Transom Steps

Discussion in 'Multihulls' started by Boatguy30, Aug 22, 2013.

  1. Boatguy30
    Joined: Dec 2011
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    Boatguy30 Senior Member

    Ok, so trying to figure out if I should use smaller steps in fore and aft width closer together vertically or wider steps with more vertical distance.

    I have 27" from the rudder post to the end of the boat. The height above the swim platform of the top of the transom is about 32". I plan on the swim platform area being about 16" long for and aft to provide a secure seat for putting on fins, snorkel, etc.

    That leaves just 11" fore and aft to rise the 32" to the deck. I could either do 2 5.5" steps with about 11" step up (pretty standard) or one wider step that is a bigger step up 16"

    I'm leaning towards the single step, but wanted to see what others thought. Should have made the boat just a little longer!
     
  2. troy2000
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    troy2000 Senior Member

    Ergonomically speaking, a 16" stair riser just doesn't cut it. Most people would have to grab a rail and haul themselves up, instead of just stepping. You'd be better off using all the space for the platform, and installing basically a ladder with grab rails (like Navy ships have), with a rung/tread every 8".

    The general rule of thumb in construction ashore is that twice the riser + the tread should equal 25 inches, to match the stride of the average person and keep them from stumbling. But obviously, you aren't going to get that. :)
     
  3. michael pierzga
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    michael pierzga Senior Member

    Imagine lugging two cases of beer in your hands then climb up the stern ladder, down the ladder.

    Steps are utilitarian...get them correct. Also remember old folks , people who arent familiar with your boat and boarding during bad weather.

    Many times when moored stern too, stern lines are crossed..an " X ".

    Consider this
     
  4. catsketcher
    Joined: Mar 2006
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    catsketcher Senior Member

    No need to have the bottom step longer than the others. I usually put my swim gear on whilst sitting on the second bottom step with my feet on the bottom. Try it - it's easier. This gives you greater length to play with for the rest.

    I would also urge you to get some scrap ply or MDF and mock up the thing. Try to get one of your steps to line up with the underwing bottom - that is good design practise.

    The more modern idea is to cut away the inside of the hull at least for the bottom step as well. You can try it for the other steps too if you like but I am not so worried about this facet of step design.

    One other way to change step design is to play around with the height of the transom. On my cat it is 200mm. I would not go lower than this and higher may be fine. The higher you go here the less rise you need later. You also have to work out how to fit in the ladder with the steps or use the trailing edge of the rudder as a mount for a step which is what I did. The rudder does need to have its trailing edge right at the back of the boat though.

    I can get out without the step but friends like it.

    Can we have a picture of the stern?

    cheers

    Phil
     
  5. Boatguy30
    Joined: Dec 2011
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    Boatguy30 Senior Member

    Pic

    I think the single high step is the way to go. I thought about the hull cut away and a platform between the hulls, but its roughly 1.5m from the hull edge to the aft end of the cockpit and there's no way I want that big a platform at this stage.

    I think I may just do the single step for now. The stern pulpit has a brace that swings down to just outboard the rudder post which will be a good grab rail.
     

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  6. Boatguy30
    Joined: Dec 2011
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    Boatguy30 Senior Member

    Opps on pic

    Sorry the pic is upside down, major PITA when using an iPad to post pictures like this.
     

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  7. Boatguy30
    Joined: Dec 2011
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    Boatguy30 Senior Member

    One big step. Could always add 2 later? Will have filler pieces on the side to cover stringers.
     

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  8. cavalier mk2
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    cavalier mk2 Senior Member

    How about adding a folding mast step? They are only about 2x3 inches deployed and would keep the big step from being a stretch for smaller folk.
     
  9. michael pierzga
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    michael pierzga Senior Member

    Mast steps are killers. Hard to walk down. You need two feet planted.

    A full ladder that also doubles as a swim ladder is worthwhile
     
  10. cavalier mk2
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    cavalier mk2 Senior Member

    Nonsense, we used one for years with a big step down from the pilot house and nobody had problems. I did eventually replace with 2 steps but my "swim" step is still a maststep on the transom near the waterline used in conjunction with the outboard leg.

    In boatguys case I'd probably use a ladder with 2 steps but the other way would let him use one big step and still have an option.
     
  11. Boatguy30
    Joined: Dec 2011
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    Boatguy30 Senior Member

    Ok, so closed the transom in today with the one step. In hindsight would have made the boat just a foot or so longer. The lower edge of the bottom panel is intended to be clear of the water by around 30mm so will probably need a 2 step ladder especially initially as I expect to be at least 100mm above loaded waterline at initial launch.

    thanks,
    jeff
     
  12. cavalier mk2
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    cavalier mk2 Senior Member

    You can still pull out the electric plane and start on the scarfs- stringers and all- to make it that foot longer...
     
  13. Boatguy30
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    Boatguy30 Senior Member

    I'll get right on that. Need to redo the bottom curve as well to bring the transom height down when projected aft.
     
  14. cavalier mk2
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    cavalier mk2 Senior Member

    I'd keep the stock bottom curve and project it up along the extended stern length to the new transom location. Yes your stern will be a little higher but you will float on the stock lines and be able to handle more overload. If you haven't found the link from Richard's site check out the Gypsy 28, I think called Light Wave, from BC. They stretched in that manner down in Mexico to handle the loads they were carrying. ( Fewer big cat features might have helped too.....)
     

  15. catsketcher
    Joined: Mar 2006
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    catsketcher Senior Member

    Having a look at your pic I would say STOP! As you are making the boat it is really easy to get it right now rather than any time in the future. Here is an example.

    I showed a little video of my little cat to a broker about 6 months ago. He said it looked good but where were the stern steps? I felt a little resentful - What did this guy know? Who was he to tell me? I wanted to keep the boat shorter on the trailer. But it burnt. Inside I was upset because he was right and I knew it. Thankfully I had not sprayed the boat yet and so it ONLY took two weeks to extend the hulls, add the steps and fair it in. Two weeks full time - bummer.

    Now I look at the boat and it is so much better. Everyday I use the steps to get on and off and the extra time seems worthwhile already and she is not even floating yet. So my advice is

    Work out what the best arrangement is and do it before fairing and painting. You already know the boat should be longer so make it longer - just for the bottom step. It will take about 30 hours to extend the hull 300mm. Your boat will sail better, look better, pitch less and be better to use. When you use your boat you will be proud you did the right option rather than the easy option.

    Do it right the first time.

    cheers

    Phil
     
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