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Hylander

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Charlie, been giving this ice issue some thought and I think I might have a couple of ideas – see the attached precise, technical drawing.

BA Defelctor.jpg


 

Ok, so the drawing skills need some improvement.  Anyway I thought about a cut of wood - it does not need to be especially thick so could be anything, but would need to be about 12ft in length so was wider than the beam of B.A. It may also need some  weight attached to it so it would half submerge. Keeping it dirty and simple this could be some half bricks – anything to stop the wood just floating on its side atop the water. 

From now on I’ll refer to this as the ‘Deflector’.  The Deflector would then be hung over the bow and be attached to the cleat used for the mud weight – it then would be the first point of contact with ice and so protect the hull.  

The issue then is the moment the boat is not ‘centre on’ with any ice, the Deflector is free to move into the hull from the left or right thus the opposite side of the hull is then exposed to the ice. 

To counter that you take the two bow lines and attach to the left and right outer edge of the Deflector (perhaps through a couple of holes drilled through the Deflector’s outer edge) and then secure these lines on the fender eye brackets further alone the hull. 

When the Deflector was about to push and twist, for example, to the right then the left hand line would become taught and prevent that happening.  It would work when ice pushed from the other side too. In short it would stop the Defector ‘twisting’ out of alignment. 

It would be a pretty crude looking affair, but simple and might just work – even if only once.

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Ok, I've had a look at that, the obvious issue is that the force of the ice would stop us dead in the water and even with 'B.A's torque / 4 x bladed prop she would not be able to push through it.  Secondly the fender eyes would rip out in seconds as the force on the ropes would be huge.   The only 'Safe' method of ice breaking in a timber hull that I know of without making false bows, attaching steel plates and the like is the 'Transom to ice prop wash lift method'  This needs a minimum crew number of three, is hugely tiring on all three crew members and takes an age to make progress but at least there is no damage to the hull. We have had to do it once getting back to the wet shed from the start of Richo's dyke, took us a veritable age, Bro and Steve were aching for days afterwards.   The obvious answer is not to go ice breaking with 'B.A' in the first place at all whatsoever.  We have time on our side for the wx to warm up and the river ice to melt

Griff

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16 minutes ago, BroadAmbition said:

Ok, I've had a look at that, the obvious issue is that the force of the ice would stop us dead in the water and even with 'B.A's torque...

I agree, but was thinking if not too thick it would be the best solution I could think up should you arrive to take BA down to Horning and find your passage blocked. It's a shame there are not more steel hulled boats on the Broads to assist, here is hope for a proper change in weather in the coming weeks :)

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As Griff said the problem is you cannot drive through the ice.  The only effective method of icebreking is to have stem-post shape that allows bows to ride-up onto the ice.  The weight of the vessel can them smash the ice downwards.

The design principle of icebreakers has not really changed since the 19th century.

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In this case the journey really is.  We have an appointment at Southgates for 'B.A' to come out of the water Friday 3rd, I won't get onboard til Thursday night 2nd, then it's a solo cruise to Horning Friday forenoon.  If I don't get her there Friday she won't come out of the oggin till Monday which will cock up the whole job as we are on a limited time scale for the crew, the shed and Southgates

Griff

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1 hour ago, BroadAmbition said:

In this case the journey really is.  We have an appointment at Southgates for 'B.A' to come out of the water Friday 3rd, I won't get onboard til Thursday night 2nd, then it's a solo cruise to Horning Friday forenoon.  If I don't get her there Friday she won't come out of the oggin till Monday which will cock up the whole job as we are on a limited time scale for the crew, the shed and Southgates

Griff

According to the Met Office, the weather is likely to be milder at the beginning of February so you should be ok.

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I never thought I would see the river freeze at Wroxham this side of the bridge but yesterday morning it certainly did. Mind you it certainly doesn't phase some of these fishermen when they whizz past in their boats cutting through the ice like a knife through butter. The swans were not amused with it all. The good thing is it soon goes with the sun which has been like Spring when it has shone. Quite a few.privateers and hirers about today.

Hubby has caught some good sized Pike. Such a pretty fish when you look at the colours. I wish people would treat them with more respect.

 

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Griff - I think you need to get here a few days earlier with as many of the lads as possible - go out on the booze and fill up with tons of grub as the pubs are not very full at this time of year, and then get them all to huddle together on the aft deck, give it some wellie and just hope the bow gets out of the water by about an extra foot or so!!

Easy peasy but it may be a trifle expensive given the fact you have to foot the bill for booze, fags and grub!!

OR Alter your schedule a bit to allow a bit more flexibility - it is Norfolk after all and expecting things to run to plan and expectation is probably not entirely on the cards.  You know what they say about cup and lips!!!!

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'One Eyed Stag' or no eye dear :?

But as a guess I reckon the concrete would look like it had been attacked with blunt jigapick which in turn would lead to water ingress within the seacrete, this in turn if allowed to freeze would splinter and crack the material with bits then falling off - Not good, but that really is just my best guess

Griff

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OR Alter your schedule a bit to allow a bit more flexibility

Unfortunately customers booked in right up to and including the Thursday, I don't want to let them down and tar 'GriffTiles' reputation, plus I need to be earning good and proper in readiness for the forthcoming open wallet surgery.  B.O.A.T  = Bung On Another Thousand

Griff

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1 hour ago, trambo said:

Just as a matter of curiosity, besides paint damage how would a Seacrete hulled boat cope with ice?

Fred

I've done a certain amount of icebreaking in GRP vessels, with ice so thick that it eventually stopped all progress (and in trying to break it up in the dyke before we set off, I swung a 22kg mudweight to about 15 feet above ice level, it dropped with a thud, and made no appreciable dent in the ice). The GRP in question, despite us backing off and making multiple attempts to maintain progress, suffered no discernible damage whatsoever. I suspect that had we continued all day into ice this thick (4-6 inches) we may have begun to damage the laminate, but I'm not certain.

Given that a ferrocement (of which seacrete is a trademarked name used by Windboats) hull is immensely strong when built properly, I'd expect the hull itself (as opposed to the paintwork) to get through totally unscathed in any conditions where the boat was able to make progress, as would a steel hull.

Incidentally, I've heard all the stories about steel vessels on the canals icebreaking and damaging GRP or wooden vessels by pushing sheets of ice in to them. (In some of these stories the GRP hull was apparently 'sliced in two'.) Despite talking to a lot of boat owners and surveyors over the years, I have never yet come across anyone who had actually seen such a thing with their own eyes, or dealt with the aftermath. I have also never seen any photographic evidence relating to such an event. Whilst something like that may have happened, I'm now firmly of the opinion that until I actually see some evidence, I don't believe those stories.

I have seen evidence of damage to the bows of wooden craft caused by icebreaking, which took the form of the wood being worn away around the waterline. My opinion would be that some sort of V-shaped ice board, similar to Robin's suggestion, in contact with the bows and points on either beam (obviously with padding to avoid paintwork damage) would be a usable option for making progress in ice up to a couple of inches thick. After that, you start to need a properly shaped ice breaking hull that rides on to the ice and breaks it with the weight of the boat from above, rather than just using brute force.

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To add to what Teadaemon has rightly said -

I have found the most dangerous ice is the thin stuff, known as rime ice, just a couple of millimetres thick, which sits on the surface on a still day and you don't really notice it when driving, until an hour or so later when your boat looks as though someone has attacked the stempost with a cross-cut saw.

GRP will indeed resist for a long time but once the ice has worn through the gel coat it will get through the matting in only a minute or so. This depends on who moulded the hull and how much gel they used. No names mentioned, but you tend to get what you pay for!

I also agree that the theory that a boat is crushed by the ice on a Broads mooring is spurious. I must admit though, that we always broke the ice around the Albion when she was moored at Womack Water. Wouldn't want to test out the theory on her!

Since you can't even screw into Seacrete I don't suppose ice would have much effect on it. It is basically re-enforced concrete, but I remember we did have one problem. When Jenners bought Windboats there were some aft cockpit boats a bit like an Elysian - I forget the name - which had a Perkins diesel with a short shaft on solid engine mountings. After a couple of years the whole transom literally fell off!. 

 

 

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Re GRP & ice, I have seen the damage done to the gel coat on moored boats by the ice being carried along by the tide. Indeed ice boards are not unheard off in places like Reedham.

Further to the above after the big freeze of 63/64 boats at Yarmouth & Reedham were damaged by ice being washed out to sea as the big thaw took place. I understand that there was a repeat some years later but I don't remember the year.  I have never heard of any crush damage, only damage by abrasion.

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1 hour ago, ScrumpyCheddar said:

Rock salt is your answer... and will melt it.. as soon as it hits the ice it liquidised... its good up to -8c/-9c of the ice... 

Give it a good spreading in front of you as you move forward ...slowly... and watch it melt down...... 

rock salt in the shotgun cartridges - also good for burglars

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