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W54 Machinery & Equipment list

When compiling an equipment list for a vessel there are three main considerations we adhere to:

  1.  Fit for purpose
  2.  Worldwide parts or replacement availability
  3.  Price

Note the order of priority. This is important. It is unfortunate, but for the majority of  boats it is in the reverse order. This is not the way to deliver value to the customer.

Building a boat has three costs: labour, typically 50%, materials and equipment; 30% and overhead; if controlled 20%.

In our experience it makes no sense to cut costs by including inferior materials, machinery and equipment. The portion saved is of very little benefit in the overall cost and the cause of problems that invariably follow.

What is interesting about the equipment list for the new W54 – it differs little from the W48 & W60 - is the country of origin for which I have added a separate column. 

Item

No

Description

Country

Main Engines

2

John Deere 4045 TFM75 121 BHP @ 2500rpm

USA

Gearbox

2

ZF W220 4.636:1 reduction

BRAZIL

Silencer

2

Cowl T.S 40 PR/PL 4"

CANADA

Cooler

 

Heat exchanger

 

Controls

 

Electronic twin lever

USA

       

Genset

1

Onan QD 13.5Kw heat exchanger cooled

USA

       

Steering Gear

1

BCS Manual & electro-hydraulic

ITALY

       

Bilge Pumps

2

Tellarini ENM40 self priming

ITALY

Bilge Valves

 

Esanel

NZ

Bilge Strainer

2

Groco ARG-1500

USA

F.O Trans. Pump

 

Tuthill KPT P 24-42 24v DC

ITALY

F.O Filters

2

Separ dual

GERMANY

Fuel Purifier

1

RCI Technologies MFP800

USA

Tank Gauges

 

John Ernest

USA

Tank Valves

 

Parker Hanifin

USA

Ball Valves

 

Paykels

 

Strainer

 

Y-strainer

 

Tank Drains

 

Paykel - self close type

 
       

Water Maker

1

SK 600gal

USA

FW Press. Set

 

Jabsco 29190-0024 24v

UK

H.W. Cylinder

 

Isotherm

ITALY

       

Marine Toilets

3

Tecma 24v

ITALY

Grey/black W. Pumps

2

Mono 230v

UK

Black/grey tank gauge

 

Itim™

AUSTRALIA

       

Propellers

2

38" B4-55 High Skew ISO 484 Class1

TAIWAN

Prop. Shaft Matl.

2

2 1/4" AISI 318L St. Stl

SWEDEN

Prop. Shaft Bushes

2

Morse Cutlass Rubber

UK

Stern Gland

2

Manebar EY

UK

Rudder Bushes

 

Acetal

 

Anchor Winch

1

Lofrans “Titan B”

ITALY

Anchor & Cable

2

60kg Pool "N" c/w 1/2 chain

 

Bow & Stern Thrusters

2

Sidepower

NORWAY

Stabilizers

 

Wesmar RS900

USA

Port Holes

8

8" Aluminium c/w deadlights

TAIWAN

Deckhouse/Wheel Windows

 

Seamac™ windows, 3 Seamac™ doors

NZ

W.T. Doors

 

PML Standard 3 Dog

 

Hatches & Skylights

 

Cule™, skylight dead lights PML standard

NZ

       

Boat Davit

 

Steelhead Marine electro hydraulic

CANADA

Pantograph wipers

 

Vetus

HOLLAND

Searchlight

1

Jabsco with remote            

UK

Air Horn

1

   
       

Liferaft

1

Six man

 

EPIRB

1

406 MHZ

 

Flares

4

Red parachute

 

Flares

2

Red hand

 

Flares

2

White hand

 

Flares

2

Orange smoke day signal

 

Life Jackets

6

38 M adult

 

Life Buoys

2

30"

 

Life Buoy Lights

2

Self Igniting

 

First Aid Kit

1

Excluding prescription drugs

 

Bolt Cutters

1

30"

 

Axe

1

   
       

Fire Extinguisher

4

1kg Co2

 

Fire Extinguisher

2

2.5kg Dry powder

 

Fire Blanket

1

1m x 1m

 

Fire Alarms

 

Elpro Electrical supply

 

Bilge Alarm

 

Elpro Electrical supply

 

Landing Valve

 

Bronze R.A. c/w hose attachment

 

Fire Hose

 

1” lay flat c/w adjustable nozzle

 
       

Compass

1

Saura binnacle

JAPAN

Clock

1

5" Brass porthole

JAPAN

Barometer

1

5" Brass porthole

JAPAN

Nav. Instruments

 

Parallel rule, dividers, compass

USA

Nav. Lights

 

Port/Star. M/Head & Stern

GERMANY

       

Stove

 

Electric oven, gas hobs

ITALY

Fridge/Freezer

 

Isotherm

ITALY

Microwave

 

Invertor

 

Dishwasher

 

Fisher & Paykel Dishdrawer™

NZ

Air Conditioning

 

Cruiseaire™

USA

The big question is of course what influences the decision for each piece of equipment? The answer is never simple. As an example, due to its importance, we will look at the stern gear. That is the equipment that makes up the drive line from the reduction box to the propeller. For this I will use the W60 example with photos.

Each shaft transmits up to a maximum of 153 BHP at 518rpm. The whole assembly runs smoothly in next to absolute silence. The question for the naval architect is what are the forces generated here and how are they to be contained? What are the components and what is the duty of each?

THE PROPELLER SHAFT

The propeller shaft is 21/2” dia. Centreless ground type 318 (2205) stainless steel. This is a relatively new stainless steel with approx. 22% chromium and approx. 5% nickel content and correspondingly high cost.

drive shaft

It is virtually immune to pitting corrosion which is a problem with 316 steels, particularly in tropical conditions.

ASA 318 has a tensile strength about twice that of the 316 steels. In some ways this is a disadvantage as there is a tendency in boatyards to fit shafts of too small a diameter which are far to slender for the thrust forces that occur. This is one of many features of boat design where common sense should overcome pure mathematics. 

TORSIONAL VIBRATION

One of the forces that must be accounted for is torsional vibration. This is an invisible and silent vibration that is a result of a mismatch of the rotating components of the drive line.

Starting with the propeller, the screw can be a source of these problems or the mass of entrained seawater in a rotating screw itself can be the culprit. For this reason propellers should always be manufactured to ISO Class 1.

The spacing of propeller shaft bearings can be another invisible cause.

At the gearbox coupling there is a large differential of rotating mass. The propeller may rotate at 518 rpm but the crankshaft is running at 2400 rpm.

Engine builders ensure that all their components are arranged to limit the machines inherent vibration. But not being responsible for vibrations caused elsewhere in the driveline they will recommend doing a driveline analysis of the complete system.

SOFT MOUNTING

Today it is common for all engines to be mounted on rubber mounts which are designed to isolate the engine from the hull. The main consideration here is limiting noise and vibration transfer through the hull. From this arises another problem – how does the builder isolate the engine from the rigid propeller shaft.

A common solution is a rigid bolted steel coupling connecting a vibrating engine to a rigid propeller shaft. This is certainly a low cost solution but a method which can only end in trouble. This is not to be recommended except for small low speed cruisers. High hours and power can only lead to eventual destruction of the coupling shaft fit and internal parts of the transmission.

drive shaft

The solution is to install a flexible coupling like the one shown in the photograph. In this case we have used a “Centa™” A.G.M. coupling. This has the ability to absorb shock and vibrations in all directions, thrust fore and aft, torsion, axially. Although the initial setup is always done accurately the out of line can be up to 2 degrees under running conditions. The coupling is torsionally soft, ironing out vibrations both from the engine and propeller.

flexible coupling

PROPELLER SHAFT TUBE SEAL

We now pass to the propeller shaft seal. The seal in the photo is a Deep Sea Seals Ltd EY Manebar Seal. This is a flexible face seal with bronze housing and Manetex™ face material. 

bellows

The seal is fitted with an inflatable bellows which when pumped up allows maintenance of the seal faces without dry docking the vessel. 

bellowspump

In the photo above, for demonstration purposes, a simple foot pump is hooked up to the bellows air valve. Once the bellow is inflated the seal can be loosened and any adjustments undertaken.

PROPELLER SHAFT BEARINGS

Immediately aft of the seal is the first propeller shaft bearing. This is usually termed the “neck bush”. It provides a support to the propeller shaft seal and serves to centralize this part of the shaft. In this case the bearing is a “Countrose” cutless type. A scavenge sea water main engine supply is provided through both seal and this bearing.

drive shaft

Up to this point all the shaft components are visible and are able to be dismantled from inside the engine room. This is one reason you will never find a “vee” system in a Watson vessel; the “Achilles heel” of the sail boat designer. Apart from the lousy propulsive efficiency, all this equipment would be located under the engine – the worst possible place.
 
The propeller shaft is supported by three bearings. The second bearing is mounted in the aft end of the stern tube and again is a “Countrose” cutless type. This bearing however runs not on the shaft itself, but on an aluminum bronze sleeve which is heat shrunk onto the shaft. The reason for this is that the second and third bearings carry proportionally more load than the first. 
 
The last bearing once again is larger in diameter and runs on an aluminum bronze sleeve. This bearing is much larger again and is also of the cutlass type.
prop
 
props
 
Our preference in propellers is for four blade high skew type aluminium bronze. For the W60 above, each is designed to absorb 153 B.H.P @ 518 rpm. This requires a 4.61:1 reduction ratio through the ZF W220 transmission.
 
The W54 propellers are designed to absorb 121 BHP @ 606 rpm. This requires a 3.960:1 reduction with a propeller dia of 38” (900mm).
 
All of the equipment and material above is of the highest quality with prices to match. An expense well worth it as a working life over 10,000 hours is easily achievable with this type of arrangement. In fact we have examples of well engineered stern gear installations that have run without trouble for over 50 years and logged well in excess of a million miles of service.
 
The W54 engine room will differ very little from the W60. Our aim has been to standardize machinery and equipment where practical through our range of vessels – all at the highest quality. To view a slide show click here….
 
 
© T.C. Watson & Sons Ltd 2013

Last Updated (Tuesday, 07 May 2013 23:29)

 
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