Yachting

technical

78 http://www.yachtingmonthly.com MAY 2016

Yachts are sometimes damaged by

hitting floating objects. Ken Endean

Avoid that suggests one way of reducing the risk

sinking

feeling

T

he benefits of a collision

bulkhead are obvious,

but how do you install

one in a small yacht

without spoiling her

forecabin? It’s a question that I’ve

pondered and has always niggled

me as it’s something I could find

no way of achieving until a simple

solution came to me.

In sailing, as in other activities,

securing improvements in safety

depends on identifying each

likely hazard, assessing the risk

that it poses and then finding a

way to eliminate or reduce that

risk. Semi-waterlogged shipping

containers and other heavy

objects are scattered around the

world’s oceans and occasionally

yachts are holed by hitting them.

Keeping a good lookout is a

conventional solution, but who

can spot the corner of a weed-

covered steel box that is floating

low on the surface, especially in

choppy conditions or at night?

A collision bulkhead on our

27-footer, London Apprentice,

would be a safeguard, but the

main bulkhead is set well aft;

a watertight door of sufficient

strength would be a major

project and a flooded forecabin

could cause the boat to adopt a

dangerously bows-down attitude.

A few small boats have been

fitted with collision bulkheads

set forward but some of these

are little more than watertight

anchor lockers.

Eureka moment

My inspiration came while lying in

the bath, but it had nothing to do

with floatation. Hanging on our

bathroom wall is the designer’s

drawing of our boat, a Sabre 27.

It is a copy of Alan Hill’s original

layout drawing, from 1968,

and now I noticed that he had

included a dimension to show

the top of the forecabin bunk

platform eight inches (20cm)

above the waterline. It occurred

to me that if the hull was holed

within the area covered by that

bunk, it should be possible to

confine the inflow to within that

space, without requiring a full-

height bulkhead.

The forecabin bunk moulding

has a central footwell that can

be covered by a panel to make a

double berth. The volume under

the bunk is subdivided into three

lockers, each is accessed via a

top hatch and all the subdivisions

were glassed to the hull, making

three separate compartments.

However, the compartments

had holes to accommodate fresh

water pipework for the tank

under the berth.

A watertight solution

With a little thought I was able

to seal the holes at points 1 and

2 through the port compartment

(see diagram, right) by applying

silicone sealant around the pipes,

but at point 3 on the centreline

there needed to be some limber-

hole drainage from the anchor

locker. I decided to restrict the

hole in the bulkhead with two

triangles of plywood, fitted fairly

closely around the pipe, and

then screwed on a third piece of

ply with neoprene incorporated

between the layers.

A couple of bucketfuls of water

were poured into the locker space

and the screws then tightened

until the seepage slowed to a

trickle that could easily be

dealt with by

pumping.

The scenario

that Ken

imagined was

recreated during

our Crash Test

Installing a partial seal around the fresh water pipe on the centreline Boat series

The forecabin has under-bunk mouldings with top access to each of

three lockers. There is also an access panel in the cabin sole

PHOTOS: LESTER McCARTHY/YM

PHOTO: kEn EndEAn

PHOTO: kEn EndEAn