Side-Power SE 130/250T User manual

Keep this
manual onboard !
SIDE-
POWER
Thruster systems
Installation and user's manual
GB
NInstallasjons og brukermanual
Made in Norway
©Sleipner Motor AS 2008
SLEIPNER MOTOR AS
P.O. Box 519
N-1612 Fredrikstad
Norway
Tel: [phone]
Fax: [phone]
www.side-power.com
[e-mail]
SE 80/185 T
SE 100/185 T
SE 130/250T

2SE 80/185 T - SE 100/185 T - SE 130/250T 1.0.1- 2008
Innhold
N
SAMSVARS ERKLÆRING
Sleipner Motor AS
Postboks 519
N-1612 Fredrikstad, Norge
Erklærer at dette produktet med tilhørende
standard kontrollsystemer er i samsvar med
helse, og sikkerhetskravene i henhold til Direk-
tiv 89/336/EEC FRA 23 Mai 89, korrigert av
92/31/EEC og 93/68/EEC.
Installasjons instruksjoner
Tekniske spesikasjoner.............................................................3
Planlegning og viktige forbehold.................................................4
Tunnel installasjon
Plassering av tunnel/thruster......................................................5
Utforming av tunnelåpninger ......................................................6
Hvordan unngå turbulens rundt tunnelåpninger .........................7
Forslag til tunnelinstallasjon på seilbåt.......................................8
Tunnel installasjon i glassberbåter ...........................................9
Thruster installasjon
Gearhus og motorbraket...........................................................11
Propeller ...................................................................................12
Elektromotor .............................................................................13
Elektrisk installasjon .................................................................14
Kontrollpanel og kontrollkabler .................................................15
Koblingsskjema elektrisk ..........................................................16
Koblingsskjema ........................................................................17
Sjekkpunktliste for kontroll av installasjon ................................18
Brukermanual
Viktige forbehold.......................................................................19
Hvordan operere Sidepower thrustere .....................................20
Vedlikehold og servise..............................................................21
Problemer og løsninger ............................................................22
Garantierklæring ....................................................................23
Reservedelsliste ....................................................................24
Servicesentere ...................................................................... 28
Installation instructions
Technical specications............................................................. 3
Planning & important precautions.............................................. 4
Tunnel installation
Positioning of the tunnel / thruster ............................................ 5
How to shape the tunnel ends................................................... 6
How to prevent drag from tunnel installation ............................. 7
Possible tunnel installation in sailboats ..................................... 8
Tunnel installation in a GRP boat .............................................. 9
Thruster installation
Gearhouse and motorbracket.................................................. 11
Propeller.................................................................................. 12
Electromotor ............................................................................ 13
Electrical installation ............................................................... 14
Control panel and control-leads............................................... 15
Visual wiring diagram .............................................................. 16
Technical wiring diagram ........................................................ 17
Checklist for control of the installation..................................... 18
User's manual
Important user precautions...................................................... 19
How to use Sidepower thrusters.............................................. 20
Maintenance & service ............................................................ 21
Troubleshooting....................................................................... 22
Warranty statement .............................................................. 23
Spareparts list & drawing .................................................... 24
Service centres ..................................................................... 28
Contents
GB
DECLARATION OF CONFORMITY
We, Sleipner Motor AS
P.O. Box 519
N-1612 Fredrikstad, Norway
declare that this product with accompanying
standard remote control systems complies with
the essential health and safety requirements
according to the Directive 89/336/EEC of 23
May 1989 amended by 92/31/EEC and
93/68/EEC.

3
SE 80/185 T - SE 100/185 T - SE 130/250T 1.0.1- 2008
Motor: Spesialutviklet reversibel DC-motor.
Girhus: Sjøvannsbestandig bronsje. Kulelagre på pro-
pellaksel. Kule og glidelager komb. på drivaksel.
Motorbraket: Sjøvannsbestandig aluminium.
Galvanisk isolert fra motor
Tunnel: Kryssvevet glassber.
Aluminium og ståltunnel på forespørsel.
Propell: 5-llads skew "Q"-propell i kompositmateriale.
Batterier: Minimum anbefalt batteri størrelse.
(Kaldstart kapasitet etter DIN/SAE std.)
SE 80/185T 12V : 550 CCA DIN/1045 CCA SAE
SE 80/185T 24V : 300 CCA DIN/570 CCA SAE
SE 100/185T 12V : 750 CCA DIN/1425 CCA SAE
SE 100/185T 24V : 400 CCA DIN/760 CCA SAE
SE 130/250T 12V : 750 CCA DIN/1425 CCA SAE
SE 130/250T 24V : 400 CCA DIN/760 CCA SAE
Drift tid: S2 = 3 min. Eller gjennomsnittlig 7-10% innen
en begrenset tidsperiode.
Sikkerhet: Elektronisk tidsforsinkelse forhindrer motorskade
ved rask retningsendring.
Motoren stanser automatisk ved overopphetning
(slår seg automatisk på etter nedkjøling).
Brytepinne mellom drivaksel og motor beskytter
gir hvis propell blir blokkert.
Om orginalt Side-Power panel blir brukt så vil
dette slås av automatisk etter 6 minutter etter
siste gang trøsteren ble brukt.
Integrerte microprossessor føler hele tiden på
releet, reduserer slitasje og risk for ”heng” på
relé. Trøsteren vil stoppe automatisk etter 3
minutter om det oppstår ”heng” på relé, eller
om trøsteren går kontinuerlig i 3 minutter.
Tekniske spesikasjoner
N
Motor: Custom made reversible DC-motor.
Gearhouse: Seawater resistant bronze. Ballbearing at
propellershaft and combination of ballbearing
and slide bearing at driveshaft.
Motor bracket: Seawaterresistant aluminium,
galvanicly insulated from motor
Tunnel: Cross spun with rowing G.R.P tunnel
Steel & aluminum tunnels available at request.
Propeller: 5 blade skew "Q"-propeller,
breglass reinforced composite.
Batteries: Minimum recommended battery capacity
(cold crank capacity by DIN/SAE standard)
SE 80/185T 12V : 550 CCA DIN/1045 CCA SAE
SE 80/185T 24V : 300 CCA DIN/570 CCA SAE
SE 100/185T 12V : 750 CCA DIN/1425 CCA SAE
SE 100/185T 24V : 400 CCA DIN/760 CCA SAE
SE 130/250T 12V : 750 CCA DIN/1425 CCA SAE
SE 130/250T 24V : 400 CCA DIN/760 CCA SAE
Max. use: S2 = 3 min. or appr. 7-10% within a limited time
frame.
Safety
: Electronic time-lapse device protects against
sudden change of drive direction. Electric thermal
cut-off switch in electromotor protects against
over heating (auto reset when electro motor cools
down).
Flexible coupling between electro-motor and
driveshaft protects electromotor and gearsystem
if propeller gets jammed.
If original Sidepower panel is used, the panel
shuts off automatically 6 minutes after last use.
Integrated microprocessor monitors solenoids,
reducing wear and risk of solenoid lock-in. Auto-
stop of thruster in case of accidental solenoid
lock-in or if run signal is continous for more than
3 minutes
Technical specications
GB
SE80/185T SE100/185T SE130/250T
Thrust [lbs] 176 212 284
A [in] 7,28 7,28 9,84
B [in] 13,9 15,3 15,7
Cmin. [in] 7,87 7,87 9,0
D [in] 6,7 6,7 11,2
D recommended [in] 13,4 13,4 22
Emin. [in] 0,24 0,24 0,28
Emax. [in] 0,31 0,31 0,39
Motor output [Hp] 6 8 8,7
Voltage [V] 12/24 12/24 12/24
Weight [lbs] 44 68 77
Note: Emin.: wall thickness of a standard Sidepower tunnel
Emax.: maximum wall thickness when using other GRP,
steel or aluminium tunnels
SE80/185T SE100/185T SE130/250T
Thrust [kg] 80 100 130
A [mm] 185 185 250
B [mm] 352 389 398
Cmin. [mm] 200 200 230
D [mm] 170 170 285
D recommended [mm] 340 340 560
Emin. [mm] 6 6 7
Emax. [mm] 8 8 10
Motor output [kW] 4,4 6 6,5
Voltage [V] 12/24 12/24 12/24
Weight [kg] 20 31 37
Note: Emin.: wall thickness of a standard Sidepower tunnel
Emax.: maximum wall thickness when using other GRP,
steel or aluminium tunnels
METRIC
IMPERIAL
4
SP 75 Ti / SP 95 Ti / SP 125 Ti 2.5.1- 2007
Technische Daten
D
C
Waterline
A
F
Motor: Custom made reversible DC-motor.
Gearhouse: Seawater resistant bronze. Ballbearing at
propellershaft and combination of ballbearing
and slide bearing at driveshaft.
Motor bracket: SP 75 Ti / SP 95 Ti / SP 125 Ti:
Seawaterresistant aluminium
Tunnel: Cross spun with rowing G.R.P tunnel
Steel & aluminum tunnels available at request.
Propeller: Symmetrical 4 blade propeller, fibreglass reinforced
composite.
Batteries: Minimum recommended battery capacity
(cold crank capacity by DIN/SAE standard)
SP75Ti 12V : 550 CCA DIN/1045 CCA SAE
24V : 300 CCA DIN/570 CCA SAE
SP95Ti 12V : 750 CCA DIN/1425 CCA SAE
24V : 400 CCA DIN/760 CCA SAE
SP125Ti 12V : 750 CCA DIN/1425 CCA SAE
24V : 400 CCA DIN/760 CCA SAE
Max. use: S2 = 3 min. or appr. 7-10% within a limited time
frame.
Safety
: Electronic time-lapse device protects against
sudden change of drive direction. Electric thermal
cut-off switch in electromotor protects against over
heating (auto reset when electro motor cools down).
Flexible coupling between electro-motor and
driveshaft protects electromotor and gearsystem
if propeller gets jammed.
If original Sidepower panel is used, the panel
shuts off automatically 6 minutes after last use.
Integrated microprocessor monitors solenoids,
reducing wear and risk of solenoid lock-in. Auto-
stop of thruster in case of accidental solenoid
lock-in or if run signal is continous for more than
3 minutes
Technical specifications
GB
SP 75 Ti SP 95 Ti SP 125 Ti
Thrust [lbs] 165 209 275
A [in] 7,28 7,28 9,84
B [in] 13,9 15,3 15,7
Cmin. [in] 7,87 7,87 9,0
D [in] 6,7 6,7 11,0
D recommended [in] 13,4 13,4 22,0
Emin. [in] 0,24 0,24 0,28
Emax. [in] 0,31 0,31 0,39
Motor output [Hp] 6 8 8,7
Voltage [V] 12/24 12/24 12/24
Weight [lbs] 44 68 77
Gear oil capacity [fl.oz]2.367 2.367 6,736
Note: Emin.: wall thickness of a standard Sidepower tunnel
Emax.: maximum wall thickness when using other GRP,
steel or aluminium tunnels
SP 75 Ti SP 95 Ti SP 125 Ti
Thrust [kg] 75 95 125
A [mm] 185 185 250
B [mm] 352 389 398
Cmin. [mm] 200 200 230
D [mm] 170 170 280
D recommended [mm] 340 340 560
Emin. [mm] 6 6 7
Emax. [mm] 8 8 10
Motor output [kW] 4,4 6 6,5
Voltage [V] 12/24 12/24 12/24
Weight [kg] 20 31 37
Gear oil capacity [ml] 70 70 200
Note: Emin.: wall thickness of a standard Sidepower tunnel
Emax.: maximum wall thickness when using other GRP,
steel or aluminium tunnels
METRICMETRIC METRICMETRIC
METRIC
IMPERIALIMPERIAL IMPERIALIMPERIAL
IMPERIAL
Motor: Gleichstrommotor
Getriebegeh.: Seewasserbeständige Bronze. Kugellager an
der Propellerachse, Kombination von Kugel-
und Gleitlager an der Antriebsachse.
Motorhalterung: SP 75 Ti / SP 95 Ti / SP 125 Ti:
Seewasserbeständiges Aluminium
Tunnel: Glasfibertunnel (Kreuzgewebe)
Stahl- & Aluminiumtunnel auf Anfrage.
Propeller: Symmetrischer, 4 flügeliger Kaplanpropeller aus
Glasfiberverbundmaterial.
Batterie: Empfohlene mind. Batteriekapazität
(Kaltstartkapazität nach DIN/SAE)
SP75Ti 12V : 550 CCA DIN/1045 CCA SAE
24V : 300 CCA DIN/570 CCA SAE
SP95Ti 12V : 750 CCA DIN/1425 CCA SAE
24V : 400 CCA DIN/760 CCA SAE
SP125Ti 12V : 750 CCA DIN/1425 CCA SAE
24V : 400 CCA DIN/760 CCA SAE
Betriebszeit: S2 = 3 min. oder ca. 7-10% innerhalb eines
beliebigen Zeitraumes.
Sicherheit
: Elektronische Zeitverzögerung zum Schutz des
Getriebes bei plötzlichem Wechsel der Drehrich-
tung. Elektrischer Thermoschalter zum Schutz
des Motors gegen Überhitzung (erneute Betriebs-
bereitschaft nach Abkühlung).
Scherstift zwischen Elektromotor und Getriebe-
achse als Schutz, wenn der Propeller blockiert
ist. Nach der letzten Benutzung schaltet das
Original Side-Power Panel automatisch nach 6
Minuten ab. Der integrierte Mikroprozessor
überwacht das Relais und reduziert sowohl
Verschleiß, als auch Relaisblockade. Das
Bustrahlruder stoppt automatisch bei Relais-
Blockade, oder bei Betrieb des Bugstrahlruders
von mehr als 3 Minuten.

4SE 80/185 T - SE 100/185 T - SE 130/250T 1.0.1- 2008
Viktige forholdsregler og planlegning
N
Før installasjon må instruksjonsmanualen leses gjennom, og bruker må gjøre seg kjent med produktet.
Thrusteren må ikke installeres i rom som der gnister og høy varme medfører brannfare.
Elektromotoren vil produsere karbon støv fra børstene under drift slik att en lagringsplass må fysisk avskilles fra thrusteren for å unngå att det man
lagrer blir støvete / møkkete.
Elektromotoren er avhengig av god kjøling, sørg derfor for ventilasjon eller god plass rundt motoren ved montering.
Elektromotoren kan monteres i alle vinkeler i fra vertikalt til horisontalt der hvor plassutnyttelsen krever det.
Hvis elektromotoren monteres i en vinkel på mer en 30o, må den støttes opp separat.
Elektromotoren må håndteres forsiktig. Den må ikke bæres etter kontaktpunktene, og motoren må ikke settes ned på drivakselen.
Følg de anbefalte målene som er oppgitt i manualen, propell eller girhus må ikke stikke ut av tunnelen.
Elektromotoren, tilhørende komponenter, kontakter eller åpne ledd i strømkabler må monteres så de ikke utsettes for vann.
Vi anbefaler å male girhuset med bunnstoff. PS sinkanoder, pakninger og propellaksel skal ikke påføres bunnstoff.
Ikke påfør gelcoat / topcoat eller lignende inne i tunellen. Det er bare plasee til ett lag primer og to lag bunnstoff mellom tunellen og propellene.
Når båten ligger på land har ikke elektromotoren den motstanden den har i vann. Motoren bruker derfor ekstremt kort tid før den oppnår ødeleggende
høyt turtall. Med båten på land, unngå hurtig bytte av driftsretning da det kan forårsake skade på truster.
Denne manualen er beregnet som støttemateriell for montører med erfaring / utdanning, og har derfor ikke all informasjon nødvendig for å oppnå en
korrekt installasjoner.
Installer ikke elektromotoren i nærheten av lett brennbart materiale, da motoren oppnår temperaturer over 100oC ved før den stopper automatisk.
Området intill thrusteren må ikke benyttes som lagringsplass da motoren vil bli varm samt att dette vil medføre en fare for att elektriske koblinger blir
løse eller kortslutter
I de tilfeller båter skal godkjennes eller klassiseres i henhold til internasjonal, eller spesielle standarder, er montør ansvarlig for at de gjeldende lover
og regelverk følges. Sleipner Motor AS kan ikke garantere at instruksjonene i denne manualen er i henhold til alle gjeldende regelverk og standarder.
NB ! Ved feilaktig installasjon av panel, thruster eller tunnel frafaller all garanti stilt av Sleipner Motor AS.
Planning and important precautions
GB
Prior to installation, it is important that the installer reads this guide to ensure necessary acquaintance with this product.
The thruster must NOT be installed in compartments that require ignition proof electric equipment. If necessary, make a separate
compartment.
The electromotor will generate some carbon dust so that any storage compartment must be separated from the thruster to prevent the stored items
from becoming dusty/dirty.
If you are installing the Sidepower in a small room /compartment, it should be ventilated to ensure cooling of the electromotor.
If the height in the room you are installing the Sidepower is limited, the Sidepower can be installed horizontally or at any angle in between.
- If the electro motor is positioned more than 30o off vertical, it must be supported separately.
- The electromotor must be handled carefully. Do not lift it by the internal connections/main terminals or put it down on the driveshaft.
- Beware to keep installation within advised measurements. No part of the propeller or gearhouse must be outside the tunnel.
The electromotor, its components, contacts / plugs or other joints in the control cables must be mounted so that they will keep dry at all times.
We advice to paint the gearhouse and propellers with antifouling. PS! Do not paint the zinc anodes, sealings or propellershafts.
 Do not nish the inside of the tunnel with a layer of gelcoat / topcoat or similar. It is only room for a thin layer of primer and two layers of
anti-fouling between the tunnel and the props.
With the boat on land, only run the thruster for a fraction of a second, as without resistance it will accelerate very fast to a damaging rpm.
Also, while the thruster is in air, make sure that the propellers have come to a complete stop before performing a directions change of the
thruster, as it might cause damage to the thruster.
 This manual is intended to support educated/experienced staff and is therefore not sufcient in all details for the correct installation.
 Don’t install the electromotor at close range to easily ammable objects as it will reach over 100°C before the temperature switch is
activated.
Do not store items close to the thruster motor as it gets hot as well as any loose items near the thruster motor can cause problems with electrical wir-
ing coming loose and short-circuiting.
 When installed in boats approved or classied according to international or special national rules, the installer is responsible for following the demands
in accordance with these regulations / classication rules. The instructions in this guide can not be guaranteed to comply with all
different regulations/classication rules.
These instructions are only general instruction. If you are not skilled to do this work, please contact professional installers for assistance.
NB! Faulty installation of the tunnel, thruster or panel will render all warranty given by Sleipner Motor AS void.

5
SE 80/185 T - SE 100/185 T - SE 130/250T 1.0.1- 2008
Plassering av tunnel og thruster
N
Tunnelen bør plasseres lengst mulig frem i baugen (Fig. 1)
For å oppnå mest mulig moment rundt båtens dreiepunkt, er det meget
viktig å plassere tunnelen så langt fremme som mulig. Avstanden fra
båtens dreiepunkt til thruster vil ha stor betydning på thrusterens effekt.
Eks.:
A: 55kg skyvekraft x 11m moment = 605kgm skyvekraft
B: 55kg skyvekraft x 10m moment = 550kgm skyvekraft
Posisjon A vil gi 10% mer skyvekraft til rotasjon.
Tunnelen skal plasseres dypest mulig (Fig. 2)
Tunnelen skal plasseres så dypt som mulig av to grunner:
1. Så luft ikke suges ned i tunnelen å ødelegger skyvekraften.
2. Ved å øke vanntrykket jobber propellen mer effektivt.
Hovedregelen er at tunnelen skal plasseres minimum ½ x tunnelen dia.
under vannlinje. Anbefalt dybde er minst ¾ x dia. under vannlinje (). Når
tunnelen er plassert 33-35 cm under vannlinjen bør andre faktorer vur-
deres som viktigere, d.v.s. å plassere tunnelen lengre frem.
Optimal tunnel lengde
Dersom tunellen blir for lang vil friksjonen i tunellen reduser vannhastig-
heten og derved effekten.
Dersom tunellen blir for kort (normalt bare i nedre del av tunellen) kan det
oppstå kavitasjons problemer da vannet ikke har tid / av-stand til å «rette
opp strømningsretningen» før det treffer propellen (Fig. 3&4). Denne
kavitasjonen vil redusere effekten og lage mye støy.
Den optimale tunell lengden er 2 til 4 ganger tunell diameteren og dersom
tunellen blir så mye som 6 til 7 ganger diameteren i lengde vil effekt tapet
bli klart merkbart.
Positioning of the tunnel / thruster
GB
The Thruster should be as far forward as possible (Fig. 1)
Because of the leverage effect around the boats pivot point, it is very
important for the thrusters actual effect in the boat to get it as far for-ward
as possible. The relative distance change from the boats pivot point to the
thruster will be the change of actual thrust for the boat.
Example:
A: 55kg thrust x 11m leverage = 605kgm torque to rotate the boat
B: 55kg thrust x 10m leverage = 550kgm torque to rotate the boat
In position A you will get 10% more thrust to turn the boat around.
The thruster should be placed as deep as possible (Fig. 2)
The tunnel should be placed as deep as possible for two reasons:
1. So that it does not suck down air from the surface which will
destroy the thrust completely.
2. To get as high as possible a water pressure to get maximum
efciency from the propeller.
Generally the top of the tunnel should be a minimum of ½ x the tunnel
diameter below the waterline. This is an absolute minimum and we rec-
ommend that it is at least ¾ x tunnel diameter () below the waterline.
A really good distance is about 1/1 x tunnel diameter () below the
waterline.
When you get the top of the tunnel 30-35 cm*/1 feet below the surface,
other factors should be considered more important, i.e. moving the thrust-
er further forward.
Optimal tunnel length
If the tunnel gets to long, the friction inside will reduce the water speed
and thereby the thrust.
If the tunnel gets to short (normally only in the bottom section of the tun-
nel) you can get cavitation problems as the water will not have had time to
“straighten” itself before reaching the propeller (Fig. 3&4). This cavitation
will reduce performance as well as creating a lot of noise.
The optimal tunnel length is 2 to 4 x tunnel diameter and you should avoid
tunnels longer than 6 to 7 times the tunnel diameter as the performance
reduction is then clearly noticeable.
10
SP 75 Ti / SP 95 Ti / SP 125 Ti 2.5.1- 2007
Tunnelplazierung soweit vorne wie möglich (Fig. 1)
Um einen möglichst großen Abstand vom Drehpunkt des Schiffes zu
erreichen, ist der Sidepower möglichst weit vorne einzubauen.
Eine Vergrößerung des Abstandes vom Drehpunkt des Schiffes
hat eine direkte Auswirkung auf die verfügbare Schubkraft.
Beispiel :
A: 55kg Schubkraft x 11m = 605kgm zum Wenden des Bootes
B: 55kg Schubkraft x 10m = 550kgm zum Wenden des Bootes
In Beispiel A stehen damit 10% mehr Schubkraft zur Verfügung.
Den Tunnel so tief wie möglich positionieren (Fig. 2)
Den Tunnel aus zwei Gründen so tief wie möglich positionieren:
1. Damit nicht Luft mitangesaugt wird, die die Schubkraft
vollständig herabsetzt.
2. Um einen möglichst hohen Wasserdruck zu erhalten, um die
maximale Effizienz des Propellers erreichen.
Die Oberkante des Tunnels muß mind. einen halben Tunnel-
durchmesser unterhalb der Wasserlinie liegen. Dieser Wert ist ein
absolutes Minimum. Besser ist ein Wert von ca. ¾ des
Tunneldurchmessers (-). Optimal ist eine Abstand von 1/1 x
Tunneldurchmesser (--) zur Wasserlinie.
Liegt die Oberkante des Tunnels 30-35cm* / 1fuß unterhalb der
Wasserlinie, können andere Faktoren berücksichtigt werden.
Optimale Tunnellänge
Bei einem zu langem Tunnel reduziert der Reibungsverlust die
Wassergeschwindigkeit und damit die Schubkraft.
Bei einem zu kurzem Tunnel (häufig im unteren Bereich des
Tunnels) können Kavitationsprobleme entstehen, da sich das
Wasser nicht gerade auszurichten kann (Fig. 3&4). Diese Kavita-
tion ist leistungsreduzierend und kann starken Lärm verursachen.
Die optim. Tunnellänge ist das 2-4 fache des Tunneldurchmessers.
Tunnellängen von mehr als dem 6-7 fachen des Tunneldurch-
messers sollten vermieden werden, da dadurch die Leistung
reduziert wird.
Positionierung von Tunnel / Thruster
D
Positioning of the tunnel / thruster
GB
A = 11,0m
B = 10,0m
A
B
Pivot
point
min.
1/3Ø
Ø
min.
1/3Ø
3/4Ø
-
1/1 Ø
--
30 - 35 cm*
min.
1/2Ø
Fig. 1
Fig. 2
Fig. 3
Fig. 4
The Thruster should be as far forward as possible (Fig. 1)
Because of the leverage effect around the boats pivot point, it is very
important for the thrusters actual effect in the boat to get it as far for-
ward as possible. The relative distance change from the boats pivot
point to the thruster will be the change of actual thrust for the boat.
Example:
A: 55kg thrust x 11m leverage = 605kgm torque to rotate the boat
B: 55kg thrust x 10m leverage = 550kgm torque to rotate the boat
In position A you will get 10% more thrust to turn the boat around.
The thruster should be placed as deep as possible (Fig. 2)
The tunnel should be placed as deep as possible for two reasons:
1. So that it does not suck down air from the surface which will
destroy the thrust completely.
2. To get as high as possible a water pressure to get maximum
efficiency from the propeller.
Generally the top of the tunnel should be a minimum of ½ x the
tunnel diameter below the waterline. This is an absolute minimum
and we recommend that it is at least ¾ x tunnel diameter (-) below
the waterline. A really good distance is about 1/1 x tunnel diameter
(--) below the waterline.
When you get the top of the tunnel 30-35 cm*/1 feet below the
surface, other factors should be considered more important, i.e.
moving the thruster further forward.
Optimal tunnel length
If the tunnel gets to long, the friction inside will reduce the water
speed and thereby the thrust.
If the tunnel gets to short (normally only in the bottom section of the
tunnel) you can get cavitation problems as the water will not have
had time to “straighten” itself before reaching the propeller (Fig. 3&4).
This cavitation will reduce performance as well as creating a lot of
noise.
The optimal tunnel length is 2 to 4 x tunnel diameter and you should
avoid tunnels longer than 6 to 7 times the tunnel diameter as the
performance reduction is then clearly noticeable.