How Much Of A Cat Walk Do You Really Need

Discussion in 'Boat Design' started by Boston, Mar 15, 2010.

  1. Boston

    Boston Previous Member

    as some of you know I've been thinking retirement build for a while now and Im still working out a few things

    one of which is how much actually foot room I need to run for and aft to handle lines when docking or to throw a life ring to the occasional numskull


    how much room would you say was allowed between the edge of the deck cabin and the edge of the hull on old Widgeon pictured above

    the boat is 46' and I believe has about a 12' beam

    looks like not much
    maybe a foot at best

    and how much room would you folks think it should have ideally

  2. u4ea32
    Joined: Nov 2005
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    u4ea32 Senior Member

    On my boat, I've got 8 inches of deck, and that's plenty, because there is also a hand rail that is 12 inches high aft, increasing to 18 inches high forward. The low rail is kinda like a VERY effective toe rail: I can push my lower leg against it. I've got hand rails on the T top too, the T top is about 3 feet above the deck. Forward of the t-top, where I've only got the outboard handrail, the handrail is about 18 inches high.

    I was quite surprised, but that little works great, even with that low of a hand rail.

    The rail is really a very long pulpit (from the bow to about midship), and welded in one piece of stainless steel. So its quite sturdy, very little flex, load is spread all along it so I don't have a problem with the stanchion bases. Being stainless steel, it seems transparent from the helm -- while its almost directly on the horizon sometimes underway, I never notice that it obscures my vision.

    Also, I spent a couple of weeks chartering a Nordic Tug 32 in Alaska. It had about 6 inches alongside the "wide body" main cabin. With the hand rails on top of the cabin, no rail outboard, it was possible but a bit dicey to move fore and aft along that cabin. The low outboard handrails on my boat make a big difference! Also, that two inches seemed to make a big difference.

    By the way, that Widgeon is one beautiful boat!
  3. TollyWally
    Joined: Mar 2005
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    Location: Fox Island

    TollyWally Senior Member

    More is better to a point, handrails make a huge difference. One hand for yourself, one hand for the ship etc. 12" is ample, 10" is adequate.

    As a younger man I've gone forward on smaller boats, gillnetters, under extremely harrowing conditions. Falling into the water would most likely have been fatal, getting to the foredeck was not optional. Handrails are your friends. Something to take into consideration is how much the house etc. slopes inward and if you can lean in over the top of it etc. As I age up I appreciate wider margins. What feels good at 25 is only adequate at 50.

    For a retirement build I'd err on the side of wider. Losing 4 or 5 inches in the trunk cabin or what have you maynot be noticed after a bit. Feeling good walking up to the foredeck will give you a smug feeling of satisfaction every time you do it. After all isn't that the point of a custom build? getting the personal details customized to your criteria rather than one size fits all.
  4. Frosty

    Frosty Previous Member

    Bos that looks like a Thames gentlemans yacht. There is lots of them around Windsor etc and on the broads of UK. Its a river boat.

    Wood being wood a lot are moored up permanently as house boats.
  5. Boston

    Boston Previous Member

    max beam is 12' and the length is 48
    I got the profile the way I want it and a preliminary weight budget works out as well as the power plant I intend to use
    displacement is ~25,000lbs
    construction is cold molded hull chine form with a modified sharpie type bottom


    reason I ask about the cat walk is that need to start the plan view and obviously its decision time on the width of the walks

    I had planned on one foot with rails

    the rails are not shown in that drawing but they come straight back off the line of the raised deck and continue around the entire deck structure

    thanks for the tips kids

  6. Boston

    Boston Previous Member

    ya I increased the free board and have a few other tricks up my sleeve for making a better coaster

    besides I might just end up living in a river at this rate

    funny thing is how shallow the draft works out to

    at 25000 its got all of about 10~12" draft
    48 long 12 wide .75 one way and .9 the other
    works out to about 9 inches in dead calm water
  7. Frosty

    Frosty Previous Member

    Why don't you copy the bottom of a good known sea boat like a Grand Banks.
  8. Boston

    Boston Previous Member

    cause I want a shallow draft so I can sneak up river in a pinch

    the Dashew once again has a nice shallow draft and a keel bulb for balance on blue water

    Im thinking of a cross between Ted Brewer modified sharpie and the Dashew
    but let just get the right cat walk for now
    Ill detail the bottom once I get a few more basics worked out
  9. mark775

    mark775 Guest

    If you will leave the marina, you will appreciate side decks that you don't need to crab or slither to negotiate. Boats with big cabins are gay - What's the cut of your jib, Bos?
    Kidding, I know. Now put some beefy rails and some deck space. Side decks need at least the width of one's hips. The best boats allow full stride running with a net containing three silvers behind fishermen at the rail. The best boats make room for friends in a wheel-chair to go forward and watch the orca, too. Skiffs wedged in there, piles of deer carcasses, room to pass a barbeque to the boat that's cookin' tonight, room to get on the hip of the broken boat ya gotta' tow, room to lay your .270 on the rail as you kneel on one knee, all need to be accomodated. Those East Coast lobster boats (ugly as they are) got this right - if it's a narrow boat, put the cabin to one side BUT ALWAYS LEAVE A SIDE DECK! Anything else is a compromise - mine has mini side decks (18") and I curse them. I cannot go forward without thinking of my cabin (10' 10" wide) on a boat 16' wide.
    I hope I may have convinced you tp go an inch or two wider!
  10. rasorinc
    Joined: Nov 2007
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    rasorinc Senior Member

  11. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    I would say that too little is not good, and too much is not good either. You do need a space to move comfortably fore and aft, but your feet also need lateral walls to push against when waves start rockin' and rollin' your boat. The numbers will depend on your body size.

    By the way, that's one really handsome boat. :)
  12. Boston

    Boston Previous Member

    thanks for all the input folks
    with this kind of help I'll get this thing right first time
    which is kinda the big goal

    if it were a house I'd say 3' on all walkways or better
    but on a boat who knows

    Mark has a point
    silly as it sounds I need to be able to drag supplies on and off the boat without to much trouble and without beating up the brightwork
    I was originally thinking 12~18" but 2' would be ideal

    so now I start thinking of beam to length ratio
    boat is 48 long so I can have 12' beam and still be at 4:1
    which isn't great but isn't to bad for efficiency
    ( water line its 10 which gives it a better ratio of 4.8:1. I want this thing as narrow as possible )

    the aft cabin is big 18'6" long as pictured
    ceiling height varies from 6'6" to 7'2"
    width is yet to be determined but I was hoping for 10'

    wheel house is 13'+ long as pictured
    ceiling height varies from 6'6" to 7'2"
    width I was hoping to be the same as the aft cabin but I really want that 2' walk which means the wheel house is 8' wide and the aft cabin will want to be wider than the wheel house

    at 8 feet the wheel house would be one cramped office what with the two stairways leading forward and aft

    and so that is the root of my question

    if I made the cat walk only 1' I could have my 10 wide wheel house and after cabin
    but the issues Mark brings up would not be being addressed and his is in the end right
    would drive me nuts eventually to have no room like that

    if I made the cat walk 2' wide I end up with a wheel house thats fine as a wheel house but sucks as an office space
    I want a desk and computer set up along with a few chairs as well as a pilot station and nave area

    still working on it

    thanks for all the tips


    once I get a few plan views worked out Ill post them but for now that elevation is the only thing I feel good enough about to show the group
    its been through the ringer and Ive worked it out to all kinds of different scales but at 48 it seems to fit best both the budget and the look I was after

    Im beginning to think 1' is all I will be able to manage

    if I have to haul a barbecue or take a shot off the deck I can always either go through the cabin or sit on the aft cabin roof
    I made it *** high so folks could sit on it
    even thought maybe I'd but a back rest and cushions up there either side of the Jolly boat


    oh hey Mark
    there gotta be a gun rack with the 7 mil ultra mag in it in the back window
    thought you might get a bang out of that

    back when I was a kid we always has a riffle in the back window
    hows Alaska on me sporting a weapon but the way?
    if Im in Alaska I plan on doing some hunting

    oh and hey Tad
    funny how our numbers worked out so close
    length draft beam even the displacement I got close

    Im working on righting moment and that weight budget you spoke about by the way

    cheers and thanks for all the help folks its greatly appreciated
  13. Tad
    Joined: Mar 2002
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    Tad Boat Designer

  14. Tad
    Joined: Mar 2002
    Posts: 2,321
    Likes: 214, Points: 73, Legacy Rep: 2281
    Location: Flattop Islands

    Tad Boat Designer

    Where on earth did this idea come from?

    View attachment yachting_review.pdf

  15. Boston

    Boston Previous Member

    your right I was thinking of a different designer

    my bad

    well I was thinking also if I made the aft cabin full width and the wheel house only with a cat walk
    but then tying off your running through the boat rather than over decks
    also in the event of trouble having good maneuverability round the decks might come in dam handy

    its posing quite the dilemma though as I really want a workable office space in the wheel house

    something tells me you and mark could really have it out over this one

    deck space is a must at least for me
    that area forward is for laying out goofing off
    an area aft would be equally as nice for sitting down to a few beers and a barbecue
    access between the two over decks would be great if I can work it out

    Ive considered going with a shallower draft and a wider boat but that screws up a lot of the numbers on stability
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