An improved stern gear arrangement

COMMUNICATION No. 22 M

October 1970

NEDERLANDS SCHEEPSSTUDIECENTRUM TNO

NETHERLANDS SHIP RESEARCH CENTRE TNO

ENGINEERING DEPARTMENT

LEEGHWATERSTRAAT 5, DELFT

*

AN IMPROVED STERN GEAR ARRANGEMENT

(EEN VERBETERD ONTWERP SCHROEFASONDERSTEUNJNG EN

_{- DOORVOERING)}

by

IR. C. KAPSENBERG

RESEARCH COMMITTEE

IR. J. FASSE

IR. J. VAN HAASTERT TH. D. H. VAN HALDEREN IR. C. KAPSENBERG IR. B. ROETERINK IR. C. VAN DER WEELE IR. A. DE MooY (ex officio)

VOORWOORD

Gesteld mag worden dat aan de technische ontwikkeling van de constructie van de schroefasondersteuning en schroefasdoor-voeñng, ondanks de toename van de door de schroefas geleide vrmogens en de daarmede samenhangende toename der afme-tingen, gedurende vele jaren nagenoeg is voorbijgegaan. Pas sinds kort is men aan deze constructie aandacht gaan schen-kòri wat geresulteerd heeft in een aantal, van de conventiònele constructie afwijkende, nieuwe ontwerpen.

Een door het Nederlands Scheepsstudie Centrurn TNO vervaar-digd ontwerp werd uitvoerig beschreven in rapport 118M: ,Stern gear arrangement and electric power generation in ships propelled by controllable pitch propellers". Dit ontwerp wordt in de eerste plaats gekenmerkt door het korte (LID 1), druk-gesmeerde schroefaslager en in de tweede plaats door een zee-waterafdichting, waarin het zeewater en de l.agersmeerolie mid-deis een ruimte van elkaar gescheiden zijn en hun onderlinge ver-menging voorkomen wordt.

Het ontwerp is voorgelegd aan de classificatiebureaus Lloyd's Register of Shipping en Bureau Ventas, die er beide hun goed-keuring aan hebben gehecht.

Op verzoek van een reder werd, uitgaande van de in rapport no. 118M beschreven conceptie, een studie gemaakt naar de toe-pasbaarheid van deze constructie voor een 20 kn multi purpose" vrachtschip, waarvan de plannen reeds in vergevorderd stadium waren. Dit onderzoek heeft tenslotte geresulteerd in een tweetal alternatieve ontwerpen, die in het onderhavige rapport worden beschreven. Bij beide ontwerpen werd rekening gehouden met de mogelijkheid dat een en ander vervangen kan worden door een schroefasondersteuning en -doorvoering van het conventionéle type. De ontwerpen kwamen tot stand na uitvoerig overleg met deskundigen, terwiji tevens de classificatiebureaus Lloyd's Re-gister of Shipping en Bureau Ventas nauw bu dit overleg werden betrokken.

NEDERLANDS SCHEEPSSTUDIECENTRIJM TNO

PREFACE

Itmay be stated that stem gear design was for many years proba-bly the most neglected area of development in marine engineering in spite of increases in size of propellers, propellers shafts and propulsive powers.

It is only in comparatively recent years that attention is. paid to this construction which resulted in a number of new designs which deviate from the conventional sterntube.

A design made by Netherlands Ship Research Centre TNO was published in Report No. 118M "Stem gear arrangement and electric power generation in ships propelled by controllable pitch propellers". This design is characterized by the short (L/D 1)

forced lubricated tailshaft bearing and by a propeller shaft seal in which seawater and lubricating oil are completely separated by means of a space in communication with the bilges. Both Lloyd's Register of Shipping and Bureau Ventas granted their approval to this design.

On request of a Dutch shipowner a study was made, based on the concept as described in Report No. 118M, if the design would suit a 20 knots"multi purpose" freighter of which the plans were well on the way.

This study resulted in two alternative designs both published in the underlying report. Full account was taken of the possibility that both new stern gears could be changed over to a convention-al sterntube.

Specialists in the field of propeller shaft seals as well as the clas-sification societies Lloyd's Register of Shipping and Bureau Ventas were consulted.

CONTENTS

page

Summary.

. 7

i

Introduction

. . . 7

2

Practical evaluatioú of the stern gear arrangement

7

2.1

Stern gear with a "Crane" radial face seal

7

2.2

Stern gear with a "Simplex" seal

9

3 Exchanging the new stern gear for a conventional type of sterntube

9

4

Future work

. 9

5 Acknowledgement 9

AN IMPROVED STERN GEAR ARRANGEMENT

by

Ir. C. KAPSENBERO

Summary

Two alternative, improved stern gear arrangements, both based on the concept as has already been published [1], are discussed by

illustration of their application for a 20 knots multi purpose freighter The first design mcorporates a radial face

Crane type

seal and the second one incorporates the well known Simplex seal In both designs provisions are made to change over to a conven tional type of sterntube.

i

Introduction

A description of an improved stern gear design,

óhar-acterized by a short 1eght forced lubricated aftermost

bearing and a special sealing arrangement, was given

in Report No. 118M.

The features of the aftermost bearing are completely

the same as those of the main bearings ofa large marine

diesel engine. It is well known that these

hydrodynam-ically lubricated bearings with a length/bore ratio of 1

or less can withstand not only very high specific

pres-sures but also a high dynamic loading.

Due to the fact that the specific pressure of the

after-most propeller shaft bearing amounts to

6-10%

when

compared with the specific pressure of the main

bear-ings of slow speed diesel engines, the propeller shaft

bearing may be regarded as lowly loaded indeed. The

lubricating oil for the propeller shaft beanng,

incorpo-rated in the design already mentioned, has. to circulate

in a closed system consisting of a tank of limited

content and a lubricating Oil pump delivering the oil

to the bearing under a pressure of say 2 kgf/cm.

COntamination Of the lubricating oil with seawater

must be prevented. The seals available do nt meet this

requirement satisfactorily and it looks like being almost

impossible to make a seal that remains tight during a

period of years. Therefore an attempt was made to

design a special sealing ar angement in view of

trouble-free operation for rather a long period. A detailed

des-cription of this design can be found in Report No.

118M. The main feature of this seal is that any leakage

of seawater is kept away from the shaft and other

seal-ing elements by means of cylinders, mounted to the

stern frame and the propeller hub.

In this way it is possible to catch any leakage of

sea-water and discharge it to the bilges.

The short, hydrodynamically lubricated aftermost

pro-peller shaft bearing, will be. suited in particular in those

cases where heavy propellers, such as c.p.p.'s, or

pro-pellers ranning at low speed are envisaged. The stern

gear arrangement as is shown in reference [1.J has been

fully discussed with the classification societies Lloyd's

Register of Shipping and Bureau Ventas who both

granted their approval to the design.

2

Practical evaluation of the stern gear arrangement

The more or less theoretical design [1] has been worked

out for a newbuilding contract. The results of this

study, compiled in the underlying report, may be

re-garded as some kind oía "shadòw"-design.

Details concerning the controllable pitch propeller,

shaft and the ship's afterbody were known and it

was

regarded to be of great interest to see how the design

would look like when fitted to this particular .ship

un-der construction.

The ship's principal particulars are as follows:

Length, o.a.

165.0 _m

breath, moulded

_{24.0 m}

deadweight

15850

_tons

main machinery output

17500

bhp

speed on trials

_{21.3 knots}

propeller speed

120

r.p.m.

propeller diameter

6400

_mm

propeller weight

32

tons

In fact two alternative designs were made viz, one

in-corporating a radial face seal of Crane Packing Ltd.,

Slough, Buckinghámshire, England and one

incorpo-rating a "Simplex" seal of Deutsche Werft, Hamburg,

Germany.

2.1

Stern gear with a "Crane" radial face seal

The design of the stern gear, incorporating the radial

face seal of Crane Ltd., is shown in more detail by the

drawings, viz. fig. 1, 2, 3, and 4.

Because details in each drawing are captioned the

fig-ures are regarded as self-explanatory:

When compared with the drawings of ref. [I] it will be

noticed that two inflatable seals around the shaft are

introduced.

The reason for doing so can be understood when one

considers the "Crane" seal should fail which can be

observed when the amount of leaking seawater

be-comes inadmissibly high. In that event the inflatable

seals can be puffed up so that the lubricating oil will

still be separated from the seawater. In order to

length-en the life of the sealing surfaces lubricating facilities in

between the two seals have been introduced.

When the ship is drydocked the "Crane" packing can

be dismounted, reconditioned or renewed from the

outside.

Pulling of the propeller shaft, always a laborous job in

particular for controllable pitch propellers, will ñot be

necessary anymore.

2.2

Stern gear with a "Simplex" seal

The second design of the stern gear arrangement,

in-corporates the well-known "Simplex" seal.

In order to meet the requirement of preventing any

contamination of the bearing lubricating oil the

exjst-ing chamber, that separates the two sets of liprexjst-ings in

the after gland, is connected to an oil system that keeps

up a small oil flOW, originating from a header tank and

emptying into a tank at low level, that takes the leaking

seawater along.

The liprings situated near the bearing have to be

abso-lutely tight against contaminated oil and clean oil.

Becausé this cannot be gtiaranteed there always

re-mains a chance of clean bearing lubricating oil getting

contaminated with seawater. Therefore this design must

be considered as less reliable as the design described in

paragraph 2.1.

The. complete design can be studied by means of the

figures 5, 6, 7 and 8.

Figure 8 illustrates how the necessary oil pressure is

exerted on the lipig. The bearing lubricating oil is

supplied by the lubricating oil pump 1 ), with a suction

from the lubricating oil sumptank 2 and discharging

through pipeline 3 to the bearing. This oil runs back

through pipeline 4 to the sumptank 2 after passing the

header overflow tank 5 situated above the waterline.

In this way a sufficient oil pressure is always exerted to

the liprings of the "Simplex" seal.

The circulating and cooling circuit consists of a small

lubricating oil pump 6 with suction from a circulating

oil sumptank 7 at low level and a discharge t an

over-flow header tank 8. The oil runs through pipeline 9 to

the space between the liprings of forward and aft seals

and returns through pipeline 10 to the sumptank 7. In

1) _{The numbers refer to the details captioned in figure 8.}

Fig. 4 Hydraulic spanner. Steel bolt. Steel nut.

Hydraulic'cylinder. Steel pivots.

this way leaking seawater from the aft seal is

transport-ed to that sumptank from which it can be draintransport-ed at 11.

As far as renewal or repair activities are concerned it

has to be poiñted out that the seal cannot be

dismount-ed Without pulling the tailshaft.

However, the first lipring behind the bearing can be

replaced after removing the propeller shaft backwards

and pushing the after lipringhouse towards the

pro-peller as far as possible.

The space so created enables the lipring to be taken out

and replaced by a new one after the old specimen is cut.

The new lipring has to be glued and vulcanized. For

that purpose special tools are available.

3

Exchanging the new stern gear for a conventional

type of sterntube

Both designs are based on the possibility tô replace the

new stern gear by a conventional sterntube and

"Sim-plex" seals just iñ case the new design did not work out

well. Figure 9 shows how this can be accomplished.

The long, white metal lined bush has to be

water-cooled.

4 FUtuÑ work

The "Crane" type as well as the "Simplex" type of seal

are designed in view of perfect tightness against

pene-trating seawater.

lt must be emphasized that with the seal arrangement

which forms part of the new stern gear design as

de-scribed in paragraph 2.1 no perfect tightness against

seawater needs to be pursued.

A limited amount of leakage may be accepted because

the seawater does contact neither the propeller shaft

nor the bearing lubricating óil.

Therefore a more simple seal can be used. Future work

will comprise the design and testing of a more simple

seal arrangement with a good life expectancy.

5 Acknowledgement

The Netherlands Ship Research Centre TNO gratefully

acknowledges the Vereenigde Nederlandsche

Scheep-vaartmij. N.y., Koninklijke Nederlandsche Stoomboot

Mij. N.Y., N.Y. Koninklijke Rotterdamsche Lloyd,

N.Y. Stoomvaartmij. Nederland and the Royal

Inter-ocean Lines N.Y. who made possible the work reported

herein.

The designs were made by the N.Y. Koninldijke

Maat-schappij ,,De Scheide".

References

1. C. KAPSENBERG, 1968, Netherlands Ship Research Centre TNO, RepOrt No. 118 M: "Stern gear arrangement and electric power generatiOn in ships propelled by controllable pitch propellérs".

Fig. 6 Arrangement of propeller shaft aftermost bearing. As figs 2, however with a lubricating oil system, suited for a "Simplex" seal. I. "Simplex" sealing device.

Lubricating oil supply for circulating aft seal and cooling forward seal. Lubricating oil outlet forward seal. Lubricating oil outlet from aft seal.

I

1

-ii

/

/

t

41.2 .5(CTION I-I

320

N

/

/

/

/ /

////////t//// t/////////////////

Í

rA

'WAF'A

ri

4-4.'

mi

14

ìt

/V

/

/

/////// /

// //////

/

Fig. 7

"Simplex" sealing device withlubricating:oil circulation.

Annular space, used for circulating lubricating oil to drain off leaking seawater. Annular space used for cooling the liprings by lubri- cating oil. Lubricating Oil discharge for bearing.

12

-

I1tI,.

Il

iI

-'III

III

I

I

'1ÍÍI'frny2

'--".'---

-'---i,

11.i1IIIUII1U

OIL SWOL flW

#200

1600

'4

Fig. 9

Replacement by a conventional sterntube.

PUBLICATIONS OF HE NETHERLANDS SHIP RESEARCH CENTRE TNO

PUBLISHED AFTER 1963 (LIST OF EARLIER PUBLICATIONS AVAILABLE ON REQUEST)

PRICE PER COPY DFL.

10,-M = engineering department S = shipbuilding department C = corrosion and antifouling department

Reports

57 M Determination of the dynamic properties and propeller excited vibrations of a spethal ship stem arrangement. R. Wereldsma, 1964.

58 S Numerical calculation of vertical hull vibrations of ships by discretizing the vibration system, J. de Vries, I 964.

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 Nätural frequencies of fiee vertical ship vibrations. C. B.

Vreug-denhil, I 964.

61 S the distribution of the hydrodynamic forces on a heaving and pitching shipmodel in still water. J. Gerritsma and W.

Beukel-man, 1964.

62 C The mode of action of anti-fouling paints : Interaction between antifouiiÌig 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 Mitchell 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 adiled mass of a horizontally oscillating

shipmodel. G. van Leeuwen, I 964.

66 S Investigations into the strength of ships' derricks. Part I. F. X.

P. Soejadi, 1965

67 S Heat-transfer in cargotanks 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. vän Tijen, 1965. 69 M Stress measurements on a propeller model fcr a 42,000 DWT

tanker. R. Wereldsma, 1965.

70 M Experiments on vibrating propeller models. R. Weretdsma, 1965. 71 S Research on bulbous bow ships. Part II. A. Still water perfor-mance of a 24,000 DWT bulkcarrier with a large bulbous bow. W. P. A. van Larnmeren and J. J. Muntjewerf, 1965.

72 S Research on bulbous bow ships. Part H. B. Behaviour of a 24,000 DWT bulkcarrier with a large bulbous bow in a seaway. W. P. A. van Lammeren and F. V. A. Pangalila, 1965.

73 S Stress and strain distribution in a vertically corrugated bulkhead. H. E. Jaeger and P. A. van Katwijk, 1965.

74 S. Research on bulbous bow ships. Part I. A. Still water investiga-tions into bulbous bow forms for a fast cargo liner. W. P. A. van Lammeren and R. Wahab, 1965.

75 S Hull vibrations of the cargo-passenger motor ship "Oranje

Nassau", W. van Horssen, 1965.

76 S Research on bulbous bow ships. Part I. B. The behaviour ofa fast cargo liner with a conventional and with a bulbous bow in a sea-way. R. Wahab, 1965.

77 M Comparative shipboard measurements of sürface temperatures and surface corrosion in air cooled and water cooled turbine outlet casings of exhaust driven marine diesel engme turbo chargers. R. W. Stuart Mitchell and V. A. Ogale, 1965.

78 M Stern tube vibration measurements of a cargo ship with speciäl afterbody. R. Wereldsma, 1965.

79 C The pre-treatment of ship plates: A comparative investigation on sóme pre-treatmCnt methods in use in the shipbuilding

industry. A. M. van Londen, 1965.

80 C The pre-treatment of ship plates: A practical investigation into the influence of different working procedures in over-coating zinc rich epoxy-resin based pre-construction primers. A. M. van Londen and W. Mulder, 1965.

81 S The performance of U-tRnks as a passive anti-rolling device. C. Stigter, 1966.

82 S Low-cycle fatigue of steel structures. J. J. W. Nibbering and J. van Lint, 1966.

83 S Roll damping by free surface tanks J J van den Bosch and

L H Vugts, 1966.

84 S Behaviour of a ship in a seaway. J. Gerritsma, 1966.

85 S Brittle fracture of full scale structures damaged by fatigue. J. J. W. Nibbering, J. van Lint and R. T. van Leeuwen, 1966. 86 M Theoretical evaluation of heat transfer in dry cargo ship's Uinks

using thermal oil as a heat transfer medium. D. J. van der

Heeden, 1966.

87 S Model experiments on sound transmissiOn from engineroom to accommodation in motorships. J. H. Janssen, 1966.

88 S Pitch and heave with 6xed and controlled bow flñs. J. H. Vugts, 1966.

89 5 EstimatiOn of the natural frequencies of a ship's double bottom by means of a sandwich theory. S. Hylarides, 1967.

90 S Computation of pitch and heave motions for arbitrary ship forms.

W. E. Smith, 1967..

9 1 M Corrosion in exhaust driven turbochargefs on marine diesel engines using heavy fuels. R. W. Stuart Mitchell, A. J. M. S. van Montfoort and V. A. Ogale, 1967.

92 M Residual fuel treatment on board ship. Paît H. Comparative cylinder wear measurements on a laboratory diesel engine using filtered or centrifuged residual fueL A. de Mooy, M. Verwoest and G. G. van der Meulen, 1967.

93 C Cost relations of the treatments of ship hulls ànd the fuel cOn-sumption of ships. H. J. Lageveen-van Kuijk, 1967.

94 C Optimum conditions for blast cleaning of steel plate. J.

Rem-melts, 1967.

95 M Residual fuel treatment on board ship. Part L The effect of cen-trifuging, filtering and homogenizing on the unsolubles in residual fuel. M. Verwoest and F. J. Colon, 1967.

96 S Analysis of the modified strip theory for the calculation of ship motions ançi wave bending moments. J. Gerritsma and W.. Beu-kelman, 1967.

97 S On the efficacy of two different roll-damping tks. J. Bootsma and J. J. van den Bosch, 1967.

98 S Equation of motion coefficients for a pitching and heaving des-troyer model. W. E. Smith, 1967.

99 S The manoeuvrabiity of ships on a straight course. J. P. Hooft,

1967.

100 S Amidships forces and moments on a C = 0.80 "Series 60"

model in waves from various directions. R. Wahab, 1967. 101 C Optimum conditions for blast cleaning ofsteel plate. Conclusion.

J. Remmelts, 1967.

102 M The axial stiffness of marine diesel engine crankshafts. Part I. Çomparison between the results of full scale measurements and those of calculatiOns according to published formulae. N. J.

Visser, 1967.

103 M The axial stiffness of marine diesel engine crankshafts. Part H. Theory and results of scale model measurements and comparison with published formulae. C. A. M. van der Linden, l967 104 M Marine diesel engine exhaust noise. Part I. A mathematical model.

J. H. Janssen, 1967.

105 M Marine diesel engine exhaust noise. Part H. Scale models of exhaust systems. J. Buiten and J. H. Janssen, 1968.

106 M Marine diesel engine exhaust noise. Part Ill. Exhaust sound criteria for bridge wings. J. H. Janssen en J. Bu ten, 1967. 107 S Ship vibration analysis by finite element technique. Part I.

General review and application to simple structures, statically loaded. S. Hylarides, 1967.

108 M Marine refrigeration engineering. Part I. Testing of a decentrai-¡sed refrigeÑting installation. J. A. Knobbout and R. W. J.

Kouffeld, 1967.

109 S A comparative study on four different passive roll damping tanks. Part I. J. H. Vugts, 1968.

110 S Strain, stress and flexure of two corrugated and one plane bulk-head subjected to a lateral, distributed load. H. E. Jaeger and P. A. van Katwijk, 1968.

111 M Experimental evaluation of heat transfer in a dry-cargo ships' tank, using thermal oil as a heat transfer medium. D. J. van der

Heeden, 1968.

112 S The hydrodynamic coefficients for swaying, heaving and roiling cylinders in a free surface. J. H. Vugts, 1968.

113 M Marine refrigeration engineering. Part H. Some results of testing a decentralised marine refrigerating unitwith R 502. J..A.

Knob-bout and C. B. Colenbrander, 1968.

114 S The steering of a ship during the stopping manoeuvre. J. P. Hooft, 1969.

II 6 M Torsional-axial vibrations ofa sii ip's propulsion system. Part I. Comparative investigation of calculated and measured

torsional-axial vibrations in

the shafting of a dry cargo motorship

C. A. M. van ckr Liuden, H. H. 't Hart and E. R Dolfin, 1968. 117 S A comparative study on four different passive roll damping

tanks Part Il. J. H. Vugts, l969.

118 M Stern gear arrangement and electric power generation in ships propelled by controllable pitch propellers. C. Kapseñberg, 1968. 119 M Marine diesel engine exhaust noise. Part IV. Transferdarnping

data of 40 modelvariants of a compound resonator silencer. J. Bùiten, M. J. A. M. de Regt and W. P. H. 'Hanen, 1968. 120 C Durability tests with prefabrication primers in use of steel plates.

A. M. van Londen and W. Mulder, 1970.

121 S Proposal for the testing of weld metal from the viewpoint of bnttle fracture initiation W P van den Blink and J J W Nib

bering, 1968.

122 M The corrosion behaviOur of cunifer IO alloys in seawäterpiping-systems on board ship. Part 1. W. J. J. Goetzeeand F. J. Kievits, 1968.

123 M Marine refrigeration engineering. Part 111. Proposal for a specifi-cation of a marine refrigerating unit and test procedures. J. A. Knobbout and R. W. J. Kouffeld, 1968.

124 S The design of U-tanks for roll damping of ships. J. D. van den Bunt, 1969.

125 S A proposal on nOise criterià for sea-going ships. J. Buiten, 1969. 126 S A proposal for standardized measurements and annoyance rating of simultaneous noise and vibration in ships. J. H. Janssen, 1969. 127 s Thebraking of large vessels !1.H. E. Jaeger in collaboration with

M. Jourdain, 1969.

128 M Guide for the calculation of heating capacity and heating coils for double bottom fuel oil tanks in dry cargo ships. D. J. van der

Heeden, 1969.

129 M Residual fuel treatment on board ship. Part III. A. de Mooy, P. J. Brandenburg and G. G. van der Meulen. 1969.

130 M Marine diesel engine exhaust noise. Part V. Investigation of a double resonatorsilencer. J. Buiten, 1969.

131 S Model and full scale motions of a twin-hull vessel. M F. van

Sluijs, 1969.

132 M Torsional-axial vibrations of a ship's propulsion system. Part H. W. van Gent and S. Hylarides. 1969.

134 M The corrOsión behaviour of cunifer-lO alloy.s iO seawaterpiping-systems on board ship. Part II. P. J.. Berg and R. G. de Lange, 1969.

135 5 Boundary layer control on a ships rudder. J. H. G. Verhagen,

1970

137 M Torsional-axial vibratiOns of a ship's propulsion system. Part III; C. A. M. van der Linden, 1969.

138 S The manoeùvrability of ships at low speed. J. P. Hooft and M. W. C. Oosterveld 1970.

141 S Resistance and propulsion of a high-speed single-screw cargo liner design. J. J. Muntjewerf, 1970.

142 s Optimal meteorological ship routeing. C. de Wit, 1970. 143 s Hull vibrations of the cargo-liner "Koudekerk". H. H. 't Hart.

1970.

Communications

II C Investigations into the useofsome shipbottom paints, based on scarcely saponifiable vehicles (Dutch). A. M. van Londen and P. de Wolf, 1964.

12 C The pre-treatment ofship plates:. The treatment of welded joints prior to painting (Dutch). A. M. van Londen and W. Mulder,

1965.

13 C Corrosion, ship bottom paints (Dutch). H. C. Ekarna, 1966. 14 5 Human reaction to shipboard vibration, a study of existihg

literature (Dutch). W. ten Cate. 1966.

15 M Refrigerated contáinerized transpon (Dutch). J. A. Knobbout, 1967.

16 S Measures to prevent sound and vibration annoyance aboard a seagoing Passenger and carferry, fitted out with dieselengines

(Dutch). J. Buhen, J. H. Janssen, H. F. Steenhoek and L. A. S. Hagemañ. 1968.

17 S Guide for the specification, 'testing and inspection of glass reinforced polyester structures in shipbuilding (Dutch). G. Hamm, 1968.

¡8 S An experimental simulator for the manoeuvring of surface ships. J. B. van den Brug and W., A. Wagenaar, 1969.

19 5 The computer programmes system and the NALS langùage for numerica] control for shipbuilding. H. le Grand, 1969.

20 S A case study on networkplanning in shipbuilding (Dutch). J. S. Folkers, H. J. de Ruiter, A. W. Ruys, 1970.

5

VIw ACCORD/r'16 11 _{Fig. I General arrangement of propeller shaft with c.p.}

pro-peller and aftermost bearing. Propellór shaft with c.p. propeller.

Aftermost propeller shaft bearing, forced lubricated. Sóaling arrangement "Crane" type.

Lifting jacks for facilitating removal of underliìier. Entry to shaft tunnel.

Escape to main deck.

z

e

/;,

!.

u1iiii

in

Fig. 2 Arrangement of aftermost bearing. Split shaft liners.

Bearing cap.

Filling piece.

Hydraulic spanners.

Lubricating oil catching devices. Lubricating oil Supply.

Lubricating oil discharge. Leaking seawater discharge.

2

o

Fig. 3

Sealing arrangement with "Crane" face seal and mila- table seals forpropeilershaft. i .

"Crane" face seal arrangement.

2. Inflàtable seal&

Split cylinder fixed to the propellerhub. Split cylinder fixed to the stern. Lubricating oil discharge Leakingseawater discharge Rope guard.

-& Spjjt seatof phosphor bronzeS 9.. Lubricating oil inlet for inflatable seals.

_{lo. Air inlet to infiatableaIs.}

_11.

Flexible bellowofthe"Crane" seal.

I2

J,,,/J//a/,iS««/z///ZÁ ki

/Ä

(

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Iî

ìîii

I

-r

:--I

" :Ä1I:

I __7

i

5CTION I-I

Fig. 5

GeneraI arrangement of propeller shaft with cp pro- peler and aftermost bearing. i .

Propeller shaft with c.p. propeller. Aftermost propeller shaft bearing, forced lubricated Sealing arrangement, "Simplex" type. Lifting jacks for facilitating removal of under liner. Entry to shaft tunnel. Escape to main deck.