The bulbous bow-a glimpse of its past and present status. Part I

The Bulbous

BowA Glimpse

of Its

Past and Present Status

TAKAO ¡NUI

Bulbs on Parade

Recently the number of ships which hase bulbous bows has been increasinti mirkedls.. As a result. today. in contrast to the past. a ship which has a bulb is normal.

and the one with a normal how which has no bulb is

rather exceptional. Thus, what was once a "normal" is

now an "abnormal" how.

Another thing which s conspicuous is th tact that

there are a variety of bulbous how s with difierent shapes and izes depending ('n the ships to which thcs are

ad-opted. JLtSI by looking at journals

hand tor a tew

minutes. one can pick ('W a ,tr?ets iii bulbs as shown

in table

i. and Photos I 7. whIL'h were used tor the ships inaugurated in Japtn

n the r'

months be-tween March and September in l')f. In table I. sesen

ships are dividc into 1w' groups. with tise

and tw'

ships each. The shIps in the first group has. full hull

torms and those in he scc'nd tri'up are flne. Ihe bulbs shown in Photo I and Photo t' 're those which are usual-I'. called conventional bulbs and hase shares and sites noi

sers different from the pre-war bulbous bows. Howes.er.

the bulbs in the first group become larger as one proceeds

!rom Photo 2 to i and 4. At the sanie time, the forward

projection from F. P. also increases. I he last example ot

'his group show n in Photo S has characteristics

considera-hlv different from those shown in Photos 1 4 samIs.

the latter has a large swelling part near the bottom rather than near the water line, hut the former hase the shape

of the swelling part, which is nearly uniform

drati'ht-same of Ships K' t/AR t-t SHI %tARI \l()IitE JAPAN

jP.\5. ROSF

SHO/s\ s.1ARt

\ .xMA(t ( Hl

\IARU SI RAA1

I I1AMI

Table 1.

ships With Varioui Types of Bulbous Bows Built in Japan,

Launched

During March Sept. 19fi3

Kir

o'Siip

( .viier Ore ( .irrier t .rker licker l4ui. I t i'r (

t!eo I hr

'.

wise. If one uses the terminology in hdrodynamics. a

hull which has the sharpended

normil torni without a

bulb is represented by cturct's or doubh'zc which are

continousl distributed in the longitudinal direction. where.Ls the swelling part of a bulb is reprensented by the sciurct' or doublets which are concentrated

length-wise. If there is almost no necking-down between the

bulb and the main hull, one calls

the former a bulb

which is mainl' sourc'es. whereas if the necking-down is 'arge. one calls it a bulb which is mainly doublets. The bulb'. in Photos I 4 are three dimensional bulbs and

hase the s.ar%ing strength of the concentrated sources and

doublets draughtwise. whereas the bulb in Photo 5 is a two dimensional bulb which has a uniform distribution

of the si'urce and douhletc draughtwise. In this sense,

the bulb in Photo is usually called a cylindrical bow.

Photo (i shows. as we stated previously, a conventional bulb. But the main hull form has been carefully

im-rrosed. although ihe details of it can not be seen in the

picture. ihe bulb with a somewhat strange chape which

is shown in Photo 7 is quite different from that of Photo

ft in size and shape although it belongs to a high-speed

cargo liner iust as the bulb in Photo 6 does.

lt i. natural for the following question to arise here.

It may he natural that the bulbs

for the ships of

dif-ferent groups ma have different sizes and shapes

be-cause of the difference in the condition such as the

Froude number tor speed-lenglh ratio) for the designed speed and so on under which the chips have tobe

design-ed. What is the reason. however, for the large variety

.tres I mci i \etherl.inils Dr. Ene. Protesor ¡ he I 'flit'trsitv if i ok vo En'ineering Ship Owners Jicosi'.en'.k.i ()..eanska Ps :dba ii ugslis I Ships ards

Kiire. Kure Shiph

Date of t 'iunching Aug. 1 tTh

Reference

Photo I.

N'tK line

Lp..n' H roshinia. Nl itsuhishi Sept. b% Photo 2. Socoris. Mobil Oil ( o I .rniflo. \Iitsuii \I.ireh t96 Photo 3

Inc iLSA

Japan Lire. I ti Jipar ¡1iktt nd . IHI July I96 Photo 4.

Showa Shrppin I o

lid

isiiriimi. \irtp1tr. Kok,in Sept 1965 Photo 5

K line

i J.ip.' i

t

s:g istki. 51

'''hi

Mas 1965 Photo (i.

Photo 1.

"Kozara" Bulk-Carrier

Photo 2.

"Fushu Mani" Ore-Carrier

Photo 3.

"Mobil Japan" Tanker

--4

Photo 4.

"Japan Rose" Tanker

Photo 5.

'Shozan Maru" Bulk-Carrier

of bulbs even for the ships in the same group in the

above examples?

This question is not as easy to answer as it appears although it is a naive question even a layman might ask.

In fact, it

is the central problem of ship hydrodynamics

today. As a matter of fact, the history and the progress of ideas in ship hydrodynamics can most clearly be seen

in the thoughts on the bulbous bow. In the present

article.

the author intends to take up the problem of

bulbs as an introduction to the wider problem of changes in thinking on ship hydrodynamics or on the scientific methodology in general because the latter is believed to be more important than the problem of the bulb itself. It is, however, extremely difficult to accomplish the task within these limited pages, especially without using the

I

y

J

Photo 6.

_{'Yamaguchj Maru" Cargo Liner}

Photo 7.

_{"Straat Futami" Cargo Liner}

tools of mathematics. _{We shall, therefore, look at the}

history ol the bulbous how in general _{to see how it has}

been studied tank-experimentally and then see how the theory has been used and what role ii has been playing in the stud of the problem. lt is hecause th

under-standing of these suhjccts is essential for the understand-ing of the changes _{hich have taken place in these few}

years in ship hull forni designs. _{rhese changes are the}

niost _{important point on which the present article is}

focussed. _{Because of the reason stated above, however.}

we restrict ourselves to sketching only the rough outlines

of them, deferring the discussion of the details to the

next opportuñity.

Historical Sketch of the Bulbous

Bow

The idea of the bulbous how has _{something diagonally}

opposite to the normal sense and intuition _{of ordinary,}

men. If one wants to decrease the resistance, particularly

the wave resistance of ships, he would consider first to sharpen the ends of ships. _{In this sese, an attempt to} make the ends blunt may be a fantastic idea _{indeed. To} make clear when such thought was conceived _{and by} whom it was irt»troduced in shipbuilding_{i a cry}

inter-esting thing. _{The author has tried to in vain.}

There is, however, a short description in the _{books written}

by D,W. Taylor (I) and H.E. Saunders

_{(2) that this} bulbous bow probably originated from the ram bow

pro-vided in the old warships such as the "Victory". the

flagship embarked by Admiral Nelson in the Battle of

Trafalgar.

This ram bow was not originally equipped _{to decrease} the resistance of ships, hut to crash through the sides of the opponent ships with, like a horn of an ox. in the midst of the melee that was caused by the limited range of

weak guns of those days. As technology of guns

advanc-ed. the original merit of the ram bow

became

doubt-ful. Unexpectedly, however, the ram bow was found by chance to be useful sometimes for reducing _{resistance of} ships, and it was definitely proved later by accurate measurements of the resistance through model lests _on completion of experimental tanks, In this connection, an

interesting story is found in the _{paper of R.W.L. Gawn}

(3) (1941).

William Froude himself conducted _{a field test for a} comparison of the bulbous and normal forms in a creek in the River Dart near Dartmouth Harbour in 1867, four years before completion of the first tank of Torquay (1871). In the picture of Photo 8. the model _"Swan"

Swan

Raven

Photo 8.

_{Models "Swan" and "Raven"}

(Reference (3) and Photo. 5)

the upper, has a blunt-ended bow like _{a bulb, while the} model "Raven". the lower, _{presents the sharp-ended}

nor-mal form. In this test, W. Froude also confirmed

fea-sibility of the "law of similitude" _{called after his name by}

exercising tests of geosim series

_{models varying L=l2,}

6. 3 feet. Fig. lis the result of the field

_{test with L=l2}

ft model. _{Model A shows Raven type and model}

13

Swan type. _{Compared to the sharp-ended Raventype,}

the Swan type of blunt bow end _{shows a little higher}

value of resistance in low speed, but a considerable

re-duction resulted in _{a higher speed range above 37c}

ft/mm. _{W. Froude was deeply concerned about}

the

results of this test, _{On completion of the first tank at}

To uay, he immediately renewed the models of both

ty _{and conducted again the tests with incompirahjv}

HALF WAT¼INES OF THE MODELS DIAGRAMS OF 12 FT MODELS MODEL A. MODEL B.

---MODEL A.

"A

MODEL

BU.

VELOCITY IN FEET PER MINIJTE

higher accuracy than the first field tests. is interesting that he attained the result of same tendency in the whole.

In early days, the British Navy ventured to adopt the

bulbous bow based on the results of this and successive

tests.

According to the paper of H.E. Saunders.4

the

U.S. Navy has conducted repeatedly the tests with ram

bow models, since the first Washington tank was

con-structed in 1900.

This led to the present concept of the

bulbous bow, and the studies have been made by the

staff including D.W. Taylor.

The results of the

experi-mànts in the initial stage were applied to the U.S. bat.

tleship "Delaware" constructed in 1907 and attained an

epoch-making success in its

speed, and the height of

bow wave was observed much lower than that of the

existing hull forms.

¡n designing, however, guide rule has not been

established enough to be applied in general.

So, the

'designers, in individual cases, had to rely upon their own

experiences and intuition.

Naturally, on the other hand,

with such success made as "Delaware", there should have

been disgraceful failures in which not only the expected

decrease in resist$jce was obtained, but reversely the

re-sistance increased.

These situations, however, were remarkably

improv-ed in

1921. when large-scaled bulb-series

tests were

performed in the tanks of the U.S. Navy on 43 models

in total with A and B types of parent forms and the

results were published in the book written by Taylor.

This is the noted bulbous form of Taylor regarding f,

chart. The features of two types of parent forms can be

expressed as per Table-2 by the symbols used by Taylor.

A is a fine form such as fast passenger vessels or battle

cruisers while B is a full form such as battleships.

Gen-eral commercial ships other than passenger vessels are

more closely allied

to B than A. Fig. 2 shows an

ex-ample of chart for B-series, speed length ratio V/VL=

0.805 ('F =0.2397).

In the Figure. ordinates show f,

and abscissae t are as shown in Fig. 3. It may be

con-sidered that / represents a relative size of bulb and t

presents its approximate position. The maximum value

of f adopted in the bulb series equals to 1=0.16 in

A-series, and / max=0.20 in B-series. As for t,

its positive

30

25

5

Table 2.

Eggert Taylor's Bulb-Series

Number of models

L (fi)

B/L B/H

I (Ci,)

Cm (

L \8

Fig. 1.

Model

Test

Re-sults on "Swan and

"Raven"

(Reference (3) and

Photo. 6]

value ca

sly be considered.

The negative of t( <0)

was only the case with one out of 43 models.

That is.

there was only (f=0.20. t=-0.40) in B-series.

Accord-ing to Taylor's expression, the form of bulb is "roughly

of triangular section with

its base at the keel level and its

apex at the load water line".

The contours in Fig. 2 is Rr/

or theiduary

resis-tance Rr/

per displacement ¡

(in ton) and is closely

allied in general to the tendency of the theoretical curve

,

Fig. A-2 concerning the simple wave-making

inter-ference between two sinusezidal wave systems to be shown

later in Appendix.

Putting aside further detailed

com-parison with theoretical curve, let us follow the figures

of the empirical curve in Fig. 2.

When noticed at the

change in Rr/t that varies with the increase in

, along

the datum line of 1=0 in the figure, t (optimum) for

/=0 is given as :=0.35. However, by adopting /=0 or a

bulb it

is

possible to reduce further Rr/

value.

For

this speed, the bulb of (t=0, /=0.07) is optimum, and

it is noted that Rr/

is reduced further by 13 per cent

as compared with the minimum value of Rr/

for (/=0),

without bulb.

Accurately speaking, in examining the

range of reduction in f (optimum), t (optimum) and

Rr/

due to Froude number,

or V/V L, Fig. 4 can

be obtained in B-series.

This tells that there is no

con-siderable change in t (optimum), but f (optimum) makes

20 23 20 20 0. 1142 0. 1616 3.35 3.20 0.60 0.65 0.92 0.99 60 150 -Pfrirch 1966 9 Series A B 15 20

l0<

440

260 280 300 320 340 360 380 400 420

200 220 240

Pig. 2.

Typical f-t Choit

Location and Personnel

C1rOIJRS RL

lIIIIIIIIIIIUII1ik1hhIlIlIIIIIIIUIIUIIIuIU

IIIIIIIIIiL'IuIUuIiiiuuluu

IIIIlflhIIIiIIiIuIlLIuIMIILIIIip'IiIuIuIIIII

IL'IIiIuIIIL1I11i1IIIiiIIiIIIuiIhI,mjflhIIII.

UIIIilIIIilhIIIIIII!uIIIkiIi1IuIIIIIUL 1111111111

iiIIIl!!!IUIU1I1IIL1flL1lIflhI1ulII!II1IØhIl

IIffIuuIIUiII!IIuuII'uIuI'IIIffiflL!ftui 1111111

IIhIIIÍìiiIIIIIIIIIUl liii 11111111111 IIIIIUIfl

IliiIuUIHhuU! liii,. ViUIiIUhiIItliuI IIIPIIUII

f

AREA AT.FP

AREA AT rn T

r I

2

FP

Fig. 4.

_{Results with Series B (Eggert-Taylor)}

Fn

v//Ti'

rapid increase with increasing Fn together with the

amount of reduction in Rr/.. In this connection,

com-parison with theory is interesting, but ii will be explained

later, and the description is given here about the further results of the lank tests exercised since with thebulbous how.

IO

v/,,T= 0.805

0.240

The Projected Bulbous Bow

_{of the}

Japa-nese Battleship "YAMATO"

Since the experiment of Eggert _{described previously} there has been no such methodical series test of bulbous form on a large scale. hut there have been many small-scale or fragmentary experiments such as those by E.M. Bragg18' (1930). _{There is also the unpublished prewar}

data for the

_{British ship Queen Mary with fifty-three} models and those for the Japanese battleship Yamato. Among these experiments the _{author is especially} in-terested in the process by which _{the hull shape of}

Ya-mato was designed. _{As can be seen from the picture of}

the model shown in Photo

_{9 (sca!e1/200) (this model}

was constructed by Profess,r Tagori of (he University

of Tokyo). the

_{bulb of Yamato ¡s considerably} pro-iected forward from F.P. and is clearly different from the

bulbs of the Eert-Taylor

_{type. Followin9 seems to be}

the process by which it was finally adopted. _(The

follow-me account is due to Mr. _{T. Takahashi, now at}

1.1-1.1.,

who participated in _{the experiment at that time at}

the Technical Institute of the Navy).

Out of forty-eight models _{tested for the hull form of}

Yamato only the last four _{models had bulbs. The tests}

were conducted between 1933 and 1937. _{For the}

forty-,-

ck of the British type with M=L/)ç

as the

para-( four models with the normal bows the ordinary tank _tests

\

were made and the results _{were analyzed referring to}

meter. _{Thus. by the summer of 1936 the best form nf}

the normal bow _{was decided for Lpp. 250m Lwi.}

253m . . R

m3S.9m,

H10.4m.

(slandard)62.3l5t

V m=27 knots. cruising rang 7,200 _{sea miles. and main}

enRine power I 35.000 Sl-IP

_{(the combination of 2 x}

37.500 turbine and 2 < 30.000 diesel). However, the

two diesel engines originally planned were replaced by

two turbine eneines, and the S.H.P. and . (standardt

were increased from 135,000 to 150,000 and from 62.3 l5t to 69.143t. respectively, due lo the incre.'ìse in the ton-nage which was required by the gradual reinforcement

of the armament. And yet the principal _{particulars were}

not allowed to be changed, only Lw,, being allowed _to

be increased by 3m to 256m. _{For the requirement to}

maintain the speed and the cruising range, which was im-perative from the design point of view, there was no other means than to reduce the resistance by improving

the hull form. _{There were two contradicting opinions}

at this point. _{One opinion was that the better hull form} should be searched for among the normal bows and the other oninion was that one should give up the normal

bow and adopt the bulbous bow. _{Especially, the late}

Vice-Admiral Fliraga was the strong advocate of the latter oPinion, which was _{eventually adopted, First, the} bulbs of the Eggert-Tavlor _{type which do not have}

for-ward proiection (X/L0

_{were tested with f0.07 and}

0.16. _{With these bulbs the reductions of E.H.P. by R}

and 18 ner cent, respectively,

_{were obtained at V.r27}

knots. _{Thus, the possibility of reducing E.H.P. heame}

apparent. _{It was found, however, from the}

observation

nf the wave nroflle along the model side in the lank test

for these X/L=0 groups nf bulbs

_{that the first}

-rt

immediately behind F.P. became

_{hiher wh'n the bulb}

was attached. _{As a result, the splash could even reach}

the No. I turret in a strong wind which_{could cause some}

Japan ShiphuiIdin

1.0 15 20 2.5 30 3.3 40

Fig 3.

_{Diagram Illustrating Definition of f and}

_t

040 0 30 0.20 SAVING IN Rr/

J

n o io f o L (OPTIMUM) 0. 5 ₀₂ 0.30 .15 f .10 05

trouble in the operation of the weapon.

Therefore, the

idea of the bulb with the forward projection was put

iorward, and the

tests were made tor the bulbs with

X/L=O.0l2 (X=3 m) and X/L0.020 (X=5 m) with

/=0.07 in each Case

where X is the maximum forward

projection of the bulb measured from F.P.

The latter

bulb (X=5 m) was better at the top speed of 27 knots

but at the cruising speeds of 16-18 knots the former

bulb with 1=0.07 and X/L=0.012 (X=3 m) was found

to be better, and was, therefore, finally adopted.

This

was barely before the laying down of the "Yamato" on

November 4, 1937. Aside trom the problem of resistance,

there were problems which were new at that time such

as the effect of the extended bulb of this kind on the

propulsive efficiency or the self propulsion factors and

the problem of the scale effect between the model and the actual ship.

But at the official speed trial, 27.5-27.7

knots were obtained, which were more than the designed

speed of Vs=27.3 knots, and the propulsive efficiency

was also good.

The first Japanese merchant vessels which adopted

the bulbous bows were the sister boats,

KAS}HWARA-MARU and IZUMO-KAS}HWARA-MARU, both 27,700 GT, of N.Y..K.

Line built in 1939 to 1940.

Fig. 5 shows the result of

the experiment by Dr. M. Yamagata'71 (1938) which

became the basis for designing the bulbs of those ships.

The bulbs which were tested

in this experiment were

those which had no forward projection (X=0) and their

sizes were /=0, 0.0576, 0.0752, 0.0930

and 0.1 108

respectively.

The experiment was begun with the largest

bulb (/=0.1 108) and then the bulb was scraped to

make smaller bulbs mentioned above, while the

displace-ment was kept

constant by gradually increasing

the draught.

As can be seen from the figure the residual

resistance was reduced by 25 per cent for Fn=0.30

when going from A (/=0) to E (/=0.1108).

lt was

also shown in this experiment that the curves B to E for

the models with the bulb cross at Fn=0.256 with the

curve A without the bulb and,

therefore, the model

without the bulb was the best for the speed lower than

that value, whereas at the higher speeds the models with

the bulbs were better.

The reduction of the resistance

was simply proportional.

0.014 0.0I 2 . 0.01 0 +0006 u 0.004 0.00 2 0.

Photo 9. Model

of

"Yamato" in Scale

1/200 (with

coute-cy of Dr. Tagori)

Fig. 5. Effect of Bu1bous Bow

[Reference (7) and Fig. 64 J

0.190.200.21 0.220.230.240250.2602702B029030031

Fn

viIT

H.E. Saunders' Conclusion on the Design

Rule of a Bulbous Bow

As has been described in the preceeding paragraph,

there have been so many tank tests on the bu1bcs bow

for the warships as well as for the merchant vessels

dur-ing and after the war in Japan as well as in the other

countries that one might think that the principle for

de-signing the bulbous bow has already been established.

This, however, is

not necessarily true.

As the most

prominent proof of the above statement, Let us quote the

following statements from the book by H.E. Saunders,

cited previously, on pages 509-5 10 in §67.6 entitled

Design of Bulbous Bow.

"An attempt to reconcile the model-test data of E.F.

Eggert, E.M. Bragg and A.F. lindblad, and to evolve

systematic values of the design parameters fa (=1) and

15

_{=t) from them,}

_{has so far proved unsuccessful. The}

* This kind of bulb with the forward projection from F. P. was tested by the U.S. Navy before the World War 11 and the effect of reducing the resistan was recognized. lt was adopted for the battleships when the Delaware type of l9lOs

were changed into the Arizona type of 1915s (E. E. Saunders'2', Vol 2, p. 510)

March 1966

f

2.4 2.0 1.6 1.2 0.8 0.4os 0.16 0.14 0.12 0.10 0.08 0.06 0.04 0.02 o 0.5

''- -- - ---

-- Of

--- i;E

---

---

-

---r: . .pA

----

-RANGE OF j FOR EXISTING VE SEI.S(1955) 0.6 0.7 08 0.9 1.0 1.1 V(knot)/,/ L(f i)

Fig. 6.

Design Data for Bulbous Bow

[Reference (2) Vol

II

Fig. 67D]

Cp and the fatness ratio.

The upper and Lower limits of Cp and fatness ratio for which bulb bows give beneficial results are not yet

determined.

lt

is possible that the best values of in depend

upon factors other than Tq, but if so no definire trends

are yet apparent. Selecting the proper value of t5 appears,

however, to be less important than using the proper

value of je.'

In the above quotations the parentheses and the

de4ine were added by the author for the sake of the reader's convenience or

to draw the attention of the

reader. Especially, the last part of item (d) is clearly

misleading in view of the most recent

theory of the

bulbous bow. This is a good example of the fact that a purely experimental method, having nothing to do with

the theory, can give conclusions with only a limited

validity when applied to such a problem as that of the bulbous bow, in which complicated wave-making

inter-ference comes into play.

Hafen (1932)

M. Yamagata: "Senkeigaku" Vol. I (Ship Resistan),

(Tokyo 1941)

A. Lindblad: Experiments with Bulbous Bows,

Pub-lications of the Swedish State Shipbuilding Ex-perimental Tank, No. 3 (1944)

A. Lindblad: Further Experiments with Bulbous Bow, Publications of the Swedish State Shipbuilding

Experiment Tank, No, 8 (1948)

(IO) E. S. Dillon-E. V. Leurs: Ships with Bulbous Bow

in Smooth Water and in Waves. TSNAME. Vol.

63 1955)

(Il)

K. Matsumoto: Design and Construction of the

YA-MATO and MUSASHI (Tokyo 1961)

Japan Shipbuilding & Marine Engineering

J

I

design values actually used on a considerable number of vessels whose performance bettered or equaled that of the Taylor Standard Series have been plotted, therefore, on a basis of speed-length quotient. From these plots the tentative design lanes of Fig. 67. D (=Fig. 15) were

derived.

They indicate, for Tq (=V/\'L), a lower limit

of 0.70. Fn=0.208, and a high, limit of 1.50, Fn=

0.447.

"Those who use them as interim guides until better rules are developed should recognize the following

short-comings:

The f. values do not increase indefinitely with Tq

beyond the range of Tq=l.5 shown in the diagram.

They almost certainly diminish to zero at some upper limit of Tq around 1.9 or 2.0.

The proper value of IF: appears to depend upon Cp and the displacement-length ratio .V(O.IOL)3, bui the rariou.r ,nodel-iest data shows conflicting trends.

lt

is

probable that the best value of f increases with both

References

(I)

D. W. Taylor: The Speed and Power of Ships (Washington 1943)

H. E. Saunders: Hydrodynamics in Ship Design.

Vols. 1, II (New York 1957)

R. W. L. Gawn: Historical Notes on Investigations

at the Admiralty Experimental Works, Torquay. TINA VoIS 83 (1941)

H. E. Saunders: The David Taylor Model Basin,

Part 2, TSNAME, Vol. 48 (1940)

E. M. Bragg: Results of Experime$s upon Bulbous Bow, TSNAME. Vol. 38 (1930)

CI. Kempf-E. Heckscher: Geschwindigkeitserhöhuflg

duch Vorschiffsverlangerung, Werfi Reederei

12 1.5 1.2 1.3 1.4 0.6 0.7 08 0.9 1.0 1.1 V(knot)//T(Ti) 1.3 1.4 1.2 1.5

Page 3 Contenta q a

8 Right Col.

f, n 9 Graph top left Left Col. n n

, Table 2. Right Col.

Line

Incorrect

1 Transportition

2 Takla Inul

3 Bipond 5

23

11 Noval 2 seuse 5 in troduced

6 to know

_{44 Torguay}

WATR-LINES I In is 23 resistence

J

f

L \3

000I

¡

can only be

7 siduary 9-IO curve in Fig. A-2

24 En

or V/VL,

Correct

Transportation

Takao bui

Bipod

32

Naval sense introduced to lind Torquay WATER-LINES

It is

resistance

J

f

L

\8

'ioo)

_{was be residuary}

_{curve, Fig. A-2}

Fn or V/VgL,

1Thjs line should

be put two

lines down,

that is, under

'the line "were

made..

range Bullous bu I bous

_{a higher limit}

italics Experiments Experimental

f

Dr. Eng.

i Associate

Professor,

spacial Cylindrical Should be deleted the section strain velocities formula _{Cylindrical goose-neck bottoni twisting ax is axis Should be deleted Collapsing}

Should be deleted CASE IV adopting Exp. 2,nQ N

' DHP°'

CORRIGEN DA

page _{26 Right 27 SYMBOLS:}

n 27 Right _{30 Left} a Right 33 Right Line Incorrect Correct 6 requred required 12 gigantic giantic lo To qo Qe ax-meter 6-meter 23 C=0.08O Cb=O.80 3 frequency Should be deleted gange gauge

4Th

The 10 satisfactolly satisfactory 16 LuIljcated lublicated 18 Tokyo Toyo 26 seen aun 33 heat-beat heat-treated 34 machine-cubbed machine-cut

3O2Ox

2fl' 8 inspalled installed 9 how new 15 Sulze Suizer 13, 16 Snowa Showa

900 t/h

x 8 m'mia

900 m

X 8 m

18 3,000

in 3/h

3,000 ni/h

23. 26 hanger hangar 18 U.S.S. U.S.A. 40 20°C

15C

41 15°C

2C

4 75

10 5 15-ton 15-t/h 7 trucks-one trucksone 7 8.12 8.64 8.30 8.810 8 7,760 8,566 8,035 13 ¡7.1 (7.6 22 3.3 2.3

2 3!) t/d

3!) t/day 4-5 18.7/29.1 t

x

12/6 in/min

18.7 t y 12

rn/mm OR each

29.1 t X fi

in/min each 22 two one

23AC

DC

11 its basic.

steady ex

foreign trade. At ftrst two

ships for

North America Col. 5 Ond One 4 1961 1910

Il Fatigue

Fatigue section

35 the scale

effect of the

Should he deleted

ship and

propeller. 1G ervele cycle 25 Farthquake Earthquake 26 twe two 27 :1-... r.p.c.

3.-6 r.p.s.

9 Those

ships are.

. table. Should he deleted 10 ¡03.000 118.900 11 5,000 4.500

2 prefabriratting

prefabricating 171.000 ¡91,300 169,000 ¡73.900

23 ck of

the.. .as the

paro-10 Right Col.

11 Fig

rang 5. Buldbous _bulbons 12 Left Col.

7 a high

or limit Right Col. 11-12 underlines References (5) I Experimeats a a (9) 3 Experimented 14 Writer's

title

Assodate Proffessor, f, F, 15 Left

Fig. 2.

16 Right _{17 Left 18 Right 21 Fig. 14. 25 Right} Photo 1.

_{26 Left}

Left

9 specIal

a

n

§2 Cylinderical

38 X axis is..

.a twisting axis

40 the twisting

section

7 stsain

S velociries f rmula ('ylinderical

28 groose-neck 31 botton

45 turisting

48-49 axes

2.4.6 axes

13-14 section of.

. the same up to 39 coflopsing

i (i.,2,3,4

CASE IX 2 sadoptiiig

4 Erp.

_{18 2nø}

_{19 N DH.P°.}

34 Left

Right

36 Right _{39 Left 42 Left}

Right

43 Left

Right

44 Left

Right

46 Left _{49 Right .50 Left SI 52 54}

a

&7 Loft 58 Right 64 65 Left