Lister Petter ALPHA Series User manual

ALPHA SERIES

Publication 027-08651 Edition 2, May 2007
© Copyright Lister Petter Power Systems Limited 2018, all rights reserved
Lister Petter Power Systems Limited
Broadmeadow Industrial Estate, TQ14 9AE, England

LISTER-PETTER MARINE INSTALLATION GUIDE iii
BOOK CONTENTS
page
FOREWARD....................................................................................... iv
INTRODUCTION...................................................................... v
SERVICEABILITY .................................................................... vi
HULL PERFORMANCE AND DISPLACEMENT ....................................
POWER CALCULATION TABLES....................................................
ENGINE MOUNTING AND INSTALLATION .........................................
GEARBOXES............................................................................
HYDRAULIC TRANSMISSION ........................................................
PROPELLERS ...........................................................................
THE ENGINE ROOM..................................................................
ENGINE DRIVEN ACCESSORIES ...................................................
FUEL SYSTEMS .......................................................................
LUBRICATION SYSTEMS .............................................................
ENGINE COOLING SYSTEMS .......................................................
WATERHEATING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EXHAUST SYSTEMS ..................................................................
AIR SUPPLY ............................................................................
ELECTRICAL SYSTEMS ..............................................................
ENGINE DERATING ...................................................................
LAYING UP.............................................................................
INDEX ....................................................................................
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................................................................
3
1
4
5
6
9
10
11
12
13
14
2
15
16
7
8
18
17

LISTER-PETTER MARINE INSTALLATION GUIDEiv
FOREWORD
Inlife and vessel threatening incidents at sea
news reporting often gives “engine failure” as the
cause, implying to the casual observer the engine
suffered some internal defect and stopped.
Infact modern engines are extraordinarily reliable
and true engine failure where a component or internal
system of the engine fails of its own accord are
extremely rare.
Experience shows that the majority of such
reported “engine failures” are actually caused by
incorrect installation of the engine and its asociated
systems – cooling, fuel supply, mounting, electrical
systems etc. or lack of specified maintenance to
these systems or the engine.
Unfortunately, both these latent deficiencies can
allow the engine to function at low outputs in mild
seas giving a false sense of security. This situation
is particularly dangerous for sailing craft which may
be assuming the engine will be available to get the
vessel out of any difficulty.
When called on for prolonged operation at
maximum output, often in heavy seas in an
emergency, the engine may then fail to operate. (See
particularly sections on cooling; Section 11 and fuel
tanks; Section 9).
This guide will give the boat builder or user
information to ensure that the engine and its
associated systems will give long reliable service
by being correctly installed and available in an
emergency.
Although primarily an installation guide, some
engine and engine system maintenance requirements
are also given. Refer to the maintenance manual of
your particular engine for full engine maintenance
details.
The guide is specifically intended for users of
Lister-Petter engines, however many of the issues will
have wider applicability to small boat engine users.

LISTER-PETTER MARINE INSTALLATION GUIDE v
The Lister Marine Range is designed and produced to
suit a wide range of applications including riverboats, canal
boats, workboats, yachts and fishing boats.
When installed, used and serviced correctly the engines
will give outstanding performance, reliability and long life
under extreme conditions.
This book is provided as a guide to installers in the
important aspects of engine installation and also provides
back up information on how the engine systems work and
how to get the best results.
Tomeet the requirements of the Lister Marine two
year operation warranty the installation must conform
to the minimum requirements as in this book, the laying
up procedures in "17 Laying Up" and the Maintenance
Schedule in the Operators Handbook. The Lister Marine
Installation Report must be completed by Lister-Petter or
its representatives. The engine must be tested to reach
maximum rated r/min under fully loaded conditions
Careful consideration must be given to the layout and
design of any marine installation at an early stage. This can
pay dividends later as a well-designed engine installation
will enable faster and easier maintenance, less time spent
out of service, greater reliability and longer engine life.
Safety regulations vary from country to country and the
appropriate regulations should be complied with. See "3.7
Operating Safety" for general precautions.
Details of the British Waterways 'Boat Safety Scheme'
are available in the UK from the Environment Agency. This
covers inboard engines and electrical systems as well as
other safety aspects.
Since the Lister-Petter Marine Installation Guide is
aimed at an international market, the Guide mentions many
of the most important safety points covered in the Boat
Safety Scheme, but is not as comprehensive. Therefore
this manual should be used in conjunction with the Boat
Safety Scheme.
The information, specifications, illustrations and
statements contained within this manual are given with our
best intentions and are believed to be correct at the time
of publication.
Asour policy is one of continuing development, we
reserve the right to amend any technical information within
this publication without prior notification.
Toensure the best performance is obtained from
the engine, the use of Lister-Petter approved parts
and accessories is strongly recommended as the use
of these will contribute to reliable running and easier
maintenance.
The engine design and manufacture utilise the
accumulated knowledge of the production of diesel engines
in Dursley, Gloucestershire since 1930 and benefit from
the latest CAD and CAM technology. Alpha Series engines
conform with the requirements of ISO 3046, BS 5514 and
DIN 6271 for power, output and fuel consumption.
Responsibility of Boat Builders and
Purchasers
Many problems associated with boat drive systems are
often initially referred to Lister-Petter as Warranty items.
However any problem should first be referred to the boat
builder.
Oninvestigation it is often found that the apparent
engine problem is the result of incorrect installation of the
engine and associated equipment. Examples are propeller
singing, excessive noise and vibration, poor speed, over
heating etc.
Whilst Lister-Petter are always keen to help, if it turns
out that the problem is not warrantable due to incorrect
installation, then Lister-Petter reserve the right to charge for
their time spent on the investigation of the reported fault.
Therefore we strongly advise boat builders to ensure
that these guidelines are followed.
Ifyou are a prospective purchaser, ensure that your
boat has been built to these guidelines, and that a Lister-
Petter marine installation report has been completed.
Important
Your attention is drawn to the symbols shown and
described below which are applied throughout this
publication.
CAUTION
This caution symbol draws attention to special instructions
or procedures which, if not correctly followed, may result
in damage to or destruction of equipment.
WARNING
This warning symbol draws attention to special instructions
or procedures which, if not strictly observed, may result in
personal injury.
WARNING
A WARNING SYMBOL WITH THIS TYPE OF TEXT
DRAWS ATTENTION TO SPECIAL INSTRUCTIONS OR
PROCEDURES WHICH, IF NOT STRICTLY OBSERVED,
MAY RESULT IN SEVERE PERSONAL INJURY, OR
LOSS OF LIFE.
Note:
A note is used to draw your attention to additional or
important information.
INTRODUCTION

LISTER-PETTER MARINE INSTALLATION GUIDEvi
Service Accessibility
Itis essential that specified routine maintenance
checks can be easily carried out. Experience shows
that difficult access to service points means that
maintenance is not carried out, and this causes
higher service costs, and reduced reliability.
Daily Engine Maintenance Checks
These should be easily done in less than 5
minutes overall:
a. Check the engine oil level.
b. Check the gearbox oil level.
c. Check the coolant level .
d. Check for air intake restriction.
e. Check the sea water strainer.
Attending to these items should be easily
carried out unrestricted by any engine or vessel
components.
a. Fill with engine oil.
b. Fill with gear oil.
c. Fill with coolant.
d. Drain the fuel/water separator sediment.
Scheduled Maintenance Operations
a. Remove and replace the full flow oil filter
element.
b. Remove and inspect the air cleaner element.
c. Remove and replace fuel filter elements.
d. Remove and inspect the front drive belt.
e. Remove and inspect the zinc anodes.
f. Drain the cooling system, clean the heat
exchanger core.
g. Remove and inspect raw water pump/impeller.
h. Adjust propeller shaft alignment.
i. Check belt tension.
j. Adjust valves, except on engines fitted with
hydraulic tappets (refer to the Operators
Handbook).
k. Bar engine. (Turn the round round amanually.
l. Tighten engine mounts.
SERVICEABILITY
Inspection for Service Repair
a. Remove and have the fuel pump inspected by an
authorised service agent.
b. Remove and inspect the alternator and starter
motor.
c. Remove and inspect injectors (NB testing should
only be carried out by a qualified person, at an
authorised fuel injector specialist test facility).
d. Remove and inspect the water pump.
e. Remove and inspect the thermostat.
f. Remove and inspect the turbocharger.
g. Remove and inspect all coolant hoses.
h. Check the crankshaft endfloat.
i. Check the battery.
j. Remove and inspect the engine.
k. Remove and inspect the marine gear.
Minimum Recommended Spares List
Lists of reccommended spares are available for
specific engines; consult your marine dealer. But at
least the following should be carried.
a. Oil fi l ter element.
b. Fuel fi l ter element x 2.
c. Air fi l ter element.
d. Drive belt/s.
e. Fuel injectors.
f. Injector washers.
g. Oil cooler end caps.
h. Full set of water hoses.
i. Fuel lift pump kit
j. 2 x water pump impellers.
k. Water pump repair kit.
l. Heat exchanger anode.

HULL PERFORMANCE AND DISPLACEMENT 1
LISTER-PETTER MARINE INSTALLATION GUIDE 1.1
SECTION 1
HULL PERFORMANCE AND DISPLACEMENT
CONTENTS
page
1.1 Boat Types . . . . . . . . . . . . . .........................................................1.2
1.2 Hull Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3
1.3 Speed to Length Ratio.....................................................1.4
1.4 Wave Making ...................................................................1.4
1.5 Effect of Displacement on Power and Speed . . . ...... . . . . .....1.6
1.6 Displacement...................................................................1.8
1.7 Displacement Calculations ..............................................1.8

1 HULL PERFORMANCE AND DISPLACEMENT
LISTER-PETTER MARINE INSTALLATION GUIDE1.2
1.1 Boat Types
Correct Engine Application
Before any engine can be considered for a
particular boat the use or duty to which the craft is
to be put must be looked into, since this affects the
permissible rating for that engine.
Application
Engine ratings are selected according to
expected duties. The same engine in a pleasure
craft application can be given a higher rating than
say a work boat or fishing boat application, because
the latter is exposed to many more hours of full load
operation per year.
Correct application is essential to achieve
expected working life and maintenance costs.
Incorrectly applied engines will not receive full
warranty cover.
Underloading
Under-loading is in many ways as detrimental to
an engines life as overloading. Under-loading means
the engine components may not achieve correct
working temperature.
The effects can be oil slobber, where a mixture of
oil and soot is ejected via the exhaust system, which
is unpleasant and unsightly; excessive carbon build-
up on pistons which damage bores and oil life can
be reduced due to sooting.
Toavoid these problems, and achieve full
warranty, the daily average output of the engine
should not be less than 30% of the rated output for
that application.
For example, if an engine operating for three hours
per day, is operated for one hour at idle, (effectively
zero load - undesirable), then it must be operated
for the next two hours at 45% of its rated output
to achieve a minimum daily average load factor of
30%.
Removing Slow Speed Carbon Build-up
This can be cleared by occasional operation
at maximum engine speed and power for up to
an hour. This is most easily performed on rivers
where permissible, or alternatively when tied up to a
bollard on a piled section (to avoid bank erosion) of
waterway.
Hull Design
The following sections deal with the most common
types of boats, and hull design in use today.
1.1.1 High Speed Pleasure Craft
Speedboats, high performance cruisers, open
lightweight boats with limited accommodatio
.
Figure 1.1.1 High Speed Pleasure Craft
1.1.2 Pleasure Craft
Sports fishing craft, offshore cruisers, river/estuary
cruisers, coastal cruisers, auxiliary engined sailing
craft.
Figure 1.1.2 Pleasure Craft
1.1.3 Commercial Craft
Full displacement boat capable of extended
offshore passages; hire cruisers for river and
estuary use, survey vessels, patrol craft, pilot
boats, commercial fishing boats with high speed
capability for the out and homeward journey and crew
launches.
The term ‘commercial’ can be misleading in
certain instances - as a general rule it relates to the
possibility of the engine having to operate at full
throttle for extended period.
Figure 1.1.3 Commercial Craft
1.1.4 Commercial Heavy Duty
Tugs, trawlers, barges, ferryboats, coastal
workboats on continuous service.
Figure 1.1.4 Commercial Heavy Duty
As can be appreciated, each of the previous
categories puts different demands upon the
propulsion unit.
For example, an estuary cruiser of the pleasure
craft type might require full throttle for only a short

HULL PERFORMANCE AND DISPLACEMENT 1
LISTER-PETTER MARINE INSTALLATION GUIDE 1.3
period and has a fairly limited range, whereas a
commercial craft with a longer range would need to
operate perhaps in a narrower speed range at full
throttle for longer periods.
Note:
There are certain craft, due to their type of work and
expected lifetime, that can be rated in the high speed
category, i.e. inshore rescue craft, fire tenders etc.
(all with a limited range). These applications would
require full throttle for only a short time and this is quite
acceptable so long as it does not exceed the figures
quoted in the engine specifications. Lister-Petter will
be pleased to advise on any problems encountered.
Failure to observe the above may invalidate any
warranty which may be applicable..
1.2 Hull Configuration
Consideration must be given to the type of hull
in order to estimate the power required to propel the
boat at the desired speed.
The types of hull can be broadly classified into
three groups:
1. Displacement type hulls.
2. Semi-displacement hulls.
3. Planing hulls.
1.2.1 Displacement Type Hulls
Underwater shapes are well rounded featuring a
narrow stern which can be either canoe shaped or
with a transom.
Figure 1.2.1 Displacement Hull
1.2.2 Semi-displacement Hull
These hulls are similar to the displacement type,
however they differ in that they feature:
a. A broader aft section.
b. Shallower keel.
c. Wider transom to provide more buoyancy.
d. ‘Vee’ bottom in some cases.
Figure 1.2.2 Semi-displacement Hull
1.2.3 Planing Hull
These types of hull feature the following:-
a. Wide transom.
b. High beam/length ratio.
c. ‘Vee’ bottom with flatter sections towards the
stern.
d. Small keel.
e. Hard Chine at turn of bilge.
Figure 1.2.3 Planing Hull

1 HULL PERFORMANCE AND DISPLACEMENT
LISTER-PETTER MARINE INSTALLATION GUIDE1.4
1.3 Speed to Length Ratio
Todefi n e and assess the various types of hull,
it is necessary to be familiar with the speed/length
ratio.
This is the speed of the boat divided by the square
root of the length at the water line.
Figure 1.3.1 Speed/length Ratio
Type of Hull Speed/length Ratio
Displacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.30 to 1.50
Semi-displacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.34 to 2.50
Planing.................................................. 3.00 to 5.00
This figure is very close to the optimum speed/
length ratio for narrow canoe/round stern hulls which
is 1.34.
Ascan be appreciated there are limitations to
the efficient and safe speed a displacement hull can
achieve due to its relatively poor shape.
Inany case, a displacement hulls prime usage is for
storage and not speed. (The higher the speed/length
ratio the greater the capability for increased speed).
1.4 Wave Making
Tounderstand the potential problems related to
speed and displacement hulls with narrow sterns, the
wavemaking characteristics must be considered.
Waves created by a boat moving through the
water can be attributed to:
1. Waves created as a direct result of speed and
water line length.
2. The actual friction of the boats hull in the water
due to its shape and displacement.
3. The effect of natural elements e.g. wind above
the water line.
When a boat is travelling at a very slow speed,
small waves (ripples) are made by the bow and stern;
below the water line eddies are produced.
Ifthere is an increase in speed the transverse
waves moving directly outwards from the boats side
will increase in length and depth.
Obviously there is a direct relationship between
the speed of these waves and the boat; this ratio is
1:1.
The chief factor in the resistance of making waves
is the development of transverse waves.
Figure 1.4.1 Wave Making
Itis possible therefore, to calculate the length
of the total wave system between common high
points.
Length of wave = boat speed in Knots
in feet [1.34 optimum displacement] 2
The length of wave that is produced has great
influence on the behaviour of the boat. A point is
reached, when the boat speed is increased, where
the length of the wave is equal to the length of the
boat.
Increasing the speed further will lengthen and
deepen the wave until the trough of the wave will be
directly under the after body of the boat.
Inthis situation, a displacement boat with a
narrow stern will settle in the trough. This condition
is the threshold beyond which any further attempt to
increase the speed of the vessel by more power will
be wasted. The resulting increase in propeller speed
will increase the volume of water flowing under the
stern and the boat will settle even more, with the
possible dangers of swamping.
There will be negligible increase in speed and
of course the engine will be working far harder than
is necessary, resulting in wasted energy and poor
economy.
Example:
Boat speed 8 Knots = 1.33
√Water line length 36ft. For example a boat travelling at 8 knots, the
wavelength is:
WL= [8.0 ] 2 = 5.972 = 35ft approximately
1.34
It is expressed thus:
Speed/length ratio = V - speed in knots

HULL PERFORMANCE AND DISPLACEMENT 1
LISTER-PETTER MARINE INSTALLATION GUIDE 1.5
Example of differing speed upon a displacement
boat of 36 feet water line length. Using the following
formulae, the wave length can be calculated.
Wave length = [boat speed ]2
1.34
Speed length ratio = Boat speed
√
Water line length in feet
Figure 1.4.2 Effects of Speed Relative to Size of Wave

1 HULL PERFORMANCE AND DISPLACEMENT
LISTER-PETTER MARINE INSTALLATION GUIDE1.6
Ascan be seen, the result of boat speed to wave
length concludes that the longer the boat the greater
potential for higher speed.
Using the formulae V/√ L = 1.34 e.g. a boat of
81ft water line length has a potential of:
1.34 = V
√L
Therefore 1.34 x √ L = V speed
1.34 x √ 81 = 1.39 x 9 = 12.06 knots
anincrease of 5.1 knots over the 36ft boat
1.5 Effect of Displacement on Power
and Speed
However, length is not the only contributing
factor on the underwater shape and displacement
of the boat will have a significant effect on potential
speed.
Aheavier boat will displace more water resulting
in deeper waves, i.e. more resistance more power
needed.
70% more displacement = 70% more power to
maintain original speed.
Figure 1.51 Effects of Displacement
Anincrease in the wetted surface area will cause
greater frictional resistance.
Asthe efficiency of the boat has a direct
relationship to the friction caused by its passing
through the water, the under water area (wetted
surface) should be as smooth as possible and marine
growth should be kept to a minimum.
1.5.1 Displacement Type Boats
Boats with the displacement classification are
generally heavily built and include:
a. Commercial fi s hing boats.
b. Tugs.
c. Trawlers.
d. Workboats.
e. Motor barges.
f. Sailing yachts (fitted with auxiliary engine).
g. Passenger boats.
h. Motor yachts/cruisers.
i. Inland boats with low speeds.
The speed length ratio of these vessels is usually
not above 1.4.
The width of the stern can be increased with a
transom with little change to the actual underwater
shape. This will improve the speed-length ratio only
marginally to a value of 1.5.
1.5.2 Semi-displacement Type Boats
Alarger number of boats are classed as semi-
displacement and their advantage lies in the fact that
they can travel in excess of the critical wave making
speed-length ratio of 1.4 approximately.
The main features are:
1. Different underwater shape from mid-section aft
as the depth and width of transom is increased
to provide extra buoyancy.
2. Generally of lighter construction.
Figure 1.5.2 Typical Semi-displacement Hull
When a specific semi-displacement boat is fitted
with a powerful engine it can achieve a speed-length
ratio of 2.0 to 2.5 but the average speed-length ratio
is about 1.34.
Types of boats that are often classed as semi-
displacement:
a. Fast cruisers.
b. Personnel boats.
c. Patrol boats.
d. Pilot boats.
e. Motor yacht.
Figure 1.5.3 Angle of Bow
Asthere are so many different designs of semi-
displacement boats it is not possible to analyse in
depth their characteristics.

HULL PERFORMANCE AND DISPLACEMENT 1
LISTER-PETTER MARINE INSTALLATION GUIDE 1.7
1.5.3 Planing Boats
These boats are designed to operate at high
speeds thus the critical condition associated with
wave making needs to be overcome.
They feature:
1. Flatter underwater shapes towards stern.
2. Lightweight construction.
3. Larger beam to length ratio.
The use of flat sections underwater although the
most efficient for planing, lacks directional stability,
hence boats are often given some rise as the bottom
extends outward from the keel.
This is called the dead-rise angle which can
vary at mid-section from 10° to 25° and 0° to 15° at
the transom. An average value of mid-section and
transom is usually the quoted figure.
These varying angles are critical and their
relationship has great influence on performance,
sometimes detrimentally.
Planing boats use engines with excellent power
to weight ratios to give sufficient thrust to achieve
planing i.e. when the boat actually lifts on to the
wedge of water built up at the bow.
This build up of water occurs at ratios of about 1.8
to 2.0 and to progress further, a significant increase
in engine power is required.
Figure 1.5.4 Beam/length Raio
Figure 1.5.5 Planing Boat Hull
Asthe boat lifts higher at the bow at a speed-
length ratio of about 2.5, the water resistance
reduces, therefore this higher speed, once reached,
can be sustained with slightly less power from the
engine. At a ratio of 3.0 it can be said that the boat
is truly planing.
Atthis point the wave making resistance is
lower, therefore power of the engine is the only real
limitation to the speed ratio attainable. For most fast
cruisers/speed boats the average speed length ratio
is 5.0.
Planing boats often have a 'vee' shaped bottom
with a sudden change of shape known as the chine
from bow to aft section.
Asplaning boats behave far differently from
displacement boats type boats there is a different
formulae for calculating speed and power. This is
dealt with in "2. Power Calculation".
Figure 1.5.6 'Vee' Shaped Planing Hull

1 HULL PERFORMANCE AND DISPLACEMENT
LISTER-PETTER MARINE INSTALLATION GUIDE1.8
1.6 Displacement
There are various definitions of displacement,
some of which are of no use in the calculations for
boat speed/power etc.
1.6.1 Registered Tonnage
This can be in either nett or gross tons, it is
a measure of the internal cubic capacity of the
vessel.
The nett being the total capacity available for cargo
after deductions for engine space, accommodation
and other machinery; it is of no use in power
calculations.
1.6.2 Thames Measurement
This is a classification based on measurements
of length and beam at deck level. It does not have
a direct relation to the actual weight of the boat,
therefore it cannot be used in any calculation.
1.6.3 Displacement Tons
This is the actual weight of the vessel and is equal
to the total weight of water displaced by the boat in
tons (1 ton = 2240 lbs). This is the only weight used
for calculation.
1.6.4 Deadweight Tonnage
This is the cargo weight and is the difference
between light and full load conditions of the whole
boat.
When making the calculations for engine power,
sufficient allowance should be made for full load
conditions.
1.7 Displacement Calculations
Ideally the displacement of a boat should be
obtained by measuring its actual weight; however,
in many cases this is not possible.
Ifthis data cannot be obtained from the boat
builder or designer, the weight must be estimated
by calculation.
Asthe size and shape of the wetted area has
a considerable effect on boat speed/power it is
advisable to check the position of the water line
along the hulls length in normal cruising or working
trim. There are two generally accepted methods for
calculating the displacement.
1. Simpsons' First Rule.
2. Block Coefficient.
1.7.1 Simpsons' First Rule
This can be a very accurate, if somewhat
complicated method and is dependant upon the
availability of precise construction drawings.
Inprinciple, the drawings are sectioned by vertical
lines and the respective displacement is calculated.
These drawings, if available, should be submitted to
Lister-Petter for alculation.
Figure 1.7.1 Simpsons Rule
1.7.2 Block Coefficient
This method is less accurate than 'Simpsons
First Rule', but at least it gives a starting point to the
calculations.
This coefficient is the ratio between the underwater
area and a theoretical rectangular block which
touches the boats extremities; any hull can be
assessed n this way.
Figure 1.7.2 BlockCoefficient
Figure 1.7.3 Block Coefficient Hull Types

HULL PERFORMANCE AND DISPLACEMENT 1
LISTER-PETTER MARINE INSTALLATION GUIDE 1.9
For displacement type boats the block coefficient
value is taken at the mid-section, i.e. the widest
point.
Alightweight/semi-displacement boat or planing
craft can have a greater change in depth along its
water line length, therefore any mid-section figure
taken here would probably be inaccurate.
Anallowance of approximately 15% should be
made on any mid-section figures calculated for these
boats.
Displacement tons = L x B x D x Cb
W
Where:
L= Length at the waterline.
B= Beam at the waterline.
D= Draught excluding keel.
Figure 1.7.4 Boat Dimensions
1.7.3 Rule of Thumb
Power to reach hull speed, in kw = 5 times
Displacement in tons.
Fuel consumption = 1 litre per hour per 4 kw.

1 HULL PERFORMANCE AND DISPLACEMENT
LISTER-PETTER MARINE INSTALLATION GUIDE1.10

POWER CALCULATIONS 2
LISTER-PETTER MARINE INSTALLATION GUIDE 2.1
SECTION 2
POWER CALCULATIONS
CONTENTS
page
2.1 Displacement and Semi-Displacement Boats .................2.2
2.2 Planing Boats ..................................................................2.4
2.3 Hull Limitations ................................................................2.5

2 POWER CALCULATIONS
LISTER-PETTER MARINE INSTALLATION GUIDE2.2
2.1 Displacement and Semi-Displacement Boats
Once the approximate displacement of the boat is known
reference can be made to the following tables to estimate the power
required to propel the vessel at the desired speed, remembering
that any derating calculation must be taken into account.
2.1.1 Power/Speed Estimation Table A

POWER CALCULATIONS 2
LISTER-PETTER MARINE INSTALLATION GUIDE 2.3
2.1.2 Power/Speed Estimation Table B
Waterline
Length
Displacement Semi-displacement
Disp
Tons
Speed in Knots
567891011 12 13 14 15 16 17
45 feet
14 metres
6.0 - - 15 25 35 45 60 80 100 120 140 160 185
8.0 - - 17 27 44 60 80 105 130 160 180 210 240
10.0 - - 20 29 52 75 100 130 160 195 220 255 290
12.0 - - 22 32 60 90 120 150 190 230 260 300 340
14.0 - 15 25 36 68 105 140 175 220 260 300 350 400
16.0 - 17 28 42 76 120 160 200 250 295 340 400 460
18.0 15 20 32 48 85 140 185 230 280 330 385 450 520
20.0 18 23 35 56 95 160 210 265 310 370 430 500
25.0 22 28 42 65 120 195 260 315 380 450 540
30.0 26 33 48 75 150 240 310 375 460 540
50 feet
15 metres
10.0 - - 20 28 45 55 75 100 130 165 195 230 260
12.0 - - 22 30 50 70 95 125 165 205 240 275 310
14.0 - - 24 32 55 85 120 155 200 250 290 330 360
16.0 - 15 26 36 60 100 140 185 235 285 330 375 410
18.0 - 18 28 40 65 115 170 220 265 315 370 425 470
20.0 15 21 30 45 70 130 190 255 310 355 420 480
25.0 18 24 33 52 85 165 240 315 380 450 520
30.0 21 27 36 60 106 200 290 375 455 545
35.0 25 32 40 70 140 240 340 440 540
40.0 30 36 50 85 170 270 390 505
45.0 35 42 60 100 180 310 450 580
60 feet
19 metres
15.0 - 15 25 35 52 72 100 130 175 220 270 320 380
20.0 - 17 28 40 58 80 120 160 210 270 340 410 480
25.0 15 20 32 46 64 90 150 200 260 335 415 500
30.0 20 25 35 52 72 105 180 250 320 400 520
35.0 25 30 40 60 80 120 220 300 380 480
40.0 30 35 45 65 90 140 260 350 440
45.0 35 40 55 70 100 160 300 400 500
50.0 40 45 60 75 110 180 340 450
55.0 45 50 65 85 125 200 380 500
60.0 50 55 70 95 150 230 440
75 feet
23 metres
40.0 30 35 45 60 80 120 160 220 300 400 500
50.0 40 45 55 70 90 135 190 280 400 500
60.0 50 55 65 80 100 150 220 340 500
70.0 55 65 75 90 110 165 250 410 600
80.0 60 70 80 100 125 180 280 460
90.0 65 75 85 110 140 195 320 530
100.0 70 80 95 120 160 220 380 600

2 POWER CALCULATIONS
LISTER-PETTER MARINE INSTALLATION GUIDE2.4
Figure 2.2.2 'K' Value Chart
2.2.1 Example of Calculation for Planing Boat
Length overall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30ft.
Water line length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26ft.
Beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12ft.
Displacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 tons
Angle of dead rise .........................................15°
Engines ..............................twin rated at 150bhp
From 'Figure 2.2.2 'K' Value Chart'
the value of 'K' is ........................................... 2.9
Hull .......................................................... Type B
What speed can be expected?
With some hull types it is necessary to take the
values from two designs and work out a mean figure
where the hull features characteristics from both
types.
Once the 'K' value has been identified the calculation
is as follows:
Shaft horse power = D (tons) [V Knots]2
K
or VKnots = K √shp
D tons
VKnots = K √300 = 2.9 x √75
4
Therefore the speed = 25.1 Knots
Ascan be seen, it is necessary to know the
displacement of the boat, i.e. the actual, or an
accurate as possible estimated weight in tons.
1ton = 2240lbs.
2.2 Planing Boats
Asplaning boats behave far differently from
displacement boats there is a different formula for
calculating speed and power.
Here the value 'K' is introduced which is a
coefficient value derived from the hull form and beam-
length ratio
Figure 2.2.1 Hull Types
Hull Type 'A'
'Vee' bottom design
Beam/length ratio of 2.5:1 for 25ft boat
Beam/length ratio of 3:1 for 40ft boat
Small angles of dead rise > 10°
Low line of chine at bow
Hull Type 'B''
'Vee' bottom design
Beam/length ratio of 3:1 for 25ft boat
Beam/length ratio of 4:1 for 40ft boat
Small angles of dead rise > 10°
Low line of chine at bow
Hull Type 'C''
Early 'Vee' bottom design
Beam/length ratio of 5:1 approximately
Small angles of dead rise < 10°
Low line of chine at bow
Hull Type 'D'
Round bottom hull
Bow fine shaped
Wide flat sections aft