100mm Cockpit Drain Holes

[craigsailing]

Hi Don

I've just been working up my 3D CAD model to review the implications of the 100mm cockpit drains holes and use of removable hatch covers and determining their most likely fitting position? On review, I observe that access to the 100mm drain covers from the inside of the cockpit is somewhat restricted see view A due to the life raft limiting access? Were alternatively fitting the covers to the outer face of the transom maybe not ideal either as most likely during rough weather it would mean hanging out the back of the boat to remove them...eek.

During my days sailing 5o5’s, we used a float ball and/or funnels and a piece of shock cored to block up the transom drain holes ref. my drawings here. This method worked well, as the shock cord allows any water pressure say after a knockdown to drain away automatically, where the further release of flood water can be achieved by releasing the cored from the clam cleat whilst still in the safety of the helming position...Comments, please.

[pete]

I'm intending to keep the raft in this location as well (subject to putting it in place and trying the cockpit ergonomics and trim...) so this makes total sense to me. However just wanted to find out why the removable covers in the first place and not just holes as per the pics of the Steka 5m yachts I've seen? The lowest point of the drain holes appear to be 160mm above the design water line according to sheet 2 (i think it is). Not sure what this looks like at any angle of heel, but interested to know if we can get away with no covers at all. (maybe following waves do wash up against the transom and push a load of water into the cockpit in low boat speed situations?)

[Admin]

All good comments and Ideas. The pinciple is Pretty simple...first you MUST have the two small as designed drains as per the plan at the bottom corners of the cocpit transom. What we are then saying is you MUST have two more 10cm diameter holes no higher than 30cm above the cocpit sole with an inspection port. You can leave them open all the time...or you can fit the screw in cover when needed...so there are any number of variations to this safety rule. You will see in all the safety aspects we do not say how to use an item, just that the principle must be observed. You can unscrew the inspection port when ever you want..OR leave it on permanently..or just cut the hole and leave it open and to save the money not fit the inspection port ( No problem with that) ..so all the comments above work and others may have more ideas. We do not want a full open transom and for normal sailing it is fine..so this is like a safety valve for theskipper anytime he needs it. So just a rubber flapper on the tansome would work?...Because the transom may have many things fitted, Dagger board case, windvane, outboard bracket, boarding ladder, solar pannel mounts etc..we do not want to define the actual position..just no higher than 30cm up. WE may change the wording to say a 10cm feeing port that may include a screw in hatch??? but the principle will remain THNX ....

[pete]

Ok gotcha. I understand the concept better now. I'm starting to get slightly more serious about the design details now as the kit is ordered and i want to minimise dicking about with the design too much once i'm putting together the pieces - if I can figure out the locations for the all the transom ornaments now i can allow for these (strengthening pieces/ backing plates etc) while the bulkhead is on the bench, and not part of a semi finished hull!

[jaysen]

@craigsailing, I'm going shamelessly steal this. Thank you for the suggestion.