Pawls

[jenevers]

How many of you lift a pawl as you wind a paddle up?

I always leave it alone. To me the whole idea is to stop a paddle dropping if the windlass slips of while winding, but I see lots of boaters and staff hold it away from the mechanism until the paddle is fully up.........why? Don’t they like the clicking sound?

[WotEver]

Just now, jenevers said:

why? 

To save wear.

 

I’m not getting into the debate as to whether or not it’s a good idea. 

[jenevers]

Just now, WotEver said:

To save wear.

 

Are you serious??

[WotEver]

Just now, jenevers said:

Are you serious??

Not always, no. But on this occasion, yes

 

[alan_fincher]

4 minutes ago, jenevers said:

How many of you lift a pawl as you wind a paddle up?

I always leave it alone. To me the whole idea is to stop a paddle dropping if the windlass slips of while winding, but I see lots of boaters and staff hold it away from the mechanism until the paddle is fully up.........why? Don’t they like the clicking sound?

 

No, that isn't "the whole idea".  They are there principally to stop the paddle desending again wen you have wound it up.  Any consideration about what happens if something goes wrong when winding is clearly a secondary issue to their main purpose.

[BWM]

It can provide a false sense of security, i had a dislocated finger due to the pawl disengaging because of a bent bar (gate paddle gear), if i had lifted it and placed it into the ratchet mechanism it would likely not have happened. 

Edited January 23, 2019 by BWM

[jenevers]

2 minutes ago, alan_fincher said:

 

No, that isn't "the whole idea".  They are there principally to stop the paddle desending again wen you have wound it up.  Any consideration about what happens if something goes wrong when winding is clearly a secondary issue to their main purpose.

OK.....PART of the idea is..............

6 minutes ago, WotEver said:

Not always, no. But on this occasion, yes

 

Didn’t realise that boaters were so conscientious.?

[alan_fincher]

I very much doubt working boatmen always put the pawl on before winding, but I haven't got the time to go searching for photos that proved they didn't.

 

Lots of the pawls on the GU South are sufficiently badly maintained that they don't engage with (or stay engaged with) the moving parts as you are winding, and hence you have to arrange them into place when you have finished.  Even those that do go "click" will sometimes let the addle drop again as you take the windlass off.  I now prefer never to rely on them being in full working order, having once received an exceedingly bad bruising and very swollen wrist when one failed on me.

[jenevers]

7 minutes ago, alan_fincher said:

I very much doubt working boatmen always put the pawl on before winding, but I haven't got the time to go searching for photos that proved they didn't.

 

Lots of the pawls on the GU South are sufficiently badly maintained that they don't engage with (or stay engaged with) the moving parts as you are winding, and hence you have to arrange them into place when you have finished.  Even those that do go "click" will sometimes let the addle drop again as you take the windlass off.  I now prefer never to rely on them being in full working order, having once received an exceedingly bad bruising and very swollen wrist when one failed on me.

I’ll have to look at some old YouTube footage to check. You may well be right but I would have thought just the opposite ?

[nikvah]

I particularly dislike the pawls that have a stop bar to prevent them being thrown back which means they have to be held up to wind the paddle down again. Lock 55 in Stratford on Avon has a pawl at one end of the bar that is a considerable stretch to the end that takes a windlass without hindrance from the too close bridge.

[jenevers]

4 minutes ago, nikvah said:

I particularly dislike the pawls that have a stop bar to prevent them being thrown back which means they have to be held up to wind the paddle down again. Lock 55 in Stratford on Avon has a pawl at one end of the bar that is a considerable stretch to the end that takes a windlass without hindrance from the too close bridge.

Good point. Bad design?

[Rob-M]

I always leave them down and like to hear the click.

[BWM]

2 hours ago, alan_fincher said:

 

No, that isn't "the whole idea".  They are there principally to stop the paddle desending again wen you have wound it up.  Any consideration about what happens if something goes wrong when winding is clearly a secondary issue to their main purpose.

I think the design of the type used in the Midlands (Hatton for example) backs up your opinion on this, you have to remove the retaining mechanism to operate them and replace when raised. Whereas some of these decend slowly, not all do.

[philjw]

3 minutes ago, BWM said:

I think the design of the type used in the Midlands (Hatton for example) backs up your opinion on this, you have to remove the retaining mechanism to operate them and replace when raised. Whereas some of these decend slowly, not all do.

The current arrangement for holding up the paddles on the Ham Baker gear is not as they were designed but is a later modification.  You cannot read anything of the original designer's intention from the way they are now.
I favour keeping the pawl engaged but ensuring that it is holding before removing my windlass.

[BWM]

50 minutes ago, philjw said:

The current arrangement for holding up the paddles on the Ham Baker gear is not as they were designed but is a later modification.  You cannot read anything of the original designer's intention from the way they are now.
I favour keeping the pawl engaged but ensuring that it is holding before removing my windlass.

Each to their own, but having suffered one injury i will continue to lift them off and replace manually. 

Even though they have clearly been modified, the situation now has been deemed adequate and i would doubt the original set up would involve a ratchet. 

[philjw]

15 minutes ago, BWM said:

Even though they have clearly been modified, the situation now has been deemed adequate and i would doubt the original set up would involve a ratchet. 

I asked what the arrangment was back in 2017. Ray T posted this which says that there was a ratchet:

 

387,951. Sluice valves. BENCE, E. H., Municipal Engineering Works, Langley Green, Birmingham, HAM, P. S., 70, Victoria Street, London, and MORGAN, E. I., 8, Wolverhampton Road, Sedgley, Birmingham. Aug. 24, 1932, No. 23694. [Class 68 (ii).] A sluice valve is operated by screw gearing of such a pitch that the valve, when raised and released, will descend by its own weight. The Figure shows a gearing for raising a flat sliding valve, not shown, at the lower end of a non-revolving rod 14. It comprises a gear case 19, 20, containing bevel wheels 23, 24 rotatable so that the nut 35 raises the rod 14. When raised, it is retained by pawls 33a, 33b engaging with ratchet wheels 30, 31 ; these may be released by overturning a link 34, and the valve then descends. The stop 37 is fitted with a buffer 38, or may function as a dashpot. In a modification, the rod 14 is keyed to the wheel 23, and rotates in a nut at the upper end of a tube attached to the valve rod. Buffers are fitted at the lower edge of valve ; they may be removed to enable the valve to be removed.

Edited July 17, 2017 by Ray T

[BWM]

2 minutes ago, philjw said:

I asked what the arrangment was back in 2017. Ray T posted this which says that there was a ratchet:

 

387,951. Sluice valves. BENCE, E. H., Municipal Engineering Works, Langley Green, Birmingham, HAM, P. S., 70, Victoria Street, London, and MORGAN, E. I., 8, Wolverhampton Road, Sedgley, Birmingham. Aug. 24, 1932, No. 23694. [Class 68 (ii).] A sluice valve is operated by screw gearing of such a pitch that the valve, when raised and released, will descend by its own weight. The Figure shows a gearing for raising a flat sliding valve, not shown, at the lower end of a non-revolving rod 14. It comprises a gear case 19, 20, containing bevel wheels 23, 24 rotatable so that the nut 35 raises the rod 14. When raised, it is retained by pawls 33a, 33b engaging with ratchet wheels 30, 31 ; these may be released by overturning a link 34, and the valve then descends. The stop 37 is fitted with a buffer 38, or may function as a dashpot. In a modification, the rod 14 is keyed to the wheel 23, and rotates in a nut at the upper end of a tube attached to the valve rod. Buffers are fitted at the lower edge of valve ; they may be removed to enable the valve to be removed.

Edited July 17, 2017 by Ray T

Thanks, that's interesting as when you look at them its hard to picture any way for a ratchet to be attached. I assume there was either a problem with failure of this mechanism or an unacceptable level of maintenance required due to being engaged all the time?

[philjw]

 

6 minutes ago, BWM said:

Thanks, that's interesting as when you look at them its hard to picture any way for a ratchet to be attached. I assume there was either a problem with failure of this mechanism or an unacceptable level of maintenance required due to being engaged all the time?

You can still see the remains of the ratchet ring around the spindle where you place the windlass on some of them. They were much flatter than the rack and pinion ratchet wheels on, say, the Grand Junction locks. I still wonder why they are not still in use.

[furnessvale]

2 hours ago, nikvah said:

I particularly dislike the pawls that have a stop bar to prevent them being thrown back which means they have to be held up to wind the paddle down again. Lock 55 in Stratford on Avon has a pawl at one end of the bar that is a considerable stretch to the end that takes a windlass without hindrance from the too close bridge.

This is an extremely dangerous modification which CRT has agreed should never have been fitted.  However, CRT have also said they cannot find the Manpower (money) to remove those already fitted.  Sadly, the word does not seem to have reached all parts of the empire and the occasional new one still appears.  Fortunately for CRT, civic minded boaters are gradually doing the job for them and removing these appendages.

 

George

[Ray T]

5 hours ago, philjw said:

 

You can still see the remains of the ratchet ring around the spindle where you place the windlass on some of them. They were much flatter than the rack and pinion ratchet wheels on, say, the Grand Junction locks. I still wonder why they are not still in use.

First Photo from a previous thread by A Fincher.

Edited January 23, 2019 by Ray T

[X Alan W]

1 hour ago, philjw said:

The current arrangement for holding up the paddles on the Ham Baker gear is not as they were designed but is a later modification.  You cannot read anything of the original designer's intention from the way they are now.
I favour keeping the pawl engaged but ensuring that it is holding before removing my windlass.

The original Ham Baker paddle stop was quite a good setup the crowfoot spanner type on a length of chain is not so good the bodges /modds made to other rack & pinion gear over the years has verged on improve ment to down right dangerous (pinion stop on back to front )back in my working days it was lock dependent on if he pawl was lifted or left to click on the pinion

[Boater Sam]

The pawl appears to have been pivoted on a bolt screwed into the body casting. All the ones I have seen have a broken casting where the bolt should be.

Possibly due to being attacked by countless  windlasses  to knock the pawls off.

It would have been a very rigid arrangement with no "give" to absorb the shock load of the pawl engaging a spinning cog wheel.

Edited January 23, 2019 by Boater Sam

[X Alan W]

5 minutes ago, Ray T said:

 

The black painted broken off up stand was the original part for the fitting of the pawl the cast irn obviously broke at some time & rather than effect a weld or  plate reapair to bring to near original the crowfoot/chain was fitted

[philjw]

43 minutes ago, X Alan W said:

The black painted broken off up stand was the original part for the fitting of the pawl the cast irn obviously broke at some time & rather than effect a weld or  plate reapair to bring to near original the crowfoot/chain was fitted

It's interesting that all of the castings seem to be broken in the same place. This looks more deliberate than accidental to me and I would have thought that it would have needed something heavier than a windlass to break that thickness of cast iron, brittle as it is.  The gear was designed to drop slowly so once the ratched was released there would be no need to en-engage it again. Another one of those mysteries lost in the past.

[jenevers]

YouTube “Canals in Britain in the 1950’s Flm 5749”  12.40 minutes .......pawls engaged.