Putting a Telescoping Ladder on My Montgomery 15

17 Jun 2013

      Last winter I put a telescoping ladder on my Montgomery 15.  I am happy how it came out and wrote up the installation process.  I have tried to attach that as about a 3 megabyte pdf in case others are interested. The text without the photos is copied below.

David Grah
Bishop California

Installation of Transom Ladder on
Montgomery 15 Sailboat
By David Grah
Winter 2012 / 2013

For the few years we have had our 1986
Montgomery 15, we have used a removable ladder for getting back on
the boat when we swim.  Although it worked, the removable ladder was
not very secure nor convenient to deploy and stow.

I asked on the Montgomery sailboat
discussion group for ladder suggestions and received some very good
information.  The group said to stay clear of ladders with only two
mounting points because of the stress they would put on the transom
and suggested a Garelick 18017 Marine Compact Two-Step Transom Ladder
in particular as a good four point ladder.  Dave Scobie also provided
a link to his excellent page about installing transom backing plates
for ladders and motor mounts on a Montgomery 15:

http://www.sagemarine.us/forum/showthread.php?380-Installing-transom-backing... 

After looking into ladders a bit, I was
concerned about how much the Garelick ladder might stick up above the
top of the transom when stowed and liked the idea of a telescoping
ladder.  Since I live many hours drive from anywhere I could see
ladders, I decided to buy both the Garelick and the telescoping
ladder that looked best online to see which I liked best.  The
telescoping ladder was a Windline TT-3X Transom Mount Ladder.  I
bought both from Amazon.

Here is a photo of the removable ladder
and the two new ones, Garelick in the middle, Windline on the right:

They are shown at the relative height
they would be used on the boat.  The Garelick was positioned so it
wouldn't stick up “too far” about the transom of the boat.  The
telescoping ladder was positioned so it would fold up below the lip
at the top of the transom.  Note the removable ladder extended the
farthest into the water followed by the telescoping ladder although
the steps of the telescoping ladder came pretty close to matching the
steps on the removable ladder.
I wanted to use the telescoping ladder
but needed to distribute the stress over more of the transom than the
stock mounting brackets provided.  I designed some larger mounting
brackets, purchased a small piece of 12 gauge 316 stainless steel
sheet on the internet, and had a local metal working shop cut and
bend the two brackets for me.  I drilled holes in the new brackets to
match the holes in the new ladder:

I bolted the new brackets on to the new
ladder and put a backing nut on the bolt that went through the top
hole on the ladder.  This nut helps spread the stress from the small
ladder over the full length of the new bracket and puts less stress
on the transom:

With the brackets in place on the
telescoping ladder, the stress of the ladder is spread over an area
larger than with the Garelick ladder:

To prepare the transom for mounting the
new ladder, I essentially followed the process David Scobie
described.

I added a West Marine access plate to
the starboard cockpit seat behind the lazarette:

Next I made a cardboard template of the
plywood backing I would add to the transom:

To get the cardboard to the inside
surface of the transom, I found I had to cut it into two pieces.  In
addition, the upper part of the transom already had some thickness to
it.  This thickness was apparently foam sandwiched between inside and
outside layers of fiberglass.  I needed about a ¼ inch thick plywood
to fill in below this.  My plywood reinforcing for the transom became
three pieces of ¼ inch plywood.  The smallest one was to fill in for
the foam thickness where it wasn't.  The two longer pieces were to
provide reinforcing over the large area I wanted to beef up.  And the
medium size pieces was to sort of hold the two longer pieces
together:

There is no place around here to get
marine grade plywood.  I found a scrap of nice 5 ply plywood at the
local hardware store and, since I didn't have enough of this nice 5
ply stuff, also got some standard 3 ply CDX plywood.  I used the CDX
for the small piece that filled in below the foam and the 5 ply for
the rest of the pieces.  Here is another view of the pieces.  They
were cut to match the cardboard pieces I had made to fit into the
transom:

Generally following David Scobie's
process, I epoxied the plywood in place a layer at a time.  While the
epoxy hardened I held the pieces in place with lengths of wood jammed
between the transom and the back of the lazerette and with ropes
looped through holes in the plywood and the transom and held tight
with more pieces of wood.  I found these methods worked pretty well:

Once the plywood was in place, I
drilled the mounting holes oversize, filled them with epoxy and
re-drilled them.  Two of the holes needed to be quite large to
accommodate the nuts tightened to the back of the top holes on the
ladder.  I didn't do a good job with my initial placement of the top
holes:

I installed the ladder and drilled a
hole through the deck to hull flange at the top of the transom to
accept a bolt that is dropped in place to hold the ladder up when
stowed.  I wrapped a piece of bungee around the bottom rung of the
ladder to keep it from rattling on the trailer  (bungee not on yet):

I am quite pleased with the
installation both deployed and stowed:

David Grah

George Iemmolo

Chris Smith

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