Thursday, March 17, 2011

Icing and escape hatches

                     Winch starting to ice up, I leave the winch handles in to stop socket icing up - Ideally a hard cover would be good, to enable instant use. Also in extreme conditions tiller may ice up as happened to Totorore.

The other day I was thinking about Berserk, and it got me thinking about hatches and icing and getting stuck inside a boat.... What got me thinking was that Jarle has finally spoken out
and it makes interesting reading...

So what I was thinking (all this thinking was starting to hurt..) was that in a severe icing condition at sea it seems quite possible that the hatches could get badly iced up. I have always been abit claustrophobic, and the thought of being trapped below decks with a stuck hatch is terrifying.. So I guess it would be smart to have some means of forcing them open and also another escape option, hopefully not also iced up badly and frozen shut...

Sprirt of Sydneys main hatch. Note my boots
 Spirit of Sydney had a main companionway door that opened inwards (into the cabin). This is very unusual in my experience. I have never seen one that opens inwards before on any vessel, and it can be abit of a menace. It is heavy and if it gets loose could do damage to fingers and such. From an engineering perspective it is kind of backwards as well, with the major loads from a wave going entirely onto the closing dogs and hinges and trying to open the door, forcing it off the rubber seal rather than pushing it tighter onto the rubber seal with the loads evenly spread into the rim. But the door is strong enough, it has been well proven over many years and in the worst conditions at sea on this vessel.

Thinking about this strange door in relation to severe icing conditions - It would be much easier to open even if heavy snow and ice had filled the cockpit and blocked the doors. It would also be easy to open with a cockpit full of water, or after any event that meant the cockpit was obstructed (ie a dismasting with a broken piece of boom in the cockpit) - Infact I find it hard to imagine a scenario that would trap a person below with this door. I suppose the whole door frame being distorted might jamb it, but this would jamb any door.

Actually for any offshore sailing getting stuck below decks, or maybe even worse stuck on deck would be pretty dangerous. Rolf and Deborah From Northern Light told me about a main hatch securing rope getting caught in it's V cleat inside the boat locking the hatch shut. They were both on deck and quite a few days away from land - stuck outside with no food, water, shelter or tools (all below decks). Eventually (after long enough for the seriousness of the situation to sink in) the boat rolled heavily and the line freed itself.....Whew!!

Snow Petrel has a backup escape/entry hatches - My lazarette hatch only opens and closes from outside and my main-saloon skylight is always free to be opened from inside even when the dingy is ondeck and covering the forward hatch. But both could still be blocked by severe icing.... Maybe I should add an inwards opening hatch somewhere?
Ice melting fast, and wind dropping.

The only moderate icing I have had was whist at anchor and then the main hatch was protected by the dodger. We had to make sure our ventilators remained somewhat free of ice, but that was all, I think we probably had about a ton of ice onboard at it's peak.... Gerry Clark had some very bad icing on the little 32 foot "Totorore", while heading towards Boyvetoya, deep in the south Atlantic (55 south) in late September. It sounded horrible... It's well worth reading his book, probably the most epic small yacht voyage ever, and it was a voyage that did some very useful scientific work, by getting the first accurate data on seabird populations in the southern ocean and it's islands.

I am interested to know if anybody has experienced severe icing at sea on a yacht, what problems it caused, and how best to minimise it's dangers?

Cheers

Ben

3 comments:

  1. Ben

    Have you asked Dion Poncet about this (I think he's in Tassie at present, coming to NZ next - I'll probably see him so I'll ask him) I don't recall his dad ever mentioning it or writing about it as a problem on Damien or Damien II

    ReplyDelete
  2. Stupid brain ... Leiv Poncet, not Dion

    ReplyDelete
    Replies
    1. Hi Andrew, I caught up with Leiv while he was here, but we talked mostly about his incredible trip to the Kerguelan Islands, say hi to him if you see him.

      Cheers

      Delete