Lock Surges

[Porcupine]

Hi all,

 

I am struggling to keep my boat steady when ascending in locks on the K&A. We are holding the boat on the centre line but when we let in water the rush is taking the boat across the lock. We are letting it in quite slowly. Any suggestions? Thanks, Matt. 

[Alan de Enfield]

5 minutes ago, Porcupine said:

Hi all,

 

I am struggling to keep my boat steady when ascending in locks on the K&A. We are holding the boat on the centre line but when we let in water the rush is taking the boat across the lock. We are letting it in quite slowly. Any suggestions? Thanks, Matt. 

 

 

Unless the K&A locks are vastly different to the rest of the system :

 

When ascending let the bow-button touch the gate(s) 

Leave the boat in gear at tickover and the boat will ride up the gates as the water level rises with no surging backwards and forwards.

 

No hassle and no stress.

Edited May 15, 2021 by Alan de Enfield

[Porcupine]

Hey Alan de Enfield.

Thanks, will try. The sill I think is too pronounced though. In fact I know it is. I did the Caen Hill flight today and my boat hit the sill before the bow-button could stop me. 

[BEngo]

A de E's technique is fine in narrow locks.  In broad ones, let the water in, full flow,  but only from  from the paddle on the same side as the boat., Hold the boat back from the gate so the flow goes past the bow, bounces off the far wall and holds the boat against the near wall.

 

If there are gate paddles open the one on the opposite side to the boat as soon as it is safe to do.

Don't lift any  other paddle till the lock is fairly full.

N

[Porcupine]

Yup. That is the way we are trying to do it. I think we need to keep the boat further back than we have been. Thanks. 

[David Mack]

 

When ascending let the bow-button touch the gate(s) or top cill.

Leave the boat in gear at tickover and the boat will ride up the cill and gates as the water level rises with no surging backwards and forwards.

 

If you want to use ropes when ascending, don't just hold the rope, but take a turn or two round a bollard, and hold the end of the rope. Much easier and more control. Pull the rope in occasionally as it gets slack.

 

If you do this going down, only take a single turn around the bollard and keep an eye on the rope all the time to ensure it doesn't bind or snag and hang the boat up.

[Porcupine]

Thanks. But the problem is surging backwards and forwards. It is being pushed across the lock and hitting  boat on the opposite side to the one Iits being held. 

[pearley]

13 minutes ago, BEngo said:

 

If there are gate paddles open the one on the opposite side to the boat as soon as it is safe to do.

Don't lift any  other paddle till the lock is fairly full.

N

Whilst that is accepted practice I've found that the guards now fitted over gate paddle outlets make this not always so. 

If they are vertical slats so angled into the lock then fine but there are many where they are horizontal so direct the water flow straight down the lock allowing the flow to get between the boat and lockside and pushing you out.

On the wide locks up from Shardlow rather than use the centre line I've found it easier to go through the boat and throw the front line up for Jeannette to put round a bollard and drop back down to me. Then leave the stern to do its own thing.

Edited May 15, 2021 by pearley

[Machpoint005]

Ascending a broad lock my technique is to hold the boat against one side with the centre line looped around a bollard and back to the steerer (usually me). The Memsahib opens the opposite ground paddle first, thus pinning the boat against the wall. It's a 48ft boat so I'm happy to sit back towards the bottom gates. 

 

Having said that, all locks are different, and what works in one place doesn't necessarily work in another. 

[JamesWoolcock]

23 minutes ago, pearley said:

Whilst that is accepted practice I've found that the guards now fitted over gate paddle outlets make this not always so. 

If they are vertical slats so angled into the lock then fine but there are many where they are horizontal so direct the water flow straight down the lock allowing the flow to get between the boat and lockside and pushing you out.

On the wide locks up from Shardlow rather than use the centre line I've found it easier to go through the boat and throw the front line up for Jeannette to put round a bollard and drop back down to me. Then leave the stern to do its own thing.

The Trent & Mersey wide locks are a little different from most in that the flow from the top ground paddles enter the chamber from under the top cill, so if you use the ground paddle on the opposite side, all should be well.

Thereafter open the gate paddles with care as you will.

Edited May 15, 2021 by JamesWoolcock
Typo

[dmr]

K&A is not easy, there is some variation from lock to lock so what works on one will be a bit different on others. The technique used will depend a bit on your boat.

The methods suggested by BEngo and David Mack should both work at first but the trouble is once the lock is about 1/3 full (depending on design of lock and depth of your boat) the water flow changes from hitting the side of the boat (holding it in place) to going under the boat which can cause it to swing to the other side of the lock with some force. Is this the problem that you are having?  With luck you can open the paddle on the other side at just the right moment but its not easy to get this right and once the boat starts to swing its difficult to stop it.

 

If you use the David Mack method of riding the cill/gate then if the boat starts to swing apply more revs to press the boat against the cill to control the front.

Riding the gate has risks as the button can sometimes get caught under cross beams on the gate so is mostly only used by owners of full length boats.

 

.........Dave

 

 

[nicknorman]

Generally in wide lock the technique is to open the ground paddle on same side first. Exceptions are the T&M wide locks and the K and A. With the latter, all bets are off because as Dave says, they are all different!

 

Best way is to go up with another boat, that stops you banging around. Only problem is that finding another moving boat on the KandA can be tricky!

[Alan de Enfield]

1 minute ago, nicknorman said:

Best way is to go up with another boat, that stops you banging around.

 

 

He says his problem is hitting the sharing boat ;

 

 

1 hour ago, Porcupine said:

............It is being pushed across the lock and hitting  boat on the opposite side to the one Iits being held. 

 

[magpie patrick]

2 hours ago, Alan de Enfield said:

When ascending let the bow-button touch the gate(s) 

Leave the boat in gear at tickover and the boat will ride up the gates as the water level rises with no surging backwards and forwards.

 

 

2 hours ago, David Mack said:

 

When ascending let the bow-button touch the gate(s) or top cill.

Leave the boat in gear at tickover and the boat will ride up the cill and gates as the water level rises with no surging backwards and forwards.

 

Don't do this in a wide lock unless you are experienced enough to assess the potential pitfalls in each lock, and especially not on the K&A

 

The bumper board may not be big enough and the fender ot the stem may catch under the cross beams

 

Even if the bumper board is big enough for a boat parallel to and next to the lock side the boat can slew across the lock which means the stem is close to the lock side, not central in the gate - this gets more pronounced the shorter the boat is. This can lead to the stem getting under a cross beam

Less of an issue, but still not entirely desirable, the boat being pulled forward will lead to it being in the mitre, not to one side. 

K&A locks are a bit unpredictable - when I single handed Lutine over the canal I kept her back from the top gates with a rope and accepted she would move from side to side - if you draw one paddle at a time and take it easy this isn't really a problem. Lutine was 45 foot. 

Edited May 15, 2021 by magpie patrick

[Machpoint005]

20 minutes ago, Alan de Enfield said:

 

He says his problem is hitting the sharing boat 

 

That's very easily solved, by strapping the two boats together!

[AllanD]

Hired a day boat from Hilperton Marina and headed west. Going down the Bradford upon Avon lock was straightforward as we were alongside another longer boat and with the help of 2 CRT people. 

Coming back up was a different matter. I had the centre rope around a hook but still struggled to keep the day boat alongside the lock side. 

I was truly taken aback by the force of the incoming water as the ground paddles were opened. 

Edited May 15, 2021 by AllanD

[dmr]

12 minutes ago, AllanD said:

Hired a day boat from Hilperton Marina and headed west. Going down the Bradford upon Avon lock was straightforward as we were alongside another longer boat and with the help of 2 CRT people. 

Coming back up was a different matter. I had the centre rope around a hook but still struggled to keep the day boat alongside the lock side. 

I was truly taken aback by the force of the incoming water as the ground paddles were opened. 

 

Bradford Lock is deep and possibly the hardest lock on the canal section of the K&A, and often has a big audience to watch things going badly.

The other tricky locks are the ones with (only) gate paddles down the Newbury end.

 

.............Dave

[Arthur Marshall]

A full length boat in a lock won't move much. A small one will, whatever you do. My boat's been nearly sunk a few times when someone (not me) has tried to ride the gate, twice when getting the bows stuck and once when someone being helpful opened a gate paddle and filled half the boat before my yelling got them to drop it. I've always thought riding the gate may be ok for working boats but a terrible idea for a modern one.

But the crucial thing is that you can't stop a small boat swinging in a wide lock, all you can do is try to keep it as tight as you can to the other boat so it doesn't whack it too hard.

And listen to everyone's advice and then only do what you consider to be safe.

[Mac of Cygnet]

Well. what a lot of conflicting advice!  I've never been on the K&A, but extensive experience of the unpredictable wide locks of the Calder & Hebble and Rochdale singlehanded in a 27ft boat has led me to the conclusion that the best thing you can do is to make sure that anything breakable is stowed properly.

[Ianws]

43 minutes ago, Mac of Cygnet said:

Well. what a lot of conflicting advice!  I've never been on the K&A, but extensive experience of the unpredictable wide locks of the Calder & Hebble and Rochdale singlehanded in a 27ft boat has led me to the conclusion that the best thing you can do is to make sure that anything breakable is stowed properly.

Also useful when the idiot you invite to share the lock with you enters at speed and rams your boat as a buffer to stop against, because it's easier than slowing down properly / or they don't care less. I was a newbie, idiot in question was going singlehanded from Liverpool to Leeds. He knew what he was doing and thought it okay.

[blackrose]

Being single handed, unless someone is helping me then my technique is to use a bow rope and either a centre or stern rope when going uphill in locks. If you're having problems then use your ropes. 

 

Personally I don't like the bow anywhere near the gates. Many years ago when I got my first boat the bow fender got caught in a gate going uphill. The weak fender links had been attached in a way that they would only snap the other way around if there was excess pressure from below the fender, and only very swift action dropping the paddles prevented the boat from sinking.

[Keeping Up]

Nobody seems to have mentioned, open the paddles just a little bit at first - then the water doesn't "rush" in - and then slowly open them a bit more as the lock fills up.

[Laurie Booth]

17 hours ago, Porcupine said:

Hi all,

 

I am struggling to keep my boat steady when ascending in locks on the K&A. We are holding the boat on the centre line but when we let in water the rush is taking the boat across the lock. We are letting it in quite slowly. Any suggestions? Thanks, Matt. 

Fill the lock slower than you are doing at the moment.

[mykaskin]

If you've tried different patterns of opening paddles to reduce the effect, then the only thing is to take a bow line ashore to hold it in. You may have to take several turns around the bollard, and also a stern line tied as far back in the lock to reduce the difference in length as the lock fills. Centre lines are not good for holding boats still in locks when they are filling.

[Machpoint005]

39 minutes ago, mykaskin said:

>>Centre lines are not good for holding boats still in locks when they are filling.<<

 

I rather think that depends on the length of the boat.