Canal Boat – July 2018

canalboat.co.uk Canal Boat July 2018 73

EXPERTS

Ask your questions [email protected]

TONY BROOKS

Technical Consultant

If your engine bay bilge

is dirty and full of oily

water why not devote a

couple of sunny days to

deal with it. It will then

be far easier to find

dropped nuts, bolts and

tools. It will also help

prevent oily footprints

being trodden into the

boat.

Lay a white bilge

blanket on any oily

water to absorb as

much oil as possible.

Grey ones absorb water

as well. Some people

use disposable nappies

to absorb the water but

they can and do burst if

not carefully handled.

Pump or sponge the

remaining water, oil and

muck out and spray the

whole area with engine

cleaner or degreaser.

Agitate with brushes,

adding more spray as

required then rinse off

with water and more

sponging. When the

area is clean allow it to

dry, abrade and

degrease the hull

surfaces and then apply

a suitable paint system.

TONY BROOKS

What he doesn’t know

about canal boats just

isn’t worth knowing

TERRY ROBERTSON

TR Training’s man

really knows how to

handle a boat

MARTIN LUDGATE

Our Deputy Ed is a

guru on all things to

do with canals

PHIL SPEIGHT

The country’s leading canal

painter and an expert on

paint processes as well

If you have a boating query our team of experts are here to answer it – ask your question

online at canalboat.co.uk Alternatively, you can EMAIL: [email protected] or WRITE TO

Canal Boat, Archant Specialist, Evolution House, 2-6 Easthampstead Road, Wokingham

Keep your

bilge clean

and oil-free to

protect floors

ASK ONLINE: Ask your questions online at Canal Boat’s website – what’s more, you can

read other people’s questions and answers by simply clicking on to canalboat.co.uk

Q

I have a 58 ft narrowboat

and at the last docking in

2015 the marina pointed our that

the propeller was rather too

close to the end point of the

swim.

Is there an optimum distance

for the prop boss from the end

point of the swim? I have an 18” x

13” Axiom propeller and at the

last docking fitted a stainless

weed cutter disc on the shaft for

which there was just enough

space.

We are having it blacked at the

same marina next month April

and I wanted to extend or fit new

shaft to fix the problem.

MICHAEL MARSH

A

TONY REPLIES: Yo u s a y

you have a problem, yet do

not tell me what it is and it seems

the yard gave you no reason for

their advice so I can only guess.

The problem with having the

prop too close to the stern post

is that the stern post masks the

water flow into the prop but your

boat appears to have an

exceptionally fine stern swim

and effectively no stern post at

all. The aft shaft bearing is even

in an extension to the stern tube

that brings the prop even further

back from the stern post. Be

aware that moving the prop

back might increase tiller

vibration.

I do not think there is a problem

on your particular boat and if

there is one it is more likely to be

prop-related.

For canal work I would want

the minimum unsupported shaft

overhang commensurate with

ensuring easy water flow into

the prop. Your engine will move

forwards and backwards on its

rubber mounts when you go into

ahead and astern so unless you

have thrust bearing fitted you

need a minimum clearance/

shaft length between the prop

boss or weed cutter and the

end of your stern tube of 5 to

10mm with a maximum shaft

overhang of about 1 shaft

diameter.

See http://www.prop-

protector.co.uk/information.

php?info_id=2&osCsid=5f62c99

a8ce700de444cafd34ac67a14

In your case because of that

very fine swim end you will

probably get away with the

lower figure.

Before spending money on

this, my advice is to get the yard

to give you a written guarantee

that the work they recommend

will make a measurable and

noticeable difference to the

boat’s handling and

performance.

BACKCABIN

ASK

THE

Prop too close to stern post