Friday, 27 July 2018

Speeding & damage

Overall I am fairly blasé about speeding in relation to rocking the boat. I live on a boat and expect the boat to move. I get a bit pissed off where I currently am because my ropes are slack to make allowance for the water level which can vary a foot between early morning and mid evening.  For a week I was actually stuck on the bottom so didn't move an inch after mid-day. Of course having your pins bent like this (pic) is an annoyance. This is the biggest pin Midland Chandlers sell and it was firmly in the ground right up to the ring. Oh and they do cost 15 quid! You’re right I dont have to moor here, but we have dogs and this is a shady, cool place. Pembroke from the College Cruisers stable hit me a good ‘un because he couldn’t control the boat at the speed he was doing.

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Many boats seem not to know the rules. In fact they seem not to know that there actually are rules. Ask them if they have read the Boaters Handbook and they look at you like you just spoke Martian.

The rules for not speeding are not about rocking boats and bending pins, however annoying that is, its about the environment. A chap passed me a few days ago breaking wash. Half way down the side of my boat he opened up the throttle!

If I travel on my boat at 1 mph I will do a certain amount of damage to the bank, small but some (lets call it 10). If I travel at 2 mph that damage is quadrupled, 40! So thats double the speed = 4 times the damage or wear. If I travel at 4 mph that 40 is quadrupled again, 160. Now assuming there is no breaking wash, that is a lot of damage. If there is breaking wash (and you don’t have to be doing over 4 mph for that to happen) then the damage is totally unacceptable. Few boaters know this, but it is a standard in engineering. Yes I know you are only washing a very small amount of the bank away, barely colouring the water sometimes but the next thousand boats past will do the same or worse.

Breaking wash can appear when you least expect it. The width of the canal does vary and what is a good speed for this one hundred yards is not necessarily a good speed for the next hundred yards.

Your hull can determine at what speed your wash will break, that you cant change. Also the width of the canal and the depth of the water. On a narrow canal your wash doesn't have enough time to lose its energy before reaching the bank, whereas on a wide canal it does. There are variations, a shallow wide canal as opposed to a deep narrow canal and all points in between.

Breaking wash most often appears where the water is the shallowest, on the off side where there is a slope up to the bank. So not only does normal speed damage the bank, slower speed can when the water is shallow. If you don’t want to break wash, and that is a rule, we should all be spending time looking behind us to see what is happening. It doesn’t happen in front. We should all monitor how our boat is performing in the water.

Something else that also affects affects the wash is this stupid habit people have of traveling with their fenders down and dragging in the water. Side fenders more properly known as ‘mooring fenders’ are for mooring. Almost every boat has a rubbing strake, that’s the ‘D’ section steel strip that  runs down the side of your hull, most often end to end. Its job is to protect the boat from scraping along the sides of locks etc, whereas a mooring fender is to cushion your hull from the piling/bank/etc when moored up. In fact mooring fenders are the most common cause of temporary lock stoppages. They break off in the locks and migrate to behind the bottom gate preventing it opening, or behind the sill preventing the gate closing. Come guys it is not rocket science! I know it wont have any effect on you but I laugh at idiots that think traveling with fenders down is the thing to do. It is a far greater offence than hanging your stern rope over the tiller. I don’t want any responses about this, the rubbing strake is sacrificial just like anodes.

Now then all that aside there is another factor we as boaters should be considering. The Wildlife! So often boaters don’t think about that little bundle o’ fluff sitting in the water three or four boat lengths in front (more often than not they cant even see them), or what is under the boat trying its hardest to get away from their propeller. Believing they can all get away is at best out right stupidity. This year especially I am sick of seeing little floating corpses caused by inconsiderate tiller jockeys.

4 mph is not a target, it is a maximum, but you should always take conditions into account, moored boats, wildlife, width, depth at this time of the year when you can see water has fallen below the level of the underlying silt.

2 comments:

Rog n Jane said...

You see, that's why I think your blog is still the best.
Always interesting, and thought provoking.
Rog
nb Paneke (travelling slowly ;) )

Marilyn McDonald said...

I'm with you, Maffi!

Speeding boaters, boats with fenders down - GGGRRR!!!

I didn't know about the hassles broken off fenders cause in locks, but I am unsympathetic when the fender ropes get stretched and snap in locks. From now on, I will flip other people's fenders up when sharing a lock with them.

Cheers, Marilyn (nb Waka Huia)