Using inflatable dinghy as an ice breaker

[davidbfox]

I had the interesting experience of having to use my Seago inflatable on frozen Lake Windermere this morning. There were wide expanses of ice on the still parts of the lake, which I had to get through to get to my destination. Dead calm.

It worked well enough, running the outboard on tickover and rocking a bit to create waves to break up larger bits of ice. Most plates were about 30cm across but some were much larger. Some broke, some went under the boat, some moved aside.

All went well, no problems. The boat is OK. So are we, but it was scary thinking about the possibility of the ice cutting the fabric of the dinghy. With only two chambers the possibility doing a Titanic and ending up in the water with my grandson did not seem very far away.

Has anyone any practical experience of the actual cutting power of ice?

 

[AntarcticPilot]

Well, a few things to say.

1) Many moons ago (about 1973, I think) The River Cam froze downstream of Cambridge, at the end of the Long Reach. Eights practising and hitting ice by mistake came home with nice neat gashes at the waterline in the bows. However, this was in the days when wood was the usual construction medium for eights, and it was about 1/8" thick. Hitting a thin sheet of ice edge on at 10-15 knots was NOT recommended practise!

2) More recently, I decided not to move out of my berth at InverKip when the marina was covered in ice about a centimetre thick. The ice was a continuous sheet, and I decided that while I was pretty sure it wouldn't do my hull any structural damage, it would make a mess of my boot-topping and anti-fouling, which I would like to last another season!

3) Our RIBs in Antarctica avoid floating ice like the plague except at dead slow speed. However, that tends to be substantial lumps of ice rather than thin plates.

I'd say you weren't in any danger - an inflatable has such small draft that it would ride up and over the ice, rather than hitting it edge on. Then its weight would be applied to the thin direction of the plate of ice and break it - same principle as an ice-breaker. If it DID hit it edge on in a manner that it couldn't lift up over, then I'd be worried. You'd then be seeing something like a knife-blade supported by the width of the plate of ice. And ice is strong stuff - you only need a foot or so thickness to land aircraft on it!

 

[NormanS]

I used to have a big wooden boat, and in 1980something was heading into Loch Spelve, and was called up by the salmon farm, and asked if I could break the ice to let them get to their cages. I gently approached the ice, which was probably about 4" thick, the boat stopped dead, and when I backed out, the ice was marked by my antifouling. I declined.

This year, the Caledonian Canal has been closed since Christmas by ice. It may be open now but until last week, anyway, it was still blocked by ice at Kytra. The canal used to have an ice-breaker tug, (no more), and also has / had steel plates that you borrow, to hang over the bows to guard against ice damage. Ice is not stuff to mess with.

 

[seanfoster]

Did the same last Saturday on Winderemere, had to motor through very slowly in the inflatable (near to Ferry Nab). Quite scary really as the inflatable wasn't mine and was brand new! No damage though.