REPORT No.
18 M
September 1968
NEDERLANDS SCHEEPSSTUDIECENTIWM TNO
NETHERLANDS SHIP RESEARCH CENTRE ThO
ENGINEERING DEPARTMENT
LEEGHWATERSTRAAT 5, DELFT
STERN GEAR ARRANGEMENT AND. ELECTRIC POWER
GENERATION IN SHIPS PROPELLED
BY CONTROLLABLE PITCH PROPELLERS
(DE SCHROEFASONDERSTEUNING, DE SCHROEFASDOORVOERING EN HET.
OPWEKKEN VAN HULPVERMOGEN IN SCHEPEN MET VERSTELBARE SCHROEVEN)
by
Ir.
. KAPSENBERG
RESEARCH COMMITTEE
IR. J. M DIRKZWAGER IR; N. DIJKSHOORNIR. J. v
HAsTERt
TH. D. H. VAN HALDEREN IR. A. HOOTSENIR. J. VAN DEN HouT
La. C. KAPSENBERG
IR. J. D. Ruys
IR. C. SCHERPENHUYSEN
IR. A. DE MooY (ex officio)
VOORWOORD
In 1964 werd een onderzoek verricht naar de hydrodynamische eigenschappen en de regeling van de verstelbare schroef aismede naar de economische aspecten van de toepassing van deze voort-stuwervoor een tanker en een droge-lading vrachtschip.
De resultaten hiervan werden gepubliceerd in rapport no. 59 M: ,,Controllable pitch propellers, their suitability and economy
for large seagóing ships propelled bij conventional,
directly-còupled engines".
Teneinde over, voor een economische evalua tie van de toepas sing van een verstelbare schroef, meer gedetailleerde informatie
te beschikken, werd een studie gemaakt van de wijze waarop het voortstuwingssysteem en de machinekamerinrichting van een schip uitgerust met een moderne lanaam1opende
hoofd-motor hieraan kan worden aangepast.
Deze studie heeftgeleid tot het in dit rapport beschreven
ont-werp van een, van de conventionele constructie afwijkende,
schroefasondersteuning en schroefasdoorvoering, aismede tot de
beschreven mogelijkheden van de opwekking van elektrisch
hulpvermogen, met constante frequentie, door de hoofdmotor. Het ontwerp van de schroefasondersteuning is gebaseerd op
het principe van de constructie van het geforceerd gesmeerde
hoofdlager van een scheepshoofdmotor.
Hierdoor wordt inspectie van de loop- en draagvlakken van de schroefas en het asblok, aismede devervanging van de
lager-schalen mogelijk zonder tijdrovende en kostbare schroef- en
schroefasdemontage.
Bijzondere aandacht werd gesehonken ann de constructie van de zeewateraldichting.
De beschreven ontwerpen hiervan kenmerken zich door een voorzJening in afvoer van lekwater door toepassing van een, in
open verbinding met het schip staande, ruimte tussen de zee
waterafdichting en het achterste schroefaslager. Hierdoor wordt smeeroliecontaminatie door zeewater op effectieve wijze
voor-komen.
De ontwerpen kwamen tot stand na uitvoerig overleg met des-kundigen van, in grote schroefasafdichtingen, gespecialiseerde ondernemingen terwiji tevens overleg werd gepleegd met de cias-sificatiebureaus Lloyd's Register of Shipping en Bureau Ventas.
Inäke de opwekking van het elektrisch hulpvermogen door
de hoofdmachine werd uitvóeñg onderzoek verricht naar in prak-tische of experimentele toepassing zijnde technieken.
NEDERLANDS SCHEEPSSTUDLECENTRUM TNO
PREFACE
In 1964 an extensive investigation was carried out into the hydro-dynamic behaviour of the controllable pitch propeller and into
the control and the economic aspects of the applications to a
tanker and a dry cargo ship. The results of this iñvestigation were
described in Report No. 59 M: Controliable pitch propellers,
theiÌ suitability and economy for large seagoing ships prOpelled bu conventional, directly-coupled engines".
In order to enable a more detailed economic evaluation of
the application of the c.p. propeller, the adaptation of the
pro-pulsion system and the machinery of a ship, equipped with a
modern low speed main engine, was studied.
This study has resulted in the design of a special stern gear
arrangement and in the generation of electrical auxiliary power with constant frequency by the main engine, described in this report.
The design of the propeller shaft support is based on the
principie of the construction of the forced lubricated cranksháít
bearing of a diesel engine. This design enables occasional
in-spection of the shalt and the bearing as well as replacement of the imers without time consuming and expensive withdrawal of the tail shafL
Considerable attention was payed to the design of the
shaft-sealing.
The designs described are characterized by a space between the
seal and the tailshaftbearing, communicated with the ship's
bilges.
By this contamination of lubncating oil by seawater is pre
vented effectively.
Specialists of propeller shalt seal manufacturers and the
cläsal-fication societies Lloyd's Register of Shipping and Bureau
Ventas were consulted
Concerning the generation of constant frequency auxiliary
power by the mam engme an extensive mvestigatlon was carned out into applications in practical and experimental stages.
Summary.
i
Introduction.2 The support Of the propeller shaft
2.1 Lubricated lip sea1 r . -.
2.2 Radialface seals -.
CONTENTS
LL
3 Driving a shalt álternator . . . - 12
3 1 Shaft alternator directly coupled to the main diesel engine 12
3 2 Shaft alternator driven by a variable speed gear 12
3.3 ShaTt alternator driven by an adjustable hydraulic pump . . 12
4 Shaft alternator, as under 3 1 3.2 and 3 3 simultaneously driven by a steam turbine
supplied with steam fröm the eithaustgas
..
. 145 $dtiaboût theuse of a controllable pitch propeller 15
6
Euture work ...
. . 157 AcknowIedment
. .- - . I S page 5 5 5 6 6STERN GEAR ARRANGEMENT AND ELECTRIC POWER GENERATION
IN SHIPS PROPELLED BY CONTROLLABLE PITCH PROPELLERS
by
Ir. C. KAPSENBERG
Summary
An improved stern gear arrangement is described. The special features of the design are theshort length forced lubricated tail shaft bearings and the sealing arrangement characterized by a space between the seal and the aftermost bearing in communication with the bilges Experimental and practical techniques of generation of electric auxiliary power with constant frequency by shaft alter nators- are mentioned.
i
Introdúction
The features of controllable pitch propellers (c.p.p.'s)
at sea are well known. Publication No. 59M of June
1964 of the Netherlañds Research Centre Ï.N.O.
for Shipbuilding and Navigation reports the results of
the model tests for two types of ships
To state the contents in a nutshell: for the ships
tes-ted, a 32.000 ton d.w. tanker with 18.000 shp and a
12.300 tons freighter with 7800 shp at sea there are
no advantages but no disadvantages either.
To obtain optimum propulsion efficiency at all
speeds it is necessary to achieve speeds below the
maximum by reducing the r.p.m. of the propeller to
80% of maximum and further by reducing the
pro-peller pitch in accordance with the "ABC setting" as
stipulated in the above-mentioned publication (No.
59M).
The unidirectional main engine has therefore a
speed variation limited to 20 percent below normal
maximum r.pm.
Firstly, because of the large hub and hose diámeter
relating to the c.p.p., possible improvements in shaft
support and access to the bearings from the eñgine
room are considered.
Secondly, the fact that the main engine has a speed
variation of 20% below maximum r.p.m. makes easier
the introduction f a shaft alternator, bearing in mind
the need for maintaining constant frequency and
voltage of the alternating current under all
circum-stances.
The following drawings do not pretend to give more
than a general principle of design. It is for the
engi-neering departments of the yards and the shipowners
to see how and if the suggestions made in this report
are suitable for the special ships they have in mind.
2The support of the--popeller shaft
The bearing of the propeller shaft, today usually a
long stern bush lined with lignum vitae or white metal,
is far from ideal from the standpoint of lubrication.
Even for a shaft, running in an oil bath, as normal
for stern bushes lined with white metal, the
classifi-cation societies estimate that lubriclassifi-cation is so
in-complete, that they insist on low specific bearing
pressures, and inspite of this many failures occur.
-Mr. G. Bourceau and -Mr. A. Loupéré of Bureau
Ventas have published statistics showing that
diffi-culties arise with more than 25% of propeller shafts
above 400 mm and that stern bushes of ships with
10,000 shp or above never last longer than three years
(see ,,Schip en Werf", 30th March 1962).
In his paper Mr. T. B. Hutchinson describes a tut
bine arrangement of 30,000 shp at 85 r.p.m. and shows
an unusual design of a hollow and large diameter
propeller shaft aimed solely at achieving an -acceptable
stern bush. In his comments Mr. Archer proposes an
alternative design, also unusual, that permits the use of
normal stern bushes of large diameter (see "The In
stitute of Marine Engineering", April 1966).
It is well known that the most reliable and sound
bearing for withstanding high specific pressures is the
forced lubricated bearing with a length of 0.8 tot 1.2 of
the shaft diameter.
For that reason the possibility of arranging a forced
lubricated bearing equal to the bearings- of the
crank-shaft of the diesel engine driving the propeller is
proposed. The crankshaft of a diesel engine has about
thé same diameter as the propeller shaft for a c.p.p.
The crank pin bearing in particulár has tO withstand
very high specific pressures of about 250 kg/cm2,
whereas the specific pressure for the aftermost bearing
for the propeller shaft has to work with specific
pressures of say 15 tot 25 kg/cm2, a low figure indeèd
The r.p.m. for crankshaft and propellet shaft are equal.
-In order to- incorporate a forced lubricated -bearing
there niust be absolute certainty that no ea water can
contaminate the lubricating oil.
-6
fulfil this requirement, as sea water is on one side and
lub.oil on the other side of the same sealing
arrange-ment. To be quite sure that no contamination takes
place, it is necessary for any sea water leaking in to
be caught and carried off to the bilges without coming
in contact with the shaft and the sealing arrangement.
Further it is desirable that the aftermost bearing
should be as near to the propeller hub as possible
in order to render the propeller shaft system less
sensitive to vibration due to lateral forces.
The design of propeller shaft support is shown on
figures 1 to 4. Fig. i and 2 also show the design of the
afterpeak. Small horizontal decks, one above and one
under the shaft separate a dry space in the afterpeak
accessible by a watertight cover from the engine room
or the tunnel. This dry space is of sufficient dimensions
to allow occasional inspection of the shaft and the
bearing. The longitudinal section clearly shows the
support of the propeller shaft and the way in which
the liners can be replaced by a spare liner.
The shaft support as shown is of the game sort as
that used for supporting any shaft turning a heavy and.
overhung mass.
In principle the aftermost bearing Is of the same
de-sign as the crank shaft bearings of a diesel engine, i.e.
split and adjustable with the possibility of having the
liners scraped in the workshop.
The hydraulic jacks under the shaft are intended to
lift the shaft slightly in case the under liner has to be
removed for inspection or replacement.
The design of the aftermost bearing is shown in
more detail in figure 3.
2.1.
Lubricated up seals
The sealing arrangement shown in figure 3 and in more
detail in figure 4 is a lubricated lip seal as proposed
by Freudenberg iñ Weinheim in Germany. Although
the circumpherential speed of the flange is about twice
that of thè shaft, Freudenberg has no objection to this
arrangement provided the heat generated by the lips
can easiliy be dissipated.
As the surroundings of the sealings are cooled by
sea water it is reasonable to assume that
circum-stances in that respect are favourable.
2.2
RadiaI face seals
A suitable seal for excluding sea water with air on the
inside is ..the radial face seal of Crane Packing Ltd.,
Slough, Bucks, England. It does not require any
separate supply of lubricant and incorporates a bellows
type flexible member that resists the high frequency
vibrations found in marine propeller shafts and allows
for an axial movement of the shaft.
Figure 5 shows the Crane type 383 fully split bellows
radial face seal incorporated in the proposed bearing
arrangement and in more detail on a larger scale.
Ail the parts of the seal can be examined or serviced
without removing the propeller.
The radial face seal has proved its capability of
coping with the high rubbing speeds encountered on
large diameter installations and tests have been carried
out indicating that it would 'be capable of operating
at up to 300 r.p.m. in the size illustrated in the drawing
(nominal 53" shaft size).
The flexible member in the seal is built up of a large
number of monel springs, which are fitted in four
ready assembled segments and clamped into position
with segmented cast bronze clamps, which also form
a protective shroud for the bellòws assembly. The
con-struction gives a very low spring rate in the axial
direction and great strength in the radial direction.
The bellows assembly was designed to accomodate
all forms of vibration, axial movement and shaft
de-flecting encountered in conventional wood lined stern
tube installation, thus giving a very large safety factor
in the case of this proposed installation in which the
shaft will be more accurately positioned in the
pres-sure lubricated white metal bearings.
A large number of these seals are already at sea,
mainly on water sealing applicatioñs on ships ranging
from several large tankers, large passenger liners
in-cluding S.S. "Queen Elisabeth" and a considerable
number of Naval installations.
The aftermost bearing has not only to carry the weight
of propeller and shaft, but also has to withstand lateral
forces from fluctuations in the torque and from hull
vibrations.
As to the magnitude of the torque fluctuations, it
may be remarked that they are relatively smalL
In publication No. 216a of the Netherlands Ship
Model Basin it is stated: "The mean value of the
lateral forces induced by the propeller are negligible
compared with the propeller weight as far as the
static load is concerned".
According to this publication, calculation shows
that for a ship with 18,000 shp, 115 r.p.m. and a
4-blade propeller, the amplitudes of the lateral forces
are between 4 to 5000 kgf, the propeller weight
and
part of the shaft being 33,000 kgf.
As far as hull vibrations are concerned, if the usual
bearing with a long stern bush is able to withstand
them, in all probability a forced lubricated, well
situated and low loaded bearing can withstand them
Fig.'!. Longitudinal section 1. aftermost bearing; 2.sealing arrangement; 3. bearingoil supply; 4. oil supply for sealing; 5; hydraulic jack; 6. oildräin from bearing;
7. drainleakage water to
bilges; 8; lifting bearing.'cap.with liner; 9.lifting spare liner; 10. spare liner; 11. forward!bearing.
8
SOETION I-I
SECTION FRAME 12
Fig. 2. Cross sections
1. hydraulic jack; 2. afterm6st bearing; 3. lifting bearing
cap with liner; 4. thñistbolt with hydraulic tensioning
device; 5. lifting liner; 6. spare liner; 7. forward beating; 8. watertight door.
SECTION FRAME 10
H
V7,Z'J1
ÌPP
lb OIL SUPPL SEALING' THJSTBOLT WffH HYDRAULIC TENSIONING DE VICE SECTION I-I BEARING OIL SUPPLY Fig. 3.Aftermost bearing of propeller shaft.
SEALING ARRANGEMENT
BEARING OIL RETURN
DRAIN
ar11I
\ -Ar,//f//
\\
,,,,,,,,,,,,,,,,,,,,,,,,,,,, -e-PROPELLER HUBOIL SUPPLY TO SEALING
Fig. 4.
ROPE GUARD ,CRANE'
"
SEALING ARRANGEMENT BEARING OIL RETURNFig. 5. Sealing arrangement of Crañe Packing Ltd., typé 383.
WATER
12
low frequency in order to keep the number of poles,
and therefore the outer diameter of the alternator
small. A static rectifier transforms the alternating
current into direct current that is led to a d.c. electric
motor driving an a.c. alternator.
The speed of the d.c. motor can easily be kept
constant and thus the frequency and tension of the
alternating current at the desired value.
In diagram the arrangement is as indicated in figure 6.
The auxiliary diesel engines can Work parallel with the
shaft alternator.
Except for the alternator in the shaft, all other parts
can bç arranged in the most convenient place in the
engine room.
The efficiency of the plant is quite acceptable and
will be about 0.93 X 0.98 X 0.87 = 0.80.
In principle the diagram remains the same when
the shaft alternator is driven from the main engine by
a gear at higher speed.
There are other arrangements for producing a1ter
nating current of constant frequency but none are
simpler.
3.2
Shaft alternator driven by a variable speed gear
If the well known epicyclic variable speed gear is
driven at the input side at a speed of about 600 r.p.m.
with a variation of 20 percent, then the output of the
gear can give a constant speed of 1800 r.p.m. an ideal
speed for driving the shaft alternator.
The efficiency is well above 90% as the only losses
are in the gearing.
The gear, however, is bound to be given a definite
place in the engine room and a train of gearwheels is
necessary to arrange the epicyclic gear and alternator
at a sufficient distance from the main engine.
this meañs that such an arrangement presents a
mechanical problem.
3.3
Shaft alternator driven by an adjustable hydraulic
pump
The striking feature of a hydraulic transmission is, that
the overall dimensions of pump and motor, as well as
of the rotating masses, are small.
A double gear has to be arranged on the crankshaft
near the thrustblock so that the pump can be coupled
to a shaft turning at 1260 to 1570 r.p.m. At full load
this adjustable pump delivers hydraulic oil at a pressure
of 180 kg/cm2 to the hydraulic motor, driving the shaft
alterr ator at say 1200 r.p.m.
The variable hydraulic pump delivers a constant
quantity of oil, within the input speed range, to the
non-adjustable hydraulic motor, which therefore runs
at a constant number of r.p.m.
The design of the propeller shaft support is
character-ized by:
Shaft bearings, disigned as the main bearings of
a diesel engine, forced lubricated, low loaded and
fitted for heavy slow running propellers and c.p.p.'s
The possibility of the aftermost bearing being
mounted near the propeller hub, therefore
bring-ing propeller whirlbring-ing tO higher r.p.m.
Sealing against sea water in such à way, that any
leakage is carried off to the bilges without wetting
the shaft.
Inspection of the propeller shaft and the bearing
from inside the ship;
A propeller shaft which no longer has to be pulled
out for inspection, so that a spare shaft would not
be necessary.
A propeller shaft with no tapered end but two
forged-on flanges
Simplicity and economy.
3
Driving a shaft alternator
As has already been said the problem is simplified
when the main engine is unidirectional and has a
limited speed variation of 20% below maximum.
Nevertheless it will be necessary to maintain
con-stant frequency and voltage of the alternating current.
The power required for the current at sea will be about
600 kW for the ships under consideration.
Therefore power of about 1000 shp has to be taken
from the main engine. A shaft alternator may lead
to reconsideratiOn of the number an4 power of aux
iliary alternators installed, as the latter are used mainiy
in harbour, and the number of working hours is
there-fore low. In certain cases this may save expense.
To derive the power from the shafting of a
motor-ship, it will be necessary to install an accelerating gear
of toothed wheels in a place where the torsional shaft
vibrations are small.
In many cases this will be near the thrüst block, and
installation will prove difficult and expensive.
It is much simpler tö install a slow-running shaft
alternator directly coupled to the shafting. This
alter-nator is large, but can be mounted as a f ywheel on
the flange of the crankshaft of a diesel engine and its
dimensions remain within the contours of the cross
sectión of a slow-running diesel engine.
FOr a steam turbine ship a fast-running alternator can
be driven from a pinion connected to the bull gear.
3.1
Shaft alternator, directly coupled to the main
diesel engine
The power taken from the generator determines the
oil pressure in the pump and 1otor In this öase only
plunger pumps are suitable. They can be built for large
capacities and are used in great numbers on dredgers
Figure 7 indicates the transmission at about the
actual propOrtions;
At full load efficiency is about 85 percept, but
de-creases rapidly at lower loads.
The alternator and hydrauÌic motor can be arranged
in the most convenient place in the engine room.
Dis-advañtages are that a geared transmission is necessary
for driving the pump, and that a new element is
intro-duced into the engine room, one with which the
erigi-neers would not be familiar.
Of ourse there must be controls in the transmission
line to safeguard against damage and to regulate the
pump delivery.
Fig. 6. Diàgräm df direct drivCñ haft älternätor.
i. shaft generator; 2 transformer d.c. in a.c; 3. rectifier; 4. voltage regulator; 5. auxiliary diesel generator.
r
-u
ADJUSTABLE
I HYDRAULIC PUMP 13 HYDRAULICALTERNATOR 600KW
MOTOR14
4
Shaft alternator, as under 3.1; 3.2 and 3.3
simul-taneously driven by a steam turbine supplied with
steam from the exhaust gas boiler.
If a shaft alternator is installed in the engine room,
it becomes worth making use of the heat in the
ex-haust gases. An exex-haust gas boiler delivers steam to
a turbine coupled to the alternator driven by a d.c.
motor as in figure 6 or by the hydraulic motor as in
figure 7.
In this way the diagram in fig. 8 is obtained. This is
intended for electric transmission, but the same holds
true for hydraulic transmission or transmjssion by a
variable speed gear.
This arrangement only takes just as much power
from the main engine as is needed for driving the
alter-nators, when it cannot all be supplied by the steam
turbine.
When the main engine is fully loaded there is a
great deal of steam flowing to the turbine.
If the consumption of current in the ship is high,
the turbine will supply a large part of the necessary
power and the remainder will be supplied by the 'shaft
alternator. At low load of thè main engine, and
there-fore at low steam production, the steam turbine will
deliver only a small part of the power for the
alter-nator.
This is true of any propörtions in engine load' and
Fig., 8. Diagram of direct driven shaft alternator combined with steam turbine
1. shaft geñerator; 2. transformer d.c. in a.c.; 3. rectifier; 4. voltage regulator; 5. auxiliary dieseigener-ator; 6. steamturbine; 7. exhaust gas boiler; '8. ôilfired boiler.
electrical load, without the need for complicated
reg-ulation if the couplings at both shaftends of the
alter-nator are of the "one way" type.
There is another interesting feature about this drive.
Should the main motor with a shaft alternator stop
for any reason or have to be stopped súddenly, there
is a risk of a "blackout".
To meet this eventuality, arrangements can be made
for an auxiliary diesel to be startçd ai4omatically, but
it is by no means certain that starting and
synchron-ising will occur quickly enough to prevent current
consumers cutting out. A turbine driven shaft
alter-nator, however, will continue to operate as long as
there is a supply of steam
FOr a short time this can be extracted from
accu-mulated energy in the exhaust gas boiler and the oil
fired boiler, which is usually incorporated in the steam
system and therefore always under pressure. If the oil
burner system is arranged in such a way that it starts
as soon as the frequency and tension produced by the
shaft alternator drop below a. fixed value, steam is
immediately produced and the turbine continues
de-livering all the necessary current, thus preventing a
"blackout".
The steam-driven shaft alternator of a motor ship
will Supply current partly without fuel costs and for the
rest with the cheap fuel
sedfor the main engine.
needed for harbourpurposes, say for only 1000 wOrking
hours a year.
It will hardly be necessary to install a spare diesel
alternator because in the event of breakdown the
steam turbine alternator can serve as a spare
gener-ator.
In this way the cost of the turbine and accessones can
be cut by deciding upon the number and capacity of
diesel alternators really required.
5
Facts about the use of a c.p.p.
At sea no advantage or disadvantage of any
im-portance compared with a fixed blade propeller.
Manôeuvring is effected simply,. on the bridge,
añd Without any adverse effect ipon the fuain
engine.
Manoeuvring is effected quickly,, quietly and with
out liínitation.
Power for "astern" is iñimediately available.
The ship speed can be reduced to the mniium.
6
When stopping, the headreach and speed are
notably shortened (publication
of NSMB).
Numbers -2 -to 6 together are synonymous with
increaséd a.fety.
The mäin motor álways rüns in one direction and
does not have to endure manoeuvring, which
means there is a fair expectation of decreased
repair costs and less wear and tear.
The main engine is simplified, as the manoeuvring
mechanism and safety devices are eliminated.
The propeller shaft support can be improved and
made accessible so that the shaft does not have
to be pulled out for inspection and a sparé shaft
would be not necessary.
11 A shaft alternator can be put into practice more
easily. Application means fuel economy, at sea no
diesel alternators at work and in certain cases a
reduction in the number of diesel alternators and
a simpler engine room arrangement.
12.
If the constant speed alternator is coupled to a
steam turbine supplied with steam from the
ex-haust boiler, the energy in the exex-haust gases can
be fully and automatically employed for thesupply
of current.
Blackouts are prevented and no auxiliary diesel
alternators have to stand by.
6
Future work
The total economy of the plant has to be explóred The
investments and savings must be considered.
7 Ackno'Iedgemeñt
The Netherlands Ship Reseach Centre TNO gratefully
acknowledges the co-operation and assistence received
from the N.Y. Koninklijke Maatschappij ,,De Schelde"
and Lips N.Y. for the work reported herein.
PUBLICATIONS OF THE NETHERLANDS SHIP RESEARCH CENTRE TNO
(FORMERLY THE NETHERLANDS RESEARCH CENTRE TNO FOR SHIPfflJILDING AND NAVIGATION)M = engineering department S = shipbuilding department
C = corrosion and antifouling department PRICE PER COPY DFL
IO.-Reports
i S The determination of the natural frequencies of ship vibrations
(Dutch). H. E. Jaeger, 1950.
3 S Practical possibilities ofconstructional applications of aluminium
alloys to ship construction. H. E. Jaeger, 1951.
4 S Corrugation of bottom shell plating in ships with all-welded or
partially welded bottoms (Dutch). H. E. Jaeger and H. A.
Ver-beek, 1951.
5 S Standard-recommendations for measured mile and endurance
trials of sea-going ships (Dutch). J. W. Bonebakker, W. J. Muller and E. J. Diehi, 1952.
6 S Some tests on stayed and unstayed masts and a comparison of
experimental results and calculated stresses (Dutch). A. Verduin and B. Burghgraef, 1952.
7 M Cylinder wear in marine diesel engines (Dutch). H. Visser, 1952.
8 M Analysis and testing of lubricating oils (Dutch). R. N. M. A.
Malotaux and J. G. Smit, 1953.
9 S Stability experiments on models of Dutch and French
standard-ized lifeboats. H. E. Jaeger, J. W. Bonebakker and J. Pereboom, in collaboration with A. Audigé, 1952.
lo s
On collecting ship service performance data and their analysis.J. W. Bonebakker, 1953.
1 1 M The use of threè-phase current for auxiliary purposes (Dutch). J. C. G. van Wijk, 1953.
12 M Noise and noise abatement in marine engine rooms (Dutch).
Technisch-Physische Dienst TNO-TH, 1953.
13 M Investigation ofcylinder wear in diesel engines by means of labo-ratory machines (Dutch). H. Visser, 1954.
14 M The purification of heavy fuel oil for diesel engines (Dutch)
A. Bremer, 1953.
15 s Investigations of the stress distribution in corrugated bulkheads
with vertical troughs. H. E. Jaeger, B. Burghgraef and I. van der Ham, 1954.
16 M Analysis and testing of lubricating oils II (Dutch). R. N. M. A. Malotaux and J. B. Zabel, 1956.
17 M The application of new physical methods in the examination of
lubricating oils. R. N. M. A. Malotaux and F. van Zeggeren, 1957.
18 M Considerations on the application of three phase current on board ships for auxiliary purposes especially with regard to fault pro-tection, with a survey of winch drives recently applied on board
of these ships and their influence on the generating capacity
(Dutch). J. C. G. van Wijk, 1957.
19 M Crankcase explosions (Dutch). J. H. Minkhorst, 1957.
20 S An analysis of the application of aluminium alloys in ships'
structures. Suggestions about the riveting between steel and
aluminium alloy ships' structures. H. E. Jaeger, 1955.
21 S On stress calculations in helicoidal shells and propeller blades.
J. W. Cohen, 1955.
22 S Some notes on the calculation of pitching and heaving in
longi-tudinal waves. J. Gerritsma, 1955.
23 S Second series of stability experiments on models of lifeboats. B.
Burghgraef, 1956.
24 M Outside corrosion of and slagformation on tubes in oil-fired
boilers (Dutch). W. J. Tant, 1957.
25 S Experimental determination of damping, added mass and added
mass moment of inertia of a sliipmodel. J. Gerritsma, 1957. 26 M Noise measurements and noise reduction in ships. G. J. van Os
and B. van Steenbrugge, 1957.
27 S Initial metacentric height of small seagoing ships and the
in-accuracy and unreliability of calculated curvés of righting levers. J. W. Bonebakker, 1957.
28 M Influence of piston temperature on piston foaling and pistonring wear in diesel engines using residua] fuels. H. Visser, 1959. 29 M The influence of hysteresis on the value of the modulus of
rigid-ity of steel. A. Hoppe and A. M. Hens, 1959.
30 S An experimental analysis of shipmotions in longitudinal regular
waves. J. Gerritsma, 1958.
31 M Model tests concerning damping coefficient and the increase in the moment of inertia due to entrained water of ship's propellers.
N. J. Visser, 1960.
32 S The effect of a keel on the rolling characteristics of a ship.
J. Gerritsma, 1959.
33 M The application of new physical methods in the examination of lubricating oils (Contin. of report 17 M). R. N. M. A. Malotaux and F. van Zeggeren, 1960.
34 s Acoustical principles in ship design. J. H. Janssen, 1959.
35 S Shipmotions in longitudinal waves. J. Gerritsma, 1960.
36 S Experimental determination of bending moments for three
mod-els of different fullness in regular waves. J. Ch. de Does, 1960.
37 M Propeller excited vibratory forces in the shaft of a single screw tanker. J. D. van Manen and R. Wereldsma, 1960.
38 S Beamknees and other bracketed connections. H. E. Jaeger and
J. J. W. Nibbering, 1961.
39 M Crankshaft coupled free torsional-axial vibrations of a ship's
propulsion system. D. van Dort and N. J. Visser, 1963.
40 S On the longitudinal reduction factor for the added mass of
vi-brating ships with rectangular cross-section. W. P. A. Joosen and J. A. Sparenberg, 1961.
41 5 Stresses in flat propeller blade models determined by the
moiré-method. F. K. Ligtenberg, 1962.
42 S Application of modern digital computers in naval-architecture.
H. J. Zunderdorp, 1962.
43 C Raft trials and ships' trials with some underwater paint systems. P. de Wolfand A. M. van Londen, 1962.
44 S Some acoustical properties ofships with respect to noise control.
Part. I. J. H. Janssen, 1962.
45 S Some acoustical properties of ships with respect to noise control
Part II. J. H. Janssen, I 962.
46 C An investigation into the influence of the method of application
on the behaviour of anti-corrosive paint systems in seawater.
A. M. van Londen, 1962.
47 C Results of an inquiry into the condition of ships' hulls in relation to fouling and corrosion. H. C. Ekama, A. M. van Londen and P. de Wolf, 1962.
48 C Investigations into the use of the wheel-abrator for removing
rust and millscale from shipbuilding steel (Dutch). Interim report. J. Remnielts and L. D. B. van den Burg, 1962.
49 5 Distribution of damping and added mass along the length of a
shipmodel. J. Gerritsma and W. Beukelman, 1963.
50 S The influence of a bulbous bow on the motions and the
propül-sion in longitudinal waves. J. Gerritsma and W. Beukelman, 1963. 51 M Stress measurements on a propeller blade of a 42,000 ton tanker
on full scale. R. Wereldsma, 1964.
52 C Comparative investigations on the surface preparation of
ship-building steel by usingwheel-abrators and the application ofshop-coats. H. C. Ekama, A. M. van Londen and J. Remmelts, 1963.
53 5 The braking of large vessels. H. E. Jaeger, 1963.
54 C A study of ship bottom paints in panicular pertaining to the
behaviour and action of anti-fouling paints A. M. van Londen,
1963.
55 5 Fatigue of ship structures. J. J. W. Nibbering, 1963.
56 C The possibilities of exposure of anti-fouling paints in Curaçao,
Dutch Lesser Antilles, P. de Wolf and M. Meuter-Schriel, 1963. 57 M Determination of the dynamic properties and propeller excited vibrations of a special ship stern arrangement. R. Wereldsma,
1964.
58 S Numerical calculation of vertical hull vibrations of ships by
discretizing the vibration system. J. de Vries, 1964.
59 M Controllable pitch propellers, their suitability and economy for large sea-going ships propelled by conventional, directly coupled engines. C. Kapsenberg, 1964.
60 S Natural frequencies of free vertical ship vibrations. C. B.
Vreug-denhil, 1964.
61 S The distribution of the hydrodynamic forces on a heaving and
pitching shipmodeiin still water. J. Gerritsma and W. Beukelxnan,
1964.
62 C The mode of action of anti-fouling paints: Interaction between.
anti-fouling paints and sea water. A. M. van Londen, 1964.
63 M Corrosion in exhaust driven turbochargers on marine diesel
engines using heavy fuels. R. W. Stuart Michell and V. A. Ogale,
1965.
64 C Barnacle fouling on aged anti-fouling paints; a survey of pertinent literature and some recent observations. P. de Wolf, 1964.
65 S The lateral damping and added mass of a horizontally oscillating
shipmodel. G. van Leeuwen, 1964.
66 S Investigations into the strenght of ships' derricks. Part I. F. X. P
Soejadi, 1965.
67 S Heat-transfer in cargotariks of a 50,000 DWT tanker. D. J. van
der Heeden and L. L. Mulder, 1965.
68 M Guide to the application of Method for calculation of cylinder liner temperatures in diesel engines. H. W. van Tijen, 1965. 69 M Stress measurements on a propeller model for a 42,000 DWT
tanker. R. Wereldsma, 1965.
70 M Experiments on vibrating propeller models. R. Wereldsma, 1965. 71 s Research on bulbous bow ships. Part II. A. Still water perfor-man of a 24,000 DWT bulkcarrier with a large bulbous bow.
