Tardebigge flight

[MIKE P]

In the 25+ times I have been up and down the flight.

I have often wondered what this metal hook was for. I would imagine to help slow a narrowboat entering the lock if single handed? Any ideas?

[Rob-M]

It is for horse boating, the line goes from the horse boat to the hook to the horse to help the horse start the initial pull, there is a video on YouTube showing them being used, I'll see if I can find a link.

[MIKE P]

Thanks Rob-M

[Tony Brooks]

I think a block on the mast, so the rope goes horse to block to hook, that give a double purchase. As the mast moves in front of the hook the rope loop slips off and a stopper knot jambs in the block.

[David Mack]

26 minutes ago, MIKE P said:

I would imagine to help slow a narrowboat entering the lock if single handed?

Just the opposite. It's to speed up a boat leaving the lock, as others have described.

At one time BW/CRT were cutting these off as a trip hazard, but their historic purpose is now recognised, and those still existing should remain.

[MIKE P]

31 minutes ago, David Mack said:

Just the opposite. It's to speed up a boat leaving the lock, as others have described.

At one time BW/CRT were cutting these off as a trip hazard, but their historic purpose is now recognised, and those still existing should remain.

How will it speed up exiting, if horse drawn? These hooks are not towpath side

 

[Rob-M]

The horse can get a better pull to start the boat moving, the hook being on the offside to give the rope a clear line between the open gates.  Without the block Tony mentioned the horse struggles to get the boat moving out of the lock.

[IanM]

 

As shown in Tom Chaplin’s Narrow Boats book. 
 

 

 

Edited November 3 by IanM

[Ronaldo47]

Recalling the vectors we studied in applied maths at school, a consideration of the  forces exerted on the pulley by the rope attached to the hook and the rope being pulled by the horse, shows that the resultant force acts in a line generally parallel to the axis of the lock. As well as largely preventing the boat scraping the side of the lock nearest the horse as would be the case if it simply used the rope, it gives the horse a 2:1 mechanical advantage, which assists getting the barge going from rest.

[Tacet]

I think it's known as a starting pin

[Tony Brooks]

I noticed similar on the Wey navigation locks, little hooky bits of iron/steel bar set into the coping stones at either end of the lock, but I think in this case they are to help locate the bow and stern lines while locking, as required by the NT.

[Rob-M]

Some wide locks had a hold back pin by the top gates to hook a butty line on so as the motor left the lock the butty would be held back so the motor steerer could pick the tow line up.

[Pluto]

You need to get a copy of Towpath Encounters: https://www.iarecordings.org/coproductions/sightseen/n03.html

[Tam & Di]

15 hours ago, Rob-M said:

Some wide locks had a hold back pin by the top gates to hook a butty line on so as the motor left the lock the butty would be held back so the motor steerer could pick the tow line up.

We did make a formal complaint when BWB in their ignorance were removing these at one point - although they are effectively under the balance beam BWB said they were a trip hazard.

[Mike Todd]

But in general they are under the balance beam when the gate is fully open. If some one is that side of the balance beam they are about to be sept over he side by the beam anyway! It is not clear in what way they may trip someone but not many features of locks would pass a 21C risk-averse assessment if newly proposed!

 

[MIKE P]

Thank you all.