Ladders or what under bridgedeck

[GMac]

I was just out having a damn nice sail and was cruising by a 50-55ft Cat of an unknown design to me.

I noticed it had quite small clearance between the bridgedeck and water, I've been reading the multi forums you know

What did intrigue me was what appeared to be a some ladder like looking structures on brackets so they sat about 4" below the bridgedeck. They were 3ft (approx) wide and each was centred about halfway from the boats centreline and the inside of each hull. They appeared to run the full length of the underside of bridgedeck.

Now I just can't think of any reason for such a boat, it is an offshore cruiser here on a visit, would be carrying actual ladders. All I can think of is they are maybe something to do with breaking up waves to stop pounding or similar.

Is that possible and if it is, do they work, anyone know?

[David M]

That's the mother-in-law berth.

[44'cruisingcat]

Never seen anything like that. You often see stiffening ribs under a bridgedeck, but they are attached, not 4" under it.

[GMac]

It did have some fore 'n aft ribs under there as well.

I think I know where it's parked, I'll try and get closer.

[shadow]

I can only "assume" a couple of options. One is perhaps they are used for people who are working underneath the boat and they have something to guide them where they need to be since it is a pretty large surface area. The workers can then move around and then strap in where the work is.

The other is possibly since it is such a large CAT, it may be used for people who fall in the trampoline area and can grab on to one of the rungs until they are noticed and are yanked back on deck.

Beyond that, it's just more guessing..

[Wotname]

Maybe if one looks at this from the position of the vessel being upside down, the reason will become clearer .

[Nordic cat]

Originally Posted by Wotname

Maybe if one looks at this from the position of the vessel being upside down, the reason will become clearer .

Gmac asks a question, and you try to ignite yet another of those multi/mono fights.....?

Please spare us....

[GordMay]

Could it be some sort of structural truss?

[Nordic cat]

Originally Posted by GordMay

Could it be some sort of structural truss?

Could be, but wouldn't it seem unlikely as you would want to reinforce the transverse more than the fore/aft to my thinking. If they were attached to the bridgedeck all the way, like is often seen with glassed in semi-circular or "U" shaped pieces, they have a stiffeneing effect for a small weight increase. Detached and 4" off. No idea...

[Hud3]

A lot of the large "cattlemarans" that take tourists out for booze cruises have boarding ramps or ladders that extend from under the bridge deck forward to the beach, so the passengers don't have to wade ashore when they make a shore stop. Could that be the case here?

[roverhi]

Boy are you dufus's. Those are to hang onto when the thing turns turtle.

Aloha
Peter O.

[44'cruisingcat]

Maybe they like coconuts.

[44'cruisingcat]

Originally Posted by Nordic cat

Could be, but wouldn't it seem unlikely as you would want to reinforce the transverse more than the fore/aft to my thinking. If they were attached to the bridgedeck all the way, like is often seen with glassed in semi-circular or "U" shaped pieces, they have a stiffeneing effect for a small weight increase. Detached and 4" off. No idea...

It's more usual to reinforce a bridgedeck fore and aft. Effectively you link the cross beams with longditudinal stiffeners which help hold the floor up. I haven't ever seen a bridgedeck with transverse stiffeners.

[Wotname]

Originally Posted by Wotname

Maybe if one looks at this from the position of the vessel being upside down, the reason will become clearer .

Originally Posted by Nordic cat

Gmac asks a question, and you try to ignite yet another of those multi/mono fights.....?

Please spare us....

NC,
I apologize to you if you thought my post was intended to stir trouble. I assure you it wasn't.

I wrote it quickly and did not go into detail as I assumed the detail was understood. Let me try another way.

Often things that seem strange, do so because we become accustomed to looking at objects in the way we normally see them. However once another way of viewing an unusual object is presented, the true purposes of its design become clear.

An example: some weeks back my 12 year old daughter and I were looking at a ship's lifeboat at a historic display of old vessels. She slowly worked out all the unusual features of its design like the foot driven propeller etc but was stumped by the longitudinal hand rails on the bottom of the hull. She could not work out why they were there (but did come up with some interesting explanations). When prompted to think about the vessel being capsized she suddenly could understand why they were fitted.

Now this example is a simple one and you or I would not need such prompting, the concepts already exist in our thought process. My post was intended to advance the search of an answer by considering looking at the problem from a more radical perspective. I included one such perspective such as capsize but did not intend that to be the only perspective - it was more as a primer to consider solutions that lay "outside the box".

If you are wondering why I did not go into so much detail in my first post - the answer is simple. I am not a natural writer and struggle with spelling, grammar and sentence construction. For instance, my first post took some two minutes to write while this one has taken over 30 minutes. Although my posts are often long in order to fully express my thoughts, they come at a personal price - time.

Perhaps I have misunderstood your post because I view it as being "unhelpful, not related to the original question, suggestive of an ulterior motive and directed to the person, not the argument". As such, I see it as contributing to a possible flame war rather than preventing one. I mention this as a contribution of an observation rather than as a complaint as I am very happy to let my "understanding" of your post go through to the keeper.
If I have misunderstood you, PM me to explain and I will shout you a cyber drink

[GMac]

Wot, no worries from me mate, I'm pretty thick and stuff like that just rolls on by. Tuff hides us 'I'll use anything that can carry beer, number of hulls irrelevant' yachters

I don't think the ladder things are structural, they just didn't seem to be attached strong enough to take much grunt really. They seemed to be hanging of 6 or so 1" odd things per ladder thingy.

Possibly Hud. But it's an offshore cruiser and not really that Charter like. But then you maybe right just for them to use. It is a pretty healthy sized boat and well travelled, a polite way of saying 'needs a bloody good tidy up'

There was some moulded in type stiffeners under there as well, which are probably doing the floor strength thing.

And as for them being hand rails, I'd like to think someone doesn't head into the deep blue in a big boat expecting to go tits up and they do look a bit serious to be 'just in case' type items.

I found out where she's parked today and hope to check them out tomorrow. I'm just quite intrigued to know what they are for as I've never seen anything like it.