Big Locks....

[robtheplod]

Hi All

 

Prior to our move to Droitwich I'm researching the locks in the Severn. When we came up Diglis lock when we did the Avon Ring i encountered exactly the same issue David does in the video below and wondered is there a correct procedure for these big locks that avoids the embarrassing pull over to the other side? 

 

 

[nicknorman]

1 hour ago, robtheplod said:

Hi All

 

Prior to our move to Droitwich I'm researching the locks in the Severn. When we came up Diglis lock when we did the Avon Ring i encountered exactly the same issue David does in the video below and wondered is there a correct procedure for these big locks that avoids the embarrassing pull over to the other side? 

 

 

 

I'm not quite sure exactly what you mean by "pull over the other side" - in the vid he just seems to struggle to come alongside on the intended side. This is caused by hitting reverse too hard - water is pushed forwards and pushes the boat away from the wall. Come in more in the centre of the lock and turn towards the wall, swing the back in just before it hits at the front, and hit reverse when you have momentum carrying you towards the side. If you come in slowly, you need less reverse and the effect is less.

He was going downhill, if you were going uphill and had problems with the "pull over to the other side" when the lock is filling, it is because you started out on the wrong side! Normally the Severn lock keeps tell you which side to go if there is just the one boat, such that the water flow from the paddles keeps you on that side. Mind you, with the advent of volockies, maybe that is no longer SOP.

[Jen-in-Wellies]

What @nicknorman said. If the issue is coming in to a lock and stopping adjacent to one wall, then the problem is similar to coming in to a bank, or quay side, where the water rushing down the side from the reversed prop pushes you away. As with coming in to a wall in general, the deeper the water is under the boat, the easier it is, so going down a lock is easier than coming up. My approach is to come in to the wall at an angle, with reverse prop, then a burst of forward prop and rudder to turn the boat parallel at the last moment, then reverse prop again to kill the last of the forward speed. If judged right, the turning moment of the boat counteracts the reverse rush of water between boat and wall and you come to a stop parallel to and close to the wall. Success!

With the water rush from paddles moving the boat, the direction it comes from with each paddle depends on the design of the lock and can sometimes even reverse at a certain water depth. Local knowledge and experience will soon let you know how to deal with the quirks of the local wide locks.

[dmr]

We had this problem, one of the top two locks heading up from Droitwich to Stourport. There was a bit of leakage from the corner of one of the top gates going accross the lock and getting between us and the wall. It was much worse than in the video and pushed the front out before I could get a rope round the riser. Also once we were roped up (on the other sde) it was a strong pull as the locked filled.

Big locks need a crew of two, one driving, one at the front, and this is where you realise that a cratch cover is really bad news (and why we don't have one).

Getting a front rope on to a bollard  or riser and a half turn round the T stud if needed, should keep the front under control.

[Tracy D'arth]

53 minutes ago, dmr said:

 

Big locks need a crew of two, one driving, one at the front, and this is where you realise that a cratch cover is really bad news (and why we don't have one).

 

Need a spray sheet or a cratch cover on the Bingley 5!  Or you sink!

[IanD]

Just now, Tracy D'arth said:

Need a spray sheet or a cratch cover on the Bingley 5!  Or you sink!

 

Or no well deck and/or front doors... 😉

[dmr]

2 minutes ago, Tracy D'arth said:

Need a spray sheet or a cratch cover on the Bingley 5!  Or you sink!

 

Yes, we are full length so the front is right up against the top gates. There are actually very few locks where the water comes out far enough to get over the foredeck into the well deck, but we have small scuppers so when it does happen its bad. Only had one really nasty moment in the last 14 years, and that was last year on the Rochdale.

Evesham lock is a bugger, have to be brave and wind the gate paddles up really quickly to get over the initial upward squirt problem.

[ditchcrawler]

48 minutes ago, Tracy D'arth said:

Need a spray sheet or a cratch cover on the Bingley 5!  Or you sink!

 

[robtheplod]

Thanks all for the really useful methods to use!!!

[IanD]

1 hour ago, dmr said:

 

Yes, we are full length so the front is right up against the top gates. There are actually very few locks where the water comes out far enough to get over the foredeck into the well deck, but we have small scuppers so when it does happen its bad. Only had one really nasty moment in the last 14 years, and that was last year on the Rochdale.

Evesham lock is a bugger, have to be brave and wind the gate paddles up really quickly to get over the initial upward squirt problem.

 

With worse maintenance and leaky gates it's happening more often though -- I've seen bow waterfalls on the Rochdale, C&H, L&L to name but a few... 😞

 

(and it's one reason I went for an enclosed bow where this isn't a problem)

[Jon57]

2 hours ago, IanD said:

 

Or no well deck and/or front doors... 😉

Or a large tug deck 😁

[IanD]

25 minutes ago, Jon57 said:

Or a large tug deck 😁

Which is the same thing, and what I implied... 😉

[beerbeerbeerbeerbeer]

1 hour ago, Jon57 said:

Or a large tug deck 😁

or a shorter boat,

🤡

2 hours ago, robtheplod said:

Thanks all for the really useful methods to use!!!

trick when sharing locks, go in together OR make sure the other boat goes first 😃 🤣

Edited January 29 by beerbeerbeerbeerbeer

[robtheplod]

17 minutes ago, beerbeerbeerbeerbeer said:

trick when sharing locks, go in together OR make sure the other boat goes first 😃 🤣

indeed, but on those big locks I'll be waiting quite a while to fill it up..

[David Mack]

If there's a wind blowing across the lock, some of that will be caught by the downwind wall and will circulate within the chamber. In these locks, when full in normal river conditions, the lockside is higher than the cabin top, so the boat isn't exposed to the side force from the wind, which would push it towards the downwind side, but may be carried in the opposite direction by the circulating airflow, in the same way as when filling a lock from one side only the current takes the boat towards the side with the open paddles.

[ditchcrawler]

The lock keeper will indicate which side of the lock he wants you to use.

[Wanderer Vagabond]

Have to say that I rather looked with horror at how the guy has his centre line in the lock😱

Does he REALLY have that line around his mushroom?? If it is anything like my boat, they are not big screws holding those mushrooms on and they are very easy to rip off (DAMHIK!!)

[blackrose]

21 hours ago, nicknorman said:

in the vid he just seems to struggle to come alongside on the intended side. This is caused by hitting reverse too hard - water is pushed forwards and pushes the boat away from the wall. 

 

Going back a step it's also caused by coming into the lock too fast when there's really no need to. If you come in dead slow then you don't need a lot of reverse to stop and avoiding all those excess revs in astern means you're less likely to get pushed away from your desired side of the lock. Moving a widebeam single handed has taught me to do everything much slower and more gently than when I owned a narrowboat. Use the boat's momentum, you don't need all those revs.

Edited January 30 by blackrose

[Bee]

On Bee it is dead easy to come alongside the LH wall, coming alongside the RH wall is a different kettle of fish, it takes time and careful handling or it ends up in the middle of the lock. David Macks comment about contrary winds is also something to bear in mind. Its a bit stressful for us as we get shoved into the bit of free water at the back of the commercial locks after the big stuff has filled most of the lock and pratting around whilst everybody else waits for you is embarrassing. This is when you realise that the most important person on the boat is not the person twiddling the wheel - it is the person with the rope trying to catch a bollard before the boat bounces off the wall / runs into the back end of something really big.

[Momac]

On 29/01/2024 at 18:18, Wanderer Vagabond said:

 

Does he REALLY have that line around his mushroom?? 

It appears so