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IanR

Re trimming a boat and it's handling afterwards.

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From personal experience its easy to catch something on the bottom gates heading downhill, at least in a narrow lock it is, even with the button up.

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5 hours ago, alan_fincher said:

 

Please note:  The bit of my post you have quoted says STEM (so touching bottom gates!), not STERN!

 

(Though before you point it out, I can see a letter has gone missing from my intended word "resting"!)

Not to worry I'll book you in alongside me when I go to get my brainfade filter changed ?

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5 hours ago, alan_fincher said:

Agree with all of that.

Unfortunately we find in most GU locks that when Flamingo is going downhill sharing with a non full length boat, whilst it does float back some way off the bottom gate as a level is made, it is often frustratingly not quite enough to open the gate past the stem.  This means if I'm off the boat, having worked the paddles, and am waiting to open the gate, frustratingly I regularly have to get back on the boat just to pull the boat back enough that the gates can open, (and then back off again to do the opening!)

Thinking about this situation, possibly I would be better taking a line ashore before I empty the lock so I can tug on that without a lot of clambering on and off the boat - I might experiment with that in future, now I've thought about it.

 

As an aside, using this method we had a brief scare on the way to Ricky a few weeks back.  The paddle in front of Flamingo was faulty, and restricted from fully opening.  As a result as the lock emptied the draw was insufficient to keep the boats on the gates, and it started to drift back towards the cill in an emptying lock - yet another possible condition to look out for, now so any lock don't work as well as they should.

I always took a line with me, a habit learned when first boating with a 30ft  Brumtug that was expert at wandering off in any lock and leaving me staring at it, willing it to drift back within reach of a ladder or gate.

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19 minutes ago, AMModels said:

From personal experience its easy to catch something on the bottom gates heading downhill, at least in a narrow lock it is, even with the button up.

It is equally easy to catch on the top gates when going uphill, especially with the stem fender down - hence I always run with the stem fender on the foredeck to reduce the risk.

 

I find Grand Union boats are particularly bad when running downhill narrow locks as on Woolwich's there is a lip / edge on the underside of the top guard where it meets the stempost that catches on the top edge of the metal running plates of mitred narrow lock gates, whilst the prominent stempost of Northwich's catch either between the mitre of the bottom gates or on the nut / bolt heads that are used to construct the gates with. I have had both Woolwich's and Northwich's hang up in these situations.

 

What is important is to understand where the boat has a 'design feature' and where that 'design feature' causes an issue when boating - and to never take your eye off the boat when in a lock. As far as Grand Union's are concerned it should be borne in mind that they were designed to hammer up an down the wide locks of Grand Union Canal in motor / butty pairs and it was never considered that they would traverse many of the canals that they do now :captain:

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I'm aware of at least 3 large Nortwich boats, (ours included), that have hung up at the front end when descending Hillmorton locks.

 

The reason was that the bottom gates had their rubbing plates installed with the bolts going the wrong way through the gates, resulting in the bolt ends and nuts being a projection on top of the rubbing plates.  If the stem of a Northwich got the wrong side of these, (very easy because the locks are a lot wider than the boats), then this was enough to jam the boat between the nut and the lock-side and stop its front end being able to go down.  Very scary.

CRT admitted the bolts were wrongly installed - with them the correct way around there is only the shallow domed bolt head, which a stem can't get behind.

 

They are supposed to not just have changed the Hillmorton locks to remove the danger, but also inspected other narrow locks for also having the fault, but I have no idea if they ever did elsewhere, or over how wide an area.

 

I always try to make a point at locks I don't use regularly, of walking to the front, and looking for anything a boat could snag on, exactly as George has suggested, although anything below the water when you look can't, of course, be seen, and could cause problems

 

For uphill working in narrow locks, on the other hand, too many locks now don't have the rubbing board full height - necessary to guide the stem over the balance beam.  If the plate stops short of an overhanging balance beam, the possibility of getting the stem post jammed under the balance beam as a lock fills must not be ignored.  Another visual check that people with full length boats need to make in unfamiliar uphill locks.

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This was a Northwich, stempost caught, stern dropped only about 6 inches, me and the guy on the paddles realised/reacted quickly. Slid off as he dropped the paddles but unseated the rudder on the cill even though I had it hard over just in case. 

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32 minutes ago, alan_fincher said:

I'm aware of at least 3 large Nortwich boats, (ours included), that have hung up at the front end when descending Hillmorton locks.

 

The reason was that the bottom gates had their rubbing plates installed with the bolts going the wrong way through the gates, resulting in the bolt ends and nuts being a projection on top of the rubbing plates.  If the stem of a Northwich got the wrong side of these, (very easy because the locks are a lot wider than the boats), then this was enough to jam the boat between the nut and the lock-side and stop its front end being able to go down.  Very scary.

CRT admitted the bolts were wrongly installed - with them the correct way around there is only the shallow domed bolt head, which a stem can't get behind.

 

They are supposed to not just have changed the Hillmorton locks to remove the danger, but also inspected other narrow locks for also having the fault, but I have no idea if they ever did elsewhere, or over how wide an area.

 

I always try to make a point at locks I don't use regularly, of walking to the front, and looking for anything a boat could snag on, exactly as George has suggested, although anything below the water when you look can't, of course, be seen, and could cause problems

I noticed that the bolts had been turned at Hillmorton when I came through last month, now just a domed head that presents a much reduced hazard. Interestingly I have been hung up a few times with Northwich stemposts on the Oxford Canal but going downhill south of Banbury. This is never a pleasant experience and I always assume these protruding bolt heads are present until proven otherwise.

 

The Woolwich I caught on the metal running plates when going downhill was BADSEY, and the incident was at Lapworth in 1989. I was working single handed and was preparing the next lock leaving BADSEY dropping in the lock above. It was clear that the lock was emptying but the cratch remained high, and by the time I got back up to sort it out BADSEY was at an alarming angle - but fortunately did not drop whilst the lock was slowly refilled.

45 minutes ago, alan_fincher said:

For uphill working in narrow locks, on the other hand, too many locks now don't have the rubbing board full height - necessary to guide the stem over the balance beam.  If the plate stops short of an overhanging balance beam, the possibility of getting the stem post jammed under the balance beam as a lock fills must not be ignored.  Another visual check that people with full length boats need to make in unfamiliar uphill locks.

And a good justification for running with the stem fender on the foredeck.

 

A stem fender can also catch under the top gate handrail when running uphill - especially with an empty large Grand Union boat :captain:

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Certain waterways will fill your fore end up if you went too close to front gates going uphill and unwound the same side gate paddle (no ground paddles). Couple of nasties on the Wey like that. Or lift front gate.

 

Got to look and always be aware.

Edited by mark99

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49 minutes ago, mark99 said:

Certain waterways will fill your fore end up if you went too close to front gates going uphill and unwound the same side gate paddle (no ground paddles). Couple of nasties on the Wey like that. Or lift front gate.

 

Got to look and always be aware.

That is what a full cratch prevents, rather than the deckboard or open fore end as seen on many modern boats :captain:

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1 hour ago, mark99 said:

Certain waterways will fill your fore end up if you went too close to front gates going uphill and unwound the same side gate paddle (no ground paddles). Couple of nasties on the Wey like that. Or lift front gate.

 

Got to look and always be aware.

 

9 minutes ago, pete harrison said:

That is what a full cratch prevents, rather than the deckboard or open fore end as seen on many modern boats :captain:

 

You don't necessarily need any paddles drawn.

This was Boxmoor lock the other week before we had opened any paddles.

(The picture also demonstrates having the fender stowed on the deck, as discussed in this thread)

 

IMG_4778.JPG

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I don't quite know why the Wey (NT) does not adequately cover its top gates to prevent gate lifters.

 

The Boxmoor one is really bad - even worse than this one we encountered in London ( East of King Cross). The worst bit was that the lower gates only had one paddle too. The other being chained up. ETA I think low gate - might have been upper chained up with lower gates leaking even worse than that? I do remember it took forever and a lot of messing about with force to get a level.

 

image.png.3170941a4c21433373d99d0d71446640.png

Edited by mark99

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On 07/06/2018 at 13:39, Stilllearning said:

I almost never found a lock that would let me leave our 55ft boat in the middle of it. Always was best to nudge the front gate or cill in tick over forward gear, with the added benefit of the boat opening the top gate(s). This is a single handlers trick that saves a lot of back ache on the top gates beams.

 

That's different to my experience then because I often leave my 57ft boat in the middle of locks and there's no reason for the bow or stern to be anywhere near either gate. Sometimes I don't want to be near the front gates if there is anything the bow could get caught on (with or without a fender). Also I generally don't leave my boat in gear when I'm working a lock, but as I'm on a widebeam in double locks and often on rivers it's bit different to a narrowboat in a single canal lock. 

Edited by blackrose

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On 11/06/2018 at 19:31, alan_fincher said:

 

 

You don't necessarily need any paddles drawn.

This was Boxmoor lock the other week before we had opened any paddles.

(The picture also demonstrates having the fender stowed on the deck, as discussed in this thread)

 

 

Not really sure that I'm in agreement with this lifting of bow fenders in locks, perhaps my experience in the staircase lock at Chester colours my judgement though. Travelling through with another boat that had a larger (and I thought reasonably competent) shore crew, when we were in the first chamber the top paddles were opened fully by the enthusiastic crew. Despite giving my boat maximum reverse thrust the bow was drawn onto the top gate which had/has unprotected cross-members. The button went under the cross member and as the boat rose the weakened link that I have on the holding chain broke and the button swung loose (it didn't fall off still being held by another chain). It made a bit of a bang but otherwise no harm done, the shore crew saw what had happened and reduced the flow through the paddle a bit. If however the button had not been there it would have been the bow of the boat that would have been caught under the cross-member and what would have happened next would have been entirely dependent on the shore crew realising that there was a serious problem.

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I single hand and always take a long centre rope, use the lock ladders, leave the boat in neutral and use one of the bollards to keep the boat away from the gates when going either up or down and as the boat rises or falls I either tighten or loosen the rope as necessary to hold the boat from contacting the gates and away from the cill line (60' n/b) ... the worst locks i find to hold the boat from the "firing forward on filling syndrome" are those on the T&M. Doing this also gives more control over the boat drifting forward when going up in a lock with badly leaking gates, another thing i do when going up in a single lock is put the boat in gear once the top gate is open and as it passes me knock it into reverse so as i close the top gate the boat comes back to me.

 

Rick

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