bulk J$x40x 22 '-5

Undisclosed 750x1.06x50 Co~tainer Barge J46 x40x22-t611

Two tug-barge unit designs for undisclosed European interests.

tfGulfcoast Transit tug twin screw have propellers of 15'-811 in diameter.

TarAL IIP

6000

4300

5goo

7200

6200

All tugs have positive riehting arms o.t vrell over 90. Typical tug lines appear on the next page.

It is interesting to note that '1-rhen consj.dering b:lrgcs up to 45:000 DD\l':i.', the ARTU3.'.R h.:lrd~mre and installation cost are onJ y approxir.-..c.tely e35,0GO EC>re than that required for conventional havrser towing equip-msnts. '

On pages 14 to 17 is data \..rhich is typice.l of that uhich is received from the l!odel B:1sin for each series of tests conducted.

Edwin II. Fletcher Assoc., 218 \1. Church St., Jacksonville, Fla.